Will Tiffen T1 filter reduce CA from stage lighting?

[John Peterson]

Haven't used the T1 on my EX1 yet, but was wondering if it will help reduce the CA that occurs around the edges of stage lit actors and objects. Have a shoot in two weeks.

Thanks,

John

[Andrew Stone]

Hi John,

Chromatic aberration will not be brought down with the TIFFEN T1 IR filter.

It could be a list of things playing into it.

First thing I would test is using Oliver Neubert's picture profile shown on this page (show's right now as post #506). Second thing that could be playing into it is your aperture. Oliver's picture profile should help out in allowing you to get in the right aperture range/speed setting.

I've used his picture profile on a few "stage" shoots and it has worked really well. Thanks Oliver!

One thing I will mention about Oliver's profile is the tonal range does gets crammed up a bit. The image is usable as is. However, to get the full benefit of his profile you will want to spread out the tonal values with some grading/color correction.

Failing that you should test out a picture profile using the Std 4 gamma as opposed to one of the CINE gammas and invoke the knee to bring the whites down.

Hope it works out.

-Andrew

[Bob Grant]

Originally Posted by John Peterson

Haven't used the T1 on my EX1 yet, but was wondering if it will help reduce the CA that occurs around the edges of stage lit actors and objects. Have a shoot in two weeks.

Thanks,

John

It might. Some tests have shown that the IR bleed can appear as something similar to CA.
Personally I'm sticking with using the 486 rather than the T1 for stage shows. I'm never wide enough shooting a stage show for the slight green vignette to be an issue and the light loss through the T1 and the uncorrectable caste it creates is a real problem.

[John Peterson]

Originally Posted by Andrew Stone

Hi John,

Chromatic aberration will not be brought down with the TIFFEN T1 IR filter.

It could be a list of things playing into it.

First thing I would test is using Oliver Neubert's picture profile shown on this page (show's right now as post #506). Second thing that could be playing into it is your aperture. Oliver's picture profile should help out in allowing you to get in the right aperture range/speed setting.

I've used his picture profile on a few "stage" shoots and it has worked really well. Thanks Oliver!

One thing I will mention about Oliver's profile is the tonal range does gets crammed up a bit. The image is usable as is. However, to get the full benefit of his profile you will want to spread out the tonal values with some grading/color correction.

Failing that you should test out a picture profile using the Std 4 gamma as opposed to one of the CINE gammas and invoke the knee to bring the whites down.

Hope it works out.

-Andrew

Thanks Andrew,

I am already using STd 4 Gamma, but will try that PP.

John

[John Peterson]

Originally Posted by Bob Grant

It might. Some tests have shown that the IR bleed can appear as something similar to CA.
Personally I'm sticking with using the 486 rather than the T1 for stage shows. I'm never wide enough shooting a stage show for the slight green vignette to be an issue and the light loss through the T1 and the uncorrectable caste it creates is a real problem.

I assume you mean a "green" caste. Not good. Didn't realize it couldn't be corrected.

Thanks,

John

[Duncan Craig]

Can anyone confirm that the T1 77mm screw-in is only available as a thin filter, thin enough to go under the lens hood of an EX1.

I've looked for a website reference to different types of the T1 and I can't see different types.

Cheers folks, Duncan.

[Andrew Stone]

Originally Posted by John Peterson

I assume you mean a "green" caste. Not good. Didn't realize it couldn't be corrected.

You will not find unanimity on this point. Some argue a solid white balance gets rid of the green cast (there are at least a couple of threads on this issue). I am going to be using it within the next week and doing some tests over the next few days.

[Leonard Levy]

I have a 77mm T1 . It is not a "thin " filter but a normal one with threads on both sides and it does fit behind the EX-1 hood as do most normal 77mm filters. "Thin's" are not neccessary.
Re the 486 - except for the vignetting it is a better solution however I don't think there is any way to remove the green vignette in post that I know of.

[Duncan Craig]

Thanks Leonard,

I've got a Schneider thin daylight clear filter in already, but I'll ditch that and try a T1.

Cheers, Duncan.

[John Peterson]

Originally Posted by Andrew Stone

You will not find unanimity on this point. Some argue a solid white balance gets rid of the green cast (there are at least a couple of threads on this issue). I am going to be using it within the next week and doing some tests over the next few days.

A solid white balance doesn't work very well under stage lighting because of the constant changes. I have always used a "tungsten" setting.

Thanks,

John