RE: Outdoor/daylight camera profile
RE: Outdoor/daylight camera profile
- Subject: RE: Outdoor/daylight camera profile
- From: "Michael Fox Photography News Account" <email@hidden>
- Date: Mon, 22 May 2006 15:39:47 -0700
- Organization: Michael Fox Photography
Danny,
Thanks for your input. Thoughts below.
>
> As you are aware, outdoor target profiling with a camera
> has a fundamental problem: the light color, its color
> temperature, changes with time of day, time of year,
> latitude, cloud cover (major effect in no-time), etc.
Yup. Understood.
>
> And we are not talking small changes here, thousands of
> kelvin, enough to shift any color! Because of this
> situation, I do not believe in using a single profile for
> daylight.
Yup.
> A suggestion: when you make a profile, record the color
> temperature. By having a few profiles at various
> (daylight) color temperatures, you simply select the one
> corresponding to the actual conditions.
Yes. Except that this is for outdoor/daylight/landscape photography. So I
want to see the color of the daylight in the images as it changes. For
example, I don't want the golden light of sunset to be neutralized. So, for
those purposes, I would think that I'd make a single profile at mid-day when
my color meter reads 5500K. All shots taken, whether morning, noon, or
night, could be white balanced to 5500K and the daylight profile applied.
This should render sunsets yellow, etc.
One thing I've been wondering about but haven't experimented with yet (so
I'll wonder about it out loud here)...
Obviously, early morning and late afternoon light has different
characteristics than mid-day light. So applying a mid-day profile to late
afternoon images will make them appear yellow, as they should, but also may
not properly display the color saturation, etc. For example, I have no idea
- just guessing - but perhaps some colors show more saturation in yellow
light than others.
So, I'm wondering if it makes sense to make a profile using afternoon light
but color balance the image for mid-day. The idea being to more closely
capture the color response to afternoon light, yet still show that the light
is yellow. The scenario would be the following:
-- shoot the color checker in later afternoon light
-- white balance the color checker shot
-- run the profiler and save as "...afternoon..xxx.icc"
-- then take your real afternoon photo and apply the afternoon profile but
white balance the real photo for 5500K.
Kind-of odd thinking so I haven't bothered to spend time on it yet. Just
wondering if it's an approach with any merit....
Of course, this
> requires an instrument to measure the color temperature,
> but you indicated some measurements of it, so this should
> not be a problem. I would favor diffuse illumination
> measurements, not necessarily with a tent, but 90 degrees
> off from direct sun (others may have a different
> opinion!).
For my quickie/experiment, I placed the colorchecker at 45 degrees to the
sun (with the camera pointed straight at the target). The intent was to
minimize reflections, much like copy work. Placing the target 90 or more
degrees from the direct would mean indirect lighting by the blue sky only.
That would probably be a useful profile as well, although I suspect it may
not render sunlit items as accurately.
>
> This is not a miracle cure, but it might work.
>
> > A rep for the back said that making my own profile
> >wouldn't work because of IR and/or UV affects.
>
> IR and UV filters are usually factory installed within
> some backs or part of the sensor itself. It is true that
> they can have a serious effect if they are not present /
> or removed. However, unless these filters are
> added/removed between the profile shots and the actual
> picture, I do not see what the effect could be (i.e. I
> fully agree with you!).
Thanks. That was my thinking as well.
Michael
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Colorsync-users mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden