Photography Blog

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

Your wedding will be one of the most vital moments within your life. You have possibly played it within your mind a thousand times: the lingering smell of delicious food, the air heavy with flower perfume, the resplendent, shimmering wedding dress, and excellent photography to record everything.

Weddings in modern times demand photography which goes above the formal, stiff poses, and instead captures eternal, carefree love. Forever gone are the times when wedding photographs meant waiting for a camera to click and uncomfortably smiling. These days, wedding photographs are about recording the intimate moments and unique personality of the wedding.

Reportage wedding photography, additionally referred to as documentary wedding photography, or wedding photojournalism is for individuals who wish for the feeling and emotion of their wedding day to be captured on camera. In a non-obtrusive way, the photographer will photograph the wedding day as it unfolds, with only minimal intervention. The photographer must always be within the correct place at the correct time, so he does not miss any important events.

You need to be okay with the photographer following you around a majority of the wedding day, otherwise, there might be a problem! If you can cope with that and have the ability to ignore the photographer (which is what the photographer wishes for), you will end up with natural photographs that are wonderful.

The largest challenge within reportage wedding photography includes recording the little events – all the things which go unnoticed, yet really show the wedding day magic. The key to getting the most spontaneous and natural shots involve having the ability to be fairly quiet and unnoticeable.

Reportage shots work well in black and white – this nostalgic, timeless appearance will compliment captured moments and turn them into something very special. Digital wedding photography permits photographers to convert colour photos to black and white.

Keep in mind that the photos of the wedding day will last a lifetime. You will want to show your children and grandchildren the story, not a sequence of formally posed pictures without any intimacy or warmth. It may cost you slightly more than to hire a conventional wedding photographer, yet as it comes to preserving your memories of the best day of your life, it will be money that is well spent.

Today’s digital cameras offer a bewildering array of different settings to consider before you even take a shot. This can be really confusing if you’re a beginner, and the temptation is to assume it’s all too difficult and just let the camera make all the decisions for you.

What you might not realize is that while there are a large number of settings that you can change on the average digital camera, there is a much more limited subset of really important settings, and you can learn what these do pretty quickly. This is worthwhile, because while modern cameras are clever, you’ll need to take control of your camera in order to really take your photography to the next level.

In this article, we’ll look at three of the most important and talked-about camera settings.

# Camera Modes

‘Mode’ is the most important camera setting of all. This is because mode is a ‘parent’ setting that affects which other settings are selectable by you, and which the camera will control automatically.
With the exception of the smallest compacts, most cameras will have a mode selector dial, and this will be located on the top or back of the camera. While the terminology will change from manufacturer to manufacturer, every camera will have the following modes: automatic; program; manual; aperture-priority, and shutter-priority.

Today’s cameras almost always have a selection of ‘scene’ modes as well, such as night, sports, pets, portrait and so on. If there are only a few scene modes they will be on the mode dial as well; otherwise they will probably be only selectable from within the camera’s menu system.

Most people use their camera in automatic mode most of the time. This means that the camera is doing absolutely everything for you. If you really want to take your photography above the level of basic, uninspiring snapshots, you’ll need to stop using automatic mode, and at least learn about aperture-priority and shutter-priority modes. In these two modes you are able to set (respectively) aperture and shutter speed, and ISO (in both).

# ISO

In the days of film, photographers had to choose what sort of film to use. Among other things, film comes in varieties which are either more or less sensitive to light. Films which are more sensitive to light are called ‘faster’ films, and while they are much more versatile, the downside is that they are ‘grainier’, which limits the degree to which they can be enlarged and still look good.

ISO is the digital equivalent to film speed. A low ISO number (such as 100) mean low sensitivity to light but higher-quality, less ‘noisy’ (this is the digital equivalent of grainy) results. A high ISO number (such as 800) means high sensitivity to light, but noisier pictures. You should try to use low ISOs whenever there is enough light to do so, and only use higher ISO when you are forced to. Note that in automatic mode, this is not a setting you can change for yourself.

