Digital Photography 101, Part III
Image size, image shape, white balance, digital zoom, flash settings and ISO.
In Part I of Digital Photography 101, I discussed the various shooting modes of digital cameras such as program mode, aperture priority, shutter priority and manual mode as well as an introduction to exposure and depth of field. In Part II of Digital Photography 101, I talked about choosing the correct file format as well as an introduction to Adobe Photoshop and Epson printers were covered. You might be interested in reading these articles if you haven't already done so, since a lot of basic information about using digital cameras is covered in these two articles. In this article I will discuss setting your camera for the correct image size, image shape, white balance, digital zoom, flash settings and ISO.
Image size: Choosing the correct image size is easy, just use the largest image size the camera offers. There are only a few reasons for doing otherwise. One possible reason to use a smaller size is that the memory card in your camera is very small and you are afraid it will run out of room so you use smaller images in order to get more of them on the card. However, a much better solution than using small images is to buy a larger card. Digital camera memory is pretty cheap these days so you should use at least a 250 MB card and even better a 500 MB or even a 1 G card. I use a 4 G card which allows me to shoot large images all day without running out of card space.
About the only other reason I can think of to use small image sizes is that you plan to use the pictures you take in a website which uses very small images. However, even this doesn't make much sense as it is very easy to make images smaller in an imaging program like Photoshop. So, always set the camera on the largest image size possible--you can always make the images smaller later with little or no quality loss. However, it doesn't work the other way around; you will never be able to make small images into larger ones later on since there is a definite limit to how big you can enlarge images--two or three times larger is about the limit pictures can be digitally enlarged without also adding all kinds of nasty stuff like noise, blurriness and other aberrations. If the camera is set to save smaller size images, sooner or later you are going to shoot a really great photograph and decide that it needs to be large, like maybe 24x30 or maybe even 30x40 and guess what, the small image size you set the camera for is not going to have nearly enough pixels to do the job and nothing is going to change that fact. Always shoot at the maximum image size the camera allows.
Image shape: Most digital cameras allow you to change the shape of an image as well as the size. For instance, many cameras offer the basic 4x5 format plus a 2x3 format. For example my Olympus camera offers both 3264 pixels x 2448 pixels (4x5 format) as well as 3264x2176 (2x3 format). Some people like 2x3 image format as this is the shape of 35mm camera film and this slightly longer format is also more attractive when framed. The way the camera makes this 2x3 format is to crop the 4x5 format, so the 2x3 format ends up with less pixels than the 4x5 format and this isn't a good thing since the more pixels you have the better the picture will be when enlarged. If you like the 2x3 size, crop the image later in the Photoshop, don't throw away perfectly good pixels that may be the difference between a good picture and a mediocre picture. Always set the camera to give you the maximum number of pixels, and don't worry about the shape of the image.
White Balance: Digital cameras use a built-in tool called white balance to achieve the proper color balance in a picture. Cameras do this by adjusting the whole image so that the brightest part of the image is pure white. Usually this works very well and the resulting picture is perfectly color balanced. White balance is one of the main reasons digital photography is much easier than film photography. Pictures taken with old style film cameras often had all kinds of color casts to them; they were often a little too blue, or too magenta or too green or something. Big blue skies made everything in the shadows too blue, florescent lights made everything too green, pure sunlight made everything a little to yellow, the tungsten lights in your house made everything a lot too orange. In the old film days, professional photographers corrected this problem by using colored filters over their camera lenses or by correcting color balance during printing in the old optical enlargers by adding very subtly graduated yellow and magenta filters. Getting the correct color balance in the old days was a very difficult process that required a lot of skill and experience and the ability to achieve good color balance was one of the main things that made a professional photographer a professional.
