K20D modified for IR - first shots

Yesterday I received a K20D and proceeded with some trepidation to take it to bits and replace the IR-blocking filter on the sensor with an IR-passing one. It was dark by the time I put it together, but today after a quick tweak to the position of the sensor to suit the peculiar IR characteristics of the Sigma 10-20mm I went out and took a few shots to test focus and exposure. All these are on the Sigma in manual focus via the viewfinder (effectively at the infinity mark) and ISO 200, exposures varying between 1/30th and 1/90th at f/6.7.

The adjusted AF is accurate with the kit lens, but not at all with the Sigma hence the manual focus.

Not my most artistic, but they give an idea of what it is capable of.

That may or not be true, but they certainly impress me.

regards
Bernard

Thank you. They were supposed to be test shots, but I can't bring myself not to look for something worth taking

Incidentally, the extra pixels of the K20D allows much more cropping if necessary. This is a cropped version of no. 3:




and this is a 100% crop showing the distant headstones (illustrating that the sensor position appears to be exactly right for the Sigma infinity marker - looks like I'll need to focus more carefully!)

Beautiful photos! It gives off the vibe that this is what we'll be seeing during astral projection! May I ask how the process was, and how much it cost you? Cheers!

Not so sure about the astral projection part - although I see what you mean!

I've written a couple of articles on IR which hopefully will be up for those of you with Plus membership to read before long.

The process is as follows:

1. Take a fairly expensive camera body with a large number of delicate ribbon cables, tiny soldered joints and meticulously-calibrated optical parts, and take it to bits until you get to the very core of the camera - the sensor. Try to remember what connects to what. Discharge the flash circuitry using a resistor, not your hand.
2. Remove the sensor and separate the IR-blocking filter that is attached to the front of it.
3. Get a 28x22mm piece of Schott optical glass that blocks wavelengths shorter than 830 nanometres, clean everything and attach this new filter to the front of the sensor.
4. Depending on belief system make various promises and/or penances to various deities. This includes the gods of soldering and ribbon cable seating.
5. Alter the sensor position by a fraction of a millimetre to allow for the different focussing point of IR light.
6. As Haynes manuals tend to say - 'assembly is the reverse of disassembly'.
7. Run the camera in debug mode and calibrate the AF. The kit lens on this one is spot-on at +400 micrometres.

Hardware cost is about £45 for the Schott glass. The main issue is the risk of the procedure, and the time taken to deal with 36 screws of different sizes and 21 solder joints in very awkward places.

I was just about to ask about the procedure... gulp!

Looks like a first class conversion, with excellent results.

I have an *istDS that I was going to convert, but too expensive, then the DIY route was too scary , especially with shaky hands, so I bought an R72 Hoya filter instead, easy option .

Look forward to reading your full article, once it's up.

The *ist series and Samsung equivalents are a lot simpler than the later bodies, but as you've found they are also much more capable of being used with an external IR filter than the later ones (due to their very weak blocking filter).

I'm not going to offer to convert anybody's camera due to the risk of problems. However, in a while I may be able to sell the GX1L that I've been using for a lot of shots on here, perhaps with a similar body traded in as part of the deal. Then the trade-in body could be converted and so on for the next one. Nobody would risk their own camera, since they'd always be getting a fully-tested one of the same general type. I am now familiar with the *ist DS, DL, DL2 and Samsung equivalents, K20D/GX20 (and therefore K10D/GX10 is probably almost the same) and K-m.

I'm toying with the idea of doing a K-7, but I'm not sure I can justify the risk. A really battered and bruised K-7 with high shutter count and cosmetic damage would be ideal for a first attempt...

Does an exchange scheme for conversions sound like something people might be interested in?

Seems like you have a new business in the making here, Personally I do not "get" IR but am sure lots of folks would like to try it.

karma mechanic.com has a nice ring to it.

Davex

Yes, me too.

It's this bit that made me laugh, at my own complete technical illiteracy on this subject...

Eh?

I'm happy to clean a sensor with a wet swab, but that really is my limit.

Fantastic results there. I particularly liked the cropped version of 3.

I'm glad it's found a very worthy home!

Taken already I'm afraid. I could get the .co.uk though...

I didn't want to have to tell you I'd broken your camera, so I made sure it worked

Hey, it was no longer my camera the moment you bought it. But still...I'm glad it did work out well as it would be a crying shame otherwise.

Great shots there, Richard, and I hope you still want to let me trade in the IR *ist DL for it! I have sent you an email....

That third shot is amazing..

Hmmm... I'm really liking this camera - are you sure you want it?
Like your new avatar too!

I've a K20d that isn't getting a lot of use currently hat'd I'd love to do (pay for) this conversion on but wouldn't be sure about an exchange scheme. Would the shutter count variation not be an issue?