Photography Blog

My top 20 key questions to ask yourself when buying a digital camera.

1. How many “megapixels” /resolution?

Once and for all, at least to me, you have to get the highest resolution your money can buy at the time you buy. Period.

2. Who made the lens?

Most cameras will give you an idea where the lens was made just by looking at the front of the lens. Know if the lens of your camera came from a reputable company like Leica, Zeiss, Canon, Etc… Lens quality is one of the most important factors you should consider especially if you’re going to use it for commercial, technical or scientific purposes.

3. Will I need interchangeable lenses? How many are available for my specific camera in mind?

Having the option of interchangeable lenses gives you the freedom to experiment with different kinds of focal lengths. Although some P&S (point and shoot) cameras can rival DSLR’s with a generous zoom range for a non interchangeable lens system.

Also note the number of lenses available for use with your specific camera because of flexibility reasons. You can practically cover the entire “zoom range” with interchangeable lenses versus modest zoom ranges on non interchangeable lens systems or P&S cameras.

4. Does it have a zoom capability? What’s the range?

Almost all applications that I listed above will need some form of zooming in (telephoto) or out (wide angle), especially if you don’t have the space to move around the object you are shooting.

For Landscape shots, wide angle shots are very common and appealing while zooming in on the details serves as a break and complements the wide angle shots.

For weddings and events, you need a zoom because there will be times where you are limited by the shooting space and you will have a difficult time moving around. Its a good thing to know that you can do all sorts of framing without even moving from your position.

A nice zoom will give you the efficiency and versatility in your photography, so my suggestion is to go for the longest range you can get (usually from a 7X to a 10X for Point and Shoots).

Also note the speed of zooming in or out as this will be a factor if you’re shooting events like weddings. You will fail to capture that “decisive moment” on a mediocre zoom speed.

5. Does it have the provision to capture raw images?

Many photographers will say you’ll need this digital camera feature if you want to have big prints from your pictures. Although this is correct, the main reason why you will want this is because of the benefit it will give you…pure total control of your pictures… from exposure, color, metadata, hdr and a lot more.

6. Can I attach an external flash?

Having an external flash capability will give you the power and creative freedom to light your subjects any which way you like.

You can connect your digital camera to all sorts of lighting equipment thus giving you more options and versatility. This comes in the form of a hotshoe or a PC-Sync socket.

If your digital camera doesn’t have this feature, there is still hope because accessories called flash slaves are being sold by third party companies in different flavors that will also do the same job more or less.

7. Does it have a tripod socket?

Some of the most beautiful landscape pictures that I’ve seen are undoubtedly made with a tripod, so this is a must have if you are planning to do this kind of photography.

The “available light shots” in a wedding, still life and product shots, studio and fine art shots … all need a tripod for successful execution… so guess what happens if you don’t have a tripod socket?… You cannot effectively use a tripod!

8. Does it have automatic and manual focusing?

It will not be evident at first why you’ll need this especially if you’re just starting out in photography. But if you’re like me… A total control freak when it comes to cameras… and you really want to express your creative side, this is definitely a must have.

9. Can you attach filters to it? and what filter size?

Creative expression through special effects is just one of the many reasons that makes photography fun and interesting, and experimenting with filters is one creative pursuit you should try with your photography especially if you’re a beginner.

Always remember to ask if the particular digital camera you are eyeing for can handle filters and ask for the filter size. (To save you from buying the right filter with the wrong filter size) Please note that most Digital SLRs should be able to to handle filters as most lenses that come with it have a filter thread built into the lens.

Most P&S (point and shoot) digital cameras normally doesn’t have a filter thread built-in and might need special accessories to accomplish this so you should check to know for sure.

Again, there are many third party accessories that you could buy to adapt filters to your P&S digital cameras that don’t have this provisions. I’ll discuss all about this in a future post so watch for it. (Or subscribe to my announcement list (feed via email) so you’ll know when it’s up.

10. Can I upgrade the firmware?

The good thing about some digital camera manufacturers is that they keep on improving their digital cameras even after they sold it to you… this comes in the form of a firmware upgrade.

Usually this involves an improvement on one or many features of a camera. Be sure that the digital camera you’re planning to buy has an easy way of upgrading its firmware. This comes in the form of either an easy download via the manufacturer’s website (find it and bookmark it now) or a FREE CDROM.

Another caveat – be sure to consider if a downgrade is also possible or available with your digital camera… Why is there a need a downgrade you ask?… Because, you may want to reinstall an earlier firmware… just in case you don’t like the results from a firmware upgrade.

Occasionally there’s a feature that will be removed by the upgrade that you failed to read about and you decided that you just want to keep that feature instead of a bunch of trivial upgrades from the new firmware. (Yes, I personally experienced this.)

11. Are there extra goodies or software that come with it?

Some people ignore the fact that you can save a lot of money just by doing a simple arithmetic. Did you know that you could actually get your digital camera for a lot less if you study the deals and offers on the marketplace?

If you buy a digital camera and it comes with software that you can really use… like photoshop, elements, or any other image editing software for that matter, then you already saved some money you would otherwise spend. Some dealers will throw in lots of extras… If you just simply ask.

Always try to ask for these things that you’ll end up buying anyway if you don’t – like camera bags, extra lenses, extra batteries, memory cards, tripod, lens cleaners etc. Trust me… you will end up buying these things if you don’t ask for it on the deal. What have you got to lose? Simply ASK. Would you believe that I effectively lowered one of my camera purchase cost by as much as 30%? Ask away.

12. Is there Local Support in your area?

Finding the answer to this one will give you a great benefit in the long run. Wouldn’t you sleep better at night because you feel that extra security – that in case there is something wrong with your digital camera, you can bring it in for repair at a moments notice?

Not knowing when your camera will be repaired (or if it even arrived at a distant repair facility) is one of the worst feelings a photographer can have especially if you’re in the middle of a photoshoot or project.

13. What type of warranty does it have? Worldwide / Countrywide?

If you travel a lot its good to know that a countrywide or even better – a worldwide warranty can get your camera fixed wherever you are. Always bring the warranty card and glue it on your camera bag.

