Scott Fine wrote: > Please tell me if this is correct - I subtracted one stop from the next > largest, divided that number by 2 and added the result to the larger > aperture. I cam up with the following 1/2 stop scale....
Hi Scott, Nope, sorry -- the results are close, but the method is not correct. Photographic stops are a geometric progression, not an arithmetic one. That means to generate the series, you ~multiply~ by a constant factor. To get the series of whole stops, start with 1, and multiply by 2^0.5 (that is, the square root of two). To get the series of half-stops, start with one, and multiply by 2^0.25 (that is, the fourth root of two, which is also the square root of the original square-root-of-two factor). To get the series of third-stops, start with 1, and multiply by 2^0.1667 (that is, the sixth root of two, which is also the cube root of the original square-root-of-two factor). See the pattern? Bill Peifer Rochester, NY - 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 .
