[ixc]

I am looking for some information/tips for getting started in IR photography. Ive seen some amazing photos and would like to try my hand at the technique. The trouble is that through my browsing of the internet, I haven't been able to find a true tutorial or how-to. All of the information I come across is conceptual or explains how it works (buy a digital camera, buy filter, shoot, PP).

Well I have my K100DS and kit lens (18-55) as well as a Hoya R72 filter. All of the photos I have taken are saturated red and I cannot clean it up regardless of how much PP i do.

I have a feeling that my WB is the problem. In an attempt to correct this I put the filter on the camera and tried to do a custom WB off my lawn. The problem is that the custom WB doesnt take. I get an 'N.G.' error.

Can someone point me in the direction of at least getting something that I can work with?

[OregonJim]

You can't get a valid white balance through the filter. You also can't use the meter to calculate exposure. What sort of exposure times have you been using? Usually, you'll need to be in the "several seconds" range. You will always get the red tint unless you physically remove the internal IR blocking filter and replace it with a hot mirror filter (either internally or on the lens). But then your camera will only be good for infrared - no more "normal" pictures. Most people reduce the image to B&W before PP.

[newarts]

The easiest thing to do is to put on the filter, then shoot B&W if your camera will do it, or convert to B&W (see your manual for B&W or Digital Filter) after the shot.

Then apply whatever tinting you like. Picasa is sufficient to convert to B&W & tint.

Sometimes people use an image manipulator like Image J & swap the red & blue channels.

My Pentax K100D will not shoot B&W but the Digital Filter item on the playback menu converts to B&W nicely.

Dave

[Wheatfield]

I am looking for some information/tips for getting started in IR photography. Ive seen some amazing photos and would like to try my hand at the technique. The trouble is that through my browsing of the internet, I haven't been able to find a true tutorial or how-to. All of the information I come across is conceptual or explains how it works (buy a digital camera, buy filter, shoot, PP).

Well I have my K100DS and kit lens (18-55) as well as a Hoya R72 filter. All of the photos I have taken are saturated red and I cannot clean it up regardless of how much PP i do.

I have a feeling that my WB is the problem. In an attempt to correct this I put the filter on the camera and tried to do a custom WB off my lawn. The problem is that the custom WB doesnt take. I get an 'N.G.' error.

Can someone point me in the direction of at least getting something that I can work with?

Try to find an old Canon G1 camera. I did some wonderful IR with one of those.
The problem you are going to have with more modern cameras is that they put IR filters in front of the sensor.
If you realy want to do IR, you need to have a camera that doesn't have the filter in place. This is a fairly expensive and permanent conversion.

[newarts]

A DIY conversion of some P&S cameras is practical. You can just remove the "hot mirror" IR filter. This changes the optical path length but that doesn't matter as auto-focusing takes place on the sensor that records the image.

I've done this with my Fuji F20 and am pleased with the result. I use external UV, VIS (Hot Mirror), and IR filters to select the band I'm shooting. It works well and exposure times for VIS & IR are comparable; there's not much to see in UV.

Iowa Dave

PS Removing the Hot Mirror on a DSLR requires replacing it with a clear sheet of glass the same thickness to prevent focus shift problems.

[ixc]

You can't get a valid white balance through the filter. You also can't use the meter to calculate exposure. What sort of exposure times have you been using? Usually, you'll need to be in the "several seconds" range. You will always get the red tint unless you physically remove the internal IR blocking filter and replace it with a hot mirror filter (either internally or on the lens). But then your camera will only be good for infrared - no more "normal" pictures. Most people reduce the image to B&W before PP.

From browsing over IR threads here I was under the impression that it was possible to simply use the R72 filter. I do not want to go completely IR at this time. Was I wrong?

I have been calculating the exposure by framing the scene and setting the aperature to f8+. I then would change the shutter speed to net me +1 or so exposure. after I had that set, I would slip on the filter and press the shutter release.

Here is an example of what I am getting consistently with this method:


ISO 200, 20mm, 1/4s shutter speed, f11, auto WB.

I came across a blog that had similar issues with the red channel and his solution was to pull a custom WB of green through the IR filter (which prompted my question)

[OregonJim]

From browsing over IR threads here I was under the impression that it was possible to simply use the R72 filter. I do not want to go completely IR at this time. Was I wrong?

I have been calculating the exposure by framing the scene and setting the aperature to f8+. I then would change the shutter speed to net me +1 or so exposure. after I had that set, I would slip on the filter and press the shutter release.

I came across a blog that had similar issues with the red channel and his solution was to pull a custom WB of green through the IR filter (which prompted my question)

Here is a basic reference to get you started.

[newarts]

Here's the result of in-camera B&W conversion with an un-modified K100D; I just put on the filter & shot the photo hand-held using Av mode (no preset focus, etc, just pick up the camera and shoot.)


It might help to add some exposure compensation.

