“I’m going to run a film through it to test it” is what people say. But what do they do? If you stumble across the apocryphal 50p Leica or Nikon in a flea market or charity shop, how do you even know it works?
The first thing, even before putting film in it, is to check that the shutter works. Always wind-on the camera before changing shutter speeds. You really only need to do this with Russian and some other old cameras, but it is a good habit to get into. Teach your hands the habit and you might avoid breaking something in future.
With focal plane shutters, you are looking for both curtains to move smoothly without binding. When you wind-on the camera, the gap between the shutter curtains or blades should be closed as the shutter is re-cocked. The different shutter speeds should sound different. It is not unusual for the slower speeds to either not work or to be much slower than they should be. Your decision – it might free-up with use, you could pay to get the camera serviced, or you avoid using the slow speeds.
With leaf shutters, the ones that are built into the lens, you can listen to check that the speeds sound different. The slower speeds on old cameras can often be either very slow or frozen. Again, they might loosen-up in use or you could avoid using the slow speeds. Don’t bother trying the self-timer. It has probably never been used and will stick part-way through its run. If it does you will have to try persuading it to finish so that you get control of the lens back.
What shape are the light seals in? If they are sticky, broken or absent, it’s pretty straightforward to replace them.
Does the camera back (or base for that old Leica) fit properly? If not, the camera may have been dropped. Check the lens mounting at the front as well, this might get damaged if the camera was dropped.
Take a look through the front of the camera with the lens off as you work the shutter. Do the internal bits all move as they should? Does the mirror on an SLR swing up and return? Does the aperture-closing plate on a screw-mount SLR swing forward and back? Take another look at the shutter – can you see any wrinkles, bald spots or holes?
Take a squint through the lens. Threads of fungus needn’t be the end of the world: some lenses are simple enough to clean yourself and some can be serviced. Or plan to throw the lens away. Lenses can also be cloudy, scratched, dusty or have the glued elements separating. However bad it is, at least try shooting through it to see what sort of effect you get.
Put the lens on and try focusing the camera. Does it focus at about the right distance? You can recalibrate the rangefinder on many rangefinder cameras, but I don’t know how you would fix an SLR that didn’t focus correctly (unless it’s due to having the wrong lens on it).
If it has a lens, does it focus smoothly and does the aperture close-down properly? Many SLRs have a method of closing the aperture down to the set value at just the point you press the shutter. Does this work? Does the lens close-down to the same size of hole each time? Does it open up immediately again? Sleepy apertures are a common problem with old lenses. You can pay to have it serviced or put up with it and shoot with a pre-closed aperture. Or throw the lens away and keep the camera body.
So – all that before you put a film through it. If the camera passes these basic tests then it might work. Now put the film through it.
Try to shoot at all the workable shutter speeds. Shoot stuff at infinity and close up. Shoot some close-ups with the subject in only part of the frame, so you get plenty of out-of-focus background. Make it really obvious in the close-ups where the point of focus was or shoot a ruler or a long fence. Take some shots into the light. At least one interior is useful, with bright windows and lots of stuff in the shadows.
When you get to see the results, the first things to look for are that the frames are about the same density and are evenly spaced. Even density means the camera was exposing correctly at different shutter speeds and that the lens aperture is closing correctly. Even spacing means the mechanical windy-on bits are working. You can also check the film for scratches.
Did the camera focus correctly close-up? There are ways of calibrating some rangefinders to fix this, but it would be an unusual fault in an SLR. The out of focus background in some shots will give you a sense of whether you like the lens or not. Some will give a sharp subject on a smooth background while others will make the out of focus areas look busy and distracting.
Shooting into the light will give you a sense of how well the lens resists flare. For the interior shots with bright windows, look at any halo around the bright spots and whether there is detail in the shadows or it is hidden by flare. You can improve things with a good lens hood or just call it character.
So there you have it: you now have a fair idea of how well the camera works and if there are any dodgy settings to avoid. Which might be why it was in the charity shop in the first place.