A bit of fun with a recently converted full-spectrum body

I owned an old Pentax K-5 which I had converted to 630nm IR and now I took it one step further with a full-spectrum K-3. Converting IR with Darktable and processing with Gimp/GMIC as well as Digikam. Watch out: a lot of images! But ask me anything about various IR conversion techniques and I’ll answer as best as I can.


Nice. I like that they use the IR subtly (apart from the last one, which is more artistic)

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Sorry but if you don’t mind me asking: who are “they”?

The pics. But obv I meant you


Thanks for a set of very interesting images … could you explain what mods you needed to do to your system?

Mods to my system? I’m not sure I understand what you mean by that? I use the same computer and the same software I use on regular images. I’m sorry for being a bit dense but can you elaborate on your uestion a bit further?

What changes were made to the camera

Aha, sorry for misunderstanding! I sent my camera off to have the hot-mirror filter (which sits on top of the sensor and usually filters out unwanted light such as near-infrared) removed and replaced by a 280nm glass which lets all of the light through. Once that happens, you can use either lens filters or clip-in filters of various wavelength cut-offs to capture infrared images.

You can read about the process here on the website of the company which did my conversion for me.

And here is a chart showing the impact of the sensor filter removal and addition of other wavelengths:

Where on the left axis you have the various sensor/filter setups and on the horizontal axis the outcome under different camera settings. The second column “channels swapped” refers to the fact you can often achieve various results by using a red/blue channel swap in the post-processing software - preferrably when converting from a raw file. There are other channel swapping configurations such as “RB - G split”, “GB” etc. all with different outcomes.

I mostly use a straight RB swap on shots taken with a 630nm and 720nm infrared filter and “RB - G split” on 550nm and 590nm shots.

You can ever only use infrared filters with a higher wavelength cutoff than the sensor filter. As I selected to have the lowest cutoff filter possible, 280nm which often called “full-spectrum” as it lets almost everything through, I can now use screw-in filters with varying wavelengths on my lenses to get a wide variety of effects.

When I started out experimenting with infrared, I wrote a few blogposts about it on my own blog here:


Looks really interesting. Thanks for the info

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