Digital Photo Format

If you look at the file name of any of your digital photos, you'll notice something like ".jpg" at the end. That indicates the format in which your file has been saved. Each file format has a purpose. Learn about the preferred formats for saving and working with your photo files—whether you want to edit them, post them online, share them via e-mail, or print them.

Most consumer point-and-shoot cameras only have one format option and that is JPEG (denoted with the .jpg file extension). You usually have the choice of a low, medium, or high-quality JPEG.

JPEG has become the standard for smaller cameras because it has the highest compression. In other words, it squeezes the information from your photo into a smaller file size than other formats, which allows you to take more photos.

If you are editing your photos using a photo software program, you have many options when it comes time to save your pictures. You’ll also run into the following file formats when you are scanning and saving photos, or archiving and organizing them with photo-management software.

TIFF (also known as TIF), file types ending in .tif

TIFF stands for Tagged Image File Format. TIFF images create very large file sizes. TIFF images are uncompressed and thus contain a lot of detailed image data (which is why the files are so big) TIFFs are also extremely flexible in terms of color (they can be grayscale, or CMYK for print, or RGB for web) and content (layers, image tags).TIFF is the most common file type used in photo software (such as Photoshop), as well as page layout software (such as Quark and InDesign), again because a TIFF contains a lot of image data. It is as much as similar to the Raw image file

JPEG (also known as JPG), file types ending in .jpg

JPEG stands for Joint Photographic Experts Group, which created this standard for this type of image formatting. JPEG files are images that have been compressed to store a lot of information in a small-size file. Most digital cameras store photos in JPEG format, because then you can take more photos on one camera card than you can with other formats.

A JPEG is compressed in a way that loses some of the image detail during the compression in order to make the file small (and thus called “lossy” compression).

JPEG files are usually used for photographs on the web, because they create a small file that is easily loaded on a web page and also looks good.

JPEG files are bad for line drawings or logos or graphics, as the compression makes them look “bitmappy” (jagged lines instead of straight ones).

Raw image files

Raw image files contain data from a digital camera (usually). The files are called raw because they haven’t been processed and therefore can’t be edited or printed yet. There are a lot of different raw formats–each camera company often has its own proprietary format.

Raw files usually contain a vast amount of data that is uncompressed. Because of this, the size of a raw file is extremely large. Usually they are converted to TIFF before editing and color-correcting.

GIF, file types ending in .gif

GIF stands for Graphic Interchange Format. This format compresses images but, as different from JPEG, the compression is lossless (no detail is lost in the compression, but the file can’t be made as small as a JPEG).

GIFs also have an extremely limited color range suitable for the web but not for printing. This format is never used for photography, because of the limited number of colors. GIFs can also be used for animations.

PNG, file types ending in .png

PNG stands for Portable Network Graphics. It was created as an open format to replace GIF, because the patent for GIF was owned by one company and nobody else wanted to pay licensing fees. It also allows for a full range of color and better compression.

It’s used almost exclusively for web images, never for print images. For photographs, PNG is not as good as JPEG, because it creates a larger file. But for images with some text, or line art, it’s better, because the images look less “bitmappy.”

When you take a screenshot on your Mac, the resulting image is a PNG–probably because most screenshots are a mix of images and text.

Digital Photography

Digital photography uses an array of electronic photo detectors to capture the image focused by the lens, as opposed to an exposure on photographic film. The captured image is then digitized and stored as a computer file ready for digital processing, viewing, digital publishing or printing.

Until the advent of such technology, photographs were made by exposing light sensitive photographic film, and used chemical photographic processing to develop and stabilize the image. By contrast, digital photographs can be displayed, printed, stored, manipulated, transmitted, and archived using digital and computer techniques, without chemical processing.

Digital photography is one of several forms of digital imaging. Digital images are also created by non-photographic equipment such as computer tomography scanners and radio telescopes. Digital images can also be made by scanning other photographic images.

The art and science of producing and manipulating digital photographs -- photographs that are represented as bit maps. Digital photographs can be produced in a number of ways:

·         Directly with a digital camera

·         By capturing a frame from a video

·         By scanning a conventional photograph

Once a photograph is in digital format, you can apply a wide variety of special effects to it with image enhancing software. You can then print the photo out on a normal printer or send it to a developing studio which will print it out on photographic paper.

