XP-1 and Infrared - Quick Experiment

[Benjamin Marks]

I was interested in how much IR was hitting the XP-1 sensor and whether a good IR image could be easily gotten from the camera. Answer: yes (no modification of the camera needed, can use readily available IR pass filters) and no (focusing must be calculated, hyperfocal or guessed).

Lens: 35/3.5 Summaron w/B&W 093 IR pass filter, mounted with one of Stephen's Rayqual adapters and a Milch LTM-to-M adapter. F:5.6, lens set at hyperfocal distance. Get that? It is zone focused - no manual focus available because no visible light is hitting the sensor. Camera set to ISO 640 exposure set to 'A". Camera on tripod. Exposures were in the neighborhood of 10 secs. RAW images are intensely magenta, imported into LR4 with default settings and then exported into SilverFX Pro2. The result is a pretty flat B&W file. Exposure and contrast sliders adjusted to a pleasing contrast and then exported as a small jpg using LR4. The TIFF file produced by LR4 for editing in SFX Pro is 72 MB as a 16 bit RGB TIFF file. Here are the driveway and the crown of our oak tree. Taken today November 14, 2012 - ambient temperature around 38F/3.3C.

Ben Marks

End result: For me, it is definitely worth exploring more with this. I can use the IR pass filters that I originally bought to use on my Leica M8 (now sold). Dark skies: here I come.

 

[GaryLH]

Yep I tried this as well... But I really like the xp1 ir conversion Kerry had done to his xp1 by maxmax.com.. Check this post out. I am thinking about eventually doing this as well.

http://www.rangefinderforum.com/forums/showpost.php?p=1987302&postcount=279

Look at the flickr post from that posting. He ordered the 715 conversion.

Gary

 

[Jamie Pillers]

Ben, thanks a lot for posting this. Your images are as close to IR as I'd ever need. Great to know that no camera modification is needed... VERY cool!

 

[Benjamin Marks]

Jamie: You are most welcome.

Gary: yeah, I saw that thread. In fact your back-and-forth on that thread is what inspired me to slap the 093 pass filter on there and have at it. In my case IR is less than 1 percent of the photography I do -- so I was looking for options that did not involve surgery to the camera. The downside of this method is a serious loss of "chip speed" with the IR pass filter attached -- these shots were f:5.6 at about 10 seconds -- about fifteen stops less than the metered amount of visible light. A tripod would be a necessity, I think, for even casual shots.

 

[willie_901]

It's good to know exposure was 10 sec. There won't be much IR contamination at shutter speeds used to record visible light.

 

[GaryLH]

Glad I could help get u going into ir photography, Benjamin 😀

Gary