Luminous Landscape Forum

Raw & Post Processing, Printing => Adobe Camera Raw Q&A => Topic started by: Dragan Novakovic on July 01, 2011, 09:25:30 am

Title: ACR colour temperature indication problem
Post by: Dragan Novakovic on July 01, 2011, 09:25:30 am

ACR consistetly displays much lower "as shot" colour temperatures than those actually set on my Panasonic LX3. What is more, the departure from the camera setting in ACR increases with temerature. By comparison, what Silkypix reports is almost spot-on. Otherwise, there is not much difference between the white balance of images shot at the same temperatures when opened in the two converters.

I hope that the following table is clear enough.

             Camera setting                   ACR                           Silkypix
                  5000K                  4450K  (-550)             5008K  (+2)
                  5100K                  4500K  (-600)             5102K  (+2)
                  5200K                  4550K  (-650)             5180K  (-20)
                  5300K                  4650K  (-650)             5287K  (-13)
                  5400K                  4700K  (-700)             5380K  (+3)
                  5500K                  4800K  (-700)             5493K  (-7)

I must be doing something wrong because I don't believe that ACR can be this much off the mark. Thank you for your suggestions.

Title: Re: ACR colour temperature indication problem
Post by: fdisilvestro on July 01, 2011, 09:58:50 am

Different Raw converters show different colour temperature for the same image appearance

According to Eric Chan (from Adobe) there is no standard:

http://www.luminous-landscape.com/forum/index.php?topic=49904.msg411522#msg411522 (http://www.luminous-landscape.com/forum/index.php?topic=49904.msg411522#msg411522)

The important issue is that your whites and neutral tones have R=G=B

Title: Re: ACR colour temperature indication problem
Post by: Dragan Novakovic on July 01, 2011, 10:23:35 am

Thank you very much for your post. This certainly explains it.

Title: Re: ACR colour temperature indication problem
Post by: digitaldog on July 01, 2011, 11:10:19 am

A Kelvin value represents a range of colors (not an exact color).

Any color seen on the lines of correlated color temperature can be defined with a single (simple) Kelvin value:
(http://digitaldog.net/files/LinesOfCCT.jpg)

FWIW, the two sets of lines here represent the tint and temp sliders you control in ACR/LR.

Title: Re: ACR colour temperature indication problem
Post by: 01af on July 01, 2011, 11:19:44 am

At least, the difference in the numbers indicated by Camera Raw are shifted pretty constantly by approx. +2,5 dekamired. And it's not a real colour shift but just an offset in the indicated numbers. So don't worry. It's just numbers on a slider's scale. Adjust to taste and be done with it.

Title: Re: ACR colour temperature indication problem
Post by: Dragan Novakovic on July 04, 2011, 02:43:33 pm

Thank you all for clarifying this matter for me.

(By the way, I got my figures wrong in the third column under 'Silkypix' - they should
have been +8, +2, -20, -13, -20 and -7.)

Best regards