Luminous Landscape Forum

Equipment & Techniques => Medium Format / Film / Digital Backs – and Large Sensor Photography => Topic started by: regfran on January 27, 2012, 03:08:01 pm

Title: Sinar 54 FW Unwanted color gradient
Post by: regfran on January 27, 2012, 03:08:01 pm

Hello All,

I shoot in a corporate Studio with a Sinar 54 FW on a mac. We have been noticing a magenta to green color gradient across the image. Test with different lights, lenses, and software seems to show this is a sensor problem. Shoot with the Sinar P3 and Sinar lenses. test file attached. Using the Capture controls for "adaptive color compensation" and "enhance neutral areas" does not seem to make a difference. Creating lens reference no help either. opening dng in Adobe camera raw shows same artifact.Is this a factory calibration need? Thanks in advance for any comments or help, especially from Sinar savvy folks.

regfran

Title: Re: Sinar 54 FW Unwanted color gradient
Post by: Brian Hirschfeld on January 29, 2012, 09:28:29 pm

Never used Sinar, but if you can repeat the results, couldn't you just create an LCC profile to correct for it?

Title: Re: Sinar 54 FW Unwanted color gradient
Post by: museumbrich4d on January 30, 2012, 10:15:07 am

We had two Sinar 54 FW backs that did that. Never consistently. We never solved the issue. Tried everything. Obviously shutting down and restarting, fixing permissions, connect and reconnect all wires. Switching cameras would solve the issue for the moment and it would eventually pop up on both cameras. We have the same setup as you using the P3. We are now using the eVolution 75H backs and that issue hasn't popped up. I can't remember if we ever contacted Sinar directly or went through our dealer. It really pisses you off when it happens.

Title: Re: Sinar 54 FW Unwanted color gradient
Post by: J-KNIGHT on January 31, 2012, 06:50:40 pm

Download  Sinar arTecManual V 1.1 - EN.pdf  Pages 35, 36 and 37-  "White Shading".   Download Sinar eXposure.  Removes color casts and vignetting. I do not believe this feature is available in the newer Sinar Capture yet.

Title: Re: Sinar 54 FW Unwanted color gradient
Post by: regfran on February 02, 2012, 01:02:28 pm

We were changing out computers anyway, so I did a new installation on MAC(10.5.8) put on the latest Sinar Capture shop(6.1). I then created a new lens reference. This time when I placed the diffuser over the lens, I added two stops to the basic exposure to account for ND of the diffuser. The new result is very neutral(less than one point of Green value across image, so I am good to go now. Found that tip somewhere on luminous landscape. Thank for all the replies,

Regfran