| Author |
Message |
AFryia
Joined: 09 Mar 2006
Posts: 965
Location: S.E. Michigan VPH-G70Q
|
| Posted: Tue Sep 25, 2007 12:17 am Post subject: Calibrating Color Questions |
|
|
I've been calibrating the color on my G70 and I'm not sure if I'm headed in the right direction. 
The initial problem was a hump in BLUE @40-60 IRE. So I progressively back off on the blue gain until I got to Here..
Now I have two new problems
1) the Blue GAIN is set to 25 out of a 0-255 scale so I'm loosing brightness.
2) I now notice the left side of the screen has a blue tint (blue tube side) and the right side is red (red tube side). When I was driving the tubes harder the entire screen was a more uniform in color.
Anyone have some pointers on what I may be doing wrong? Am I chasing an unrealistic goal here?
I have the later firmware on my G70 so I can't adjust G2, only BIAS and GAIN.
Has anyone ever used the manual adjustments for "Color Balance" or "White Balance" on a G70? How about on a D50 or G90?
|
|
| Back to top |
|
 |
garyfritz
Joined: 08 Apr 2006
Posts: 12088
Location: Fort Collins, CO
|
|
| Back to top |
|
|
AFryia
Joined: 09 Mar 2006
Posts: 965
Location: S.E. Michigan VPH-G70Q
|
| Posted: Thu Sep 27, 2007 1:01 am Post subject: |
|
|
| garyfritz wrote: | | You don't get rid of blue hump by reducing blue gain -- you electrically defocus the blue. |
grayfritz,
How do you gage how much to defocus verses gain reduction?
The G70 has an automatic defocus circuit for all tubes. It varies depending on scan frequency and color temperature selected. Unfortunately with the resolutions I'm running I'm getting little or no automatic defocus.
|
|
| Back to top |
|
|
garyfritz
Joined: 08 Apr 2006
Posts: 12088
Location: Fort Collins, CO
|
| Posted: Thu Sep 27, 2007 3:03 am Post subject: |
|
|
Then defocus it yourself. Go into the focus menu and adjust the MG-ALL focus for the blue. The first G70 I calibrated only took about 10 clicks off "fully focused" to level out the blue hump pretty well. For my G70 it takes a lot more.
You DON'T get rid of the blue hump by reducing blue gain! Normally blue gain is at or near max on a G70, and you adjust R/G gain to get correct color temp at 80IRE or so. Adjust the bias to get correct color temp at 30IRE.
|
|
| Back to top |
|
|
AFryia
Joined: 09 Mar 2006
Posts: 965
Location: S.E. Michigan VPH-G70Q
|
| Posted: Thu Sep 27, 2007 11:41 pm Post subject: |
|
|
I wondered why the manual said to set the the Blue to MAX to calibrate the white balance when it was only making things worse.
Now I know 
I'll give that a try this week end, Thanks!
|
|
| Back to top |
|
|
AFryia
Joined: 09 Mar 2006
Posts: 965
Location: S.E. Michigan VPH-G70Q
|
| Posted: Sun Sep 30, 2007 8:56 pm Post subject: |
|
|
Well, I gave it a try 
I had to really defocus to yield any benefit. I had to defocus too much that white lettering and boxes had a distinctive blue ring.
Can you check a tube's individual Gamma or luminance? My RED and GREEN track together fairly well. BLUE still doesn't want to cooperate.
|
|
| Back to top |
|
|
David_Web
Joined: 02 May 2007
Posts: 418
Location: Sweden
|
| Posted: Tue Oct 02, 2007 3:56 pm Post subject: |
|
|
What app it that?
I have a huey calibrator and the closest I can come to view a curve is in powerstrip and it's too small.
_________________
SNR of people are ridiculously low.
|
|
| Back to top |
|
|
AFryia
Joined: 09 Mar 2006
Posts: 965
Location: S.E. Michigan VPH-G70Q
|
| Posted: Tue Oct 02, 2007 10:44 pm Post subject: |
|
|
| David_Web wrote: | | What app it that? |
It's "HCFR Colorimeter" a free application from these gents http://www.homecinema-fr.com/
You need a compatible colorimeter probe for the software to work.
|
|
| Back to top |
|
|
|
|
