Estimate Exposure for MINOX 8X11greenspun.com : LUSENET : Minox Photography : One Thread
How to estimate exposure of MINOX 8x11 without meter
-- martin tai (email@example.com), December 21, 1998
A net rule of thumb for Minox photography is 10*ASA RULE by American Minox Photographer and Minox author Peter Zimmerman. Peter's 10x ASA rule is very simple to use: At sunny day, set Minox 811 camera shutter to 10 times ASA, that is it ! For example, if you use ASA 25 Minopan ( =Agfpan APX 25), set Minox shutter to 10 * 25 = 250.
-- martin tai (firstname.lastname@example.org), January 14, 1999.
I am a little unsure about the 10x rule of thumb formula. The general rule of thumb in general photography is the "ASA at 16" under bright sunlight. That is, under bright sunlight, set the f-setting at 16, and use the ASA speed as the shutter speed. So, at 100 ASA, the rule of thumb says: set the speed at 100, and the f stop at 16. Now, with the recomended Minox rule of thumb, I find a contradiction. The minox lens is constantly set at f 3.5. So, under bright sunlight, this should demant a speed of 500 to 1000 with 25 ASA film (since at f 16, the speed should be 25 per second). If we use the 10x formula, then the speed should be set at 250, and thus overexpose the negative by at least one stop.
-- VICKEN O. BERJIKIAN (BERJIKIAN@AOL.COM), February 24, 1999.
Vicken, many Minoxer like to expose for shadow details, hence using sunny F11 rule instead of sunny 16. I find 10*ASA suits me fine, which is only a rule of thumb, you have to find a rule which suits your style.
-- martin tai (email@example.com), February 28, 1999.
I think I have a partial explanation for VB's question about Mr. Zimmerman's 10*ASA rule.
The Minox aperature is f/3.5, and so to convert to the sunny f/16 rule, the exposure should be dropped (16/3.5)^2 or about 20 times. Remember, f/number gives the diameter of the aperature, but it is the area of the aperature which regulates the amount of light.
This would indicate 20*ASA as the shutter number to dial into the Minox. The factor of 2 difference might result from Mr Zimmerman using the f/11 rule for sunny pictures as mentioned in the Q&A, for shadow detail. He also may want to err on the side of overexpose since color film tolerates overexposure better than underexposure. Lastly, his preferred developing technique may give better results with film overexposed a bit.
-- Karl W. Kleimenhagen (firstname.lastname@example.org), March 22, 1999.