Although the resolution of digital photos is not nearly as high as photos produced from film, digital photography is ideal when you need instant, low-resolution pictures. It's especially useful for photos that will be displayed on the World Wide Web because Web graphics need to be low resolution anyway so that they can be downloaded quickly.

Types of Photography

Photographic work can be divided into dozens of categories, many with lots of sub-categories. The following list describes some common types of photography.

Aerial	From a plane, helicopter, balloon or other airborne device.
Adventure, Action	Adventure sports, daring feats, etc.
Amateur	Any type of photography practiced by non-professionals.
Animal, Pet	Pets and their relationships with humans. Note that the human content is often as important as the animal.
Architecture, Real Estate	The art of making property appear attractive. Often involves panoramic photography.
Artistic	Photography in which creative composition is the goal.
Astrophotography	Space photography, through a telescope.
Aura	A controversial type of photography which some claim can photograph a person's aura. Often confused with Kirlian photography.
Black & White	Not simply photography without colour, black and white photography explores shapes, tones and textures. Shadows and highlights become much more important.
Camera Phone	"Convenience" photography using a mobile phone's built-in camera. While not the best quality, camera phones have opened a new world of spontaneous, on-the-spot photo opportunities.
Commercial	Product shots, advertising, etc.
Digiscoping	Photography through a telescope or binoculars.
Documentary	Journalism, Events, Historical, Political, etc.
Event	Concerts, parties, festivals, weddings, etc.
Forensic	Police and legal photography.
Infrared	Photography in which the recording medium is sensitive to infrared light rather than the normal visible light spectrum.
Large Format	For use on posters, billboards, etc.
Kirlian	A type of contact print photography in which an object touching a photographic plate is connected to a high voltage source, creating an aura-like image. Often confused with aura photography.
Macro	The art of photographing very small and/or close-up objects.
Medical	Specialized photography for clinical purposes, i.e. to help reveal and diagnose illness.
Microscopic	Any technique for photographing objects too small to be visible to humans.
Modeling	Photographing objects to be converted into 3D models.
Nature	Landscapes, animals, plants, sea, etc.
Night	Any technique used to capture images at night. Often includes infrared photography.
Panoramic	Views of wide areas, up to complete 360° panoramas.
Paranormal	Ghosts, unexplained phenomena, etc.
People	Candid, Family, Fashion, Glamour, Passports & Visas, Portrait, Pregnancy, School, Sports, Wedding
Pinhole	Uses the most basic type of camera possible — a box with a tiny hole to let light in.
Scenic	Landscape, Cityscape
Satellite	Views of Earth from orbit.
Scientific	Any specialized photography used for scientific endeavour, e.g. electron microscopy photographs, medical photography, astrophotography, etc.
Sports	The specialized art of shooting people engaged in sports, games and adventure activities.
Stereoscopic (3-D)	Involves taking two photos simultaneously to simulate 3-D vision.
Stock	Photographs taken for distribution to other people, for use in their projects. These photos tend to be quite generic, e.g. people working, landscapes, places, etc.
Time-lapse	Photographs with a very long exposure, used to illustrate something happening over time. A popular example is a street at night with car lights blurred into long lines.
Travel	Photography to showcase locations, illustrate travel literature, etc.
Ultraviolet	Photography in which the recording medium is sensitive to ultraviolet light rather than the normal visible light spectrum.
Urban, Industrial	Emphasizing urban environments.
Water,Underwater	Any type of photography taken under water with a water-tight camera housing.

4 basic Camera Exposure Modes

On the subject of photography basics – it is crucial to learn and understand what the 4 basic camera modes do and not only how, but when to utilize them.  Many times when you first get your new expensive camera you want to just start shooting and expecting to find magical and majestic images but often you are intimidated by all of the buttons, dials and modes and you aren’t sure where to start.  It is my goal to fix that for you today and get you down the right path!

