On the trip to Branston water park I unknowingly took pictures in RAW format and when I returned home I couldn't get my photos of my camera onto my computer as I didn't have a program that supported RAW. Having done this I thought I'd look into different file sizes and what it all means. On my camera I have the option of RAW, and small - large JPEG's.
The digital sensor in digital cameras is known as a Bayer Pattern sensor. This relates to the red, green and blue sensitive areas. Each pixel in the sensor responds to either red, green or blue light and there are two green sensitive pixels to every red and blue. The sensor measures the intensity of light falling on it.
A digital image has pixels which can be red, green, blue or one of the millions of other colours , to generate an image from the data output by the sensor, signal processing is required. This is called Bayer interpolation which means calculate what the colour of each pixel should be. The colour and intensity of each pixel is calculated based on the strengths of the red, green and blue data from all the pixels. Each pixel in the converted image now has three parameters, red intensity, blue intensity and green intensity.
RAW data is the output from the red, green and blue sensitive pixels of the image sensor. The sensor data is collected and it is at this point that the ISO is set. RAW isn't an acronym, it just means raw, unprocessed data. One of two things can be done with a RAW file. It can be stored as it is or it can be processed into a JPEG image.
If the data is stored as a JPEG file, it goes through Bayer interpolation. White balance, saturation, sharpness, contrast etc, is subject to JPEG compression. The advantage is that the file size is smaller and the file can be directly read by many programs. The disadvantage is that there is quality loss (lossy), the amount dependant on how much the file is compressed. The more compression, the smaller the file, the easier it is to download but the lower the image quality. A larger JPEG file can save a significant amount of space without loosing much quality.
RAW data contains 12 bit data, which means that there can be 4096 different intensity levels for each pixel, but in an 8 bit file (JPEG), each pixel has 256 different intensity levels. The larger RAW 12 bit data allows you to change the image more than a 8 bit JPEG without degrading the quality and it then can be stored as a JPEG.
The main reason to shoot in JPEG is that you can get more shots stored on your memory card and it's faster, both on the camera and downloading onto PC. If shot in RAW then you have to convert them to JPEG before you can print. If you have many images this takes a long time. If you know you have the correct white balance and all the other camera functions are set at the optimum settings, then a high quality JPEG will give as good a print as one converted from RAW. If you are not sure about the exposure, white balance or as a back up, and you want to keep the maximum possible processing on the PC, then its best to shoot in RAW.
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Techniques, materials and resources used for portrait photography 1.1
There are many different formats and techniques that can be applied to portrait photography.
Framing is a technique where by you draw attention to one element of an image by framing it with another element of the image. This gives an image depth and draws the eye to a point of interest in the image.
You could do it by placing your subject in a window or doorway, have them look through a small gap or even use their hands around their face.
Shooting with a wide angle lens attached to your camera can help create some memorable shots when you’re doing portrait photography.
At very wide focal lengths you can create some wonderful distortion. Using these focal lengths will enlarge parts of the face or body that are on the edge of the frame more than what is in the centre.
It can also give a wide open and dramatic impact when your subject is in an impressive setting.
The person in your portrait is the main point of interest – however sometimes when you place them into different contexts with different backgrounds you can dramatically alter the mood in a shot.
Having parts of a portrait in focus draws attention on certain parts of the face or body, or a completely unfocused portrait can add a dreamy effect and make a picture quite abstract.
Black and white portraits can be just as dramatic as colour. By adding a shot of colour can draw attention to certain parts of the photo.
"When we shoot in color, we do not depart from what we see everyday, so our eye expects certain details in order to fill out the image. Black and white photography gives us the opportunity to diverge from this norm, and in a way view reality as an abstraction."
Framing is a technique where by you draw attention to one element of an image by framing it with another element of the image. This gives an image depth and draws the eye to a point of interest in the image.
You could do it by placing your subject in a window or doorway, have them look through a small gap or even use their hands around their face.
Shooting with a wide angle lens attached to your camera can help create some memorable shots when you’re doing portrait photography.
At very wide focal lengths you can create some wonderful distortion. Using these focal lengths will enlarge parts of the face or body that are on the edge of the frame more than what is in the centre.
It can also give a wide open and dramatic impact when your subject is in an impressive setting.
The person in your portrait is the main point of interest – however sometimes when you place them into different contexts with different backgrounds you can dramatically alter the mood in a shot.
Having parts of a portrait in focus draws attention on certain parts of the face or body, or a completely unfocused portrait can add a dreamy effect and make a picture quite abstract.
Black and white portraits can be just as dramatic as colour. By adding a shot of colour can draw attention to certain parts of the photo.
"When we shoot in color, we do not depart from what we see everyday, so our eye expects certain details in order to fill out the image. Black and white photography gives us the opportunity to diverge from this norm, and in a way view reality as an abstraction."
Equipment I have at home and what is avaliable to me at college 1.1
I have at home the Canon 450d camera which comes with the standard 18-55mm lens.
At college there is a wide range of lenses avaliable to use along with higher quality cameras. There is a studio which contains a wide range of backdrops, studio lights, reflectors and soft box.
At college there is a wide range of lenses avaliable to use along with higher quality cameras. There is a studio which contains a wide range of backdrops, studio lights, reflectors and soft box.
Canon 450D
Canon 450d
This is the camera which I have started out with, the basic entry level canon 450d. For specification details click on the image.
I don't really have any experience of digital SLR's, the only cameras I have used previously are point and shoot digital and film SLR's.
I don't have an opinion on my camera yet as I haven't really used it enough to comment other than I find it fairly easy to use and understand.
Standard 50mm lens
What makes this lens ideal for portriture is its angle-of-view is the closest to our own eyes and the easiest to use to get the most natural looking shots. You can even visualise shots without putting the camera to your eye. This doesn’t mean this lens is boring compared to the extremes that a telephoto or wide-angle will give. On the contrary, it’s just a lens that works well and keeps your photography simple. It is also ideal, as long as you remember not to get too close to your subject, which will lead to unflattering distortion to your sitters face. It works especially well with full-length portraits, but you can get some very nice head and shoulder shots.
Standard 50mm lens
70-200mm Lens
The telephoto lens allows you to take tightly composed pictures of subjects where it is impractical to get any closer and to use a wider lens, therefore they are useful for candid photography, this lens is small, lightweight and unobtrusive.
Short telephoto focal lengths are widely used in portraiture for their unnatural, non standard view makes objects at different distances appear closer together than they are in reality. Using a wide angle lens for head and shoulder close ups makes people's noses and other facial features more prominent - while a slight telephoto focal length flattens the features a touch, to give a more flattering result.
Telephotos are also useful in portraiture because when used with largish apertures, it is easy to throw a background out of focus thus drawing the viewers attention to certain parts of the scene.
Short telephoto focal lengths are widely used in portraiture for their unnatural, non standard view makes objects at different distances appear closer together than they are in reality. Using a wide angle lens for head and shoulder close ups makes people's noses and other facial features more prominent - while a slight telephoto focal length flattens the features a touch, to give a more flattering result.
Telephotos are also useful in portraiture because when used with largish apertures, it is easy to throw a background out of focus thus drawing the viewers attention to certain parts of the scene.
70-200mm lens f/2.8 IS
HI Sam,
ReplyDeletegreat info on RAW and JPEG files.
Could I ask a favour...do you still have the CDs that came with your canon as mine were stolen with the camera so have no way of downloading files...
If you do can I borrow then to upload on my PC at home
Thank you
John