14. Does it have the ability to take video and audio?

I know, most DSLRs don’t have this function. But some non interchangeable lens DSLRs have it. This is a very useful feature to have if you’re on a project or photoshoot and want to document or record a procedure, a moment, or an idea that you would otherwise have trouble remembering or even writing. It’s always a good idea to bring a P&S camera backup that have this function.

The things that you could do with audio and videoclips on a photoshoot are only limited by your imagination… interviews, documentation, funny quips, training procedures, bloopers, etc..

15. Does it have a manual white balance?

White balance is one of the most interesting aspects of digital cameras. Its fun and fascinating to work with. Having this option puts the photography fun-o-meter way way up. In future posts, I will be discussing white balance in detail so be sure to stay tuned.

16. How sensitive is it to infrared?

If you’re planning to make infrared pictures or enter the exciting world of Infrared fine art photography then you’ll want to know if your digital camera can do it.

TIP: There is a simple way to test how sensitive your digital camera is to infrared using a very common device – a TV remote control. For P&S, you can aim the remote control towards the lens and gauge how bright the LED from remote is. This should give you an idea how sensitive your digital camera is to infrared. For DSLRs you will need to take shots of the LED and experiment a little or you can simply research or google the particular camera model you have in mind for other people’s experiences and thoughts about it.

17. How high is the ISO sensitivity? Is it manually adjustable?

ISO sensitivity is a term referring to the sensitivity of film to light. In the digital camera world, it refers to the sensitivity of the electronic sensor in your digital camera in relation to the ISO standard used for film.

The higher the ISO sensitivity of your camera the faster or better it can record a specific amount of light.

High ISO sensitivity is useful for taking better pictures in dark settings… such as inside a church or at night. The higher the ISO setting, the more details you can capture of a dark scene.

One caveat – take note of the amount of noise a particular camera exhibits at higher ISOs. Some people like it and some don’t. Again, don’t be afraid to ask or do research on the noise characteristics of your camera model in mind to see if this is the right choice for you.

18. How high or low can you set the shutterspeed? What are the minimum and maximum aperture settings?

Shutterspeed and aperture settings are the basic mechanisms that drive your camera and controls the amount of light that is exposed by the film or image sensor.

You use high shutterspeeds in action shots and to prevent camera shake, and you use low shutterspeeds for movement effects and bulb or long exposures. You can check for these figures on the websites that I gave you in part 1. You can see it in the technical specifications for a particular camera.

A bulb or “T” function is a nice feature to have because you can take exposures for virtually very long periods of time. Another feature to have is if your camera has a remote control to use this bulb or “T” mode. This gives you the capability to take pictures without holding your camera and adding to the “camera shake”.

With the subject of apertures, a small one (small aperture opening) lets you have a wider depth of field so your shots are sharp from near to far versus a large aperture (big aperture opening) where your shots have a narrow depth of field and appear “selectively focused”.

19. Does it have some form of an image stabilizer?

New cameras coming out as we speak often have this feature. Simply put, an image stabilizer is some form of a mechanism built into the lens or the camera body (depending on the manufacturer and their implementation) that basically prevents you from getting blurred pictures when taking pictures in low light or you are using a long or telephoto lens. Having this feature can mean the difference between a blurry picture (aka no picture!) to a usable one.

20. How close can it focus? Macro abilities?

The closer your camera can focus… the bigger the picture of an object you can take in relation to the image dimensions of the final photo… and the bigger the picture of the object… the more detail you can get. If you want to take pictures of small objects such as flowers and fine details then this is a must-have.

That’s it. Whew.

Do you really have to go over all these questions?… Of course not, but even if you only study and ponder on half of them…and take the time… I promise you that one thing will surely happen…

You’ll be…

a lot smarter!

than when you first started asking these questions… ergo you’ll be in a better position to decide what digital camera to buy… Because you are now armed with the most powerful tool anybody can have

the power of information!

In any case, I hope you find as much value in these questions as many of my friends have and be able to get the camera of your dreams.

Enjoy!

Restoring the rare moment of one’s life is the most beautiful and expensive possession. The memories of childhood, the convocation ceremony in the college and the lonely walk at old age are the special moments for everyone. All these moments can be captured with a simple click of soft button and can be stored for life-long memory.

A digital camera captures video or still photographs digitally by recording images on a light-sensitive sensor. There are also many digital camera which can record sound and moving videos as well as still photographs. Restoring the photographs is one of the prime functions of digital camera. With the captured images manipulation can be done through digital cameras, it has all the features for making changes to photographs.
Digital cameras are becoming smaller day by day and the features are also increasing in it. The choice of digital camera depends with the requirement of the user. There are various category of digital cameras like the compact digital cameras, ultra compacts, bridge cameras, digital single lens reflex cameras, line-scan camera, compact digital SLRs and digital SLRs.

This days digital cameras are used in many devices from mobile phones to personal digital assistants and vehicles. The Hubble space telescope and other astronomical devices are having specialised digital cameras. There are high-tech digital cameras available in the market with which one can take underwater photographs. The underwater digital cameras are very useful in capturing sealife, scuba diving and something artistic under the sea.

Taking some underwater pictures is everyone’s dream and while exploring the deep sea, one can take photographs and can save magical memories that can be relived until the next undersea adventure. These photographs about looking into the eyes of rarely seen creatures can be permanent recorded from the underwater digital cameras. There are various underwater digital cameras namely sea and sea DX-1G compact digital 10.0 MP camera, Intova IC-700 7.0 MP digital camera with underwater housing, Sealife SL 320 Reef master mini underwater digital camera, VuPoint DC-WPC-ST531TBLK-VP underwater digital camera and many more.

The most important accessory of a digital camera is the memory card. It is used to store the pictures taken on digital cameras. The memory card in the digital camera can be equated with hard disks in computers. The memory card varies in capacity and the additional memory cards are generally either 128 MB or 265 MB. Memory Stick, Compact Flash and Smart Media, etc. are all different type of memory cards. The use memory card is dependent on the users camera type, the memory card can be re-used, once saving the required photographs on the computer, or copying them on a CDs etc. The most commonly used card in digital cameras is the 16 MB cards, and most of the digital cameras make use of removable storage memory for the purpose of recording images.

