DMR IR Conversion

[Danno_photoguy]

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I am thinking about having my DMR converted to a digital IR camera (replacemt of the hot mirror).  Has anyone done this?  My concern is maintaining the proper focus as it is a CCD sensor (as opposed to a CMOS), so I can not focus by looking at what the sensor sees.

 

THANKS

Dan

[jaapv]

IR photography has to contend with shifted focus anyway, only TTL viewing can solve that. Focus bracketing is your answer. Many older lenses have a red "IR-dot" on the focus scale. Best bet is to use two stops down on the DOF scale, i.e. the marking for 5.6 on a 2.8 lens. An SLR is a poor choice for IR  photography anyway, the viewfinder will black out by the required lens filter.  I would advise you to get an M8 for IR photography, it does not require a conversion.

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[gbealnz]

All valid points by Jaap, and more so the actual viewing/composing, I've tried it and it's a pain. Far easier with an optical finder (I use my SWC, or M style camera) The M8 is perfect for this, unadulterated, it can be hand-held.

Lastly, I'd not want to bastardize my precious DMR in the first place, certainly not for an I/R conversion.

Gary

[Danno_photoguy]

Thanks to you both for the advice.

[dkCambridgeshire]

DMR has an odd size 26.4 x 17.6mm sensor (1.37 crop factor). Have you checked that the hot mirror is a standard size for which there are IR alternatives available?

Might be more cost effective to buy an IR adapted Canon DSLR which is usable with Leica R lenses via an adapter.

In the UK, Ffordes regularly list secondhand IR converted Canon DSLRs …  

https://www.ffordes.com/search/infra red/   … Ffordes ship to USA and importing to USA from UK would not not incur any customs duty. The bargain price IR converted 10D would be a capable camera for IR imaging … 1.6 crop factor but not compatible with Canon EF-S lenses.  

dunk 

Edited January 19, 2019 by dkCambridgeshire

[TomB_tx]

An IR adapted Sony A7 (Kolari) can adapt R lenses, and the EVF shows you the sensor output as you work.

Edited January 19, 2019 by TomB_tx

[wlaidlaw]

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A second hand M8 which works well for IR photography with no modifications, would be another alternative. You can then use an R adapter M and get camera to lens communication. Of course you would have to scale focus or use modified scale focus (there are downloadable IR correction charts for this) or use RF coupled M lenses. I found that the near visible spectrum IR that the M8 picks up, needs no focus change from standard RF focus. I used a B+W 092 low pass filter. I keep my M8 just for IR nowadays. 

Wilson

[J S H]

IR focus can be very tough to nail, even with the benefit of checking your shots afterwards. Diffraction becomes an issue much earlier in the Infrared wavelengths, so if you stop down past F8, things get soft very quick. This is why scale focusing can be tough. 

If you want to do it right, you'll need a converted camera with live view and ideally an EVF. Sony A7, A7R, A7s and A7II are the best models to look for, as they are reasonably priced and can easily adapt Leica R or M lenses while using the EVF to focus. Anything newer from Sony (A7RII, A7SII, etc) will have PDAF capabilities and will show sensor artifacts in IR. Kolarivision is the best vendor that I have found in the US and I've used about all of them.

[wlaidlaw]

In the UK, my local camera repairer, Kelvin at http://www.protechrepairs.co.uk near Uckfield, East Sussex, does IR conversions on lots of different cameras - see his website. I can thoroughly recommend Kelvin, as any work he has done for me over the last 20 odd years, has been meticulous. 

Wilson