Red problem !

Swen Goebbels · March 18th, 2008, 12:31 PM

Sean,

Quote:

I'd be interested to see if this happens in daylight

Yes it happens also in daylight. But when I have seen this on the LCD I thought I did something wrong with the white balance or similar.

Quote:

As I said before, this happened with the F23 when it first came out, and eventually was fixed once Sony admitted it was a processing issue.

I never thought about the idea that Sony will release a camcorder with such a wrong color managment, especially because it looks like not a new problem for them. To test something like this BEFORE they release a camcorder is what they have to do. I can not explain my customers that my "high-end Cine Alta" camcorder can't show correct colors... every 300$ cam you can buy can do it better!

Sean Donnelly · March 18th, 2008, 02:05 PM

Paul, you said that you experienced this with only one subject reading incorrectly? That's starting to sound like an IR problem. Zenes, as I'm looking at your latest round of stills it seems that it is actually not just the bag, it's also the stitching that secures the strap. Another good indication of an IR problem, since the black pigments and dyes used in textiles reflect different amounts of IR light. I hope Sony is listening.

-Sean

Michael Maier · March 18th, 2008, 04:24 PM

Wow, I had no idea this was such a big problem.
Well, will the IR reflecting filter work for sure? Is the Tiffen the only option?
If it will work I will buy one for sure. This is unacceptable. A camera that can't see color properly is as useful as a record player that only plays cassettes.

Sean Donnelly · March 18th, 2008, 07:47 PM

Michael, I feel like you are experiencing a different problem. Is it possible for you to post a still of your problem with the actress' hair? If it is a similar color shift we are seeing here in Zenes' examples that's a good indication that little of this is IR related, but unfortunately I'm starting to doubt that's the case.

-Sean

Michael Maier · March 19th, 2008, 02:07 AM

Hi,

It seems to be the same thing. Somebody from the crew had a black cotton sweater and it showed reddish like the camera bag Zene posted. It seems to be the same thing. You think the hot mirror filter will work? Thanks.

Sean Donnelly · March 19th, 2008, 05:34 AM

In that case I think it will. We should start making some noise to get sony to notice this as well. It's one thing if this happens with a lot of ND in front, but under normal conditions...

-Sean

Paul Kellett · March 19th, 2008, 06:08 AM

I didn't have any filter on.

Paul.

Greg Voevodsky · March 19th, 2008, 12:16 PM

How do Polarizers work with IR - do they reflect when they are on?
I assume that when they are on, they also like NDs too.

Also would a CTB - daylight blue filter - help cut down on IR. One could color correct for in post?

Or... MAYBE, this is why the Sony does NOT have the 5600.. switch!

Would it be better to shoot exterior sunsets, to the blue, to reflect more IR (possibly?!) and then color correct in post??

Zenes Petrusin · March 19th, 2008, 12:32 PM

Greg, polarizer and ND dont cut IR, this filters works only in visible light area. IR contamination can not perfect cut in post or is imposible in post. Maybe IR cut-off/Hot mirror help (if dont change other colours or something else, i read something about hot mirror dont work on wide lens ) or SONY do change in firmware if has error doing this issue.

Matt Davis · March 19th, 2008, 02:11 PM

Quote:

Originally Posted by Sean Donnelly

We should start making some noise to get sony to notice this as well.

If I remember my induction correctly, there was a sage engineer at the BBC who patiently demonstrated why the BBC didn't think the PD150 was Broadcast Quality - he used the remote (an Infra Red remote) and pointed it through the lens.

You could see the IR LED in the viewfinder.

The engineer said that this was a bad thing, but did not elucidate further. This thread has illuminated the drawbacks to Infra Red sensitivity in an ample manner.

Maybe the Z1 design team learned this lesson, but the guys from the Cine Alta Dojo didn't think it would matter (along with the grip offset and the button placement).

Time to order a hot mirror...

Sean Donnelly · March 19th, 2008, 04:17 PM

Just received my EX1. Same problem with black fabrics. I'm going to borrow an IR cut filter tomorrow to see if it makes a difference. If it does, I think sony owes us one. Looks like I need to send it in for vignetting as well...

-Sean

Steve Mullen · March 19th, 2008, 06:00 PM

It's not just an ex1 thing. I remember shooting a wedding in India a year ago with a V1. I looked at a sari -- noted the color -- looked into the lcd -- and it was another color completely. Still good quality, but a different color. I think pure blue turned to magenta, or vice versa.

I suspect that the reason low cost cmos cameras don't show this effect is because they don't have a color-splitter prism. They are single chip cameras with a Bayer filter.

My guess -- the prism/color filter/cmos block responds differentially to the IR that does pass through whatever IR filter the lens has.

I wonder if the F23 processing was "fixed" because it had an error -- or it was "modified" to compensate for the excess red. For example, after a white balance and black balance the camera knows how much total visible light is coming from the scene. When the DSP finds areas that have more red than should be possible (hot areas) -- it assumes the energy is IR and corrects.

I really doubt Sony is going to add this type of correction to the ex1 given it's price-point.

Steven Thomas · March 19th, 2008, 09:24 PM

Well,
What do guys think about this:
http://www.bhphotovideo.com/c/produc...tal_UV_IR.html

Should it do the trick?

Greg Voevodsky · March 19th, 2008, 09:59 PM

Quote:

Originally Posted by Steven Thomas

Well,
What do guys think about this:
http://www.bhphotovideo.com/c/produc...tal_UV_IR.html

Should it do the trick?

I'll let you know, I just ordered the 'thin' version that is in stock.

http://www.bhphotovideo.com/c/produc...tal_UV_IR.html

Also, I too heard the um 'rumor' tiffen will have a nd with ir reflection at NAB to put in your mattebox.

