Last installment, lighting was covered as well as various methods for providing that light.

This time, the subject will be focus.

I have to confess that it is quite difficult to get the entire model in focus for many photographers. Frequently I get some very nice images that are just impossible to use because of issues with focus. As I tell people, digital software can fix images that are too dark, a bit too light or have a strange color cast to them from not matching camera setting with lighting conditions. However, as much as you would like to believe from movies, software cannot fix out of focus.

There are several factors that come into play when it comes to focus. One, which really can be divided into several sections, is camera settings. Another is the distance of the camera to the subject and the third is the size of the subject, which in many ways is related to the distance to the subject.

So let's start with the camera itself. There are times when one is using a camera that has no adjustable settings. Phones with cameras come to mind on this as do many 'point and shoot' cameras. This will require some diving into the instructions that come with it to find what the minimum focus might be. If it is three feet and you are two feet from the subject, your photos will be out of focus. Guaranteed. I should mention that three feet is a relatively common minimum focus distance for these sorts of cameras.

If you have the ability to adjust things like shutter speed, ASA, and f/stop (I know digital cameras don't have shutters and film doesn't come in to play, but these settings are still being used so bear with me), or which takes priority then you will have more control over the end image.

First thing is to take the camera off 'Auto'. These are usually weighted to give you the greatest shutter speed. Next, choose 'Aperture Priority' for your imaging. This will allow you to set the maximum f/stop for your camera and you need to pick whatever is the highest in terms of numbers. F/8 is better than f/2 and if you have a nice camera, you might have f/11 or f/22 available. Pick it as that will increase the depth of field and put more of your subject in focus. We are using either a tripod, flash or daylight to take the photos so this should not be an issue.

Now that you have your camera set on aperture priority you need to choose the lowest ASA setting you can. Again, take that setting off Auto or it will choose a high ASA number. What a low ASA setting will do is to reduce the amount of electronic noise you get in your image. By using a high setting (like 800), your camera will try to gather in as much light from the subject as it can. When doing this it increases the sensitivity of the light sensors and this greatly increases the amount of electronic noise it picks up. This noise is generated by the tiny amount of heat given off by the sensors themselves and will show in your image as a lot of graininess. Military grade image sensors cool the sensor array with liquid helium in order to lower this phenomenon. Your camera probably doesn't have that capability. You can see a good example of this noise in the image to the right. Notice also that this image does not have what I'd call enough light and what there is comes from the back of the subject, muting the colors and making details like the exhaust difficult to differentiate.

Shutter speed only comes into play in the fact that with a low ASA and a high f/stop setting, you will have a relatively slow shutter speed. This is where using a tripod and the timer setting comes into play if not taking your images outdoors. For instance, my camera only goes to f/8 and yet for many of my model photos, even when using the reflector as a light source, the shutter speeds are in the 1/6 to 1/4 second range; too slow for hand holding. 

That is a lot on camera settings, but it is important. The other is on the distance from the subject. Unless taking close-up images, you want to be at a distance where the entire subject is in focus. I have found that with most models, if I am between 2-4 feet away from it, I can get good depth of field. It also means that I do not introduce the sort of image distortion that comes with being too close and using a wide setting. I almost NEVER use a wide setting when taking photos. It will give you better depth of field, but to me is not worth having the distortion that comes with it. Look through some of the articles and you can tell when the photographer has used wide settings. This is where close things are huge in comparison to far away bits and where horizontal lines tend to be curved to some extent. Below are a couple of examples. In both cases the fuselage filled the frame, but the upper one was taken using wide angle settings and the lower one was on a standard or medium telephoto.

I should mention that in no case have I altered anything about any of the images in this presentation other than to reduce their size. No sharpening, no adjustment of brightness or contrast, no changing hue or increasing the intensity of the colors.

I have included two photos that help to illustrate depth of field. Both of these images were taken at the same distance, the only difference is that the one on the left (or the upper photo depending on your screen resolution) was taken at the lowest f/stop my camera will attain (f/3.5) and the one on the right with the highest (f/8). You can see which is the better image. Much more of the second image is in focus. This is the main reason you should use aperture priority and the highest setting when taking photos.

This should provide you with enough fodder to continue practicing taking photos. Look through a few articles. See if you can spot images that have poor depth of field, have wide angle distortion or are back-lit. Part of improving is knowing what to look for. Do not be afraid to rattle off a lot of images. Inspect them to see if they have enough light and if they are in focus. Practice moving your camera back and forth in relation to the subject to see what you get as results.

Back to the first installment.