Infrared light leak via internal LED with RF lenses

[chriswellerfoto]

Hello!  

I have been exploring the world of infrared photography with the use of an older 720nm converted Canon DSLR and am looking to update to a new converted mirrorless camera so that I may use my growing collection of RF lenses and consolidate gear. 

Unfortunately, it seems most modern RF lenses use an internal infrared LED light as part of their operation (well documented here:  https://kolarivision.com/canon-mirrorless-rf-lens-internal-infrared-led-fact-or-fiction/ ) This LED leaves large light leak/lens flares if the image has relatively long shutter speeds, so usage would be limited to handheld speeds only.  

Obviously I can use older EF glass on a modern RF camera to solve the issue, but that defeats one of the large points of upgrading (other than proper autofocus and image quality, of course).

Is there any way to disable this light via modern firmware updates?  Or is there a roadmap to potentially solving this (albeit niche) issue? Thanks all. 

[kvbarkley]

We are just users. We have no idea about this. Send Canon feedback. On the Canon usa home page at the bottom look for the little '+'

[chriswellerfoto]

Thanks for the reply, kvbarkley.  I'll send them the feedback, but am also curious to hear from the user base since camera modifications (like infrared conversion) are typically not supported, and sometimes alternative solutions can come up.  

[ebiggs1]

Does Canon claim that their RF lenses are currently designed for IR usage? I have no idea. If it is an internal LED it is not a light leak. As to the chance of a FW upgrade to turn it off, I seriously doubt you will see that.

[chriswellerfoto]

Canon doesn't explicitly say its lenses are designed for IR usage, and you're right that technically the LED isn't a light leak--I use that terminology for ease of explaining the flare effect that appears.  I'm not holding my breath for a fw update to allow for an "infrared mode" that disables those lights, but am hopeful that I'm not the only one in the community that has worked around this issue.  

[kvbarkley]

I'll bet you are the only one, it has never come up before.

[chriswellerfoto]

*cue sad trombone* definitely a niche area.  a boy can dream tho!

[justadude · Accepted solution]

I think this only applies to some of the RF lenses.  While I still do use EF lenses on my R8 (which has been converted to Full Spectrum), I also use a few RF lenses.  Most are handheld shots - I'm so glad that I don't have to rely on the tripod anymore for EVERY infrared photo, like in the old days... but I do occasionally like the long exposure IR images.

So ignoring anything I took on the R8 with EF glass, let me share 4 shots taken with RF glass.  

RF 50mm F/1.8
* 590nm filter - The yellow dune grass on the Lake Michigan shore was taken with a fast exposure of 1/600.  If there are IR light leaks with this lens, they do not show on fast exposures.
* IR Chrome filter - The orange grass and single tree on the Lake Michigan shore with a slow exposure of 25 seconds.  No visible light leaks.

RF 24-105mm F/4-7.1 (which is supposed to be a poor performer for infrared)
* IR Chrome filter - Red trees, channel connecting two small lakes with a fast exposure of 1/400, no light leaks.
* 850nm filter - Black & white photo, where I used a 15 second exposure.  Again, no light leaks.

I'm not saying all of the RF lenses will work as well.  Occasionally I get hot spots with the 24-105 (but never with the 50mm).  Usually these hot spots are an easy fix with a gradient mask, but not always.  Then again, I would get hot spots with my older Canon DSLRs, and still do with infrared film photography at times.  It's the nature of this type of photography.  At least with the digital you can immediatley reshoot if you get leaks, flares, etc.  With the film, you don't know until you develop it.

I'm far from the only person shooting infrared photography with Canon mirrorless and RF lenses.  

[chriswellerfoto]

Hey Gary, thanks for the reply (and excellent images, as well!)  You've given me a lot more confidence in being able to work handheld with the glass I have (which includes that same 50mm).  It seems like most of the issues are longer exposure, which I don't tend to shoot as often and will plan accordingly with some of my EF lenses. 

On a side note, that chrome filter is really something!  I've ordered a full-spectrum converted Canon RP, and will consider getting a filter for that.  Thanks for the help!

[justadude]

Glad I could be of help.  Enjoy shooting infrared!  It's challenging and fun.