There are also cheap digital cameras available in the market; these camera are very handy and useful for all purpose. The cheap digital cameras is equipped with all the high-technology features and are very result oriented. The presence of this type of camera can be felt in the market, where it has a good share in the revenue. Many renowned companies are coming up with cheap digital cameras to cater the demand of the customers and to capture the market. This cheap digital cameras are second to none in terms of quality and durability as compare to any digital camera available in the market.

The demand for digital cameras are increasing with each passing day with some brilliant and high-tech digital camera in the market. The manufacturers are catering to the demand with all new features added everyday in the cameras.

Kodak EasyShare M893 IS Digital Camera provides great image quality and advanced features in an ultra-compact and affordable package. The camera provides a resolution of 8.1 megapixels, which allows you to print clear, crisp images up to 30 x 40″ in size, and a 3x optical zoom lens that makes the camera great for typical family and vacation shooting.

In addition, the camera includes Digital Image Stabilization that detects camera movements to digitally compensate for camera shake, and blur reduction that uses high ISO settings to produce clearer pictures in low-light situations. It also incorporates Kodak Perfect Touch Technology so you can take consistently better shots under all sorts of shooting conditions.

Kodak’s Face Detection technology is provided so portraits and group shots always look great, and the Versatile Scene and Color Modes allow you to be creative without the difficulty of manual shooting. Finally, the vibrant 2.7-inch LCD screen is perfect for instantly sharing clear, bright pictures and videos, or displaying your own customized Multimedia Slideshows right on the camera.

The Kodak EasyShare M893 IS Digital Camera provides great image quality and advanced features in an ultra-compact and affordable package. The camera provides a resolution of 8.1 megapixels, which allows you to print clear, crisp images up to 30 x 40″ in size, and a 3x optical zoom lens that makes the camera great for typical family and vacation shooting.

In addition, the camera includes Digital Image Stabilization that detects camera movements to digitally compensate for camera shake, and blur reduction that uses high ISO settings to produce clearer pictures in low-light situations. It also incorporates Kodak Perfect Touch Technology so you can take consistently better shots under all sorts of shooting conditions.

Kodak’s Face Detection technology is provided so portraits and group shots always look great, and the Versatile Scene and Color Modes allow you to be creative without the difficulty of manual shooting. Finally, the vibrant 2.7-inch LCD screen is perfect for instantly sharing clear, bright pictures and videos, or displaying your own customized Multimedia Slideshows right on the camera.

The Kodak EasyShare M893 IS Digital Camera provides great image quality and advanced features in an ultra-compact and affordable package. The camera provides a resolution of 8.1 megapixels, which allows you to print clear, crisp images up to 30 x 40″ in size, and a 3x optical zoom lens that makes the camera great for typical family and vacation shooting.

In addition, the camera includes Digital Image Stabilization that detects camera movements to digitally compensate for camera shake, and blur reduction that uses high ISO settings to produce clearer pictures in low-light situations. It also incorporates Kodak Perfect Touch Technology so you can take consistently better shots under all sorts of shooting conditions.

Kodak’s Face Detection technology is provided so portraits and group shots always look great, and the Versatile Scene and Color Modes allow you to be creative without the difficulty of manual shooting. Finally, the vibrant 2.7-inch LCD screen is perfect for instantly sharing clear, bright pictures and videos, or displaying your own customized Multimedia Slideshows right on the camera.

The Kodak EasyShare M893 IS Digital Camera provides great image quality and advanced features in an ultra-compact and affordable package. The camera provides a resolution of 8.1 megapixels, which allows you to print clear, crisp images up to 30 x 40″ in size, and a 3x optical zoom lens that makes the camera great for typical family and vacation shooting.

In addition, the camera includes Digital Image Stabilization that detects camera movements to digitally compensate for camera shake, and blur reduction that uses high ISO settings to produce clearer pictures in low-light situations. It also incorporates Kodak Perfect Touch Technology so you can take consistently better shots under all sorts of shooting conditions.

Kodak’s Face Detection technology is provided so portraits and group shots always look great, and the Versatile Scene and Color Modes allow you to be creative without the difficulty of manual shooting. Finally, the vibrant 2.7-inch LCD screen is perfect for instantly sharing clear, bright pictures and videos, or displaying your own customized Multimedia Slideshows right on the camera.

The Kodak EasyShare M893 IS Digital Camera provides great image quality and advanced features in an ultra-compact and affordable package. The camera provides a resolution of 8.1 megapixels, which allows you to print clear, crisp images up to 30 x 40″ in size, and a 3x optical zoom lens that makes the camera great for typical family and vacation shooting.

In addition, the camera includes Digital Image Stabilization that detects camera movements to digitally compensate for camera shake, and blur reduction that uses high ISO settings to produce clearer pictures in low-light situations. It also incorporates Kodak Perfect Touch Technology so you can take consistently better shots under all sorts of shooting conditions.

Kodak’s Face Detection technology is provided so portraits and group shots always look great, and the Versatile Scene and Color Modes allow you to be creative without the difficulty of manual shooting. Finally, the vibrant 2.7-inch LCD screen is perfect for instantly sharing clear, bright pictures and videos, or displaying your own customized Multimedia Slideshows right on the camera

Cameras are just about everywhere in today’s day and age. There are few places you can go in public that you are not being recorded by a camera. From the streets to the local fast food restaurant you are likely being recorded. Surveillance systems have also been part of the security systems for the wealthy for many years and now they can be an affordable part of your homes.

There are several things you must consider when choosing your camera system. Just like most technology you can get more features for more money. Choosing a system will require you to consider budget along with wanted features and find a happy median of the two.

The first step is deciding how many cameras you plan to use. A system for just one camera can be set up for very little cost and be very effective. If you choose to have more cameras like 4, 8 or 16 then there are complete packages available that make cameras more cost effective. Once you know how many cameras you want, you will need to decide if you want to run wires or not. Most cameras are available in wired or wireless versions and normally the wired cameras are much more cost effective.

