Using an SLR Camera without a light-meter.

Using an SLR Camera without a light-meter, okay, so I bought a £5 SLR camera from the 60s or 70s, the russian Zenit B - it's the budget version of the Zenit E, the E has a built in light meter, the Zenit B has no such luxury. So I could buy a light-meter, but I'm being a cheap skate, especially when it comes to a cheap £5 film camera (when I've got a digital I can use most of the time), but light meter's are pretty expensive (at least £10! - twice the price of the SLR I bought in the first place!).

So I did a quick search, and found this guy, wrote up a big explanation on how to "guess-timate" the correct shutter/aperture setting based on your general weather condition. You can read it by clicking the read more button... (I would have linked to the original post but it only exists in Google's cache)

(i've hopefully enabled the ability to have really long posts here, but it only display a top section, with a link to the bottom section, as explained here)
...Many times I don't use one ... and just use this method

EV (exposure value) ... An exposure system used on some rangefinder cameras

EV (Exposure Value) based on a number usually from 2 to 18. When the EV is set, one merely has to rotate the coupled aperture/speed ring on the lens to adjust for either the speed or aperture desired, and any setting along that ring will (should) produce the correct exposure . The system is so easy to use that you really don't need the meter to work (they don't work on many vintage rangefinders) ... on my Minolta Hi-Matic 7s for example the scale is on the right side of the viewfinder, the lower the number (5.7 in my case) corrosponds to a low light reading ... It goes to #17 for a bright reading #14 is the reading I might get on an overcast day (#14 is just above the middle of the scale) ... It's pretty easy to guesstimate" your EV (even without the meter) ...

Estimating Exposure (sunny day)

Sometimes an exposure must be estimated due to a camera not having a built-in meter, not having a hand-held meter, or a meter malfunction (e.g., dead batteries/not working). Even if an estimate is not required, at least understanding approximately what an exposure should be is a sanity check of your camera (or hand-held) metering technique. All the sophisticated automated exposure electronics now incorporated into camera bodies does not mean the photographer should leave his brain in the camera bag. The following is a method for estimating exposure. With a little practice and experience one can be fairly accurate with it. Indeed, before meters were built into nearly all camera bodies, this is what nearly all photographers used! A hand-held meter was considered by many to be an expensive, cumbersome extravagance; they didn't need it or want to bother with it. Kodak still publishes outdoor daylight exposure guidelines based on this method in its film data sheets.
Outdoor Daylight

This is commonly known as the "Sunny f/16 Rule." On a bright sunny day with average subject illumination by direct sun (sun not obscured by clouds, trees, etc.) a proper exposure can be made by setting the aperture to f/16 and the shutter speed to 1 /125. Thus, with ISO 100 film under these conditions, f/16 @ 1/125th will get a proper exposure.

@ISO (film speed) =100

f/16 @ 1/125th f/11 @ 1/250th f/8 @ 1/500th f/5.6 @ 1/1000th

@ISO (film speed) =200

f/16 @ 1/250 f/11 @ 1/500 f/8 @ 1/1000

@ISO (film speed) =400

f/16 @ 1/500 f/11 @ 1/1000

Estimating Exposure (various conditions)

Not every day or situation will be under direct, unobscured sun, or the subject may be very bright water, beach sand, or snow. What then? The Sunny f/16 Rule can be adjusted for these situations:

+1 EV:= +1f/stop or +1 shutter speed ... light sand or snow
0 EV:= no change needed .............. bright or strong hazy sun (distinct, sharp shadows)
-1 EV:= -1f/stop or -1 shutter speed ... weak hazy sun (soft shadows; distinct sun outline in clouds)
-2 EV:= -2f/stop or -2 shutter speed ... cloudy bright (no shadows; sun creates bright area in clouds)
-3 EV:= -3f/stop or -3 shutter speed ... heavy overcast, but not "black" (no shadows; sun location cannot be determined)
-3 EV:= -3f/stop or -3 shutter speed ... open shade (in shadow but 60% sky not obscured)
-4 EV:= -4f/stop or -4 shutter speed ... deep shade (in shadow with obscured sky; under forest canopy

Now that you have the formula down ... understand that you can use any combination, of f/stop (aperture) or shutter speed as long as it equals the TOTAL plus or minus number ...

EXAMPLE...

Lets say it's an overcast day, and you have 400 ISO (speed) film, the "Sunny f/16 Rule" would have you set the exposure at f/16 @ 1/500 ... But you "guesstimate" that you need a TOTAL of minus 3 (to adjust to the light conditions)... on either the f/stop or shutter speed ... You could drop 2 f/stops and 1 shutter speed (the 2 and 1 equals 3) ... so your setting would be f/8 with a shutter speed of 250. The TOTAL is -3 ... IF you were using the EV method on an old rangefinder camera f/16 @ 1/500 is 17 on the EV scale ... f/8 @1/250 is 14 on the EV scale ... or minus 3.