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11-07-2015, 04:30 AM   #1
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K-30 full spectrum conversion

I have an option of buying a cheap k-30 that has apeture drive issues. Would this make a good camera for full spectrum conversion? Has anyone removed the IR filter themselves? Would the apeture drive problem effect performance once converted (infrared and astrophotograghy)?

11-07-2015, 05:38 AM   #2
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Maybe worht at shot if you are getting it for under $50, but eventually the aperture may never open.
11-07-2015, 07:51 AM - 1 Like   #3
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QuoteOriginally posted by ramseybuckeye Quote
Maybe worht at shot if you are getting it for under $50, but eventually the aperture may never open.
It would make a fine m42 camera. Those lenses don't rely on the camera for their aperture control.
11-07-2015, 08:43 AM   #4
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taking one down to the sensor is not an easy task. requires a quiet place and a lot of mental stamina. and why not also repair the aperture why youre in there?

11-07-2015, 09:47 AM   #5
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There are some places where they offer this conversion, for a fee. I think it is more than just removing a filter - you need to add another filter of equal thickness, if I remember right, for the sensor to correctly capture photos.
If you are planning on using only manual lenses (which is not bad, since those have IR focus mark), then you can probably just go full manual and not care about the aperture mechanism. Just get lenses that have manual aperture iris (m42 or those dead K-mount lenses like Mitakon). I think there is also a thread about which old manual lenses work well for IR photography. Then again, this thread may be on another forum, like the MF lenses forum.
11-07-2015, 10:42 AM   #6
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I've done full spectrum conversion with my Canon 700. This was not too hard and I had nothing to solder. But I would never do it on my Pentax.
Here is an very good video where you can get an idea of the conversion of an Canon.


EDIT.: If you apply for an conversion at "Spencers Camera" I would recommend to think twice... They did conversion of my K5. It was working but not very cheap, quite a lot of import tax and a looooooooot of time.
11-07-2015, 12:24 PM   #7
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QuoteOriginally posted by dasPaul Quote
I've done full spectrum conversion with my Canon 700. This was not too hard and I had nothing to solder. But I would never do it on my Pentax.
Here is an very good video where you can get an idea of the conversion of an Canon.

Canon T4i (650D) DSLR Camera Modification Instructions for Astro & Infrared Imaging - YouTube

EDIT.: If you apply for an conversion at "Spencers Camera" I would recommend to think twice... They did conversion of my K5. It was working but not very cheap, quite a lot of import tax and a looooooooot of time.
Note that the Canon T4i (in the video) is not a weather-sealed DSLR, and therefore much easier to re-assemble. Weather-sealing post-operation, in my opinion, is always compromised and not as tight as from the factory. So if you're willing to use the K-30 with the assumption it is no-longer truly weather-sealed, that could work.
11-07-2015, 12:39 PM   #8
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Adding a filter I thought was only needed for non-full spectrum conversion. It is the right thing to do if you want it only shots since the alternative is focus and compose and the add lens mounted filter.

11-08-2015, 02:28 AM   #9
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The problem is the focus from the sensor to the first glass element of the lens. If you remove the IR-CUT filter for full spectrum you need to replace it with clear glass with the exact refractive index plus some adjustments to compensate the different wave length into the NIR area. I think this cant be simply done by adding a filter in front of the lens.
Further if you also want to go back to normal VIS shooting with your fullspectrum it might not be enough to just add an Hotmirror/IR-Cut Filter in front of the Lens. If you shoot wideangle or something below ~25mm you will notice strong color vignetting in the images, as I encounterd with my converted K5. This is because the coating of the hot-mirror works angle-dependend. This problem is known to a lot of Hotmirror-Filters. Canon has the advantage of simple clip filters which are placed directly over the sensor. I have not seen something simmilar for Pentax.
11-08-2015, 07:34 AM   #10
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Whether converting to full-spectrum or a specific wavelength of IR, the layer in front of the sensor has to be replaced, not just removed. Its thickness is included in the equation.

If you convert to a specific wavelength of IR, you're stuck with that wavelength. This isn't as bad as it sounds. After trying various filters, I almost always use 720nM.

If you convert to full-spectrum, you will need to purchase separate IR filters for the lens you want to use. These filters are not always of the highest density. I usually had to use two filters instead of one to get the density I needed.

If you have converted to full spectrum and you want to photograph only the visible light spectrum, add the appropriate amount of IR-Cut filter to the front of the lens. For my Nikon D70, that was two 67mm Heliopan UV-IR Cut filters (and a bit of color-balance in PP). These cost about $200 each. The cost of the filter to convert the D70 was about $120. Thinking about it now, it would be cheaper to use a second non-converted camera for VLS.
11-13-2015, 07:36 PM   #11
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"It would make a fine m42 camera."

Thanks, that was what I was wondering about.

"why not also repair the aperture why youre in there?"

Good idea, but apparently the more modern DSLRs with shake reduction/sensor cleaning are much more difficult to mod. I think replacing the IR filter with optically neutral glass and putting it back together will be challenging enough

Loosing weather sealing effectiveness is not something I had considered, but its not too big a deal, as the apeture issues mean I would be using older (non WR) manual lenses.

The main problem I see with this plan now is finding a service manual for the k30.

"taking one down to the sensor is not an easy task."
jkomp316,
Have you done a conversion yourself?
11-13-2015, 11:55 PM   #12
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I question the whole "distance from rear element" thing. IR field comes into focus before primary colors on most lenses. I would be adjusting the lens to focus beyond infinity and find where it is myself. It will change after mod with or without replaced glass.
11-14-2015, 04:21 PM   #13
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QuoteOriginally posted by jkomp316 Quote
I question the whole "distance from rear element" thing. IR field comes into focus before primary colors on most lenses. I would be adjusting the lens to focus beyond infinity and find where it is myself. It will change after mod with or without replaced glass.
If you look on a manual lens with IR markings you will see that you always adjust it to be shorter focus than visible light ( which it sounds like you understand ) what is it you are saying? Are you saying that since you have more focus throw available the extra layer of glass is not needed if you focus father than normal? I'm a bit lost as to what you are trying to communicate.
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