# White Balance

You will probably have heard of ‘white balance’ before. To understand the concept of white balance, you need to know that not all light is the same. Light comes in a variety of different ‘temperatures’. An easy way to think of this is to imagine a continuum of light, with warm (orangey-yellow) tones on one end, cool (bluey-green) tones on the other, and neutral (colorless) light in between.

What setting white balance does is tell your camera what sort of light you are shooting in. The settings have names such as ‘daylight’, ‘cloudy’, and ‘tungsten’. Your camera then compensates for this temperature of light, allowing you to produce neutral photos in the nominated type of light. Without white balance, photos would have a particular color cast depending on the light they are shot in.

While it’s important to understand white balance, in practice it’s not a setting you need to change often. This is because all cameras have an ‘auto white balance’ mode which is pretty good at picking the right white balance for the light you are in.

In this photography online course we will be understanding some more image parameters and improving digital camera image quality.

Saturation: Saturation is the intensity of a particular color. An image with color saturation as zero is a gray-scale image. Some digital cameras have a sharp contrast setting that increases the saturation of all colors in an image. This attribute can be used in Photoshop also. Some image viewers also make available this option.

This feature is helpful in the still images of flowers and fruits. It depicts the natural color of the subject better. If you reduce the saturation of an object digitally; it gives a rustic effect to the photograph. The rustic effect is particularly useful when you are photographing bus, train or truck. You could also reduce the saturation and increase contrast to give a grunge feel to the picture image. This is useful for portraits or the pictures of pets.

You can also use some filters along with digital camera lenses. These increase the saturation of a particular color. For SLR and dSLR camera, obtainable filters are green, red and blue.  Some digital cameras such as Nikon Coolpix P50 and Canon Power shot SD850 IS offer saturation controls for these colors as well as custom color options.

Hue: Some dSLR cameras have hue option, which shifts all colors by a certain degree. You can do this using an image editing software also. This feature can be used for unreal digital photography to match with the tone of the event.

Contrast: Contrast increases the glowing element of a colour in terms of its brightness. A high contrast in an image makes the subject in focus to stand out against a background or it brings into focus a wide array of subjects such as photo of a marketplace. The better the contrast, better are the details brought out.

Sharpness: It is also called as acutance. It is a measure of the sharpness with which a film can imitate the edge of an object. A greater sharpness gives a grainier image while a reduced sharpness gives a washed out appearance. Sharp images are appealing in close-ups whereas it looks not natural in portraits.

Tone: The tone in an image sets the mood of the image. The tone could be warm or cool. A warm tone tends to be more redder with predominant colors red, yellow and orange. A cool tone tens to be bluer with soft and mellow colors. Warm tone is considered masculine where as cool tone is considered as feminine.

Black and white: This is a standard feature in digital cameras and dSLR cameras. This color scheme does have a charm attached to it but it is often overused. It is always a best idea to take a color photograph and then convert it into grayscale on computer. You can increase contrast to improve detailing in grayscale images.

Sepia: In olden photographs, a chemical was used to make the photographs last longer. This generates the sepia tone in photographs. Modern digital cameras and dSLRs have this feature readymade in them 

In our modern, high tech world photo ID cards are found far and wide, with many different uses. No longer are driver’s licenses or passports the main focus for photo ID. Thanks to sophisticated yet affordable photo ID systems, companies are able to easily integrate photo ID into their organizations and enjoy the benefits they have to offer.

Let’s have a quick look at just some of the places you might be able to utilize a photo ID system within your organization.

1. Educational – Colleges and universities have been providing photo ID to their students for years. However, today that practice is expanding right down to elementary school. The latest photo ID systems are able to meet individual needs. For example, some schools may be focused mainly on identification of the student to the staff, while others may be looking for a more sophisticated approach with additional security features or the ability to be used to check out library material.

