EX InfraRed Contamination Fix?

GuyB

GuyB

Well-known member
I have been hit pretty bad recently but IR contamination when filming a number of dance concerts. This is crazy for a camera like this to have such a big problem, I may wait till the off season and send it in under warranty... How can such clearly obvious black looks so muddy brown? It just looks puke with certain materials.

Anyway, in the mean time, are any of the IR filters out there the holy grail yet or the EX1 stock lens (no WA). I have read about a few over the last few months but there are always some issues with green contamination at the edges or just not being effective enough etc

I will begrudgingly buy one, but I only want to buy one, I'd rather spend more now and get the right one than have to just buy another.

Anyone? (hopefully thanks)
 
These two images show it pretty clearly.

In the first image the man's costume was as black as his shoes

In the second image with 5 kids, you can see the black material in the girls costumes is captured as a muddy red/brown yet the pants on the boy in the back right is captured as black. All costumes were black in those parts.

PS: All I have done is:
1: Capture a frame from Clip Browser (footage is SP to it is anamorphic)
2: In photoshop applied a deinterlace, then reduced by 50% using nearest neighbour and saved as jpg

The colours look identical to the original bmps on my screen.
 

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I tried to correct it with Photoshops curves by making the reds on the dark side darker.
 

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Sony does not have a fix for this.
This can be a problem under tungsten lighting.

Many have not complained about this.
If you search the "other" forum, there is a thread regarding using IR cut filters.
 
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Stevet said:
Many have not complained about this.
Click to expand...

I know I don't often see it except at concerts. The other place I do see it a bit however is when covering the 'grooms' house in wedding preperation. Often inside under tungsten lights the suits can go muddy leaving those shinny lapels black, looks garbage.

I know Sony don't have a fix, but they really need one. Even my HC7 generates better blacks in these conditions (which are not exactly challenging).

I followed that thread but there didn't seem to be any specific outcome.
 
GuyB said:
I followed that thread but there didn't seem to be any specific outcome.
Click to expand...

True, this is why I'm waiting for the final best IR-CUT filter solution.
I'm going to reignite this thread.
 
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I'd pay $410 for a 77mm filter which got rid of this problem and didn't cause any other noticable image changes (like green edges). I guess, at least in concerts, you aren't generally at the wide end of the lens so the green issue may not be a real factor to be concerned with.

Let me know how you go Steve.
 
GuyB said:
I'd pay $410 for a 77mm filter which got rid of this problem and didn't cause any other noticable image changes (like green edges). I guess, at least in concerts, you aren't generally at the wide end of the lens so the green issue may not be a real factor to be concerned with.

Let me know how you go Steve.
Click to expand...

I thought that green issue from that particular IR-CUT filter was at the widest end of the lens?
 
I don't have a matte box and would really like to avoid all that extra size and mass at the front of the camera at the moment. They look cool though.
 
sony will not fix this, I've spoken with one of the ex1's creators at IBC (with a translator of course ;) and they told me to get this image quality on a camera at this price they had to make some sacrifices. So who has tried and tested a working IR filter so far?
 
where did you buy the filter, and what on earth is ir contamination? why is this camera outputting brown instead of real black.
 
We cannot see infrared light. But cameras are sensitive enough to pick it up. Because of it's wavelength, it shows up as "red" and it especially shows up in lighting that is "hot". So daylight it's not much of a problem. But hot stage lighting can be an issue. You'll see it in the blacks because you are aware that there should be NO color there at all. So it's quite obvious.

Typically, manufacturers filter it well, but that costs money to do, and decreases the sensitivity of the camera. Sony, for whatever reason, didn't filter it as much in this camera as some others. Thus it falls to the user to increase the filtration. The filters can be had at any place that sells camera filters. This is not unique to the EXx series as these filters have been made a long time for various optics.

Frankly, I am somewhat please Sony made this compromise. I get more sensitivity when shooting under daylight, or daylight balanced conditions. And I get to simply add my own filter when it's required.

Make sense?
 
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