Getting great color balance is much easier in a digital camera. If you plan on printing your own pictures later using Photoshop and a digital printer, I would use the "auto white balance" setting in your camera. This won't do a perfect job every time but it will be pretty close and you can fine-tune the color balance when you print the pictures. If you are shooting in Raw Format you can do this job losslessly in the Camera Raw section of Photoshop. (See Part II of How To Set Up Your Digital Camera). If you are shooting JPG format, you can fine tune color quite adequately in the main section of Photoshop.
If you don't want to do your own printing but just want to just give your picture files to WalMart or some other photo processer, you might want to fine tune the color balance as you shoot by choosing one of the other white balance options your camera offers. For instance choose the little sun logo in the white balance selections when shooting in direct sunshine, or choose the cloudy logo when shooting under overcast skies or choose the shade logo when shooting in the shade.
You can also get a really exact white balance for critical jobs like copying fine art or shooting pictures of fabric that have to be exactly right by using the function for this job offered by most digital cameras. This involves shooting a piece of absolutely white paper in the same light that illuminates the picture and then using a special function provided by the camera to figure out an exact white balance. Different cameras achieve this exact white balance in different ways, so check the instruction manual for your camera.
I recommend simply using the Auto White Balance setting on your camera. Since I print all my own pictures, I use the Auto WB 99% of the time and fine-tune the color later in Photoshop. Since I shoot mostly landscapes under blue skies, my fine-tuning usually consists of adding just a little yellow (ten points) and just a little red (5 points) to the entire picture. This almost always results in perfect color balance.
The only time I don't use Auto WB is when I am shooting a large panoramic scene in several shots that I will stitch together later in Photoshop. In this case, using Auto WB will result in a slightly different color balance for each different shot which makes the pictures absolutely impossible to put together into a seamless panoramic. So I use the sunny WB or the cloudy WB settings for all the different shots, as these setting will give the exact same white balance for each piece of the panoramic. To make sure the exposure is exactly the same brightness for each shot, I also set the mode switch to manual exposure. When the camera is set up this way, all of the various sections will have exactly the same tonality and color balance and will go together seamlessly. As mentioned earlier in this series I will write an article soon on exactly how to stitch large panoramics together in Photoshop in an upcoming newsletter.
Digital Zoom: Many digital cameras have an option called digital zoom. This is a way of extending the natural zoom of your lens. Don't use this option, leave it turned off. All it does is digitally increase the image size and in the process destroy the integrity of the image. This function will add noise to the image, decrease the sharpness, and pretty much make it worthless. If you want to digitally increase the image size, the place to do it is in Photoshop not in the camera. Photoshop will do a far better job of increasing image size and it will do it much less destructively. An even better way to increase image size is to use a program called Genuine Fractles which will enlarge pictures almost losslessly. It is easy to find Genuine Fractles by searching for it online.
Flash settings: One of the most popular types of digital cameras are the so-called prosumer cameras which are halfway between the very basic consumer cameras that are quite inexpensive and professional cameras which have interchangeable lenses, no built-in flash and cost several thousand dollars. One of the really nice functions of prosumer digital cameras is the built in flash. There are several settings for the flash, most of which are not terribly useful. The setting I keep my prosumer Olympus camera set to all the time is "fill flash" which does just what it says: it fills the foreground with light until it is perfectly exposed while also perfectly exposing the background. This is a wonderful tool. Say you are at the beach taking pictures of your family. The sand, the ocean and the sky are all very bright so the camera chooses a very small lens aperture and a fast speed to properly expose all the bright background. Unfortunately your daughters face is in the shade, and without flash it will be almost completely dark. Fill flash fixes the entire problem and both the background and and your daughter's face are perfectly exposed. The logo for fill flash in digital cameras is often a green zigzag lightning like flash symbol.
The same "fill flash" technique can be used with landscapes. Landscape foregrounds are often much darker than the sky and mountains that are in the background. Turn on fill flash and the foreground and background will both be perfectly exposed . How well this trick works in landscape situations depends on how well the fill flash on your camera works; some cameras adjust the intensity of the flash very accurately for perfect fill, others will illuminate the foreground a little too much. This can usually be corrected by turning down the intensity of the flash a bit if your camera has this adjustment, which most do.
