IR flash: Myth or Miracle?

[peter_sanders2]

<p>Okay; I know both of those are extremes, but it sounded dramatic.</p>

<p>Does this: http://www.flickr.com/photos/matt/collections/72157602656044484/ really work?<br>

As well as they say? On digital?</p>

<p>Please and thank you,<br>

Peter</p>

[bob_sunley]

<p>Xenon flash tubes have a pretty level output from UV to way out in the IR spectrum. Put your had against the lens and pop a full power test. You can feel the IR. :)</p>

<p> </p>

[peter_sanders2]

<p>So:<br>

<strong>A</strong>: it will work on digital (despite the sensor-mounted IR filter)<br>

<strong>B</strong>: it only looses one stop (even though you cut out most of the spectrum! I'm guessing (since the results are in B&W) that the B&W is made from the red channel (y/n))<br>

also, does the idea about unexposed (but developed) E6 film really work?<br>

Thank you for the quick reply.</p>

[mark_sirota1]

<p>The film thing definitely works. I did it before I paid real money for a less goofy-looking solution.</p>

[peter_sanders2]

<p>Thank you; I'll keep that in mind next time I shoot velvia. Probably in a couple of weeks. Does anyone have an answer to the more important questions (on which are resting whether or not I do this project)?<br>

(no offense to Mark)</p>

[peter_sanders2]

<p>Is this an effective response to ~"Ethics of flash photography on nocturnal animals?"</p>

[joseph_wisniewski]

<p>The post you mentioned contains gems like this "Testing focus [use a narrow aperture]" which pretty much shows a lack of knowledge and skill of the subject. Longer wavelengths lead to increased diffraction. Throw in uncorrected focus errors, and you've got a recipe for "soft". Toss in reduced effective power from stopping down too much, and, well...</p>

<blockquote>

<p>Put your had against the lens and pop a full power test. You can feel the IR. :)</p>

</blockquote>

<p>Actually, what you feel is mostly visible light, which is more photokinetic, photoreactive, and photothermal than IR.</p>

<p>Now, as far as "myth or miracle", the real answer is "neither". On average, a small flash IR flash picture looks pretty crappy, and you have to hunt out exceptional subjects to get one. IR penetrates a few dermal layers, and wonderfully illuminates hair that's been shaved to (or even slightly below) the surface of the skin, as well as pooled blood, large veins, etc. It "sees through" makeup. And it sees through clothing a bit. Not enough to be the "x-ray camera" that the popular press calls it, but enough to show seems, bra straps, and other "look bad" stuff.</p>

<p>That's why I don't think there's a shot worth looking at in the "photostream" you linked. The few that come close to succeed do so "in spite of" the IR, not because of it.</p>

[peter_sanders2]

<p>I shoot nature, though. People know that the flash will not kill them, and I can use a regular flash on them. Does that change anything?</p>

[matt_needham]

<p>I've used unexposed but developed E6 as an IR flash filter with both Kodak HIE and a Canon 20D converted to IR. I used a double layer of 120. I can't remember what brand; I got it from the out of date bin. One roll was enough to make all the IR flash filters I've needed over the last decade or so. </p>

<p>For my first flash filter I mounted a double layer of the E6 in an old mini-softbox. More recently I've been using hobby foam to make a form that slides over my speedlights. One concern I've heard, although never noticed any issue myself, is that if fired in rapid succession anything over the flash head could cause overheating. With a double layer of E6 the visible light output looks like a toaster starting to warm up for a split sec. Even in dark clubs people don't see it unless they are looking right into the flash. </p>

<p>My results with Kodak HIE were so so. Mainly because it's so slow. The converted Canon 20D is awesome as the ISO can be cranked enough to get ambient IR in the background. I'm still deciding whether I like shooting people with IR, but it's a fun gizmo.</p>

<p> </p>

[joseph_wisniewski]

<blockquote>

<p>Is this an effective response to ~"Ethics of flash photography on nocturnal animals?"</p>

</blockquote>

<p>No. Most of the pigments that make up an animals markings are partially or fully transparent to IR, so you get very strange, pale animals on pale vegetation. So, if you want pictures of what may or may not have been a juvenile muskrat, and are only interested in what it was eating or where it was burrowing, with no artistic merit, sure...</p>

[jcuknz]

<p>I would point out that true IR does not have a red content. This comes when people use a dark red filter instead of a proper IR filter which cuts out all visible light and gives a B&W result.<br>

Wratten 87 is the Kodak true IR filter in several versions with different cut-offs around 720mu.</p><div></div>

[jcuknz]

<p>My astrominer freind was interested to compare my photo taken at roughly the same time as the local press guy's photo in the paper who had photographed a projected image at the local observatory as IR shows sunspots different from visible light sunspots. Fun eh :-)</p>