Color temperature of image - EX1 with Letus Extreme

[colby_gottert]

I recently bought a Sony EX1 and have begun using my Letus Extreme lens adapter with an 85mm Zeiss lens on the camera. Overall I have noticed that the color temperature of the image tends to be very warm even if I perform a manual white balance with a white card after the lens adapter and the Zeiss lens have been mounted.

I have performed a series of tests with the EX1 and the Letus Extreme and have documented my work on my blog: colbygottert.wordpress.com (http://colbygottert.wordpress.com)

I wanted to know if any one else has experimented with the Letus Extreme on the EX1 in order to find out what the optimal picture profile and white balance settings would be in order to get an image where the overall color temperature was not too warm.

[AwakenedFilms]

I use an HVX with my Letus. For me, color temperature varies with different lenses and seems like it changes with aperture settings as well. I have a scene file that I use to compensate and help it match the bare HVX. Probably similar with the EX1.


J

[MitchLewis]

I've noticed the same thing with our EX3 and Letus Ultimate. We're using the following Nikon lenses:

17-35mm f/2.8
50mm f/1.4
80-200mm f/2.8

I recently shot side-by-side with a EX1 with no adaptor except for the Sony wide-angle converter. I was using the 80-200mm on the EX3. Not surprisingly the EX1 was MUCH brighter and could shoot in much lower light. But the 80-200mm had a lot more color....almost too much. I ended up white balancing both cameras and under our tunsten lights I was surprised to see the white balance come in at 2800-2900 (3200 was WAY too warm).

I hadn't thought about the concept of the Nikon lenses effecting color. I'm going to do some more testing as well. Thanks for pointing this out Colby. (great blog....I'll be checking it often)

[colby_gottert]

Hi Mitch and J,
Thank you for your feedback. I have actually been using the Letus on my HVX200 until I bought the EX1. I found that if I white balanced the HVX before putting on the lens adapter with the Zeiss lens that the HVX's image was way too warm, however if I performed the manual white balance after putting on the lens adapter that the balance looked really good on the HVX and the whites were close to true white.

However, with the EX1, the color temperature is warm regardless of whether I white balance before or after putting on the lens adapter with the Zeiss lens.

I thought that it might have to do with the fact that I was using Andy Shipsides CINE D picture profile on the EX1, but after running the tests with the picture profile both on and off, I came to the conclusion that the picture profile did not significantly affect the color temperature, it mainly affected saturation and contrast.

It is an interesting phenomenon and I will be really interested in seeing what Mitch has to report after he does more test with the EX3.

[MitchLewis]

My "testing" is just shooting for various projects. But now that I know what to look for, eventually I should have some additional details in the next few months.

[JDDalllas]

Your just dealing with the different coating and characteristics of each lens and when you white balance with the Nikon lens on, your camera see too much warmth and try's to correct for it. What your doing, is like when you cheat on white balance with a jungle book (gel swatch). Try using a swatch to cheat the white where you want it. Too warm, put a 1/8 CTO in front of lens and white balance again etc.

[Noel Evans]

Pretty sure you can just make manual adjustment to WB on EX? EDIT: I mean you can dial in the WB to suit.

This is a common issue when using 35mm adapters and mixed lenses. Try to stick with same lenses where possible.