Another plus to using flash is stopping motion. If you are shooting a landscape with flowers or grasses or leaves in the foreground that are both dark and blowing around in the wind, and you are shooting very slowly so that a small lens aperture can be used to attain the greatest depth of field, both problems can be solved at once. Fill flash will both lighten the foreground and stop the motion of the blowing grasses.
Unfortunately, I don't use the flash option often as I am usually shooting landscapes with a professional camera that doesn't have a built in flash, so I just have to be patient and wait for a lull in the wind. Of course I could mount a professional flash on the camera or set up an entirely independent flash on it's own light stand to use as fill flash, but when you are working in the field it is difficult and cumbersome to set up all this extra equipment and by the time you do, the light is usually gone or the clouds have shifted and the picture is lost. The photographer often has to act fast to catch great shots and has to keep his equipment simple. So, sometimes a small, prosumer camera with a built in flash is actually a better tool than a professional camera with far more megapixels and much better lenses. Less is sometimes more.
As I said, I keep my flash setting dialed to "fill flash" permanently. I find the "auto flash" setting basically useless as it doesn't synchronize foreground and background exposure. Most of the time it will make the foreground correct but the background will be either overexposed or underexposed. I also never use the red eye setting. This makes shooting so slow that it is pretty much worthless to capture any kind of movement or to get spontaneous shots of people. And besides, red eye is quick and easy to fix in Photoshop when printing. I suppose the redeye function is OK if you are shooting posed pictures and tell the subjects not to move until they see the second flash, but I never use it.
ISO Settings: The film that we all used to shoot comes in various speeds. High speed film has an ISO number of 400 or 800 or 1000. Slow film has a speed of 50 or 100. High speed film allows you to shoot faster in dim light. Slow film requires quite a bit of light to be exposed using even moderate speeds. Slow film is almost grainless and will give exquisitely rendered images while fast film has very large grain and is often delivers quite harsh images.
Digital cameras don't use film, but various ISOs can be dialed in to simulate fast and slow film. Most digital cameras have one ISO speed that will result in the highest quality pictures. For example my Olympus prosumer camera takes the best pictures at ISO 50 while my professional Canon is designed to work best at ISO 100. Just as fast, high ISO number film allows the photographer to shoot at fast speeds in low light conditions while paying the price of larger grain, digital photographers can dial in higher ISO speeds which allow them to shoot in darker situations while paying the price of higher noise levels. How much noise higher ISO settings cause depends on the camera. I once had a Nikon digital camera that was very noisy at high ISOs, my Olympus is just a little bit noisy at high ISOs while my professional Canon 1Ds Mark II is almost completely noiseless at even 1500 ISO. You should experiment shooting pictures in dim light at various ISO speeds and then look at the pictures on a computer to see how much noise your camera generates at higher ISO speeds. Blow the pictures up to large sizes in your computer for this test and look for both colored and uncolored speckles in the darker areas of the pictures. Then memorize the highest ISO that you think is acceptable for your camera.
Using higher ISO's can be very handy in landscape photography. One of the constant problems of shooting landscapes is using very small lens apertures in order to get the maximum depth of field which results in very slow shutter speeds. Invariable the wind comes up as soon as you start shooting at slow speeds and the wildflowers that you have chosen as your foreground start waving around wildly resulting in blurred flowers in the picture. If you are using a camera that has interchangeable lenses, you probably don't have a built in flash and so you can't stop the motion by using flash. One way to solve this problem is to choose a higher ISO speed; use just enough to allow you to shoot at a speed that will stop the flower movement without adding too much noise. Before you do this, be sure you have tested your camera in advance so you will know exactly how much noise you are adding to the picture or you will could add so much noise that the picture will be ruined.