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Old 23rd February 2021, 01:08 PM
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MartyNL MartyNL is offline
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Quote:
Originally Posted by Bob View Post
10 seconds to 11 seconds is approx 1/7th of a stop (10s + 1/7th-stop = 11.04s). 1/6th of a stop would be 11.2s so 11s is 0.2s out, which is some silly fraction of a stop. [OK, I had to calculate it - it's 1/39th of a stop at 11s].

I believe that repeatability is more important than absolute precision (up to a point!) so as long as 10s + 1/6th of a stop always sets 11 seconds (which I am sure it does) the fact that it is 1/7th of a stop over 10s rather than 1/6th I feel, is less important.
Quote:
Originally Posted by JOReynolds View Post
Exposure times < 10 sec are displayed as decimal fractions, for example 1.0, 1.1, 1.2, 1.4.... Above 10 sec they are 11, 12, 14, 15, 17, 20, 22.... The actual rounding error is never more than 1.2%, which is negligible in photographic terms.

Another advantage of logarithmic setting is that the whole timing range, from 1.0 to 99 sec, takes just over 2 revolutions of the knob.

I'm 76 and I have to admit that it took me a while to get the hang of log scaling. I understand from SDS that several schools are using Timer 3 in their darkrooms and that they learn to use log time setting from the start.

Just for clarity, guys, because the numbers you’ve given don’t tally in my head.
When making a test-strip at 1/6 intervals manually above 10sec. and the exposures are rounded up/down to the nearest whole, what will the deviation be between each of the neighbouring test-strip exposures?
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Last edited by MartyNL; 23rd February 2021 at 01:16 PM.
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