[Avantphoto]

Ok so I removed the hot filter from my recently purchased K100D. I only have a 18-250 to test it with, everything works fine, but the 18-250 won't focus to infinity in IR and I didn't replace the filter with anything yet.

This isn't for the non electronic savvy to do either, I had to unsolder 4 wires to remove the circuit board that is in front of the sensor, it's not hard to do but there is plenty of places to mess something up.

Here are a couple first pics.

And i've added a couple RAWs for download: http://home.comcast.net/~starfire1010/ir.zip

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Last edited by Avantphoto; 07-28-2008 at 03:35 PM.

[George Lama]

Stunning images to say the least. That second one, the leaves... wow.

[Peter Zack]

Straight out of the camera? No IR filter required? So how much are you going to charge for the service. cool shots.

[heatherslightbox]

Those are great!

I see a small business idea here. Since there are so few people who do IR conversions for Pentax bodies, then I don't think you'd be hurting for business.

Heather

[frank]

Straight out of the camera? No IR filter required? So how much are you going to charge for the service. cool shots.

I'm guessing an IR filter is still needed in this case, otherwise you won't be able to take IR photos even w/ the IR hotfilter removed

Nice cool shots indeed. But it'd be even better if an IR filter being put in place where the hot filter locates This way you won't need an IR filter infront of a lens to take IR photos.

[frank]

Nice cool shots again. But in my own experience, the DA18-250 isn't the best lens for IR. It'd cost hot spots sometimes. The most IR friendly lens is the 18-55 kit lens (I or II).

[Avantphoto]

Yes that is with a filter on the front, that's the Tiffen #87 filter. I will probably do as suggested and place a filter where the original hot filter went as now you can't see though the VF, metering is also off so maybe that will help that, though IR might meter different. I'll let you all know how it comes out.

I've read the kit lens is the best also, too bad I sold mine, I'll have to pick one up.

[Peter Zack]

I czn understand the Metering and AF being off since IR is a different wavelength and the camera was never calibrated for that. Why can't you see through the VF? Filter density? The light comes through the lens to the mirror and then the VF. I know the IR's are very dark but wouldn't you put that on after composing and focus for the shot. Is it just that the IR filter is too dark to see through?

[alohadave]

I czn understand the Metering and AF being off since IR is a different wavelength and the camera was never calibrated for that. Why can't you see through the VF? Filter density? The light comes through the lens to the mirror and then the VF. I know the IR's are very dark but wouldn't you put that on after composing and focus for the shot. Is it just that the IR filter is too dark to see through?

You cannot see through an IR filter. So you would either have to guess at where you are pointing the camera, or compose and replace the filter. If you are going to remove the filter every time, you may as well leave the hot mirror in place and use a tripod.

This mod allows handheld IR shots, without needing a tripod.

[Avantphoto]

Correct, I believe the exposure on those was about 1/125@F8 so quite fast, and I plan on getting a different filter as I believe the Tiffen #87 is more selective on light transmission then the Hoya RM72.

I guess I'd be willing to attempt this for others if they wanted it, but it would be "Convert at your own risk!" Since K100, and ist's are getting so cheap to buy second hand I considered it to be a worthy investment and trial. Like I said it's not for the faint at heart, Pentax's design on the circuit board is odd that it cannot be removed without some desoldering. Also be careful of the flash capacitor, I found that out the hard way (Not that I didn't know but it seems easier to reach then I though, shocking to say the least!)

I'll post a raw later today for those that want to play with one to see what it's like. Those pics I posted have had some PS work done including the ever known Red/Blue swap.

[cornishk100duser]

I am in the process of having my K100d converted. I hope my IQ is as good as those from yours. I have a converted Fuji (by max Max) and the noise levels are extremely high (lowest iso I can do is 400).
Good shots, cannot wait to get mine back from conversion.

[Moo]

You cannot see through an IR filter. So you would either have to guess at where you are pointing the camera, or compose and replace the filter. If you are going to remove the filter every time, you may as well leave the hot mirror in place and use a tripod.

This mod allows handheld IR shots, without needing a tripod.

Unless you cut the IR filter to the size of the old hot filter, and put it in as a replacement.. That way the sensor would be IR-only but the viewfinder would still be as normal.. With live view this could be even more verstatile..

[pentkon52]

Just for comparison, here is a shot from last month, taken with a Canon G3 converted. Cut filter removed, and a R72 type filter added.


g3_ir-1436 on Flickr - Photo Sharing!

Just a smidgen of LR adjustments. I think i needed to bump the exposure up about 1/2 a stop. Shot in B&W mode. If using the live view, you can see what your photo will look like before you shoot. Very helpful in setting up for shadow effects, etc.

ISO 200 at F8, shutter some were around 1/500 -----I think-----

Dave

[Avantphoto]

OK here is a link to both a converted K100D shot in IR and also a K20D without any conversion. You can see the difference in shutter speed, the K20D is VERY restrictive to IR.

This is a 19meg zip file with both shots in RAW: http://home.comcast.net/~starfire1010/ir.zip

[DavidC]

My daughter Josie is very keen on IR.
She had been experimenting using a R72 on her Pentax K100D - and liked it enough to want to try with a modded cam.

So she recently used most of her savings to buy a second K100D...

Since we did not have any luck finding a local servicer willing to do a Pentax conversion, Josie has started dismantling the camera, with the intention of removing the IR blocking filter herself.

At the moment, she is thinking of asking a glass-cutter to cut a Hoya R72 filter down to size, to use for the internal IR replacement.

But if anyone is aware of places that sell custom-made (720nm) internal IR filters suitable for the K100D, that would be helpful...

Also, from those who have already attempted this tricky process, any further advice you have on possible pitfalls we should avoid while dismantling the camera and replacing the internal filter would be much appreciated!

Thanks,
David C.