IR contamination

[F Bulgarelli]

Hello

Has anyone had serious issues with IR contamination using the Epic?

I did a music video and when we got into the color correction stage realized that we could not get enough color saturation out of the images

RED has been looking at the R3D's and seem to think that we had issues with IR

We are still trying to determine the cause and was curious to find out if anyone else had issues like that. Basically, the image looks desaturated and low con, looks like a Raw image (that 's why it slipped thru the cracks) when we got into color correction the timer had to crank up the saturation to 200% in order to get some saturation but not enough to get strong dolors, specially greens

 

any comments or advice are appreciated

 

thx

[Adrian Sierkowski]

Any chance you can post up some stills? Also, where you heavily ND'd, like at a 1.2 or so? If so It could be you had an ND in there w/o the IR cut needed. I can't think of any lighting instruments that'd've caused it, though off hand, but I'm not a 100% expert. I do know when the red first came out, the sensor did have IR issues in daylight with ND, as the chips are more sensitive to ND. IT caused everyone to go with hot mirror filters at first, and eventually Tiffen et al to bring out NDs with a built in IR cut.

 

As for recovering the information; I dunno, but if RED has the files, hopefully they'll pull something out of 'em.

[Keith Walters]

Hello

Has anyone had serious issues with IR contamination using the Epic?

I did a music video and when we got into the color correction stage realized that we could not get enough color saturation out of the images

RED has been looking at the R3D's and seem to think that we had issues with IR

We are still trying to determine the cause and was curious to find out if anyone else had issues like that. Basically, the image looks desaturated and low con, looks like a Raw image (that 's why it slipped thru the cracks) when we got into color correction the timer had to crank up the saturation to 200% in order to get some saturation but not enough to get strong dolors, specially greens

 

any comments or advice are appreciated

 

thx

 

I don't see any reason the Epic would be any different.

This thread illustrates the basic problem: like the dyes in the test tubes, the Bayer colour filters are completely transparent to infrared, so it't basically the same as somebody shinging a white light onto the sensor from inside the lens.

 

You may be able to balance that out in Post, but you're not going to be left with many bits of dynamic range to work with

[F Bulgarelli]

Thanks Adrian

I'm starting to think that that was the problem.

Regardless of what the answer is, I've been shooting RED for a while and never had a problem, maybe there was a funky filter combination that created the problem.

Here is a still

[F Bulgarelli]

Thanks Keith

 

here is the still, I do think that was the problem.

[Adrian Sierkowski]

Not totally unusable.... 'course might not match anything else you have:

 

(5 minutes in photoshop.)

[F Bulgarelli]

yeah, that's about how far we were able to take it,

could not recover much green

[John Sprung]

The IR thing is endemic to all big single chip cameras. We got bit by it on an Alexa once.

 

 

 

 

-- J.S.