When it comes to shooting film, it's easy to be overwhelmed by all the options. When shooting a digital system, your sensor is fixed and doesn't change. However in analog photography the physical piece of light sensitive celluloid is different every time you reload the camera. Different colors, different sensitivities, different tolerance for under or over exposure. Even now in an age where there are quite a few less film stocks than there used to be, I still wonder if I'll ever try them all!
With all things photography, choosing a film stock involves a series evaluations and subsequent decisions.
1. Color or Black and White?
When deciding which film stock to shoot your first choice is obviously going to be whether you want to shoot color or black and white. Your first step is to examine and evaluate your scene. Train yourself to visualize your final image. Sometimes an image needs color to be successful, and other times a beautiful black and white image would not have been the same with the potential distraction of color.
Also, modern C41 process color films generally have a wider latitude for under and overexposure, whereas most true black and white films do not. Beginners might have better luck with color film (especially Kodak Portra 400, or Kodak Portra 160) if they are still getting a handle on metering.
2. Film Speed
Your next consideration should be film speed. Your film's ASA or ISO rating tells you how sensitive to light the film is. A film stock with an ISO of 50 is not very sensitive to light and should be used in very bright situations, whereas a 3200 speed film could be used in a much darker situation.
You will definitely need a light meter to help you make this decision. More modern film cameras have fairly accurate in camera "through the lens" (or TTL) light metering systems to help you gauge how much light is in the scene. I suggest using a hand held light meter which will give more accurate readings when used properly.
As I have learned more about different film stocks through trial and error as well as the FIND in a Box Workshop, I have discovered that the film speed on the box may not be the best way to shoot that particular film. Portra 800 for example often looks much more vibrant when shot at 200 or even 100 ISO. That's 2-3 stops of overexposure! Ilford HP5 can be pushed 3-5 stops (underexposed, and then developed longer) and still look fantastic! With film, experimentation and practice are the name of the game. If you really want to learn about a certain film stock, the best way is to shoot it allllllll the time in a variety of situations, just remember to take good notes so you know what you did. You will find your favorite ways of shooting each film stock soon enough.
3. Film Size
Now, this decision could be made for you because it depends on what type of camera you have. More common film formats are 35mm, 6x6, 645, 6x7, 6x9, 4x5, 8x10. These ratios refer to the physical size of the negative. Most people start out with a 35mm camera of some kind because they are small and generally more affordable than medium or large format systems. 35mm cameras are great because most can fit 36 exposures on a single roll! 645 cameras fit about 16 frames on a 120 sized roll of film, and a 6x7 camera can usually only fit 8. There are very few films still in production that come in 220 size (which is twice as long as 120). It's really a shame because 220 film makes shooting with a 6x7 camera much more practical. (The most accessible 220 film at the time of writing would be probably be Kodak Portra 160).
Another consideration would be grain. The simple truth is that the larger the negative, the less noticeable the grain. A 35mm negative can traditionally only be enlarged up to 8x10 because otherwise the grain would become too distracting and the image would start to fall apart. If you look at these examples you'll notice that the 35mm scan has much more noticeable grain than the medium format scan even though they are the exact same film stock. (click to enlarge)
Ok, so say I have decided I want to shoot some portraits of my model in the shade. She is wearing a white swimsuit and has silver hair. We are shooting in a parking garage with lots of gray. I first decide I want to shoot black and white. The situation isn't very colorful and wouldn't necessarily benefit from shooting a color film. I then decide my film speed. 400 ISO is generally a good film speed for shady situations (These were shot at about F4). Lastly, I need a film size that fits the camera I'm using and will correspond with my grain preference. I'm not a huge fan of grain and ended up shooting 120 size film in a 6x6 camera (Yashica Mat124). The grain is still noticeable in this film stock and size, but it would be much grainer in a 35mm format.
The most important thing to remember though, is that when you are first starting out, you will most likely fail, and fail hard, a lot. Your images will often be underexposed and out of focus, but you must persevere! Keep shooting and keep learning from your mistakes! As you shoot more, you will become more and more familiar with the nuances of the different film stocks and cameras you use. They will often shape your style and the way you go about shooting. The more you shoot, the better you will get! I hope this has been helpful to my film newbs out there! Have a questions? Leave a comment! Happy shooting my friends!