Talk:Infrared photography

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[edit] Wood effect

I have no real source (nor expertise) for this other than the memory of a college class I had, but I believe the effect with trees and water is known as the "Wood Effect" after its discoverer, which might be useful info for the article. -152.160.58.186 05:56, 27 November 2006 (UTC)

Good memory. I found it justified via GBS: [1]. Dicklyon 06:24, 27 November 2006 (UTC)

A little more research reveals 'Wood' was Robert W. Wood. See UI there and [[2]] -nbach 07:25, 28 November 2006 (UTC)

AFAIK the earliest relevant paper was presented by Wood to the Royal Photographic Society and published in the October 1910 edition of the Photographic Journal. I have a copy of this via the British Library. The paper also covers ultraviolet and includes some photographic examples to demonstrate both UV and IR. The paper may be the source of the earliest published examples of both as well. Delverie 18:34, 10 February 2007 (UTC)

[edit] "infrared film counters"

The article contains the following nugget: Many film cameras of the 1990s had infrared frame counters and their manuals often prohibited the use of infrared film because the counter could fog it.

What, pray, is an "infrared film counter"?

In the nineties, the main options were 135, 120/220, and sheet film. Of course cameras taking sheet film don't have counters. For 135, for 220, and for all but antique or very retro 120, the counter checks the film (with or without paper backing) going through it; the emulsion is irrelevant. Is this some reference to the orange or red window on the back of an older camera for roll film? -- Hoary 03:03, 27 April 2006 (UTC)

No, I guess the diode pair that counts the holes that pass by when winding the film is meant. --Dschwen 06:56, 27 April 2006 (UTC)

Cameras have diodes that do that? Well well, I sit corrected. (Seems to me that the 35mm cameras I have that lack batteries do the job of advancing film well enough, but perhaps I'm not sufficiently "prosumer".) -- Hoary 07:00, 27 April 2006 (UTC)

Check out this picture:

--Dschwen 07:37, 27 April 2006 (UTC)

It's odd, though. I have an all-electric, nineties Hexar -- I mean, I can't wind the film with my thumb even if I want to -- that has infrared capability as a sales point. It automates focusing for infrared. -- Hoary 10:12, 27 April 2006 (UTC)

Then perhaps you can shoot infrared film in your camera without the sprockets getting fogged. I shot a roll of infrared in an old EOS film camera and the whole lower third of every frame was fogged. ShutterBugTrekker 21:32, 3 May 2006 (UTC)

[edit] Infrared focus

According to the current article, "A sharp infrared photograph can be done with a tripod, a narrow aperture (like f/22) and a slow shutter speed without focus compensation,..." The principle here is that increasing depth of field by stopping down can compensate for the focus shift that results from focusing a non-IR corrected lens in visible light, then shooting in IR -- but one must be careful. Stopping down to f/22 will result in a loss of sharpness from diffraction. Therefore, if the situation permits, a better solution is using a mid-range f-stop, say 5.6., 8, or 11, and making a series of exposures starting with the visible light focus and working through a series of exposures at focus points around the focus point for visible light. If the focus points are marked, the focus point for the sharpest image will serve to calibrate the lens for IR. If the object of the exercise is calibrating the lens for IR, the focus point should be infinity -- a distant skyline works well; so do stars or distant point sources of light. —Preceding unsigned comment added by Pixeljim (talk • contribs) 07:25, 11 September 2007 (UTC)