Decent exposure --------------- I wrote previously[1] about shooting film in manual mode without a lightmeter. I really enjoyed the process, want to do more of it and really get good at estimating exposure with nothing other than my eye and brain. For the last roll I put through my Spotmatic, for each shot I set the camera to my best guess and then check with the meter before taking the shot. I definitely got better toward the end of the roll. At some point I told myself that I should stop checking and go with my instincts, but I was very rarely able to overcome the temptation. I think I'm going to take the battery out for the next roll so I have no choiced but to trust my gut, like when shooting my FED. Part of getting better throughout this last Spotmatic roll was just experience, but a big part was lots of reading and study. This post is my effort to share some of what I learned but also systematise some of the things I think I've figured out for myself, just to help clarify my own understanding. I'm going to propose an alternative set of rules of thumbs to the traditionally Sunny 16. I want to emphasise that I haven't actually tested these rules yet. I'm going to with my next few rolls. For now they're just ideas. They are nothing radical, they are 90% the result of applying standard exposure arithmetic to the traditional recommendations to come up with a system that makes more sense for me, based on my style of photography. The classic rule-of-thumb for manual shooting is the so-called "Sunny 16 rule"[2], which tells you that on a sunny day you can get a correct exposure by setting your aperture to f/16 and your shutter speed to the value that is closest to the reciprocal of your film speed, e.g. 1/125 for ISO 100, 1/500 for ISO 400, whatever. Of course you don't have to actually shoot at that setting, but it's a starting point for adjustments, e.g. instead of f/16 at 1/500 you could shoot f/22 at 1/250 or f/11 at 1/1000. All well and good, but what do you do in the not uncommon situation when it's not actually sunny? Obviously if it's less than sunny you'll need to expose for longer, and/or open the aperture wider, but by how much? After shooting semi-automatic modes on cameras with built-in meters for years, I have very little intuition about judging how many stops darker than "sunny" a given situation is. With a little searching I came across an expanded version of the rule, which offered recommended apertures for various other weather conditions. They are: Light Aperture ----- -------- Sunny f/16 Slight overcast f/11 Overcast f/8 Heavy overcast f/5.6 Sunset f/4 To some extent, this doesn't help too much. It just replaces the problem of guessing "is this light two or three stops weaker than sunny?" with the problem of guessing "is this weather *heavy* overcast or just ordinary overcast?". It's not totally useless, though, it's informative just to know that there are about four stops of exposure between the brightest and dimmest levels of sunlight. More detailed guides to using this rule (which, by the way, are rarer than you might hope - the vast majority of online articles about the Sunny 16 rule are written for people, and maybe even by people, who don't even understand the basic idea of the exposure triangle!) have made this a bit easier to judge by describing typical shadows. When it's "heavily" overcast, no shadows are visible, when it's "normally", shadows are faintly visible, when it's "slightly" overcast shadows are clearly visible but have soft edges and when it's "sunny" shadows have clear, solid edges. I like this advice, it removes some guess work. One thing I don't so much like about this extended Sunny 16 rule is that it's stated in what we might think of as "shutter priority" format: as the lighting conditions change, you keep your shutter speed fixed at 1/ISO and change your aperture to let in more/less light. I understand *why* the rule is formulated this way: it's easy to state one rule which applies for all film speeds when you link film speed to shutter speed, because film speed and shutter speed both vary linearly with amount of exposure, whereas aperture f-stops have that pesky sqrt(2) factor in there. So, the rule more or less has to be stated this way for the sake of generality. Fair enough. But as an actual table of settings to study, memorise and use in the field when shooting, this makes very little sense for most people, or at least for me. Shutter priority is for sports photographers! If you are photographing mostly stationary things, then shutter speed makes very little difference to how the resulting photo will look - any two speeds fast enough to avoid camera shake are identical. In contrast, aperture can have a dramatic effect on the result. It determines depth of field, and also influences image quality; Most lenses give their best results around f/8 or f/5.6, and suffer increasingly worse problems (diffraction, soft edges, vignetting, chromatic aberations) as you push them to either extreme. I think it makes much more practical sense to try to memorise an "aperture priority" table of rule-of-thumb expoures. Yes, a table like this is ISO-specific, but plenty of people only shoot one film stock anyway, and I get the impression that few routinely shoot more than two speeds. Let's convert the extended Sunny 16 table above into a table for shooting ISO 400 film, which I would say is