View Full Version : Fixes For The Red Problem?
Frank Howard April 25th, 2006, 05:58 PM OK... It looks like there are sometimes problems with the way HC1s and A1s pick up on red (I've seen it myself on very bright reds).
On the main thread on the problem there were several tentative suggestions (adjusting the WB manually, fixing in post, etc.) on fixes, but after looking at dozens of posts I still haven't seen anything conclusive.
What are the fixes (if any) in camera and/or in post (settings that can be plugged in)?
Cooleye Hu April 26th, 2006, 08:06 AM unfortunately there is no solution availabe right now to completely solve this issue. The only hope will be sony itself ! But we can try to avoid shooting the bright red in our practical footage.
Frank Howard April 26th, 2006, 10:32 AM I apologize for the confusion. I should have used the term workarounds to the red oversaturation issues, such as tweaks to settings that can be applied in post.
I'm starting to seriously doubt if there are any in camera workarounds though.
Mikko Lopponen April 27th, 2006, 02:13 AM Use manual white balance and don't let bright reds go too bright. Bring the exposure down. Works pretty well.
Alex Thames April 27th, 2006, 09:32 PM I've heard of people talking about +2 or +3 on the color balance, but then I hear about -2 or -3. Which is it?
Stu Holmes April 28th, 2006, 09:28 AM check your camera manual Alex. It looks like you're referring to the WB SHIFT feature and one way will make things more cool/blue and the other way will make things more warm/red. The way you'd probably want to go to help with the lilac/pinky-reds is to make it more warm/red. (i.e. lose some of the blue thats' turning the reds into lilac/magenta).
So : WB SHIFT more towards the warm side.
also:
- Increase the color saturation (to avoid 'pastel' colors)
- Decrease exposure, prob. via AE SHIFT at -2 or something.
Frank Howard April 28th, 2006, 10:21 AM Some people, like Alan Roberts who has done extensive testing of the A1, are of the opinion that the red issue is due to OVERsaturation of the red.
You can look at his findings here:
http://img.hexus.net/v2/lifestyle/al...n_res_sets.pdf
This seems to be born out by the fact that other colors do not seem to come out pastel, just bright red.
John Jay April 28th, 2006, 10:36 AM Are you all not taking account of 709 colour gamut?
For example when I shoot HDV for DVD I convert between ITU-R BT 709-5 (HD) and ITU-R BT 601 (typically SD) colour values.
This action alone makes the red change from a crimsonish red to a fuller red which is 'bout right.
Stu Holmes April 28th, 2006, 01:44 PM So John, you say that you change between 2 different colour-palettes (or whatever the correct term is) in post-prod yep? That right?
Which NLE are you using out of interest?
John Jay April 28th, 2006, 02:41 PM Yes,
I use Edius 3 pro, and export to DVD using Canopus Procoder 2 which has the necessary 709 to 601 gamut correction plugin.
Of course you wouldnt use the plugin if the target was HD for screening on 709 compliant HDTV
Alex Thames April 28th, 2006, 03:01 PM Stu, you're suggesting:
+2 WB shift
+2 Color
-2 AE Shift?
Before I was just referring to color as that's what I thought most people had mentioned changing, but I should change WB shift and AE shift as well?
Stu Holmes April 28th, 2006, 03:20 PM Well i'm not sure if WB SHIFT of +2 is more red or more blue, but it'll be one or the other. Do a quick test and you should see. It's logical that if you shift it more towards the warm/red end of the spectrum, that should decrease (a little anyway) the blue tones that are causing the magenta/lilac tone. Red + blue = lilac / magenta / purple.
It'll probably be a fairly subtle shift though.
Increased saturation is an advisory based on that i've heard that a lot of people think the HC1/A1 is, at default, somewhat undersaturated.
-2 AE Shift will underexpose 1 stop (each AE notch = 0.5 stops) relative to the metered expsosure. I think this should help too.
In the end, you'll just have to experiment really and see what works. Manual one-push white-balance is probably the most important thing to do though.
And at the end of the day, you should be able to fix these sort of problems in your editing package in post-production.
John Reilly April 29th, 2006, 12:28 AM I understand this feature may be more of a gimmick than anything, but I was curious as to whether anybody has tried it?
Does it prevent you from using any of the manual features of the HC-1 when in this mode?
How did it perform? I thought I read somewhere it caused "strobing" or some such similar undesired result....
I was hoping it would enhance/soften the "tape" look to more of a "film" look.
Appreciate your comments/advice!
--"Reilly"
Mikko Lopponen April 29th, 2006, 03:36 AM How did it perform? I thought I read somewhere it caused "strobing" or some such similar undesired result....
I was hoping it would enhance/soften the "tape" look to more of a "film" look.
Film look is strobing as film is run at 24 fps.
Graham Hickling April 29th, 2006, 12:03 PM Unfortunately, and unlike the A1, it disables your manual exposure control options.
Also it reduces resolution by about 30-40% (some sort of field blending is being done in-camera). The resolution drop affects both the HC1 and A1.
John Reilly April 29th, 2006, 11:22 PM Mikko and Graham:
Thanks for the responses...So, I gather there is no desirable effect.....I will give it a shot, however...just to check it out.
I appreciate it!
Reilly
Evan Dowling April 30th, 2006, 08:10 AM I get much better results by leaving the camera in manual mode and changing the shutter speed to 30. It's not 24, but it looks much better than using the cinema mode on HC1. Also, I have found that the HC1 tends to overexpose if left on AE. When in bright situations, I let it pick an auto exposure level and then I drop it down a few clicks. This seems to help a lot with the red problem.
Bruno Donnet May 2nd, 2006, 07:03 AM Stu, you're suggesting:
+2 WB shift
+2 Color
-2 AE Shift?
When you mention camera corrections (taken into account by the auto-mode), you must precise if you're talking about the A1 or the HC1 because the scales aren't the same.
The options:
- 'WB shift' ,
- 'Camera Color',
- 'AE Shift',
- & 'Sharpness'
have a -8/+8 latitude on a A1, and only a -4/+4 latitude on a HC1.
(The owners of the HC1 can see what is proposed to the owners of a A1 with the menu option 'LCD color': only here the proposed scale is -8/+8 like on a A1).
Consequence: if somebody mentions +1 for the 'Camera color' option on an HC1, that means '+2' on an A1... If somedody mentions -1 for the 'Sharpness' on an A1, that means quite nothing for a HC1 (because 0.5 is not possible! or you stay at +0, or you jump to -1 but that equals in fact to -2 on a A1).
Alex Thames May 2nd, 2006, 07:14 AM I'm asking about the A1.
Michael Stowe May 5th, 2006, 05:19 PM So was there ever a conclusion on the A1? Or was it just trial and error. My A1 arrived this afternoon. Sweet little cam and ironically I was wearing a red shirt when I tested things out. Definately turned it pink. Curious what others have found to adjust this without creating havoc everywhere else.
Thanks
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