2. Churches – With today’s religious environment where religious organizations are working around the world providing aid, proper photo ID is often necessary.  They also hold large conventions where security can be an issue. A quality photo ID system will allow you to produce the type of photo ID you need for the delegates and coordinators to be easily recognizable.

3. Conventions – Organizations from all walks of life gather together in facilities to hold conventions of all sizes. Behind those conventions are always the people that make it all happen. But in today’s environment of hostility, it is important for all of those behind the scenes to have proper photo ID. Sometimes it’s even necessary for those attending the convention depending on the type of convention.

4. National Security – There are many levels of security within the country. There are also many types of facilities, all requiring photo ID.  There will be various levels of security associated with national security depending on its purpose. With the many photo ID systems on the market it’s very easy to meet these needs.

5. Cities and Hospitals – Municipalities and hospitals around the world cannot possibly have all their staff know each other.  Therefore proper photo ID is necessary for security in many different levels. These photo IDs must be of the highest quality.

6. Airlines – In our insecure world where terrorists and other security threats are a reality, security is of the utmost importance. After 911 the way airlines handled security of those that worked on the plane, and worked in the airports changed dramatically. In most cases, the photo ID must be so much more than just a photo. It will be associated with entering secured areas, and often will have embedded electronics. Many airlines outsource the production of these photo ID cards, yet with the sophisticated photo ID systems available for in-house printing, there’s an opportunity for increased savings by in-house production.

That’s only a few of the types of customers that find themselves in need of photo ID. With the range of photo ID systems available on the market there’s a system for everyone. Of course we can’t possibly address all the photo ID system options in one short article, so let’s look at a few of the features to give you an idea of what is available on the market.

1. Superior Print Quality – In today’s market there is simply no reason to settle for anything less than superior print. Even level entry photo ID systems have exceptional quality available. Fargo’s high definition printing™ technology is recognized throughout the industry as the standard to aim for.

2. Holographic HDP Film – For the most secure HDP card you simply need to print them with HDP holographic film. Holographic imaging has become very popular in the past few years. Its popularity is based on the reduced ability of reproduction. An added bonus is its superior ability to recognize fake photo ID.

3. Card Printers & Encoders – There are many choices in card printers and encoders, and there is a wide range of pricing associated with them. There are options such as laminators, encoding, oversized printing, financial card encoders, dual or single side printers, color or black white printing, and more.

4. Larger Photo Printing – Traditionally photos were always a bit small, but now many of the photo ID systems allow for much larger photos. This makes identification much easier because of these more detailed photos.

5. Integration – You want to choose a photo ID system that’s easy to integrate into other components of your business. With so many different photo ID systems on the market there’s simply no reason why you can’t have this integration.

Not so long ago photo ID cards were more of a novelty then a real asset. Photo ID systems were far too expensive for most companies to consider adding to their office. Today, things are much different. Technology has changed and become more available, and our world has become more threatening and less secure. That means more companies are looking to integrate some type of photo ID into their workplace. Today it’s easier than ever to do with so many photo ID systems available for in-house printing.

Digital photography, though pretty much the industry standard at this point, is still a young technology.  Many of the greatest advances in digital happened within the last ten years, and if you’re a later adopter it’s nothing to be ashamed of – there are millions of people out there that have never touched a digital camera. And learning digital photography is luckily enough a lot easier than you may think!

The Most Important Part – the Camera
There was a time when a decent digital camera was far outside the price range of non-royalty, but that time has thankfully come and gone.  Now you can get your hands on a totally decent point-and-shoot camera for less than 0 (Nikon Coolpix cameras are a good fit here), or a totally decked-out digital SLR for under 00 (the Canon Digital Rebel is a bestseller in this bracket at right around 0).

Which camera you choose is up to you, but try to keep in mind what you’re using it for.  If your primary picture taking is to capture memories of your friends and family, then the high image quality of an SLR doesn’t do much for you.  Think about when you use your camera most, and buy one that will be suitable for that purpose.

