|
|||||||||
|
Thread Tools | Search this Thread |
July 12th, 2004, 03:54 PM | #16 |
Wrangler
Join Date: May 2002
Location: Vallejo, California
Posts: 4,049
|
Interesting, my Sony CCD-3300 came with a cap that has a white center for color balancing. I immediately took it off and used another cap.
I think you are suppose to point the camera at the light source and then white balance.
__________________
Mike Rehmus Hey, I can see the carrot at the end of the tunnel! |
July 13th, 2004, 06:12 AM | #17 |
Major Player
Join Date: Sep 2002
Location: Belgium
Posts: 804
|
A diffuse ""filter" (a white diffuser?) captures all the ambient light (Lambertian sensitivity) Pointing to the lightsource is OK if e.g. there is not a red wall close to you...or near the subject.
|
July 14th, 2004, 04:09 AM | #18 |
New Boot
Join Date: May 2004
Location: Exeter, SW England
Posts: 16
|
Put the camera in the subject position, turn it around to point at the camera shooting position. The light on your coffee filter is now these same as that on the subject. In an auditorium, set it all up beforefand, and do a trial if poss. Stage lighting is notoriously fickle, and of course can vary from scene to scene.
If you are out of doors, just turn the camera around on the tripod, and ensure it is in the same light (or shade) as the subject. Works fine. N
__________________
f8, and be there! |
July 15th, 2004, 06:02 AM | #19 |
Regular Crew
Join Date: Jan 2004
Location: Toronto, Canada
Posts: 84
|
For those of you still looking for the original post in Fred Miranda's forums, here's the link:
http://www.fredmiranda.com/forum/topic2/92389 I'm still a bit 'uneasy' about WB with incident light as opposed to reflected light. I thought the WB with incident light is OK for photo cameras, but not for camcorders. Perhaps someone could comment on this, thanks. |
July 15th, 2004, 07:59 AM | #20 |
Major Player
Join Date: Sep 2002
Location: Belgium
Posts: 804
|
There is no difference between incident and reflected measurements as long as the reflected spectrum is the same as the one transmitted through the diffusion filter. In both cases the cam gets "white" light on the CCD's.
|
April 3rd, 2006, 02:33 PM | #21 |
Regular Crew
Join Date: Oct 2005
Location: Fairbanks, Alaska
Posts: 86
|
I was thinking about holding the filters together with a needle point hoop. Then you can just hold it in front of the lens. Will that work??? There are small hoops that won't take up much space. I am going to town today and will try and find one. WBing here in Alaska is easy in the winter but soon we loose our natural cards from heat ;) I'll be bak.....
(Link about hoop and more below) http://www.dvinfo.net/conf/showthread.php?t=63738
__________________
"Finding Gold In Tailings" www.dredgingworld.com Last edited by John L Scott; April 3rd, 2006 at 07:11 PM. Reason: Went to Jo Anns and found a hoop... |
April 3rd, 2006, 02:50 PM | #22 | |
Inner Circle
Join Date: Mar 2005
Location: Hamilton, Ontario, Canada
Posts: 5,742
|
Quote:
__________________
Good news, Cousins! This week's chocolate ration is 15 grams! |
|
April 3rd, 2006, 03:10 PM | #23 |
Major Player
Join Date: Sep 2002
Location: Belgium
Posts: 804
|
White balancing on a white card at the subject position is of course the best way to go, but got to the subject position is not always possible...Reflected light measurement is not such a straightforward story as the red vase example. A red vase will not change the WB which will be kept to an average value..Saturated colors are skipped in the calculation.
|
April 3rd, 2006, 07:12 PM | #24 |
Major Player
Join Date: Mar 2005
Location: Ventura, California, USA
Posts: 751
|
|
April 4th, 2006, 09:20 AM | #25 | |
Inner Circle
Join Date: Mar 2005
Location: Hamilton, Ontario, Canada
Posts: 5,742
|
Quote:
__________________
Good news, Cousins! This week's chocolate ration is 15 grams! |
|
April 4th, 2006, 09:42 AM | #26 |
Major Player
Join Date: Sep 2002
Location: Belgium
Posts: 804
|
Reflected scene light WB techniques are not at all based on "avarage scene light". The analysis is much more complex. The basic systems search for very low saturation areas in the picture and use these values (and only these) for correction. These are also the areas where we "see" if the white balance is off, not on a saturated red vase...If there are no desaturated areas the WB is locked to an average color temperatures. More sophisticated approaches also analyse the IR content in the scene, some analyse flicker properties. Out of all this information, the WB is calculated
|
| ||||||
|
Thread Tools | Search this Thread |
|