the mostly likely candidate for a general purpose film speed, and at f/8, which is again a typical "general purpose" aperture ("f/8 and be there", as they say) at which most lenses will perform well, DoF is wide enough that you have some margin of error for focussing, etc.: Light Shutter @ ISO 400 f/8 ----- --------------------- Sunny 1/2000 Slight overcast 1/1000 Overcast 1/500 Heavy overcast 1/250 Sunset 1/125 Well, that's not ideal, is it? Shooting on a sunny day requires a shutter speed of 1/2000. Most classic film cameras from the 60s or 70s, or at least the Japanese SLRs that I'm most drawn to, have maximum shutter speeds of 1/1000, or sometimes even 1/500. According to this table, they're unusable at f/8 until the clouds roll in. For this reason, ISO 400 film is actually a touch fast, IMHO, to really be considered a good general purpose film. ISO 200 honestly seems better, and while ISO 200 film exists, there is a much wider range of stock at ISO 400 and ISO 100 (or roughly 100 anyway, for whatever reason manfacturers seem to like producing just slightly faster films, e.g. Ilford FP4 is rated at ISO 125 and Kodak make Portra in ISO 160), and those speeds have much better availability both online and offline than ISO 200. So, what do we do? Well, personally, almost all my cameras can do 1/1000 and I'd be reluctant to acquire any more which can't. So, one option for me is to deliberately overexpose every shot by one stop, yielding this table: Light Shutter @ ISO 400 f/8 ----- --------------------- Sunny 1/1000 +1 Slight overcast 1/500 +1 Overcast 1/250 +1 Heavy overcast 1/125 +1 Sunset 1/60 +1 Now, this is a very practical table! Every shutter speed which is fast enough to be shot handheld with a 50mm lens with no risk of blurring is used, and it lets me shoot in any daylight condition outdoors at a very nice aperture of f/8. Of course, sometimes I might want to use something other than f/8, but in those cases I will usually only want to move one or two stops away from this table, whereas the traditional extended Sunny 16 table is likely to have the reference point for a given lighting condition much further away from what I want. But, this nice table has come at the cost of +1 overexposure across the board. How do I feel about that? Well, not fantastic to be honest, but I don't doubt that it will yield workable results. Modern film stocks have quite wide exposure latitutde and tolerate overexposure better than underexposure. In fact, quite a lot of people online think that a lot of films look *better* when a little overexposed and so add half or a full stop, even when shooting automatic or semi-automatic with a light meter. Personally, I'm not at all convinced that I know better than the big film companies with expensive measuring equipment and decades of careful calibration experience, and I think a lot of the talk in forums etc. about routine overexposure is because people like to feel special by not shooting at "box speed" like the masses but instead applying their own secret adjustment. But I admit I could be wrong about this, and at the end of the day, the web is full of pages showing the same photo taken on various film stocks at box speed plus one or two stops over or under, and I can't deny that one stop of overexposure, even if not necessarily *better* looking, certainly does not look bad and is very, very usable. Certainly, it looks better than an equivalent amount under exposure. So, I think it's a perfectly decent price to pay for a very practical rule-of-thumb table for shooting without a light meter. Before going any further, I'll say that the table above for ISO 400 film shot at f/8 with one stop of overexposure also applies, as-is, to ISO 100 film shot at f/5.6 with the recommended exposure. f/5.6 generally still seems to be within the "sweet spot" of image quality for most good lenses, and the DoF is still very workable, so by just remembering to do one adjustment of aperture you can use one set of light-to-shutter-speed mappings for the two most common types of film. Heck, keeping in mind that this whole thing is just a rule of thumb and not an exercise in precision, and also remembering the wide exposure latitude of modern films, I might even offer this: if your lens allows half-stop adjustment of aperture, set it *between* f/8 and f/5.6 and then use the table above for ISO 100, 200 or 400! You'll be underexposing by half a stop compared to Sunny 16 if you're shooting at ISO 100 (although not if you're shooting FP4 or Portra 160!), overexposing by half a stop at ISO 200, and overexposing by 1.5 stops at ISO 400. None of these should be disasterous, and then you can use one table of values for any film speed that's commonly encountered today. Nice! For the rest of the post, though, I'll continue talking about ISO 400 at f/8 with one stop of overexposure. So, the extended Sunny 16 rule, which we've now converted to a more useful aperture priority format, covers typical outdoor daylight shooting conditions, which admittedly covers a lot of my photography. But it doesn't help you out at all if you want to shoot indoors, or at night, or during the day but in deeply shaded areas like a forest. To get a feel for how to work in these conditions, you need to to graduate from describing your light in weather forecasting terms to using Light Value (LV) numbers[3,4,5]. The LV system is a way of assigning