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-   Sony XDCAM EX Pro Handhelds (https://www.dvinfo.net/forum/sony-xdcam-ex-pro-handhelds/)
-   -   Red problem ! (https://www.dvinfo.net/forum/sony-xdcam-ex-pro-handhelds/117058-red-problem.html)

Piotr Wozniacki April 5th, 2008 03:19 AM
Quote:
Originally Posted by Leonard Levy (Post 854711)
In Adam Wilt's test he saw this on both the F-23 and the Ex-1.

Can I put the 486 over my Ex-1 lens then add a 35mm adapter over it, or do I always want the 486 to be on the front?
I second that question!

Also, I believe Sean is right - we should all complain to Sony about the red problem; realy don't see a reason for $200 expenditure and hassle with additional filter just to get right colours from a CineAlta, "professional" camera...

Don Deignan April 5th, 2008 07:55 AM
Quote:
Originally Posted by Piotr Wozniacki (Post 854714)
I second that question!

Also, I believe Sean is right - we should all complain to Sony about the red problem; realy don't see a reason for $200 expenditure and hassle with additional filter just to get right colours from a CineAlta, "professional" camera...
Is my problem the same? My reds are too orange. When I put up my color bars my red bar is orange. I take a cherry red jacket and I can not get the color right unless I color correct. This turns my orange colors pink. I am getting much better reds with my Canon A1. What can I do?

Don Deignan

Sean Donnelly April 5th, 2008 09:39 AM
that sounds different. This problem is really only visible on black subjects with certain dyes in them that reflect IR light. Sounds like a processing problem, although I don't think it's related to this. It does seem like it is a processing problem, and we should start a new thread about it so as not to hijack this one.

-Sean

Graeme Fullick April 8th, 2008 06:07 AM
Quote:
Originally Posted by Brian Carrell (Post 843188)
I have a 77mm B+W 486 IR Cut (blocking) filter, I can't remember who else makes them (at the time I was looking for this solution, all I could find in the States, was this filter by B+W, which I got from B&H)

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

I'm wondering if this is how this particular sensor reacts to differing wavelengths. As I did not encounter this with my Canon XHA1 or older Sony DV camcorders.

Outdoor use in San Diego, I can't see much noticeable difference. Outdoor use when I was up north closer to the Arctic in Canada, I really could see a difference, especially in Reds, Greens and Blacks. I manually white balanced and included a white/gray reference in the beginning of each shot, so I know the balance was correct. I also noticed a difference in this situation with my Canon HV20 as well as the PMW-EX1.

Then indoors under various types of indoor lighting I started noticing this effect as well by using and not using the filter, which varied under different types of lighting. Again this effect is stronger than with the Canon XHAI in the same setup.

I stumbled on a few German sites that discussed this type of filter and there were actually stronger ones mentioned, that I have been unable to find here, one was darker in color and reduced light by about 2-stops.

Maybe one of our more tech savvy engineer memebers can shed some more light on this. But this filter does help a lot with this camera's sensor, I'd still like to find even a stronger one. Of course I haven't shot in a red room or set yet.

Brian - or anyone else - does this filter fit under the EX1 hood? I would prefer it to the slimline version as I can attach things to the external thread if necessary. I know that the slimline version does fit.

Michael Maier April 8th, 2008 06:22 AM
I ended up buying the B+W 489 instead of the 486 as the 486 did not work with 35mm adapters because it has to reflect the light back and it would be behind the adapter. The 489 absorbs it instead of reflecting it and it works great with the Mini35 for example.

Graeme Fullick April 8th, 2008 06:30 AM
Michael,

Does the 489 fit under the hood, and does it have a thread on the outside?

Michael Maier April 8th, 2008 11:38 AM
Quote:
Originally Posted by Graeme Fullick (Post 856312)
Michael,

Does the 489 fit under the hood, and does it have a thread on the outside?
If it fits under the hood I have no idea, as I haven't tried that yet. I always use a mattebox. But it does have a thread on the outside.

