Talk:Circle of confusion computation

Comment from article

<this moved here from an HTML comment at the top of the article> -Splash - tk 23:49, 20 October 2006 (UTC)

What follows is a computation of the Circle of confusion in Wiki format using "modern" notation and showing all of the steps.

(NOTE: Some of the symbols may be poorly chosen, as the original author is not intimately familiar with the conventions used in the optics literature. Wiki's are for fixing, right? The author can provide the Visio source for the diagram.)

Why?

I'm unclear on the point of this article. What is the so-called "modern" notation? Why can't this calculation, maybe less belabored, go into one of the existing articles, using notation consistent with them?

It ends up with "This confirms the assertion in the Depth of field entry that the depth of field is a function of the actual aperture size, independent of the sensor size," but I don't find the referenced assertion when I search for "independent" on that page. What exactly was the assertion, and how does the notation of this page confirm it?

Dicklyon 03:00, 11 August 2006 (UTC)

Why not?

I found the JPEG's from 1866 difficult to follow, and I failed to find a clearer derivation after searching the Internet for quite some time. There ought to be a link to something like this from the CoC page; if you have a better reference, then go ahead and change the link. 64.81.245.28 14:35, 11 August 2006 (UTC)

Why not do it up concisely on the COC page, with notation taken from depth of field and/or hyperfocal distance? There's nothing modern about using B for COC diameter. Dicklyon

"This difference between formats goes away if the cameras are compared with equal aperture diameters rather than equal f-numbers" 64.81.245.28 14:35, 11 August 2006 (UTC)

I thought that might be it. I wrote that, in a context where I think it was more clear what was meant. I would never say the DOF is independent of sensor size, though, as it assumes too much about what you mean about the other variables. Dicklyon

I think the last sentence of this article should be removed, because it's at least strongly misleading. I just had a discusson on an other forum, where someone referred to this article's last sentence to "prove" that DOF is in deed independent from format size... Szeder 14:16, 9 October 2006 (UTC)

Well you're right that it's misleading, or even downright wrong. But the whole article is so messed up it's hard to see how to work on it incrementally. I'd start with a new figure... Dicklyon 16:28, 9 October 2006 (UTC)

So I took it ouk. The article is still pretty bogus, with strange terminology, complex equations, and results in a form that is hard to interpret. I'm not even sure it's right, and the approximations certainly limit its domain of applicability. It would be easier to redo using magnification and the blur circle in the field plane, but it would mean starting over with a drawing, new terms, and all new equations. Dicklyon 05:07, 10 October 2006 (UTC)

Recommend for deletion?

I don't think this article can be rescued, or has any point. I intend to recommend it for deletion unless someone objects and volunteers to work on it. Dicklyon 05:12, 10 October 2006 (UTC)

Done. Listed AfD. Dicklyon 04:19, 11 October 2006 (UTC)

• I am in favour of keeping the information. It is useful, but needs more work. --Thorwald 05:01, 11 October 2006 (UTC)

Articles for Deletion debate

This article survived an Articles for Deletion debate. The discussion can be found here. -Splash - tk 23:49, 20 October 2006 (UTC)

Huh? What do you mean by survived? Looks to me like the consensus was delete, but add a bit about it into the other article. Shouldn't we then at least have a merge tag? Dicklyon 00:09, 21 October 2006 (UTC)

OK, since the consensus seems to have been to delete the article but merge its contents into circle of confusion, I did so, with a new diagram and a greatly simplified derivation. Only trouble is that my arrowheads from Inkscape disappeared, so if anyone knows how to fix this, please say so or just do it. Dicklyon 18:42, 22 October 2006 (UTC)

I got the arrowheads back by "stroke to path" conversion. Dicklyon 21:13, 22 October 2006 (UTC)