I’m far too novice to give anyone lessons. I’m apt to give bad advice in photography. Warning out of the way, I thought that I would share my experience in shooting on fully manual cameras, without any light meter at hand, other than my old eyes and feeble nervous system. Really you shouldn’t be doing it. Old light meters, often the cheap selenium types, can often be found at car boot sales, or online (although I’d recommend calibrating them). First alternative: most smart phone systems now have downloadable light meter apps – some even free (still worth calibrating). Second alternative – carry a modern camera, preferably one with aperture or shutter priority, that displays the auto-exposure settings. Use that as a light meter.
I’m lazy, and perhaps I like to take chances. If you are daft enough to be using a manual camera with no light meter, for opportunistic candid photography, then it goes without saying, you have to expect some crap exposures from time to time. But I’m a crap photographer who isn’t always bothered if I’m off a stop or two. Anyway, film can be so forgiving to old bodgers like me. Modern digital cameras have so much technology targeting the perfect exposure – all sorts of light sensors built into them, with an array of programs, and micro-stops between the micro stops. A digital-only photographer might balk at the idea of using nothing but your eyes. Still, their images are very perfect. Mine are not. I don’t care.
When I carry a medium format film camera, be it system SLR, TLR, or folding, I more often than not risk it with eyes only. I might sometimes, just check myself now and then using a light meter app on my smart phone. So how do I manage to make photographs with no light meter?
I use a dumbed down Sunny F16 rule. I don’t carry a guide card, but I can see the wisdom in doing so, especially at first. You should know the rule, if not, go to a search engine now. On a very sunny, cloud free midday, you set the shutter speed to (nearest) your film speed. For example ISO 100, set the shutter to speed 125, for ISO 400 film, set shutter speed to 500, etc. You then in theory, set your aperture to F16. Actually, I don’t. I might go for F11, or on a step between F11 and F16 – unless very, very sunny, on a beach or in snow, etc. Film is more forgiving by a stop or two to over exposure than is digital, so it is best to over expose a little than to under expose in my humble opinion.
The Sunny 16 Rule then goes on to recommend that as the light degrades through scattered cloud, shade, cloudy, to abysmal, that you open your aperture more and more. There are guidelines! I just can never remember them.
Of course, you do not have to keep your shutter speed set to the film ISO. Once that you have ascertained the desired exposure value, you can start to trade between aperture and shutter speed in terms of “stops”. A stop is a traditional aperture, ISO, or aperture setting. Each roughly doubles or halves the volume of light exposed in the camera. I said roughly!
The traditional stops for shutter speed (those that are useful in natural light without a tripod) – each one in order increases speed, and halves the amount of light allowed to travel to the film, are: 30 (very steady hand), 60 (quite a steady hand), 125, 250, 500, 1000.
The traditional stops or aperture, each one in order opens up wider, and allows (roughly) double the volume of light to pass through, are: F22 (smallest hole), F16, F11, F8, F5.6, F4, F2.8 (largest hole to past most light).
All stops in terms of the amount of light, are roughly, equal.
Once you understand that, and you have decided upon your exposure value, you can trade one for the other. For example, if, using the Sunny F16 rule on a miserable grey cloudy day, with ISO 200 film loaded, your shutter speed is 250, aperture F5.6, that you need more depth of field (a smaller aperture), you can swap 250/ F5.6 for 125 (one stop up) F8 (one stop down). Alternatively, you need a faster shutter? then step the shutter up to 500, and open the aperture by one stop to F4.
I’m sure that any regular readers will be already perfectly aware of this – or will know better, and will want to hit me around the head, as a dumb amateur giving bad advice.
However, just maybe, people even more n00b than myself, perhaps people growing up in a digital age where camera craft is disappearing, might just benefit from this. If they are daft enough to listen to me.