Montag, 11. September 2017

How to avoid/minimize color casts using vintage lenses on the SD1 Merrill

How to avoid/minimize color casts using vintage lenses on the SD1 (Merrill)
(thanks to user 'motionride' from bilderforum.de)

The Sigma SD1 is known to have problems with vintage lenses. Depending on the lens and aperture setting, you get strong color shifts/vignetting.

Previous generations SD9/SD10/SD14/SD15 do not show this behaviour, or only very little.
Until now, the procedure has been as follows:

Set your camera to A (Aperture Priority) and choose the "Reference Aperture":
F5,6 for the SD9
F2.8 for the SD10
F1.0 for the SD14, SD15 and SD1*
And now you’re good to go..... *but not with the SD1

With the SD1 it has been found that color shifts can be minimized by setting the camera aperture to the same aperture as the lens. 

How does it work?

1. Use the standard method: 
-Set your SD1 camera to A mode and set it to F1.0
-Set your preferred aperture on the lens (for example F5.6) and the camera will display the correct exposure. (for example 1/250)
The exposure will be correct now but unfortunately this causes color shifts.

2. Remember the suggested exposure time (1/250) and switch your camera to M (Manual Mode) 
Now set the time to 1/250 and set the aperture to the same aperture as on the lens (F5.6 in this case)

3. Shoot and be amazed how the color shift has gone.

The following screenshots from SPP show the difference between the two methods.

Even though the same exposure time and aperture was used for the images, the color shift is virtually eliminated:

SD1 with Cosinon 55mm F1.4 (M42-mount)
click for full res
SD1 with Carl Zeiss 135mm F3.5 (M42-mount)
click for full res


Kommentare:

  1. Hi, the problem is that the cast pattern varies from a homogenous single color to a very strange radial bicolor one depending on the lens. Even with same focal length , the cast may come in different forms depending on the lens model. It's really weird.

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  2. Hi. Your method worked partially with a Leica 35-70 F4 lens at F4. The color cast almost vanished at 70mm, but at 35mm it shifted from a strong magenta to a medium green at the borders.

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    1. Thanks for your test. I only tried 4-5 fixed vintage lenses and it worked quiet good.

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    2. I was expecting to use the Leica Elmarit-R 28/2.8 with the SD1 Merrill but the cast was so strong that I had to give up with this lens. My impression is that the cast goes worse with wide angle lenses, but I'm not sure.

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