DV Info Net

DV Info Net (https://www.dvinfo.net/forum/)
-   JVC GY-HD Series Camera Systems (https://www.dvinfo.net/forum/jvc-gy-hd-series-camera-systems/)
-   -   Bleach Bypass for 200/250 (https://www.dvinfo.net/forum/jvc-gy-hd-series-camera-systems/92766-bleach-bypass-200-250-a.html)

Brian Duke April 30th, 2007 10:44 AM

Bleach Bypass for 200/250
 
Tim,

Have you had a chance to do the Bleachbypass for the HD200/250 yet?

You know my story =)

Tim Dashwood April 30th, 2007 11:42 AM

I emailed it to you, but for everyone else.

MASTER BLACK -6
BLACK COMPRESS 5
KNEE MANUAL
LEVEL 100%
WHITE CLIP 108%
CINEMA OFF
COLOR MATRIX STANDARD
R GAIN -4
R ROT -2
G GAIN NORM
G ROT NORM
B GAIN 1
B ROT -3
GAMMA STANDARD
LEVEL -2
COLOR GAIN -8
WHITE PAINT NORM/NORM

I've done HD200/250 versions of all of my HD100 scene files, as well as some brand new ones that take advantage of the new gamma curve shapes, but just haven't had a chance to put them into a grid and make a nice downloadable pdf sheet. That will happen soon. I promise.

Adam Letch April 30th, 2007 04:44 PM

Tim without wanting to wear thin on you
 
but since you've worked out the scene files, can you confirm at least in simple terms whether you think the HD200 series has a cleaner or noisier image than the HD100 series. You might go more in-depth later with pics and all, but just a simple "Yes, in general I found it displays a cleaner image" or " Nay, they got to fix something here" kind of statement.

Thanks mate, I've got a few projects that would use your Bleach Bypass preset. And as with any of the presets provided by the community here will be aptly recognized in the credits.

cheers

Adam

Brian Duke May 1st, 2007 07:54 AM

Thanks Tim. You rock! I'm starting today on production. Didn't hear back from JVC, so I think the 250 will be out of the question unless I purchase or rent one within this week.

PS. I never got your email on the bleech bypass, only the one on JVC.

Tim Dashwood May 1st, 2007 09:19 AM

Quote:

Originally Posted by Brian Duke (Post 670537)
PS. I never got your email on the bleech bypass, only the one on JVC.

Re-sent it just now.

Tim Dashwood May 1st, 2007 09:33 AM

Quote:

Originally Posted by Adam Letch (Post 670193)
but since you've worked out the scene files, can you confirm at least in simple terms whether you think the HD200 series has a cleaner or noisier image than the HD100 series. You might go more in-depth later with pics and all, but just a simple "Yes, in general I found it displays a cleaner image" or " Nay, they got to fix something here" kind of statement.

My observation is that the gamma curves are significantly different in the HD200, which "seems" to increase the sensitivity over the HD100.
This means that a scene file in a HD100 using Cine Gamma set to NORMAL might have to use the Cine Gamma set to -4 in the HD200 to achieve the exact same response on the waveform monitor. The same goes for COLOR GAIN. The net result of "matching" the curves is that there is no difference in the noise levels when matched - at least in my 'laboratory setting' shooting charts. Time will tell in my practical tests to come later this week if this is true.
I've been using DSC's Toni chart with cavity black to map out the shape of the new curves, but I think I might go back to my home-made pure linear chart to determine the complete shape of the new curves.
I have a theory that the curves might not actually be shaped that differently, but instead something in the new cameras is set by default to be at least a stop more sensitive. This might appear to be analog gain - even though gain is set to 0dB. I still haven't solved this mystery.

My method for creating the HD100 matched scene files was to use a stock lens, with the aperture (F/2.8) & zoom locked down with tape (focal length around 20mm to avoid vignetting) and shoot a DSC Chroma DuMonde using all of the scene files. Frame grabs were taken of the waveform and vectorscope results and cataloged. I then removed the lens from the HD100, replaced the camera with a HD200 on the locked-down tripod, put the lens on the HD200 and 'matched' the waveform/vectorscope frame grabs from scratch. The POV of the cameras was exactly the same from the same tripod, and the chart didn't move.
Obviously I made sure that the white balance and shutter speed settings were exactly the same as the HD100.


All times are GMT -6. The time now is 07:19 AM.

DV Info Net -- Real Names, Real People, Real Info!
1998-2024 The Digital Video Information Network