Surveillance cameras can come with many different functions including night vision, covert, color, black & white, weatherproof, high power wireless, pan tilt zoom cameras and many other options. If you need special application cameras they are likely available at a cost. Currently the most commonly used cameras for homes and businesses are dome cameras, bullet style cameras and hidden cameras. The type of camera will greatly depend on the application.

Next you will need to find a way to record your cameras. Recording is not necessary and it is possible to just view the cameras using a monitor, but you will find that having a recorded system has many advantages. The cost of recording can vary greatly depending on your choice of recorders. Below are the different recording options you have to choose from.

VCR -The cheapest may be an extra VCR you have lying around. Most cameras can be plugged directly into a VCR or TV’s video input. If the connection is not the same then there are adaptors available. You may be limited when using a VCR to just one camera. You can split the video of more cameras and use them with a VCR if you purchase a quad. A quad splits video inputs so they take up just a portion of the screen. Most quads are 4 channel, but more channel quads are available. VCRs can’t be viewed over the internet.

Surveillance Software and Hardware – This method of recording can also be a very cheap way to record. You must have a computer with some extra RAM and a USB port . This software will turn your computer into a feature rich DVR or digital video recorder (more on this later). To connect a camera to the computer you will need a analog to digital video converter. Just plug the camera into one end and the other end into the USB port on the computer. Most software will be able to see the camera as soon as it recognizes the video converter. If you have more cameras, you will need more converters and more free USB ports. You can also use a quad between the cameras and the video converter cord to increase the number of cameras you can view using this method. This is a great economic way to go if you only have a few cameras. These systems can be connected to the internet and viewed from anywhere in the world that has an internet connection.

DVR Card – a DVR card will need to be installed into one of the PCI ports in a PC in order to work. If you can’t add a card to the inside of your PC, then this may not be the best solution for you unless you can get some help. There are many people that have the ability to install a PCI card so help should be easy to come by. These cards range from 4 to 16 cameras and some can be used in sets for systems up to 36 cameras. The exposed part of the card on the back of the computer will allow you to connect the number of cameras the card allows. Most DVR cards will also allow audio microphones to be connected along with the cameras. DVR cards can be full of features and can compared with a high end DVR. DVR cards usually can be connected to the internet and viewed from anywhere in the world that has an internet connection.

DVR – is a digital video recorder. This device basically allows your cameras video to be recorded onto a hard drive or internal disk. There are 2 types of DVRs, windows based and embedded. Windows based DVRs are similar to a computer and use the Windows operating system to run surveillance software. Most people find Windows based DVRs much easier to use than embedded DVR. The embedded DVR does not use any software and all functions are embedded on software encoded computer chips. Embedded DVRs are cheaper than Windows based DVRs in most cases. DVRs are generally the most expensive way to record your cameras. Both types of DVRs allow you to connect the cameras directly to the back of the DVR. Some DVRs can be connected to the internet and viewed from anywhere in the world that has an internet connection.

You may also want to hook a monitor up to your system. The monitor will allow you to review the recorded video and also watch it live. Depending on the system you are setting up, the monitor may be a TV or may be a computer monitor. Monitors are available in all different sizes and qualities. If you plan on building a surveillance system you may want to consider one of the many systems available that provide everything you need in one discounted package. For the beginner it is many times easier to purchase a complete surveillance system then to try to piece together each thing individually.

These basics should be enough to get you started on finding a home surveillance system to meet your budget. Many times if you speak to a surveillance expert you can simply tell them your needs and your budget and they will put together a system that will work well for you. There are a lot of options for you to protect your home and family, be sure the system purchase will meet your security needs.

Abstract

When looking to select an infrared camera, it is extremely important to better understand the attributes of these cameras that most impact the quality of the infrared images that are produced. This paper covers the three primary areas that influence thermal image quality: pixel resolution, thermal sensitivity and fixed pattern noise. Each area has a significant impact on thermal image quality.

 If you’ve purchased a digital camera in the past, your purchase was likely influenced by your belief that the number of pixels was the most important specification when trying to judge image quality between all the camera choices offered.  For anyone that reads Consumer Reports™ and their detailed evaluation of digital cameras you’ll appreciate that camera performance includes careful analysis of much more than the pixel count. Because a thermal camera is basically an image converter (radiant thermal energy to visible image), you need to understand what are the primary attributes that determine thermal image quality and how they each contribute to the image quality that you may be experiencing in your application.

Pixel Resolution  

The first consideration is the number of pixels. Today there are three resolution standards (some manufacturers’ cameras deviate slightly)

Low Resolution -  160×120 (19,600 pixels)

Medium Resolution – 320×240 (76,800 pixels)

High Resolution – 640×480 (307,200 pixels)

How much resolution you need (verses want) is primarily determined by your application and by the value you give to image quality. When evaluating a digital camera with 5 verses 10 mega pixels most users will never benefit by purchasing a camera with 10 million pixels because they will never print the images on large enough paper where the resolution would provide better print quality. Whereas you will always print and display the full resolution of an infrared camera since the highest resolution available is relatively modest by today’s digital camera standards. Even at 640×480 pixel resolution a high definition thermal image will only take up a fraction of today’s computer displays and the resulting thermal image print quality will always be fully realized. Therefore when evaluating a thermal camera the number of pixel is relevant and increased resolution is the most significant consideration in improving image quality.  

Another benefit to high resolution is the ability to zoom into a scene and maintain good image quality. The majority of thermal cameras feature a standard optic with a horizontal field of view of approximately 25°. Regardless of pixel resolution the performance of a 640×480 camera set to 2X digital zoom is going to equal the performance of a 320×240 resolution camera with an optional (and often costly) 12° (2X) lens. If you anticipate the need for imaging objects at distances further than 20 feet you should consider the increased costs of a 2X lens for a 320×240 thermal camera when comparing the total costs between 320×240 and 640×480 systems.  

