I have been meaning to write this post for about two or three years. I pick up the subject, do a few test shots, write a bit, then shelve it. I don’t know why that is, perhaps because I’m doing it out of annoyance, rather than because I am excited to share something with you all.
The thing that has been annoying me is the constant advice on social platforms to beginners that you can just shoot ‘Sunny 16’ and all will be perfect. There are a few myths in photography that regularly crop up in articles, blog posts and comment sections, and If you try to suggest that any of these commenters might be mistaken, you are immediately pounced on by a number of people who are totally convinced of the thing, despite never having tested it. The Sunny 16 Rule is one such myth in my opinion. Perhaps I should qualify that statement and say that it’s not so much a myth, because it does work sometimes. More a mistaken belief that this method is going to produce perfect results all of the time.
The sunny 16 rule is very old, and was originally devised as a way of shooting transparency film at a time when light meters were less common, and not very reliable. It was important to avoid overexposure with transparency film, so slight underexposure was preferable. Exposing for negative films is different, they benefit from slight overexposure (but not over development).
Let me explain what Sunny 16 actually is for those of you who do not know. The rule states that; ‘In sunny conditions, the camera can be set to f16, and the shutter speed will be the same as the ASA/ISO’. My preferred film is Ilford HP5 400 ASA/ISO, so for the purposes of this article I will be using that as a example. In sunlight the setting would then be a 400th of a second at f16. Now there are no cameras that allow you to manually select 400th of a second (actually I can think of just one, -Mamiya RB67), so most people go for the nearest speed, which is 500th. If you wanted to compensate for this slightly faster speed you could open your aperture to between f11 and f16, but it is my belief that you will still be underexposed in a number of situations (and anyway, that wouldn’t be sunny 16 would it?).
I shoot Ilford HP5 every day (Inland in the UK), and I’m consistently getting 125th at f16 in sunny conditions. This is two stops away from the sunny 16 setting and I’m not getting really overexposed negatives, this exposure gives me just enough shadow detail for the type of negative I like to print from. When I am at the coast, I get 250th at f16, and only at mid day there, with the sun behind me do I get 500th at f16.
The difficulty with a statement that suggests all exposures to be the same, is that location is not taken into account, never mind the time of day. brightness of the sun is not constant from the Arctic to the equator, and even varies a full stop between coast and countryside. In the UK, bright sunny days are not common, so the rule might not be any use for 80% of the year anyway.
In the UK in summer, if you are near the sea, you might just get sunny 16 if you have the sun high in the sky and it is directly behind you. Inland, earlier or later in the day it will be less, and if you turn 90 degrees to the sun it will be reduced even more. Extra exposure is needed to bring tone to the areas not lit by the sun, so the rule does not apply any more. This is never mentioned when the rule is suggested, the advice is passed on because the reader saw it somewhere, but never tested it.
If you photograph in a city, you may be getting extra light reflected off pale concrete and large glass covered buildings, so you might find my setting quite different from your own. From my tests it would seem that the best time of day to get enough light for sunny 16 to work is mid day, but the harshness of the light at that time is not good for photography. Personally, I think it is the worst time of the day for pictures, but street photographers might disagree with me on that one. There is a fashion among current street photographers for solid black areas in pictures. This is basically underexposure with the highlights lifted afterwards. If this is the look you are after, then sunny 16 is probably fine for you.
One thing that needs clarifying here is that most new film photographers these days are scanning their negatives, rather than printing in a darkroom and underexposed negatives can be easily rescued in Photoshop. if you have never tried to print your negatives in a darkroom, and have only used software to make images, then you might not be aware that your negs are a bit underexposed. Printing in a darkroom requires negatives with more density and a different approach to estimating exposure. If you make the switch from scanning to printing, you may find your negatives are not dense enough.
You may think that I am making this up, but you can test it even with a digital camera, and they don’t need as much exposure as a negative. Set your camera to 400 ASA/ISO, set the aperture to 16, and your shutter to 500th, it’s the setting that most people use when shooting sunny 16 with a 400 speed film. Go out and shoot a number of frames in different directions, and don’t chimp, don’t look at the pictures until you have done 10 or 12. If the theory is correct, then all of your pictures should be perfectly exposed. I’m betting that they are not.
The first of these digital shots was taken at 1/500th at f16. The camera was set to 400 ASA/ISO. The second shot was with aperture priority and the camera chose 1/140th.
Now try shooting in sunlight with film. Take one shot at ‘sunny 16, and then take an incident reading and do a shot at that setting. If you have the time, repeat this with a number of situations and with the sun behind you and also to your side. Process your film and look at the difference in the negatives.
Some of the comments I have seen online illustrate the attitude many have; Sunny 16 is ‘incredibly reliable’, and ‘It has been the standard for over a century’, (actually only since 1960 when ASA standards were set). ‘It’s not foolish to believe in Sunny 16, because it’s not an opinion, it’s a fact’, -It’s not a fact, it only applies in limited situations.
One person even showed a picture with the details; ‘Sunny 16, Kiev 4AM (camera)’ -the picture was a night shot!
Don’t believe what you read, test things for yourself and make your own mind up.