The Second Most Important – the Software
Most digital cameras come with some sort of software that allows you to upload and manage your image files.  Some of these are better than others and if you have a Mac you’re ahead of the pack with iPhoto, but for the most part you don’t need to worry much about uploading – as long as your computer can see your camera or the card reader you can bring the files in however you want.

In terms of photo editing software, there is a lot of options available in a wide variety of price ranges.  Paint.net is a fairly powerful and completely free image editor that features layer editing and quite a bit of other things that the big bits of software do, or if you’re going the professional route you can’t beat Adobe Photoshop.  But remember with Photoshop you’re buying a professional tool with a lot of features you are probably not going to need right away.

The Result of Your Work
Finally, once you’ve uploaded and edited your images, you’ll probably want to share them with your friends and family.  There are many different ways to share photos, but the most popular are using sites like Facebook or Flickr.  Sharing your photos online allows your friends and family to see how you’re doing without you taking the time and effort to print out and mail them pictures.

You can print them to real photo paper at home, through online services like Snapfish, or share them to a site – it all depends on what you want to do with them.  You could even start a family blog through a free service like WordPress or Blogger and share your family stories and photos right there.

Digital photography is one of those things that is easy to learn, but tough to master.  The best thing about digital is that anyone can pick up a digital camera, upload their photos, and share them with friends with very little knowledge in the field. Once you’ve got the basics under control it can get as complicated as you want it to.  If you’ve never tried digital photography, try picking up one of the less expensive point and shoots and see how it works for you – you may find yourself taking more pictures and keeping in better touch with your loved ones!

Most people tend not to think about the details of their online photo sharing experience. As long as their photos get from their computers to their online photo album, they could care less about the processes that got it there. The way that digital cameras designed, this really isn’t a problem, as most cameras and photo editing software support this approach. However, there’s a lot more that goes into online photo sharing than is obvious on the surface.

Those who are interested in the fundamentals of digital photography may be curious about different file formats. Many have heard or seen the terms for picture file extensions, such as .jpg (or JPEG), .gif, .tif, and .png. What do all these different three letter extensions mean?

JPEGs

The term JPEG actually stands for “Joint Photographic Experts Group” – the group that initially created the standard back in 1992. Since then, the JPEG has become the most commonly found picture file type on the Internet. This is primarily because JPEGs offer a tremendous amount of flexibility in terms of its compression and picture quality. That is, its possible to significantly reduce the storage size of a JPEG file by also reducing the quality. Back when the Internet was first starting out, downloading mutli-megabyte picture files just wasn’t practical. JPEGs could maintain a reasonable image quality while making the file size of the image much smaller.

JPEGs have remained an Internet standard thanks to this quality. People are able to make images much easier to transfer between computers without losing a significant amount of picture quality. The drawback to JPEGs is that it is a “lossy” format – this means that each time a picture is edited and resaved in the JPEG format, it loses a degree of quality.

TIFFs

TIFF stands for Tagged Image File Format. TIFF files are versatile and high quality, supporting up to 48-bit color depth (compared to 8-bit for GIFs and 24-bit for JPEGs). The downsides of this format are two-fold. For one, TIFF files have a wide variance and an image viewer that can view one type of TIFF file can’t necessarily view anther. Secondly, TIFF files are not widely supported by web browsers, making them impractical for online photo sharing.

GIFs and PNGs

GIF stands for Graphics Interchange Format. Like the JPEG, GIF files are also commonly found all around the Internet. GIF files are comparatively limited in their color palette – having only 256 colors to work with. This make GIFs a good choice for relatively simple pictures without a lot of color differences, such as cartoons and simple logos. While it a lossless format that doesn’t degrade in quality, it’s pretty rare that you’ll see a photograph in a GIF format in the modern age, since most cameras are able to take pictures with significantly more color depth.