Iowa Dave

[ixc]

Here is a basic reference to get you started.

thanks for this. I just did a quick test shot w/ the following settings:

a. custom WB of grass (non filter)
b. F8
c. 2s exposure time

While the normal preview of the image is pretty washed out, flipping it to BW restores all clarity. This will definitely give me a starting point.

[xs400]

I used my K100D for IR photography a couple of years ago and had pretty good results. I wrote up a description of my post processing technique so I wouldn't forget what i did. If interested, take a look at Frank's Intro to Digital Infrared Photography to see what i did.

Here's an example of what i was able to achieve using the K100D + DA 18-55mm + R72 filter + Photoshop CS2



Frank

[pentkon52]

Try to find an old Canon G1 camera. I did some wonderful IR with one of those.
The problem you are going to have with more modern cameras is that they put IR filters in front of the sensor.
If you realy want to do IR, you need to have a camera that doesn't have the filter in place. This is a fairly expensive and permanent conversion.

I picked up a converted G3 of ebay last year for about $250

Does a great job.

Dave

[RioRico]

Virtually all digicams have sensors that are sensitive to IR. Virtually all have "hot filters" in front of the sensor, to block the IR. There are exceptions. It's common to just mount a 720nm IR filter on an unmodified cam and shoot LOOOOOONG exposures. There are tricks.

Sony "NightShot" cams (video and PNS) have a lever that flips the hot.filter away. But since IR penetrates cotton and Sony doesn't want to be known for making Xray cams, there are severe restrictions on speed and aperture (slow and wide-open only!) built into the cams. The trick: on my 5mp Sony DSC-V1, I use ND and/or IR (780, 900, 930, 1000nm) and/or deep red (#25) filters. These allow handheld daylight work, at about f/2.8-4 and no faster than 1/50 shutter.

(IR filters: the higher the number, the more visible light is blocked. 720nm looks deep red; 1000nm looks black. Low-number filters are easier to use but diminish the IR effect.)

As mentioned, one can buy modified PNS cams on eBay that have the hot.filter removed and replaced either with plain glass of the same thickness, or, more commonly, with a 720nm IR filter. My 5mp Minolta F300 cost about US$300. (More megapickles = more money.) You can do it yourself IF YOU ARE BRAVE. I attempted such surgery on a couple cheap web cams and killed them both. Oops.

If shooting LOOOOOOONG exposures on your dSLR isn't appealing, you can remove and replace the hot.filter, or have it done by someone who knows what they're doing and probably charges above US$500. For any normal-light work with that cam, you'll then need to place an IR-block filter on the lens.

Fuji and Sigma make 'forensic' dSLRs (I think they both take Nikon lenses) where the hot.filter is easily removed and replaced with filters that isolate any portion of the UV-visible-IR spectrum. These are used for criminal and scientific work, and artistry, and aren't hideously expensive, although a full set of filters ain't cheap.

And that's the skinny on commercial-grade IR hardware. Have fun.

[xs400]

If shooting LOOOOOOONG exposures on your dSLR isn't appealing, you can remove and replace the hot.filter,

The K100D is particularly good for IR. With the R72 filter, exposures are longer than regular exposures, but not LOOOOOOOONG. The shot below was shot at 1/8 sec at f/6.7.

[Just1MoreDave]

...I have a feeling that my WB is the problem. In an attempt to correct this I put the filter on the camera and tried to do a custom WB off my lawn. The problem is that the custom WB doesnt take. I get an 'N.G.' error.

Can someone point me in the direction of at least getting something that I can work with?

I know someone else has said you can't do this, but I was able to get the grass thing to work just a few days ago. I think it helped keep the red channel from clipping. It took several tries to get the custom WB to work, and it ended up at 3600ºK. My other idea was to set the WB to tungsten, the closest thing to the 2000ºK I usually end up choosing. That can help when you haven't got green available. I haven't tried this yet. I don't claim to know what I'm doing, but I seem to be getting better.

[OregonJim]

I know someone else has said you can't do this, but I was able to get the grass thing to work just a few days ago. I think it helped keep the red channel from clipping. It took several tries to get the custom WB to work, and it ended up at 3600ºK. My other idea was to set the WB to tungsten, the closest thing to the 2000ºK I usually end up choosing. That can help when you haven't got green available. I haven't tried this yet. I don't claim to know what I'm doing, but I seem to be getting better.

I was the one who said that. To expand a little, the camera is likely to give an "N.G." error ("No Good") when attempting to capture a custom white balance through an IR filter. Having said that, the R72 filter is 'iffy' - since it extends pretty far below IR and into the visible red region, you 'might' be able to get the camera to lock WB if you point at a bright, pure green/blue surface. But any of the higher numbered filters (low pass cutoff above 720nm) will most definately confuse the camera's custom WB. You'll have to set it manually in camera - adjusting in PP won't help as you'll have already blown out the red channel.