The 4 major modes are:

P – Program Auto

A (Av) – Aperture Priority

S (Tv) – Shutter Priority

M – Manual

(Av, Tv) for Canon

How the Modes Work:

P – In program auto mode the camera automatically selects the correct exposure for you.  Meaning it will select what it thinks is the appropriate aperture, shutter speed & ISO*

A (Av) – In Aperture Priority mode, you select the aperture that you want to use and the camera then selects the shutter speed and ISO*

S (Tv) – In Shutter Priority mode, you choose the shutter speed you want and the camera chooses the right aperture and ISO*

M – In Manual mode, you choose everything, aperture, shutter speed and ISO* to get the proper exposure.

*ISO can be set to “Auto ISO” having your camera adjust automatically or you can manually set ISO, for any of the above modes.

When to Use:

P – Aside from fully automatic mode, often shown in green “AUTO” on the mode dial, this is the most “automatic” you should want to get.  I’d recommend starting out with this mode only to get started when you first are learning – think of “P” mode as only a stepping stone to the other 3 modes, which is really where you can get the most out of your camera.  One instance of where “P” mode may come in handy is if you are anywhere outside where there is plenty of light and you just want to be able to take some snapshots without much thought.  This way you can enjoy the benefits of having the nicer image quality, but yet still just push the shutter without much thought.

A (Av) – This is the mode that we use 75% of the time.  Aperture mode lets you select the aperture on your lens, which determines two things: 1. how much light is coming into your camera thru the lens and, 2. how much  depth-of-field you want in your photo – which in laymen terms you can think of depth-of-field as how much of the foreground or background from your focus point you want to be in focus.  The lower the aperture number like (1.8), the less depth-of-field you have, meaning the more blurry your non-focused areas will be.  The greater the aperture number (f9) the more depth of field you have, so more of the photo will be in focus, even the photo elements that you didn’t specifically focus on.  Common real life examples for either scenario is: if taking a portrait of someone, by having a low aperture we can put the focus on our subject and have a nice out of focus background, letting the subject “pop”.  Conversely, if shooting a far away landscape photo we may want as much of the scene in focus as possible and a higher aperture number would be chosen.

S (Tv) – Shutter mode should be utilized most often when shooting sports or anything where your subjects are moving fast, like birds in flight or even concerts where performers are constantly moving.  By dictating the shutter speed you can ensure that you will have a fast enough shutter speed to freeze the motion that you are capturing, and thus eliminate unusable photos that may have too much motion blur from a slow shutter speed.  How fast of a shutter speed do you need?  A lot of that depends on the lens being used, on full frame cameras the old rule was the “minimum” to be at least 1/lens focal length, but on newer, more entry level cameras that are crop sensor cameras (not full frame) the rule becomes 1/(1.5 x lens focal length).  So if your lens is a 50mm, make sure to have a minimum shutter of 1/80.  Keep in mind though that this rule is for everyday shooting and for mostly stationary subjects – to freeze motion or fast moving objects a much faster shutter is needed.

M – As guessed, manual mode gives supreme control of each element of your cameras exposure.  Use manual for the very tough lighting situations that the digital camera just isn’t smart enough to give proper exposure.  A good example is if your subject is back-lit and your shooting into the sun, your camera will measure the light for the overall scene and by seeing all the light from the sun it will expose for that and the sky will look nice but your subjects will be severely under-exposed or even silhouetted.  If you don’t want to use flash to light your subject and fill in those shadows you can in manual mode expose correctly for your subject, rather than the overall scene.  Manual mode is also very useful and needed when shooting indoors with flash because indoors the lighting often isn’t changing and you can control the amount of ambient room lighting vs flash lighting mixture to give you proper and most importantly consistent results.

ISO

ISO is actually a common short name for the International Organisation for Standardization.

The ISO setting on your camera is something that has carried over from film. Remember back in the ‘old days’ when you used to go and buy your rolls of film and you would buy film rated at 100, 200 or 400, maybe even 800 or 1600? Well that number refers to the film’s sensitivity to light. The higher the number, the more sensitive to light the film is. The ISO bit is from the standards for film sensitivity, and the number refers to it’s rating.

So what does sensitivity mean? Well a low sensitivity means that the film has to be exposed to light for a longer period of time than a film with a high sensitivity in order to properly expose the image. With a lower sensitivity you also get a better quality image too which is why you should always try and use the lowest sensitivity you can get away with. Let’s not get ahead of ourselves though, a little more explanation is required.