PNGs, or Portable Network Graphics files, are the successor to GIFs. Unlike GIFs, they support truecolor, a 16-million color palette. PNGs are lossless, making them great for editing photos. Most web browsers support PNGs, but they can still be quite large. In many cases, the best choice is to edit a file in PNG format, then convert to JPEG for distribution.

Photography is a hobby that people will never get tired of. This is because it captures those moments that a human mind cannot store for long. It makes the scene immortal and helps keep memory of that which should be cherished.
If one wants to take up photography as a hobby or a profession, it is necessary to know about the accessories and elements of the camera in addition to knowing the technicalities of photography.
There are basically three components to a camera:
1. The lens or the optical element
2. The film or the chemical element
3. The camera body or the mechanical element
When these three collaborate, the image can be recorded.
From the traditional manual camera, technology has now brought us the digital cameras or the digicam. The digital camera has made photography accessible to the layman with its array of accessories and advanced features.
The difference between the analog camera and a digital camera is that in the latter, the pictures get stored in a digital format. This format allows the picture to be previewed before it is developed. It is also very convenient to print pictures using a digital camera.
The following are the present hot camera accessories:
Electronic flashes
For exposing the picture or scene on to the filmstrip, flashes are required. The shutter, on releasing, emits a large amount of light and exposes the film correctly at the time of illumination. An electric flash is especially useful for indoor photography when a picture needs to be taken in the dark.
Storage Devices
In those days, storage devices could not be removed. Nowadays, with the advent of the digital camera, there are many flash memory devices such as the memory stick, compact flash cards, and flash media cards that can be detached.
Batteries
Nowadays, digital cameras run on either disposable batteries or the rechargeable ones. The alkaline and lithium batteries constitute the non-rechargeable kind of batteries, while the NiCd and lead acid batteries constitute the rechargeable type.
Other accessories are the camera case or bag, straps and a tripod.
Knowledge about elements and accessories of a camera is not sufficient to practice photography. You must also know how to use these devices properly and should be able to maintain them for as long as possible. If you can do that, you will have an enjoyable experience while taking photographs.

Many of us do not think twice about the usage of our digital camera’s flash assuming that the camera will use the flash automatically as needed. Flash however can and should be manually set in many scenarios resulting in high quality digital photos.
The most common usage of flash photography is when there is not enough ambient light for example when taking an indoor digital photo in a dark room. There are many other ways in which you can use your digital camera’s flash to get high quality digital photos. One such usage is fill-in flash.
Before setting your flash to manual mode and making more efficient usage of it you should know a bit more of the technology and history behind flash photography. Flash photography has been around for more than a century. During the early days of photography flash was implemented as a powder that was literally lit by either fire or electrical current. At that time flash photography was a risky business. Digital cameras today use a safe implementation by utilizing electronic flash tubes that are automatically synchronized with the camera’s shutter.
You have two options for using flash with your digital camera. The first option is using the digital camera internal flash. Practically all digital cameras have build-in flash units. Most cameras also allow the usage of an external flash unit. Such flash units can be either mechanically attached to the digital camera or they can be connected to the camera via a cable and mechanically positioned on a tripod or any other mechanism. They are synchronized and controlled by the digital camera. External flash units vary in price and features. They can have different maximum light energy that they can emit and different mechanical capabilities (tilting, skewing).
In automatic flash mode the camera sensors evaluate the amount of ambient light in the scene. The digital camera fires the flash if the amount of ambient light is not high enough. There are limitations to the cameras automatic sensors resulting in either firing the flash when it was not needed or vice versa.
In some scenarios the usage of flash can result in poor digital photos. For example when the object is too close to the digital camera the flash light will be too strong and will wash out the object. Another example is in scenarios where the flash creates unwanted shadows in the digital photo. Yet another example is exaggeration of details such as when shooting a digital photo of an older person the skin wrinkles and imperfections details can be overly detailed.
Digital camera’s flash units have a certain effective range. This is a limitation of how much light energy the flash unit can emit. Internal flash units usually have shorter range than external flash units. If the object in the photo is outside of the flash range the flash will not be effective and the object will be dark. On the other hand if the object is too close to the flash unit or the flash unit emits too much energy the object will be washed out. If your object is outside of your flash unit effective range you should turn off the flash and use slow shutter photography preferably with a tripod or another stabilizing mechanism. If your flash units allows the setting of the light energy that will be fired (usually by setting the distance to the object) make sure that it is set right to prevent washed out objects.
In some scenarios there will be enough ambient light to take a digital photo but without the usage of the flash the digital photo quality will be very poor. In such scenario if the camera is left on automatic flash mode it will not fire the flash. For example daytime photography with an object that is shadowed. If the object is wearing a hat it can create shades on the object’s face or when the object is lit from the side the object’s nose can create shades too. Putting the flash in manual fill-in mode will force the flash to fire. The flash will lit those shadowed areas and prevent the shades in the final digital photo. The object of course must be in effective flash range. Another example is an object that is lit from behind such as when taking a digital photo of an object against a sunset. Without a fill-in flash the photo will likely be just a dark silhouette of the object.
These were some basic concepts behind flash usage. There are many other advanced options for your digital camera flash. For example bounce flash can result in great digital photos in that mode instead of pointing the flash directly at the object it is pointed to some reflecting surface like a wall or a special reflector. The result is more natural light and color rich digital photos.