Piotr Wozniacki April 9th, 2008 03:18 AM
Quote:
Originally Posted by Michael Maier (Post 856311)
I ended up buying the B+W 489 instead of the 486 as the 486 did not work with 35mm adapters because it has to reflect the light back and it would be behind the adapter. The 489 absorbs it instead of reflecting it and it works great with the Mini35 for example.
Do I understand it right, that you will need one such filter for each lense you're using with your 35mm adapter (if they are different filter thread size, of course)?

Giroud Francois April 9th, 2008 05:10 AM
there is so many glass in a mini35 adapter , i doubt a filter would still be necessary.
imagine that you add , the lens, the gg screen, the condenser, the macro lens. and you still need to go through the camera lens.

Piotr Wozniacki April 9th, 2008 05:23 AM
Quote:
Originally Posted by Giroud Francois (Post 856895)
there is so many glass in a mini35 adapter , i doubt a filter would still be necessary.
imagine that you add , the lens, the gg screen, the condenser, the macro lens. and you still need to go through the camera lens.
And yet, even with the Letus and a 50mm Canon lense, the black clothes are still brownish when shot in artificial light.

Sean Donnelly April 9th, 2008 07:08 AM
IR passes through many things that visible light does not. The 1 1/2 stops of light loss from the mini35 doesn't really matter, this problem is seen with the RED camera when using heavy ND's like 1.5 and 1.8 (5 and 6 stops!). I used to shoot infrared ektrachrome, and I'd use an opaque filter which blocked all visible light and only transmitted infrared. As far as the 486 behind or in front of the adapter, I'm thinking it doesn't matter. First off, the 486 doesn't reflect the IR light outward like a mirror, it dissipates it between the layers of the filter coating. Also, even if it did reflect the light, why should that matter? The camera won't see it anyway, the filter still blocks it even if it's not traveling straight in. The amount of IR and wavelength we're talking about isn't like a heat lamp, so you won't melt your lens. Later this week I'm going to try a 486 with a mini 35 and cooke S4's. I'll keep everyone informed.

-Sean

Bob Grant April 9th, 2008 07:53 AM
Quote:
Originally Posted by Piotr Wozniacki (Post 856878)
Do I understand it right, that you will need one such filter for each lense you're using with your 35mm adapter (if they are different filter thread size, of course)?
That's why we buy matte boxes. They might seem expensive but compared to a set of screw on filters for every lens thread they start to become cheap.

Sean Donnelly April 11th, 2008 10:34 AM
The 486 filter does work to solve the problem, but it really shouldn't have to be there. I ran into a situation today where I needed the filter, but also a wide angle adapter. Even if I could find a filter in the approriate size, the wide angle doesn't have threads, and I can't put it behind since it mounts to the bayonet. In this case I wouldn't be able to do the shot. I spoke to someone named Lou at Sony support again today, to express my displeasure in the camera not performing as it should. He said he had heard of this earlier in the week from someone who saw it only in certain lighting conditions. He sounded genuinely concerned about the problem and said he would have the engineering team investigate at the beginning of next week. I referred him to this thread, but I think if we all call and complain maybe we can force Sony to step up and fix this. I don't like having to put extra glass in front of the lens.

-Sean

Peter Brugman April 16th, 2008 06:21 AM
B&W 486 works fine, when you put it directly on the cameralens there is only a very very slight green coloring of the extreme corners when you zoom out all the way.
The Heliopan UV/IR cut filters give a greenish cast all over the frame and even more so in the corners when zoomed out.

Sean Donnelly April 16th, 2008 06:57 AM
Peter, while the 486 does work fine and I haven't seen any green cast (unlike the 489) I still maintain that it shouldn't have to be there. This is a design problem. A lot of companies use a weaker IR filter to increase sensitivity, but just like they did with a batch of F23's, Sony used one that allows a couple of wavelengths to pass that shouldn't.


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