The second major issue that impacts image quality is thermal sensitivity. While there are a number of tests used to quantify this specification, thermal sensitivity basically defines how well the camera will image as you increase image contrast. Thermal sensitivity varies with object temperature, as object temperature increases the slope of the signal output of the detector increases with increased temperature. This means that the signal (increasing) to noise (fixed) ratio improves as you view hotter objects. However this is not usually a benefit because the applications where better thermal sensitivity can be exploited are low temperature (room temperature) applications where the thermal contrast (temperature delta within an image) is very low. Typical low thermal contrast applications include building diagnosis where the camera is imaging interior walls with very little temperature variations or emissivity differences and issues like moisture or insulation quality can only be visualized by increasing the contrast to the point where the cameras thermal sensitivity limits the useful temperature span settings.  

As you review published camera specifications you will see thermal sensitivity specifications range between 0.25°C (250mK) and 0.05°C (50mK). While you might consider a quarter of degree to be adequate thermal sensitivity as soon as you look at a low contrast scene you’ll discover the image quality adversely effects the image quality as noise begins to dominate the image.  

Thermal imagers usually display images in palettes comprised of 256 discreet color or gray levels. Imagine your target has a temperature difference between 0°C and 256°C each gray or color level would represent 1 degree of temperature difference. Now apply this same color mapping into a scene with temperatures between 25°C and 35°C or 10 degrees. Each color now represents 0.03°C (10°C ÷256), a value lower than the most sensitive uncooled cameras. The result is some display of noise. There are many applications in which it is very important to set the span as narrow as possible in order to see the smallest temperature variations possible. If you are using a camera with 0.25°C sensitivity and wanted to maintain the same level of noise you would have to set a temperature range of 65°C (150°F) which would likely result in a very low contrast image. You should recognize that the difference between a camera with 50mK sensitivity verses a camera with 100mK sensitivity is 100% better and not as 0.05°C better.  

Thermal Sensitivity  

NETD is the scene temperature difference equal to either the internal noise of the detector (detector NETD) or the total electronic noise of a measurement system (system NETD). As a camera buyer you need to evaluate system NETD.   The test setup consists of temperature control blackbody reference and some type of ambient (passive) object that creates a simple slit target for the camera to visualize. The temperature of the black body is adjusted until it nearly equals the ambient target temperature. An oscilloscope measures the analog video output of one horizontal line and at the point where the temperature delta between the reference and the ambient targets no longer creates a measureable signal the NETD is determine by the measured temperature difference between the reference and the ambient reference targets.  

MRTD – Minimum Resolvable Temperature Difference

This is a system test. An observer is asked to assess the minimum temperature difference at which a 4 bar target can be resolved by watching the video output displayed as the temperature set points of the reference and the ambient targets are brought close together. This minimum difference will change with the spatial frequency of the bar target used. A curve of MRTD against spatial frequency is obtained which characterizes the performance of the imaging system. Modern infrared imaging systems can have low spatial frequency MRTDs of tens of milli-kelvins.  

The benefits of large format cameras is significant we you combine the need for high sensitivity while viewing high spatial frequencies.

To simplify explaining the fundamentals of thermal sensitivity let’s focus on a single pixel of the infrared sensor in an uncooled infrared camera. Each pixel in an uncooled focal plane array image sensor is essentially a resistor fabricated using MEMS (micro electro mechanical systems).  

The basis structure of a thermal uncooled camera pixel is a microscopic bridge structure on which a thin resistor material and an absorbing layer have been deposited. Legs suspend the deck of bridge above an integrated circuit and provide electrical connection between the resistive bridge and the silicon readout circuit. The readout IC controls the voltage that biases the thin film resistor and multiplexes all the pixel signals out to the cameras imaging electronics.  

As infrared radiation is absorbed by each pixel its temperature changes as the photon energy (8-14 micron wavelength) is converted to heat which in turn changes the resistance of the pixel’s thin film resistor. The readout IC sends a voltage across each “micro bolometer” element and a signal proportional to heat absorbed by each detector is the basis of a real time video image.  

The electrical circuit of an infrared sensor is very simple, a voltage is turned on to each pixel and a change in resistance of the thin film resistor based on the pixels temperature is sampled and converted into a digital value. All analog signal carry some level of noise along with the signal generated by the sensor. The ratio of signal to noise strongly impacts the image quality of a camera because the noise level is usually a fixed amount and as the detector gain is increased the system will begin to display the signal noise and you’ll begin to see “snow” in the image.  

The signal level of this noise is commonly specified as Noise Equivalent Temperature Difference.

Like any electrical circuit there are a lots of opportunities for electrical noise to get into systems, but the quality (signal to noise) of the signal coming directly off the infrared pixel has the most impact on thermal sensitivity, since nearly all camera developers have access to the same electronic components with which to create a camera. Therefore the thermal sensitivity in large part is based on the quality of the infrared imager array.  

Other issues like the f number of the lens also impact thermal sensitivity. Your camera’s lens is likely ƒ1.0 (the focal length is equal to the lens diameter) which is considered a “fast” lens. By comparison the f number in your digital camera is likely between ƒ3 and ƒ5 while the cameras used in cell phones and other low cost systems can be as high as ƒ20! As application demands lead to longer focal length lenses it is practical to go to “slower” optics in order to reduce the size, weight and cost of telephoto lenses and trade off some thermal sensitivity. For example, an F1.4 optic will result in 2X reduction in thermal sensitivity and an F2.0 optic a 4X reduction in thermal sensitivity. Therefore a system with 50mK sensitivity using a standard lens will still maintain good sensitivity (100mK) when a ƒ1.4 telephoto lens is attached to the camera verses another camera whose thermal sensitivity started at 100mK and becomes 200mK when viewing through a “slower” (ƒ number higher than 1).

As you can see from the various issues raised within this paper the nature of thermal sensitivity is very complex but in the real world the human eye is extremely good at differentiating small differences in image quality that you’ll know it (good sensitivity) when you see it.  

