Shutter speed tolerances according to Flutot's Camera Repair are shown here.
Shutter speed tolerances according to Flutot's Camera Repair are shown here.
Y’all are right, I’m not trying to be super accurate. I tend to round up a lot for exposure and yes, lens specs are rounded up or down, the real focal length, the true aperture. Just wondered why there were two standards for lenses. Still, would be handy to have a list of actual aperture size for reference in 1/10 stop increments.
Not rocket science... 5/10's is a half stop, but for something critical like on the edge of a white background, 1/10 would not be seen by LF chrome film, but 2/10's would start to be visible... Between 3 and 4 10's is a third of a stop, so that's a guide for you...
Happy metering!!!
Steve K
Not rocket science indeed. Here are the multiply factors to get the aperture in 1/10 of a stop. After that are are the common maximum apertures of older lenses, and their decimal equivalent.
.0414 - .1 stop
.082 - .2 stop
.1242 - .3 stop
.1656 - .4 stop
.207 - .5 stop
.2484 - .6 stop
.2898 - .7 stop
.3312 - .8 stop
.3726 - .9 stop
.414 - 1 stop
3.5 - 2.8/6
4.5 - 4/3
4.7 - 4/4
6.3 - 5.6/3
6.8 - 5.6/5
7.7 - 5.6/9
9 - 8/3
12.5 - 11/3
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