Talk:F-number

I don't like your edit it's a ratio for example : Diaphragm diameter = 12,5 mm Focal lenght = 100 mm -> 100/12,5=f/8 Diaphragm diameter = 25 mm Focal length = 50 mm -> 100/25=f/4 Is it logarithmic ? Not really f/4 means twice more light on the film that f/8. and 8=2x4.

You're right, it's misleading: I could have phrased it better. I hope you prefer this version. The Anome

Is there a difference between f-stop and f-number. It's unclear in the article.

I think so: a set of f stops are (by convention) particular f-numbers that form a geometric series with a factor of 2 of exposure as the ratio. The Anome

I think to "half f-stops". F-stop is simply the scale on the lens ?

can you copy-edit the article ?

I think so, although apparently there used to be aperture plates called 'stops' according to one reference. If we ignore the f-number markings, the f-stops make a logarithmic scale of exposure value. Given this interpretation, you can then think of taking a half-step along this scale, to make an exposure difference of "half a stop". The Anome

Suite or serie ? Which one is correct English ? Ericd

I was wondering the same thing. I.e., it says "geometric series" and I wondered if "geometric sequence" should be used instead. A series is a sum, but many persons not schooled in mathematics use "series" when they ought to use "sequence". -- Mike Hardy

Correct word is "suite" in French. Geometric sequence is more correct ? Ericd

French "suite" corresponds to English "sequence", not to English "series". Mathematical illiterates often write "series" where "series" is wrong and "sequence" is right. -- Mike Hardy

This seems OK now. See Geometric progression Ericd

"Geometric progression" will also serve. -- Mike Hardy

I should probably move these f-stop demonstration pics to a separate page? I think it's useful to see the difference, maybe I'm wrong, but I also think that I should take these off for now because many are still on dialup. Opinions. Koyaanis Qatsi

The images are not too big, so that is OK. They belong in the depth of field article, thouch, I'd say. Puut a good referrence to them in f-number. -- Egil 05:15 Jan 29, 2003 (UTC)

I moved them. Koyaanis Qatsi