Most people tend not to think about the details of their online photo sharing experience. As long as their photos get from their computers to their online photo album, they could care less about the processes that got it there. The way that digital cameras designed, this really isn’t a problem, as most cameras and photo editing software support this approach. However, there’s a lot more that goes into online photo sharing than is obvious on the surface.
Those who are interested in the fundamentals of digital photography may be curious about different file formats. Many have heard or seen the terms for picture file extensions, such as .jpg (or JPEG), .gif, .tif, and .png. What do all these different three letter extensions mean?
JPEGs
The term JPEG actually stands for “Joint Photographic Experts Group” – the group that initially created the standard back in 1992. Since then, the JPEG has become the most commonly found picture file type on the Internet. This is primarily because JPEGs offer a tremendous amount of flexibility in terms of its compression and picture quality. That is, its possible to significantly reduce the storage size of a JPEG file by also reducing the quality. Back when the Internet was first starting out, downloading mutli-megabyte picture files just wasn’t practical. JPEGs could maintain a reasonable image quality while making the file size of the image much smaller.
JPEGs have remained an Internet standard thanks to this quality. People are able to make images much easier to transfer between computers without losing a significant amount of picture quality. The drawback to JPEGs is that it is a “lossy” format – this means that each time a picture is edited and resaved in the JPEG format, it loses a degree of quality.
TIFFs
TIFF stands for Tagged Image File Format. TIFF files are versatile and high quality, supporting up to 48-bit color depth (compared to 8-bit for GIFs and 24-bit for JPEGs). The downsides of this format are two-fold. For one, TIFF files have a wide variance and an image viewer that can view one type of TIFF file can’t necessarily view anther. Secondly, TIFF files are not widely supported by web browsers, making them impractical for online photo sharing.
GIFs and PNGs
GIF stands for Graphics Interchange Format. Like the JPEG, GIF files are also commonly found all around the Internet. GIF files are comparatively limited in their color palette – having only 256 colors to work with. This make GIFs a good choice for relatively simple pictures without a lot of color differences, such as cartoons and simple logos. While it a lossless format that doesn’t degrade in quality, it’s pretty rare that you’ll see a photograph in a GIF format in the modern age, since most cameras are able to take pictures with significantly more color depth.
PNGs, or Portable Network Graphics files, are the successor to GIFs. Unlike GIFs, they support truecolor, a 16-million color palette. PNGs are lossless, making them great for editing photos. Most web browsers support PNGs, but they can still be quite large. In many cases, the best choice is to edit a file in PNG format, then convert to JPEG for distribution.