numbers to the amount of light reaching your camera from a subject. LV0 is defined as the amount of light which would require an exposure time of 1 second at f/1 for ISO 100 film. An increase or decrease of LV by 1 corresponds to one stop more or less light. The "sunny" condition in the Sunny 16 rule correspond to LV15. The three resources linked above have tables full of approximate LV values for a range of different indoor and outdoor lighting conditions and subjects, and I've found them really valuable. There is far too much information in them to remember completely, but you can easily extract some useful things to remember, e.g. typical indoor lighting is 9 stops dimmer than "sunny" outdoors - there's no use in actually memorising the absolute LV values. Something I really like about the table at Ken Rockwell's site is that it recognises that the amount of light on e.g. typically overcast days varies by latitude. His table has entries for "California bright overcast" and also "Dark, dreary overcast day in Boston, London or Paris". The dark and dreary days in relatively Northern cities are actually one stop darker than the "sunset" condition of the Sunny 16 rule (which presumably is sunset on a clear day), and I've definitely had days here in the past month which my Spotmatic metered at about this level. So contrary to what I said earlier, I actually now think of there as being a five stop range of brightness in outdoor natural light, depending on the weather. The table below extends my earlier "aperture priority Sunny 16 for ISO 400 at f/8" table below the "sunset" condition all the way down to LV0. The settings it shows for ISO 400 are derived according to the following strategy: keep aperture at f/8 for as long as possible, using longer shutter speeds to compensate for decreasing light. Once shutter speed hits 1/60, start opening up the aperture to let more light in instead, so that handheld shooting remains viable as long as possible. Once aperture hits f/1.4, which is already in the realm of rare and expensive fast glass, finally start decreasing shutter speed to 1/30 and lower. But beyond 1/15 (which some people claim can be shot handheld with a 50mm lens if you are careful, who knows if they're just bragging), just start to accept the inevitable underexposure as being preferable to badly blurred shots. LV ISO 400 settings -- ---------------- 15 (sunny) 1/1000 f/8 +1 14 (slight overcast) 1/500 f/8 +1 13 (overcast) 1/250 f/8 +1 12 (heavy overcast) 1/125 f/8 +1 11 (sunset, deep shade) 1/60 f/8 +1 10 (dark and dreary) 1/60 f/8 9 1/60 f/5.6 8 (bright office) 1/60 f/4 7 (typical indoors) 1/60 f/2.8 6 (dim home) 1/60 f/2 5 1/60 f/1.4 4 1/30 f/1.4 3 (bright night street)1/15 f/1.4 2 (typical night st.) 1/15 f/1.4 -1 1 (dark outdoors) 1/15 f/1.4 -2 0 1/15 f/1.4 -3 I didn't bother coming up with this table because I plan to actually memorise and use it as a guide - that's not really practical. I did it because I wanted to get a better feel for what sort of practical limits are imposed on your shooting by certain film and lens speeds, if you follow common sense principles. An important take away, for me, is that if you are only planning to shoot outdoors while the sun is up then you are *absolutely* just fine and dandy using ISO 100 film (which everyone knows is "slow film") and a lens with maximum aperture of f/3.5 or f/2.8 (which, again, everyone knows is "slow glass"). With ISO 100 and f/2.8 you'll be able to shoot handheld when it's "dark and dreary" without even using your lens' fastest setting. You really only need ISO 400 if you plan to shoot indoors (something that photography has really opened my eyes to, if you'll pardon the pun, is how amazingly adaptable the human eye is to different levels of light. Who'd have thought the light in a typically lit home was *five hundred and twelve* times dimmer than a sunny day outside?!). And you really should only bother chasing fast lenses if what you acually want is extremely narrow depth of field and crazy bokeh effects during the day; any realistically specced lens is seriously struggling to be shootable handheld outdoors at night at ISO 400, whilst indoors even f/2 is probably enough. You'll pay more to go from f/2 to f/1.8 or f/1.7, and then a lot more to go to f/1.4, and a whole lot more to get to f/1.2. But you're only getting fractions of a stop more with each upgrade, when several whole stops are what you would actually need. Faster film, or push processing, are really the only viable options for handheld night shooting. Or flash, of course, but I know next to nothing about flash photography, so can't really say anything about that. I'm really excited to try shooting a roll without a meter using nothing but my aperture priority version of the Sunny 16 rule for ISO 400 with one stop of overexposure. I'm hoping it will let me shoot manually much faster than the traditional Sunny 16 rule, which usually has me working in two steps: first adjusting from the "sunny 16" anchor point to somewhere else, based on the lighting, and then shifting from *that* point to one that gives me a more usable aperture value. [1] gopher://zaibatsu.circumlunar.space:70/0/~solderpunk/phlog/look-ma-no-lightmeter.txt [2] https://en.wikipedia.org/wiki/Sunny_16_rule [3] https://en.wikipedia.org/wiki/Exposure_value [4] https://kenrockwell.com/tech/ev.htm [5] http://www.fredparker.com/ultexp1.htm