You might remember buying film for a sunny holiday and the shop assistant would recommend using a film rated at 100 or 200. If, on the other hand, you were going to be taking pictures indoors, then you might be recommended a higher sensitivity like 400 or maybe 800. If you used ISO 100 film and decided to take some pictures indoors, chances are you would need to use the flash, or your pictures would come out quite dark. This is because the film’s sensitivity is so low that the shutter would need to be open for a long time to let enough light in. Your camera may not have had the features to allow it to keep the shutter open for long enough, which is why you ended up with dark pictures.

This was one of the problems with film. Once you’d loaded it into your camera, you were pretty much stuck with that film sensitivity for 24 or 36 shots.

Bring on digital cameras and you can now change the ISO setting for each shot you take. That is one of the big advantages of digital photography.

So why do you only get choices like 100, 200, 400, 800, 1600 and maybe 3200 when it’s digital, surely you could set 154 or 958 if you wanted it? It’s only electrical currents and circuits after all, not a piece of film. Well, in theory you could choose any setting you wanted, but imagine how tricky that would be. There are three settings which combine to give you the exposure, these are Aperture, Shutter Speedand ISO. Each one can be changed individually to allow you to set then to what you think will give you the perfect exposure, or you can let the camera set them for you to what it thinks is the perfect exposure for the conditions it can detect. Already with three different options, each having several settings themselves, the combinations are numerous, so keeping ISO to set values, which people will understand makes it a little less confusing.

Now, I mentioned quality too, and that better quality images are achieved with a lower ISO number. If, again, you go back to film days you may remember the sort of grainy effect some images had. Well this grain effect is what is introduced with a higher sensitivity film. Digital has it’s own grain effect with higher sensitivity and is known as Noise. Digital noise can be seen a sort of speckley effect in areas of similar colour, like skies or dark shadow areas. It is a subject of much discussion and the camera is often judged on the amount of noise it produces at these higher sensitivities. This is why you should always try and keep your ISO set to the lowest number, and use aperture and shutter speed to get the right exposure. If you can’t do that with aperture or shutter speed, move up to the next ISO setting and try again. One of the big selling points about digital cameras is how they handle the digital noise at higher ISO settings. The top pro level cameras from Nikon or Canon will have better control over noise than the cheaper models and this allows the pros (or anyone that can afford a Nikon D3 or Canon 1Ds for example) to get away with using a higher ISO and still getting good enough quality for print.

Why is a high ISO setting needed? Well for indoor work, where flash isn’t allowed and the light levels are fairly low. Or you can use it deliberately to get the grainy gritty feel to the image.

It’s well worth experimenting with ISO settings so you can see just how your camera performs at the various levels. Once you have got to grips with how changing Aperture, Shutter Speed and ISO effect your image, you’ve pretty much got all the technical fundamentals nailed. This should be useful in Night time photography.

Depth of Field

Depth of field is the amount of distance between the nearest and farthest objects that appear in acceptably sharp focus in a photograph. A preferred selection Depth of field ("DOF") in a focused subject in an image can be quite subjective. Remember this, adequate selection of DOF for one situation, application may be unacceptable for another photographer. It is all a matter of personal preference when trying to determine the appropriate use of DOF to enhance an effect in a photograph. 

In simpler term, we define depth of field as the zone of sharpest focus in front of, behind, and around the subject on which, when lens is focused on a specific subject; with TTL (through the lens) SLR camera, DOF can be previewed in the viewfinder of a camera - the preview is very handy for critical type of work. For an example, when taking a product shot, when you require absolute certain if DOF is adequate to cover the object you intend to photograph Generally, the closer the subject to the camera, the more evenly with the distribution of depth of field in front and behind the subject. As distance of focus extends, DOF usually will be more behind than in front of the focused area.

A few factors may have a direct relationship with depth of field, they are: 

1) the diaphragm opening of the lens (the Aperture), 

2) the focal length of the lens in use, and 

3) image size (it has a direct relation to distance).