Non-Uniformity Correction

As the number of pixels increases and their sensitivity improves the quality of image is increasingly dependent on a process called Non Uniformity Calibration or NUC. As we described earlier a microbolometer imaging array is essentially an array of tiny resistors, and because of the micro scale of these devices, there are variations in how each pixel responds to the infrared energy from an object.   During manufacturing the infrared camera’s sensor must be normalized, meaning that the differences in response and DC output for each detector must be zeroed out. Thermal cameras typically feature an internal flag or iris that periodically is positioned in front of the detector as a constant temperature reference to zero out differences amongst the pixels. This is a fine tuning of the factory NUC process and is sometimes referred to as a “touch up.”

Because the touch up source is inside the lens, additional image quality improvements are possible when performing a touch up calibration through the lens either using a lens cap or exposing the camera to a large uniform surface. As camera performance improves the non-uniformities created by the lens will begin to be seen and for the ultimate image quality a simple through the lens calibration step will ensure the highest image quality the camera is capable of generating.  

Benefits of high increased image quality

Much greater flexibility to inspect targets are varying distances

Ability to visualize low thermal contrast targets

More intuitive diagnosis of heat related problems

Improved infrared visible fused image quality due to better matching of infrared and visible camera resolution..

Flexibility to incorporate lower cost and lighter weight optional lenses

More intuitive diagnosis of temperature anomalies  

For full article with images and reference material, please visit www.electrophysics.com/tiqab

 

For more comprehensive White Papers visit our online Knowledge Center www.electrophysics.com/thermal-imaging

Security cameras are one of the most important devices for surveillance. Security cameras are the best way to protect your home or office. They offer complete security against vandalism of property, trespassing, and more. With a wide range of cameras, ApexCCTV provides the perfect solution to meet all your security concerns. Security camera systems not only monitor but record incidents for future reference. They have a wide range of applications in places, like schools, hotels, hospitals, retail stores, and more.

Security video cameras use CMOS or CCD chips to produce quality images. Image quality depends on the size of CCD chips that are 1/4, 1/3, and 1/2 inches. Larger the chip size better will be the image quality. 1/3-inch chips are commonly used in security video cameras. Choose from infrared security cameras, dome security cameras, IP/network security cameras, or wireless security cameras and enjoy high level of security. It is extremely important to keep certain points in mind before choosing a security camera, like the location and lighting conditions. Proper placement of the hidden security camera helps to prevent many crimes. Security camera systems are also effective in monitoring babysitters.

Black and white cameras are ideal for home use, as they provide higher resolution than color cameras. Infrared cameras have the ability to switch over from black and white to color and vice versa depending on lighting conditions. Pick weatherproof cameras or bullet security cameras for outdoor use. These cameras are compact and rugged. Outdoor security cameras can deter criminals before they break in. But now-a-days, most security cameras come with features, which make them effective in both internal and external environments.

You can go for high-quality PTZ cameras to have adequate surveillance in all directions. These cameras can pan, tilt, and zoom offering maximum coverage of an area. They are versatile and can pan 360 degrees, thereby allowing you to view objects directly below them. One of these PTZ cameras is as effective as 10 fixed cameras. These cameras are suitable for law enforcement and casino applications. They can also be used in retail stores. You can place them outdoors or indoors. Dome security cameras are high-end cameras, which are extremely useful because it is very difficult to judge in which direction these cameras are pointed unless you look at them from a close range.

With network cameras, surveillance has become a breeze, as the user can manage the camera through a browser. For covert monitoring, mini spy or hidden cameras are quite effective. Wireless security cameras are highly versatile and portable. You can set them up anywhere and in no time as there are no wires to deal with. Box camera or full body cameras are highly trusted for professional security surveillance. Get incredible deals on security cameras at ApexCCTV, which is your one stop for CCTV package needs.

In the present vulnerable scenario, security seems to have become the prime concern of the common people.

All those who do not have the liberty as well as the money to keep body guards should not worry. To tackle the problem of security, various types of security camera have been launched in the technological world. Security cameras are recognised as the standard in monitoring property and detection of criminals. Surveillance video is claimed to be the most successful home monitoring device by its ways to protect oneself against theft and violence. This is because these cameras are very effective in deterring criminals, thus protecting your house against theft and violence and further help them to catch those perpetrators.

Surveillance cameras that are primarily used for monitoring but today their scope has not been restricted to government offices or banks.

Today, these CCTV cameras are applicable in houses as well. Cities such as London have installed several surveillance cameras throughout the city as a means of deterring and capturing criminals. Car theft is one arena where these cameras are extremely helpful. So much so is the advantage of security cameras that even cities like New York and Chicago are beginning to use surveillance cameras throughout the city. Though some people argue that surveillance cameras evade the privacy of people, thus stripping them of their civil rights. Critics have also charged that surveillance cameras are used more for social control than as criminal deterrents. However, with the rise in many anti social happenings, these cameras have proven to be very useful.

Initially these security cameras were analogue, but the digital phase has taken over them now.

These digital security cameras transmit their data feed via WiFi technology to the Internet. From there a digital video recorder or a computer can view the feed with a specially configured Web browser. The video recorders are thus able to store data feed to a DVD-ROM.

Apart from the digital video security cameras that are present in a variety of options in the computer hardware industry, digital still surveillance cameras are also available. These cameras are equipped with motion detectors that alert the camera to take a photo when any activity occurs. This camera is very much in methodology like the digital cameras that hold hundreds of photographs at one time.

In this world where a new technology is born everyday, there are a wide variety of options to choose from in the security cameras segment as well.

There are spy cameras that are the smallest and most powerful covert spy camera/recorder in the world. The micro hidden camera, though looks like an air freshener, is ultra-covert with 2GB of RAM for fast-action snapshot video when motion is detected. Then there is the night vision camera that capture footage even in complete darkness. This type of motion-activated wireless night vision camera has a 150 foot night vision range, which is capable of recording anywhere, anytime.

Many popular companies like Sony, today, are involved in the manufacturing of these CCTV cameras.

All one needs to do is to choose the one that suits one’s requirements. In recent times, they are used by many government branches, businesses and by private homeowners. Choose from Wireless Cameras, Hidden Cameras, Secure Recording Devices, and even Decoy Cameras to protect your home or office.

