Leica M3 w 90mm Summicron: f/5.6@1/125th second | Leica M3 w 50mm Summilux f/4@1/60th second
Sunny 16:
You already knew this one, but on the off chance that you didn't:
Your shutter speed should be the ISO (ASA) of the film you're shooting with your lens set at at f/16 in bright sunlight. Increase your exposure by 1/2 stop for morning or afternoon, and 2 stops for just prior to sunset or just after sunrise.
Increase by about 1 stop for more shadow detail, and 2-3 stops for open shade. For deep shade, such as within a forest, it's closer to 4 stops.
For print film, make that sunny 11.
When in doubt, overexpose print film. I usually shoot up to a stop under the rated film speed. After all, when a film's spec sheet claims that it has a stop under exposure latitude, and three stops over exposure latitude, the manufacturer is simply telling you that the higher speed is a marketing ploy.
Slide film is touchy. Plan on doing lots of bracketing. Expose this stuff mumbling the mantra: "Film is cheap... Film is cheap..."
Ever since I started relying on an incident light meter, my percentage of acceptably metered exposures has risen by at least 50%. Reflected light meters, either handheld or in the camera are easily thrown off by light or dark backgrounds.
IMHO, Leica really blew it when they replaced the self timer (a useful gadget) with the meter in the M4-P and subsequent cameras.
I've stopped using in camera meters. Until I got an M7. There's somthing to say for an in camera meter where you can lock the exposure on that part of the scene that you want to show up as middle grey. It's also much faster and more accurate for indoor work, where generally you have a very wide range of exposure possibilities.
Meter the darkest part of the scene that you want to have detail in, and the lightest. If there's more than about 4 stops difference (slow film) or 6 (fast film), you're going to loose detail. You have to decide what you want to emphasize. It's a good time to bracket.
There's no substitute for experience here. You really have to experiment with a few rolls of film, photographing high contrast, back lit subjects, low contrast, flat lit subjects on overcast days to see what sort of results that YOU like. After a hundred or so ruined exposures, you'll start get a feel for what works and what doesn't. This is important. All too many photographers, getting that first roll of disasters back from the photofinisher's, give up on manual cameras. They do not realize that it is part of their learning curve, and they need to learn from their errors, and immediately go shoot another roll!
My own preference for meters in the Gossen Luna Pro. I've used it for so long that I've come to see light in terms of it's 1-22 scale. It's a bit more sensitive than the Silicon meters I've tried. I've also tried a Sekonic L-308B, L-318B, a few Vivitars, the Gossen Luna Pro F, and an old Weston Master V. Well, they all worked, some even measured flash (I never used this feature, the thyristor circuitry in the flash does an excellent job here). The Silicon based meters are fast, but not quite as sensitive, and the Sekonics have an annoying initialization sequence that lasts a few seconds after you turn it on. Don't take this too seriously. All of the meters mentioned above work just fine, in most light you're likely to encounter in general photography.
Shoot the moon:Add 19 stops to the sunny 16 rule for exposures in full moonlight. If you're shooting 1/1000th @ f/16, you'd be shooting 2 seconds at f/1.0. Better add a second or so for reciprocity. Add another 2 stops for a half moon.
For the moon itself, add 3 stops to sunny 16. To begin to fill the frame with the lunar disk, you'll need a 2000 mm lens.
Preset the exposure and focus, and put the camera on a shelf or brace it against a wall, and use the self timer. This trick works best with wide angle lenses, as they are a bit more forgiving of framing errors.
f stops:
full, + 1/3, + 1/2, + 2/3: full, + 1/3, + 1/2, + 2/3
| 1.000 | 1.122 | 1.189 | 1.260 | 1.414 | 1.587 | 1.682 | 1.782 |
| 2.000 | 2.245 | 2.378 | 2.520 | 2.828 | 3.175 | 3.364 | 3.564 |
| 4.000 | 4.490 | 4.757 | 5.040 | 5.657 | 6.350 | 6.727 | 7.127 |
| 8.000 | 8.980 | 9.514 | 10.079 | 11.314 | 12.699 | 13.454 | 14.254 |
| 16.000 | 17.959 | 19.027 | 20.159 | 22.627 | 25.398 | 26.909 | 28.509 |
| 32.000 | 35.919 | 38.055 | 40.317 | 45.255 | 50.797 | 53.817 | 57.018 |
| 64.000 | 71.838 | 76.109 | 80.635 | 90.510 | 101.594 | 107.635 | 114.035 |
| 14mm | 104.250 x 81.203 | 114.182 | 55mm | 36.244 x 24.616 | 42.943 |
| 15mm | 100.389 x 77.320 | 110.527 | 75mm | 26.991 x 18.181 | 32.180 |
| 17mm | 93.273 x 70.435 | 103.678 | 90mm | 22.620 x 15.189 | 27.032 |
| 20mm | 83.974 x 61.928 | 94.493 | 135mm | 15.189 x 10.159 | 18.208 |
| 21mm | 81.203 x 59.490 | 91.702 | 180mm | 11.421 x 7.628 | 13.706 |
| 24mm | 73.740 x 53.130 | 84.062 | 200mm | 10.286 x 6.867 | 12.347 |
| 28mm | 65.470 x 46.397 | 75.381 | 300mm | 6.867 x 4.581 | 8.249 |
| 35mm | 54.432 x 37.849 | 63.440 | 400mm | 5.153 x 3.437 | 6.191 |
| 50mm | 39.598 x 26.991 | 46.793 | 1000mm | 2.062 x 1.375 | 2.479 |