The general rule of thumb for selecting the right aperture for a desired depth of field is: give the same object distance and the image size, the bigger lens opening (aperture) used (like f/2.8, f/2, f/1.4 etc.) will have a narrower band of depth of field - meaning critical focusing will be required in this kind of situation because when you use a large aperture (in particularly when focuses at a near to the subject), the zone of sharpness (DOF) can be very limiting; while on the other hand, if extended depth of field is required, you can just choose a smaller lens opening like f/8, f/11, f/16, f/22 to make the plane of sharpness is extended, so everything will be in sharper focus.

The "amount" of light allows to strike the film plus the duration (time) for the light to strike the film forms an exposure. The camera has two mechanisms to control exposure, the lens diaphragm (lens section - aperture) and the timing of the OPEN/CLOSE of the shutter curtain (camera section - shutter speed). If this confuses you, the lens diaphragm (inside a typical SLR camera lens) consists of multiple blades which can be open and closed to certain size openings, the variations in the lens opening is called aperture. The size of the aperture determines the amount of light which will fall on the film. Various sizes of the lens opening are indicated by a set /series of numbers called f/stops or f/numbers. Each f/stop represents a specific quantity of light that pass through the lens. The smaller numbers are called large f/stops while the larger numbers are called small f/stops. This is because the larger numbers represent smaller apertures and allow less light to pass through the picture taking lens. Each time you move from one f/stop to the next smaller f/stop (larger number the amount of light allowed through is exactly halved. In effect, the amount of exposure itself is also halved. 

The larger number such as 11, 16, 22, 32 marked on the lens is called the lens minimum aperture. The smaller f/number indicated on the lens (such as 1.4, 2, 2.8 etc) is called the lens maximum aperture. The maximum and minimum apertures differ according to the lens-types. The maximum lens aperture is important because it indicates the largest amount of light that the lens will transmit through it to strike the film "hiding" behind the camera shutter. 

Depth of field decreases with increasing focal length (given equal subject distance) In other words, if subject distance stays the same, a long lens gives less depth than a short.There are times when you need to affect the amount of depth of field for a particular scene. In a scenario like low light where you need to to shot wide open and wish to have extended depth of field or cases where you are force to live with a fixed-aperture mirror lens, if you suspect that the aperture is too wide to deliver adequate depth of field, simply move back. The depth of field surrounding your subject will expand.

White balance

White Balance is an aspect of photography that many digital camera owners don’t understand or use – but it’s something well worth learning about as it can have a real impact upon the shots you take.

So for those of you who have been avoiding White Balance – let me introduce you to it. I promise to keep it as simple as possible and keep what follows as useable as I can:

At its simplest – the reason we adjust white balance is to get the colors in your images as accurate as possible.

Why would you need to get the color right in your shots?

You might have noticed when examining shots after taking them that at times images can come out with an orange, blue, yellow etc look to them – despite the fact that to the naked eye the scene looked quite normal. The reason for this is that images different sources of light have a different ‘color’ (or temperature) to them. Fluorescent lighting adds a bluish cast to photos whereas tungsten (incandescent/bulbs) lights add a yellowish tinge to photos.

The range in different temperatures ranges from the very cool light of blue sky through to the very warm light of a candle.

We don’t generally notice this difference in temperature because our eyes adjust automatically for it. So unless the temperature of the light is very extreme a white sheet of paper will generally look white to us. However a digital camera doesn’t have the smarts to make these adjustments automatically and sometimes will need us to tell it how to treat different light.

So for cooler (blue or green) light you’ll tell the camera to warm things up and in warm light you’ll tell it to cool down.

Adjusting White Balance

Different digital cameras have different ways of adjusting white balance so ultimately you’ll need to get out your camera’s manual out to work out the specifics of how to make changes. Having said this – many digital cameras have automatic and semi-automatic modes to help you make the adjustments.

Preset White Balance Settings

Here are some of the basic White Balance settings you’ll find on cameras:

Auto – this is where the camera makes a best guess on a shot by shot basis. You’ll find it works in many situations but it’s worth venturing out of it for trickier lighting.

Tungsten – this mode is usually symbolized with a little bulb and is for shooting indoors, especially under tungsten (incandescent) lighting (such as bulb lighting). It generally cools down the colors in photos.