Also, NOTE - tiffen's hot glass reflects and thus has to be the out filter, whereas the 486 obsorbs IR and UV and can be screwed on and be the inner filter - ie - replace your lense protection filter.

David Hadden · March 20th, 2008, 12:12 AM

I'm quite curious to hear about this, because I'm buying in a short time, and if I can run a nice Red Filter over top of this lens and shoot some B&W, I could quite possibly pull some B&W IR Video recording for artsy stuff :)

Dave

March 19th, 2008, 06:08 AM	#37
Paul Kellett Trustee Join Date: Nov 2007 Location: Bristol UK Posts: 1,273	I didn't have any filter on. Paul. __________________ Round 2 GH5,FZ2000

March 19th, 2008, 12:16 PM	#38
Greg Voevodsky Regular Crew Join Date: Sep 2006 Location: Portola Valley Posts: 105	Polas and IR? How do Polarizers work with IR - do they reflect when they are on? I assume that when they are on, they also like NDs too. Also would a CTB - daylight blue filter - help cut down on IR. One could color correct for in post? Or... MAYBE, this is why the Sony does NOT have the 5600.. switch! Would it be better to shoot exterior sunsets, to the blue, to reflect more IR (possibly?!) and then color correct in post??

March 19th, 2008, 06:00 PM	#42
Steve Mullen HDV Cinema Join Date: Feb 2003 Location: Las Vegas Posts: 4,007	It's not just an ex1 thing. I remember shooting a wedding in India a year ago with a V1. I looked at a sari -- noted the color -- looked into the lcd -- and it was another color completely. Still good quality, but a different color. I think pure blue turned to magenta, or vice versa. I suspect that the reason low cost cmos cameras don't show this effect is because they don't have a color-splitter prism. They are single chip cameras with a Bayer filter. My guess -- the prism/color filter/cmos block responds differentially to the IR that does pass through whatever IR filter the lens has. I wonder if the F23 processing was "fixed" because it had an error -- or it was "modified" to compensate for the excess red. For example, after a white balance and black balance the camera knows how much total visible light is coming from the scene. When the DSP finds areas that have more red than should be possible (hot areas) -- it assumes the energy is IR and corrects. I really doubt Sony is going to add this type of correction to the ex1 given it's price-point. __________________ Switcher's Quick Guide to the Avid Media Composer >>> http://home.mindspring.com/~d-v-c

March 18th, 2008, 02:05 PM	#32
Sean Donnelly Regular Crew Join Date: Jan 2008 Location: New York, NY Posts: 188	Paul, you said that you experienced this with only one subject reading incorrectly? That's starting to sound like an IR problem. Zenes, as I'm looking at your latest round of stills it seems that it is actually not just the bag, it's also the stitching that secures the strap. Another good indication of an IR problem, since the black pigments and dyes used in textiles reflect different amounts of IR light. I hope Sony is listening. -Sean

March 18th, 2008, 04:24 PM	#33
Michael Maier Trustee Join Date: Apr 2005 Posts: 1,269	Wow, I had no idea this was such a big problem. Well, will the IR reflecting filter work for sure? Is the Tiffen the only option? If it will work I will buy one for sure. This is unacceptable. A camera that can't see color properly is as useful as a record player that only plays cassettes.

March 18th, 2008, 07:47 PM	#34
Sean Donnelly Regular Crew Join Date: Jan 2008 Location: New York, NY Posts: 188	Michael, I feel like you are experiencing a different problem. Is it possible for you to post a still of your problem with the actress' hair? If it is a similar color shift we are seeing here in Zenes' examples that's a good indication that little of this is IR related, but unfortunately I'm starting to doubt that's the case. -Sean

March 19th, 2008, 02:07 AM	#35
Michael Maier Trustee Join Date: Apr 2005 Posts: 1,269	Hi, It seems to be the same thing. Somebody from the crew had a black cotton sweater and it showed reddish like the camera bag Zene posted. It seems to be the same thing. You think the hot mirror filter will work? Thanks.

March 19th, 2008, 05:34 AM	#36
Sean Donnelly Regular Crew Join Date: Jan 2008 Location: New York, NY Posts: 188	In that case I think it will. We should start making some noise to get sony to notice this as well. It's one thing if this happens with a lot of ND in front, but under normal conditions... -Sean

March 19th, 2008, 12:32 PM	#39
Zenes Petrusin Regular Crew Join Date: Sep 2007 Location: Czech Republic Posts: 52	Greg, polarizer and ND dont cut IR, this filters works only in visible light area. IR contamination can not perfect cut in post or is imposible in post. Maybe IR cut-off/Hot mirror help (if dont change other colours or something else, i read something about hot mirror dont work on wide lens ) or SONY do change in firmware if has error doing this issue.

March 19th, 2008, 04:17 PM	#41
Sean Donnelly Regular Crew Join Date: Jan 2008 Location: New York, NY Posts: 188	Just received my EX1. Same problem with black fabrics. I'm going to borrow an IR cut filter tomorrow to see if it makes a difference. If it does, I think sony owes us one. Looks like I need to send it in for vignetting as well... -Sean

March 19th, 2008, 09:24 PM	#43
Steven Thomas Trustee Join Date: Sep 2005 Location: Gilbert, AZ Posts: 1,896	Well, What do guys think about this: http://www.bhphotovideo.com/c/produc...tal_UV_IR.html Should it do the trick?

March 20th, 2008, 12:12 AM	#45
David Hadden Regular Crew Join Date: Sep 2007 Location: Fargo, ND Posts: 149	I'm quite curious to hear about this, because I'm buying in a short time, and if I can run a nice Red Filter over top of this lens and shoot some B&W, I could quite possibly pull some B&W IR Video recording for artsy stuff :) Dave