These days, the digital camera has become the more popular choice for those seeking to make a brand new camera purchase. Lower prices over the past few years have enabled camera buffs of all ages and abilities to indulge in purchasing a digital camera. Without the need to constantly purchases a stock of film and then pay again for the developing, digital cameras have led to people being able to practice their art of photography to their hearts content without in becoming a financial burden. If you are on a budget, simply seek the lowest price. Digital camera technology enables the absolute beginner to snap a perfect shot following little instruction.

The variety available when seeking a new camera is rapidly increasing. Whether you search for the brand Canon, Nikon, Olympus, Casio, Kodak, Sony, Fuji or Panasonic, all these digital cameras can be obtained in both store sales and online for the lowest price. Digital camera purchasing may now offer a few too many choices rather than too few.

Sometimes the style of camera model may be the clincher when selecting a digital camera, even when searching only for a camera of the lowest price. Digital camera shape, color, size, or function can all play a part in the purchase decision, but sometimes the look alone can make the final decision. Perhaps you are looking for a sleek black compact model, or maybe a silver feature-filled style of camera fits your purpose better. You may alternatively prefer a red or green modern design.

Some of the features you may be concerned with include the zoom and megapixel counts. Zoom comes in both optical and digital zoon, and frequently a combination of the two is offered. The megapixel count may be of importance to you, the better models of digital camera having the higher rating if you have a choice between models of the lowest price. Digital camera features also include various sizes of on-screen display. If you want to ensure the optimum photograph before taking it, a larger display screen will offer extra detail.

Some purchasers of the lowest price digital camera may make their choice based on the battery. There are two main styles of battery, the easily inserted and often rechargeable AA size regular camera battery and the smaller watch-like batteries made from materials such as lithium-ion. These also are rechargeable, and some camera packages offer a free recharger among their contents. Cheap priced battery chargers for digital camera batteries are also purchasable from most camera stores, both online and off.

The higher classed models available on the market often come with a variety of detachable lenses. These may add to the zoom capacity, or simple alter the photographic image. Some lenses allow for fisheye shots, others cater for distortions or microscopic imaging. These tend to appeal most to the camera buff seeking something new in their images, or the expert, professional photographer who needs to cover a wide range of options for their occupational use of the digital camera.

Some of the more expensive brands and styles of digital camera can still be purchased at a lower rate during sales and other opportunities to buy at the lowest price. Digital camera sales increase at sales time accordingly. However, this can also happen when a camera store sells off former stock to make way for new models, at which time many fantastic bargains are obtainable, allowing for purchasers to buy a better model with their money than they expected.

If you are simply searching for an everyday digital camera at a great price, many of the features will be irrelevant and you simply need to ensure that all necessary items are included to save further purchases later on. The essentials generally include batteries, a battery recharger, a camera case, and a memory card or USB attachment, the latter two enabling you to transfer your pictures from camera to computer or printed photograph. These complete camera packages can be located online or in sale for the lowest price. Digital camera use is now within everyone’s budget.

If you want to find the best source for the Lowest Price Digital Camera, then your search has ended. You will also find thousands and thousands of the lowest priced consumer electronics at Consumer Home Electronics

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PowerShot A95 Digital Camera (5.0MP, 2592×1944, 3x Opt, 32MB CompactFlash Card) Strengths: High quality 5MP pictures, Camera feels great in hand, swivel LCD screen, best bang for the buck camera. Weaknesses: Included 32MB CF card is too small. Summary: This camera is awesome. I upgraded from a Canon A70 and it was well worth the money. The Canon A95 uses 4 AA bateries, but it eats through normal alkalines way too fast. I highly recommend getting rechargeable NiMH AA batteries and a quick charger.The swivel screen is a major plus, it’s 1.8″ compared to 1.5″ from the Canon A70. The screen is also higher resolution than the A70.I have used the camera for 3 weeks and printed about 50 pics so far. The pics look great and I even cropped to zoom in on some pictures and you couldn’t see any sign of pixelation. I love the manual flexibility with this camera, plus the automatic modes make it easy for anyone to use.The camera has a nice solid feel to it and fits well in the hand. I prefer the Canon A95′s size rather than the ultra compact cameras like Sony’s T1 because you can easily hold the camera in one hand and take pics. But if you have an ultra compact camera, you have to hold it awkward and it my easily fall from your hand.I highly recommend this camera to anyone looking into getting a 5MP camera that’s affordable, flexible, and normal size.

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Cyber-shot DSC-W1 Silver Digital Camera (5.1MP, 2592×1944, 3x Opt, 32MB Memory Stick)

Strengths: Size, LCD, AA batteries, movie mode and black & white modes are GREAT – use ‘em all the time. Weaknesses: Flash is weak, zoom inadequate at times. Summary: I spent a LOT of time investigating digital cameras online -one would think I was buying a car or something. Anyway I am a novice camera user and remain very impressed with this little guy. I would certainly recommend it. The movie mode is great for ‘vignettes’ or small movie snapshots. I also use the black and white a lot. I also didn’t think the LCD would matter very much, but it does: I never use the viewfinder. I appreciate the large size of the LCD when passing the camera around to friends to view pictures and movies.Hint #1: Immediately jack up the megapixel resolution to 5 so that you can capture moments in the best resolution possible. Then, bypass Sony’s ridiculous profit margins- for memory cards buy SanDisk instead. The 512 MB is fantastic – you will get a lot of memory space. I saved .00 this way – 0 vs. 5. The 32 MB is inadequate for daily usage. I use it as ‘emergency’ memory when my 512 has filled up on me and I need an extra pinch of memory to get me through the moment.Hint #2: Do NOT buy the Sony camera case. They charge a ridiculous price for a shoddy version. Go for a Lowepro – I paid ten dollars and it is very sturdy – also has a nice inside pocket to keep memory cards.Hint #3: Buy a separate set of rechargeable batteries you can swap on the go. The AA battery format is a huge plus.Picture clarity is great for the size and price of the camera. The camera and case are small enough that I WILL take it anywhere, and have. In other words, it is a convenient model.I did find that for indoors the flash was inadequate at a distance. The zoom could also have been 4x or 5x.All in all I am quite happy with this model – but stay away from buying Sony brand ‘peripherals’ unless you like spending money.This camera fulfills my needs. The only reason it does not get five stars for the above drawbacks. Otherwise, a great job by Sony and their third-party peripheral competitors!