Fluorescent – this compensates for the ‘cool’ light of fluorescent light and will warm up your shots.

Daylight/Sunny – not all cameras have this setting because it sets things as fairly ‘normal’ white balance settings.

Cloudy – this setting generally warms things up a touch more than ‘daylight’ mode.

Flash – the flash of a camera can be quite a cool light so in Flash WB mode you’ll find it warms up your shots a touch.

Shade – the light in shade is generally cooler (bluer) than shooting in direct sunlight so this mode will warm things up a little.

Shutter Speed

Shutter speed along with the aperture of the lens (also called f-number) determines the amount of light that reaches the film or sensor. Conventionally, the exposure is measured in units of exposure value (EV), sometimes called stops, representing a halving or doubling of the exposure.

Multiple combinations of shutter speed and aperture can give the same exposure: halving the shutter speed doubles the exposure (1 EV more), while doubling the aperture size (halving the focal number) increases the exposure area by a factor of 4 (2 EV). For this reason, standard apertures differ by √2, or about 1.4. Thus an exposure with a shutter speed of 1/250 s and f/8 is the same as with 1/500 s and f/5.6, or 1/125 s and f/11.

In addition to its effect on exposure, the shutter speed changes the way movement appears in the picture. Very short shutter speeds can be used to freeze fast-moving subjects, for example at sporting events. Very long shutter speeds are used to intentionally blur a moving subject for artistic effect. Short exposure times are sometimes called "fast", and long exposure times "slow".

Adjustment to the aperture controls the depth of field, the distance range over which objects are acceptably sharp; such adjustments need to be compensated by changes in the shutter speed.

In early days of photography, available shutter speeds were not standardized, though a typical sequence might have been 1/10 s, 1/25 s, 1/50 s, 1/100 s, 1/200 s and 1/500 s. Following the adoption of a standardized way of representing aperture so that each major step exactly doubled or halved the amount of light entering the camera (f/2.8, f/4, f/5.6, f/8, f/11, f/16, etc.), a standardized 2:1 scale was adopted for shutter speed so that opening one aperture stop and reducing the shutter speed by one step resulted in the identical exposure. The agreed standards for shutter speeds are:

1/1000 s

1/500 s

1/250 s

1/125 s

1/60 s

1/30 s

1/15 s

1/8 s

1/4 s

1/2 s

1 s

The Camera Obscura

The Camera Obscura 

On 24 January 1544 mathematician and instrument maker Reiners Gemma Frisius of Leuven University used one to watch a solar eclipse, publishing a diagram of his method in De Radio Astronimica et Geometrico in the following year. In 1558 Giovanni Batista della Porta was the first to recommend the method as an aid to drawing. Photographic cameras were a development of the camera obscura, a device dating back to the ancient Chinese and ancient Greeks,which uses a pinhole or lens to project an image of the scene outside upside-down onto a viewing surface.

Before the invention of photographic processes there was no way to preserve the images produced by these cameras apart from manually tracing them. The earliest cameras were room-sized, with space for one or more people inside; these gradually evolved into more and more compact models such as that by Niépce's time portable handheld cameras suitable for photography were readily available. The first camera that was small and portable enough to be practical for photography was envisioned by Johann Zahn in 1685, though it would be almost 150 years before such an application was possible.

What is an "aperture" ?

Aperture is referred to the lens diaphragm opening inside a photographic lens. The size of the diaphragm opening in a camera lens REGULATES amount of light passes through onto the film inside the camera the moment when the shutter curtain in camera opens during an exposure process. The size of an aperture in a lens can either be a fixed or the most popular form in an adjustable type (like an SLR camera). Aperture size is usually calibrated in f-numbers or f-stops. i.e. those little numbers engraved on the lens barrel like f22 (f/22),16 (f/16), f/11, f/8.0, f/5.6, f/4.0, f/2.8, f/2.0, f/1.8 etc. Each of this value represents one time the amount of light either more or less in quantity. Meaning to say, f/16 will let in 1X the amount of light than a diaphragm opening of f/22 and so forth; while on the other hand, an aperture of f/4.0 will let in 1X lesser than that of f/2.8 etc.

Photography

This blog is about to give some information about the photography that which we know. We like to give you the information and software that related to photography.