Color balance on CP950?
Charles M. Kozierok
I took some detailed PC component shots today, mostly with pretty good
success. However, I noticed something strange. One item I was
photographing was a yellow ribbon cable. No matter what I tried to do I
could not get the CP950 to render it the proper color. I tried a white
backdrop and a light blue one. Tried with auto white balance, and also
tried metering the white balance by sampling the white backdrop with
the lighting I was using for the shots. The yellow in each case seems to
come out more as a washed-out white/gray.
Any suggestions? Thanks.
cheers,
-*-
Charles M. Kozierok (mailto:ix...@PCGuide.com)
Webslave, The PC Guide - http://www.PCGuide.com
Comprehensive PC reference, troubleshooting, optimization and procedures...
Arnie McCullers
>
> Hi Everyone,
>
> I took some detailed PC component shots today, mostly with pretty good
> success. However, I noticed something strange. One item I was
> photographing was a yellow ribbon cable. No matter what I tried to do I
> could not get the CP950 to render it the proper color. I tried a white
> backdrop and a light blue one. Tried with auto white balance, and also
> tried metering the white balance by sampling the white backdrop with
> the lighting I was using for the shots. The yellow in each case seems to
> come out more as a washed-out white/gray.
>
> Any suggestions? Thanks.
I had similar problems with colors. I sent it back to Nikon, and
they replaced the lens unit. Now it's perfect. Send it to repair.
Arnie
Timo Autiokari
luminance). You just have encountered a situation where (1) there is a
distinct hue in your scene and (2) you still have the possibility to view that
scene in the real-life and compare it againt the digital image from your
camera. The problem with your CP950 is not only with that particular yellowish
hue, it is all over the color-space.
My suggestions is to complain to the manufacturer. Ask them in what
color-space the camera is in and what is the transfer function. If you get to
know these then you can get -very- accurate colors for every shot. Ask them if
they can provide you with an ICC profile for the camera, that would also help
greatly. Everyone who are interested in high quality and accuracy should do
this, maybe they would listen if say only 100,000 users would complain.
In the mean time you could purchase a Kodak Q-60 color input target (it is
only 29$ in USA). This target allows you to easily see how enormously large
the hue and tonal errors of your camera are. More importantly it allows you to
create a calibration for it. I understand that you are shooting macroscopy
indoors, if so you will also need good quality daylight simulating fluorescent
lighting (CRI at 98 and color temperature in the range 5500K...6500K).
The digicam manufacturers are tweaking the colorspace and the tonal range of
the cameras as they see "necessary" to "please" the "average" customer. And
oh, they do tweak. The problems are most often seen in closeups and macroscopy
since it is usually a single object so it's colors are distinct and it is sill
there in the real-life when the images are downloaded to the PC. Please see
my page about Kodak Q-60 at:
http://www.pp.clinet.fi/~timothy/aim/calibration/kodak_q60/index.htm
There is no easy way around it, but to calibrate accurately (or in other words
to de-tweak the tweaking that is built into the camera firmware).
Timo Autiokari
On 6 Mar 2000 17:29:07 -0500, ix...@PCGuide.com (Charles M. Kozierok) wrote:
>Hi Everyone,
>I took some detailed PC component shots today, mostly with pretty good
>success. However, I noticed something strange. One item I was
>photographing was a yellow ribbon cable. No matter what I tried to do I
>could not get the CP950 to render it the proper color. I tried a white
>backdrop and a light blue one. Tried with auto white balance, and also
>tried metering the white balance by sampling the white backdrop with
>the lighting I was using for the shots. The yellow in each case seems to
>come out more as a washed-out white/gray.
>Any suggestions? Thanks.
>
Charles M. Kozierok
Arnie McCullers <L.A.Mc...@LaRC.NASA.gov> wrote:
} Charles M. Kozierok wrote:
} >
} > Hi Everyone,
} >
} > I took some detailed PC component shots today, mostly with pretty good
} > success. However, I noticed something strange. One item I was
} > photographing was a yellow ribbon cable. No matter what I tried to do I
} > could not get the CP950 to render it the proper color. I tried a white
} > backdrop and a light blue one. Tried with auto white balance, and also
} > tried metering the white balance by sampling the white backdrop with
} > the lighting I was using for the shots. The yellow in each case seems to
} > come out more as a washed-out white/gray.
} >
} > Any suggestions? Thanks.
}
} they replaced the lens unit. Now it's perfect. Send it to repair.
Thanks for the suggestion Arnie, but I don't think there's anything
wrong with the lens. I think it's a color balance issue. Almost all of
my shots normally are just fine color-wise; in fact, they usually look
quite nice. It just seems to get a bit confused with a light pastel
color and a different pastel color in the background. Perhaps I need to
experiment more with the white balance?
Arnie McCullers
>
> Thanks for the suggestion Arnie, but I don't think there's anything
> wrong with the lens. I think it's a color balance issue. Almost all of
> my shots normally are just fine color-wise; in fact, they usually look
> quite nice. It just seems to get a bit confused with a light pastel
> color and a different pastel color in the background. Perhaps I need to
> experiment more with the white balance?
Been there, done that, didn't even get a T-shirt. I took hundreds
of test shots over 4 months playing with white balance, lighting,
subjects, etc. I finally gave up and sent it in. I wish I had
done it 4 months earlier. I have no idea why they replaced the
lens unit for a color problem. That's just what it said on the
repair order.
Arnie