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FinePix E550 Digital Camera (6.3MP, 4048×3040, 4x Opt, 16MB xD-Picture Card)

Strengths: Well priced, 6+mp, all features including raw image Weaknesses: This camera uses 2 AA cells in a hurry Summary: As a professional digital camera lecturer, I must admit that the Fuji E-550 was a very pleasant surprise for me. Priced at about 0, this digital camera produced digital photos that were much sharper, more detailed, and more excellent than I, frankly expected.I found the digital camera very easy to use right out of the box. While this digital camera does have a 12mp interpolated image size available, I found the 6mp native image size to have more contrast, detail and resolution.As you might expect in a consumer digital camera, the digital camera’s flash is not very powerful. At 200 ISO it will produce excellent exposures out to 13 feet. By adding a supplementary slave flash such as the Sony HVL-FSL1B and a bit of flash compensation, I was able to extend the effective flash range out to 25 feet, making the Fuji E-550 useful for indoor photos of large groups.The Fuji E-550 does an equally amazing job with macro or close-up digital photos. It will focus quite close making it very effective for photos of small items and jewelery that might be photographed for sale on auction sites such as www.ebay.com.The strongest suit for the Fuji E-550 is it ability to record a great deal of detail with extreme sharpness and clarity while being handheld. The Fuji E-550 is also very capable of taking excellent night photos when it is placed on a tripod.All in all, I was extremely impressed with the Fuji E-550. I received a lot more digital camera than I expected for the samll price of 0. For those who like to use the raw image format, you will understand that you can essentially re-take the digital photo all over again right in your computer. This is a huge advantage.Of course, being a Fuji digital camera, the Fuji E-550 uses the somewhat more expensive XD electronic data chips. However, the Fuji E-550 is very speedy. From power on to being ready to take the first digital photo takes 1.4 seconds. This digital camera is equally as fast in writing your digital photo to the XD chip.The newer Fuji digital cameras are marketed to compete dollar for dollar with the Kodak line of digital cameras. Therefore, they tend to be very competitive with Kodak and offer in most cases, a lot more features.There is available for the Fuji E-550 an adaptor as well as both a wide angle and a telephoto (1.9X) supplementary lens. The supplementary lenses are very fairly priced and readily available through Fuji’s own website. This is a pleasant contrast to the accessories offered by Sony, through their own website, whose wide angle and telephoto supplementary lenses are unreasonably high in price.

Conclusion: The Fuji E-550 is a top quality digital camera. It more capable than most might expect. In addition, it is quite small and pocket sized, extending its appeal to many more digital camera users. It is worthy of your attention. The digital photos produced by this digital camera are amazing and compare most favorably with much more expensive consumer digital cameras. I would happily purchase this camera again.I will be very confident in introducing the Fuji E-550 to the attendees of my workshops all over the world. It is a digital camera that I can point to with a lot of pride, simply because it gives the digital camera user many features and excellent digital photos for a very resonable price.

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Selecting either a home security camera system, or a camera to be used for a commercial reason, can be frustrating if you don\’t know what you are looking for in protection. For instance, do you want a real or fake home security camera system, meaning, do you need a system that will actually alert the police, or do you feel that the aesthetic of having a camera visible on the premises is good enough to ward off predators? Are you interested in the way that a monitor is going to look? Do you want something that is obvious or discrete? Regardless of what your needs are, there is something that can come close to what you want. Cameras will come in three basic forms, hopefully learning the basics will help to cut down on some future decisions.

The first kind of home security camera is known as a dome camera. Obviously, this camera comes in the shape of a dome and it fits conveniently on the ceiling of your home or business. You will find the dome cameras often times in casinos where they are used to monitor the tables. You will also find home security at its most fashionable with the dome lens. There are dome cameras that can be placed outside, however, you must use a special armor type in order to do this kind of mounting. Sony carries two different types of dome security cameras and they are a leader in the industry. You can choose from the Verifocal dome camera, which has the highest resolution (420 lines) and an adjustable lens. You can also purchase Sony\’s Infrared Armor dome camera, which acts as a hidden camera and is the most durable of all of the dome cameras. Dome cameras are the most popular security cameras because they are impossible to detect which angle they are viewing unless you are at close range. They come in black or white and they all have adjustable lenses.

The second type of home security camera is the bullet camera. The lens is long and resembles a rifle, which is where the camera finds its name. Bullet cameras are easily visible and can be mounted to a wall or a ceiling. They use a 12V DC voltage, and the power cable should be included when the camera is purchased. Most of these cameras will film in color and then change their resolutions to black and white when the light levels are lower. The resolution during the day is much better with the bullet security systems, but if you have an alternate form of lighting, like a streetlight, people can sometimes be seen from up to 70 feet away. The most popular brand of bullet security cameras is the SPECO CVC-6805SX, which is color and has a fixed lens of 4mm.

Many businesses rely on a home security camera at night. However, it can be hard to see the footage when there is no light. The infrared camera has built in lights around the lens so you are able to view your taped footage with ease. However, the infrared lighting can cause a problem when it is used at a home due to the glare that is created from the windows. Some people will think that an infrared camera is the same as a night vision camera, although the night vision camera does not have built in lighting around their lens. Prices can vary on the infrared cameras, but the most affordable home security model is the QSVC422 CCD color outdoor camera made by Digital Peripheral Solutions.

Security cameras can provide a cushion of comfort for a secure home, especially when you have an investment that you want to protect. A home security camera can scare an obvious thief, and also catch an unsuspecting one if it is a strategically hidden camera. Home security cameras have become more popular with people who own second and third homes, and feel like they need an insurance policy for their property, so to speak while the business owner has been protecting his own with security cameras since the advent of the entrepreneur. Just remember that it can never hurt to be proactive about your safety.