I am fairly new to photography (3 years) and, while I am better at the math these days, it is still a source of confusion for me.
I am under the impression that f-stops are measured in a scale that is either based on 1 or 1.4, as in: 1, 1.4, 2, 2.8, 4.0, 5.6, 8, 11, 16, 22, 32... Of course I am familiar with 1.7, 2.5, 3.5, 4.5, 6, 9, 13, 14, 19... because these are either fast Pentax lenses or the numbers show up in the meter when I shoot shutter priority or automatic. (Question coming up, I promise.) My questions concern the measurements between stops. I believe that the difference between 2.8 and 4.0 is a full stop which can also be measured in shutter speed, e.g. 1/250 to 1/500. Assuming that this is correct, I can deduce that a change from 2.8 to 3.5 is a 1/2 stop. Unfortunately, this can only be true if 3.5 is the only stop that can exist between 2.8 and 4.0, and this, of course, must be false. So, finally, the questions are: 1. What is the real scale? 2. Other than setting the auto bracket feature to 1/3, how does one make a 1/3 shift? s/ http://www.eyecafe.net - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
