I've gotten into daylight infrared photography.

[jon_williams1]

<p>Using a Hoya R72 filter on a Sony DSC-F828 camera, I've recently started taking daylight infrared photos, mostly of trees in nature preserves.</p>

<p>I quickly realized this really needs to be done with a tripod (longer exposure than with visible light), so I was carrying a tripod for several miles on my last hike. It's not the best tripod, but it will have to do for now. Even so, there's still some camera-shake when pressing the shutter-release, so I plan to get the cable-release (wired remote) for this camera. Eventually, I'll get a better tripod that's easier to carry.</p>

<p>I have also been carrying an extra camera to take a visible-light reference image to go with every infrared image. (I don't like to remove the filter outside.) I found it a bit of a pain to have the tripod in one hand and a point-and-shoot camera in the other hand. One thing I'm going to do next time I go out shooting is to make use of a "twin bar" that I've had for several years but never used. (This "twin bar", made by Jasper Engineering, was something I had originally planned to use for 3-D photography. It lets you put two cameras side-by-side on a tripod.) I plan to put the twin bar on the tripod, the Sony on the left, and the reference camera (in this case a very cheap 1.3 MP camera made by Oregon Scientific) on the right.</p>

<p>I've been using the Sony camera in the Raw mode, though so far I have only used the JPEG that it produces alongside each raw file. These images are of course heavy on the magenta, and are supposed to be converted to greyscale and the contrast maximized. So far I've only completed that process with one of the dozens of infrareds I have shot.</p>

<p>Other things I might do later include geotagging (with a beltloop unit, and matching times and locations up later). Also, keeping a big garbage bag in my pocket to cover the whole rig up if there's a surprise rain. And finally, jumping to the other extreme of the light spectrum and trying a filter that admits only ultraviolet light. I understand you can photograph some interesting things (e.g. patterns on flowers that look solid in visible light) in ultraviolet.</p>

 

[jon_williams1]

<p>Oops! I accidentally clicked "Confirm" twice. Didn't mean to double-post.</p>

[Mike Gammill]

<p>The R72 seems to be a good match for most digital cameras. Although I usually convert to grayscale, I've found that I rather like the strange colors that result.</p><div></div>

[aldrich]

<p>Jon,</p>

<p>Please post some shots you get with the R72. I have long wanted one. Ironically, an hour ago I just posted two critique requests on shots I gave a B&W infrared effect in photoshop. It eliminates the need for a tripod because you just can just shoot normally, but I would assume the R72 would blow them out of the water!</p>

<p>--Ryan</p>

[Mike Gammill]

<p>Another filter that will work with some digital cameras is the Lee #87. I think it passes everything beyond 750nm as opposed to 720nm for the R72. Really need a tripod for this one, more so than the R72.</p><div></div>

[jon_williams1]

<p>One of mine, using the Hoya R72 on the Sony DSC-F828, as saved on the camera before any editing, except size reduced for web:<br>

<img src="http://i632.photobucket.com/albums/uu46/jw15973/IR%20sample/DSC09495.jpg" alt="" width="640" height="480" /><br>

<br /></p>

[guendanadxi]

<p>Hi!</p>

<p>The best way to avoid the red cast is to use a custom white balance, You can then adjust the levels swap the red and blue channels and desaturate the foliage... :)<br>

On the left is the original image, on the right the end result.</p><div></div>

[guendanadxi]

<p>sorry posted twice :(</p>

[Jeff Lear]

<p>This is with an R72 on a Canon 20D. I haven't shot IR in a while, is there a solution to the "IR Hotspot"? Or, if there's not a solution, can anyone enlighten me to the cause?</p>

<p><img src="http://i140.photobucket.com/albums/r34/F1Addict/Infrared/IR_Aspens.jpg" alt="" width="400" height="600" /><br>

The tree in the foreground, on the right, is in shadow with just a little sunlight falling on the leaves at the very left of the tree.</p>

[aldrich]

<p>Jeff,</p>

<p>Hmm...I would say the cause is simply the intensity of the sun on the other leaves. Just a guess though...</p>

<p>Maybe ND filter would somewhat help?</p>

<p>--Ryan</p>

[Jeff Lear]

<p>The photo I posted above is not a good example of the "hotspot" phenomenon. This photo <em>is</em>...<br>

<img src="http://i140.photobucket.com/albums/r34/F1Addict/Infrared/IR_hotspot_pns.jpg" alt="" width="600" height="400" /><br>

The sun was at my back and the viewfinder was covered during the 10 second exposure at f/3.5, ISO 100. I blew this out a bit in post to enhance the spot for the purpose of discussion.</p>

[guendanadxi]

<p>I have read that hotspots will depend also on the particular lens that you are using, some lens seem to be more prone to show hotspots and some others are less prone to that... <br>

A good resource on IR and on lens flare with IR photography can be found at:<br>

<a href="http://heim.ifi.uio.no/~gisle/photo/ir.html">http://heim.ifi.uio.no/~gisle/photo/ir.html</a></p>

<p>Hope this helps :)<br>

Luis</p>

[aldrich]

<p>This may sound ridiculously odd, but do you think maybe there is infrared "energy" so to speak, inside the lens? Perhaps it's a glare off one of the elements? That would go with what Luis is saying, and would explain why it's not seen in the scene.</p>

[oskar_ojala]

<p>Hot spots are due interaction of the lens and the sensor, basically flare that doesn't occur with visible light. The only sensible way to get rid of them is to change the lens. Varying the aperture usually helps a bit, though.</p>

[Jeff Lear]

<p>Thanks all. I <em>have</em> noticed that the flare is more apparent on shots taken with the 18-55 kit lens than when using my 50 f/1.4 which were the only two lenses I had with a 58mm filter ring. I've ditched the 20D with the kit lens and now have big fat lenses that require an IR filter larger than I can afford ;) I still have the 50 1.4 though, and have recently inherited an old 28-80 that will work on my 5D so I'll have to do some experimenting. Of course neither of those have an IR focus scale.</p>

<p>In the past I've always shot wide open in an attempt to minimize the already long exposure times, I'll have to try closing it down a bit and live with the 45 second to 1 minute exposures to see how that affects things. I'll let you know what I find.</p>