Master Black Setting at DVinfo.net

Eugene Kosarovich · May 22nd, 2008, 06:43 PM

I want to make sure I'm setting the Master Black correctly.

With previous cameras, I've always adjusted the Master Black so that with my iris closed, at 0dB gain, I'll see 7.5 IRE on my waveform monitor here in my NTSC country.

I would do that and that was it, and I'd never adjust it again. For my scene file, I normally use the Australian settings that Uli posted, and I am quite happy with them. I also sometimes use some of the Sony scene files.

The point being, the Australian settings have the Master Black at -3, which is where it should be based on what I see on my waveform monitor, using my method described above.

But a lot of the other scene files have many different negative Master Black levels. I thought that making it match 7.5 IRE is what one had to do to stay legal, since anything lower goes into super black, which shouldn't be legal in a NTSC country with 7.5 IRE setup level.

Also, in Greg Boston's excellent F330/F350 training DVD, he mentions that a Master Black of 0 corresponds to 3 IRE in a F350. But again, based on my tests in my F335, a Master Black of 0 would put my setup level above 7.5 IRE.

But then I have my other test finding that a B&W checkerboard pattern will show spikes below 7.5 IRE at each contrast change to black, getting down right about to 0 IRE. This is with Detail turned on but set at 0. (Of course, it can be set lower than 0 or turned off entirely, though I haven't tested that setting on the waveform monitor yet to see if the spikes go away.)

So am I correct in how I set my Master Black? Or is there more creative freedom with it than I've been using? My camera doesn't have a limiter to clip me to legal, but my NLE can if I need it to, effectively crushing extreme black.

Dan Brazda · May 22nd, 2008, 08:24 PM

Sorry in advance if I'm over-simplifying this but... Digital black is 0 and analog NTSC black is 7.5. If you are shooting digital- whether it be standard or HiDef, black should be set at 0. It is only when you have to transfer to an NTSC format that you need to add pedestal or 7.5 ire black (which the machine you are transferring to normally does automatically). I'm sure others will chime in...

Greg Boston · May 23rd, 2008, 09:21 AM

To echo Dan's comments, it's okay to 'acquire' the image with wider settings than would be legal for broadcast, as that gives you flexibility in post to manipulate the image to your liking, then clamp it to legal values for broadcast if that's where it's headed.

Setting up the camera for legal NTSC values is necessary if you're doing a live shot, or predominately work in news where you don't have time to clamp it down in post.

Some people purposely drop the master black level to widen the range in the image.

-gb-

p.s. Thank you for the kind words, Eugene.

May 22nd, 2008, 06:43 PM	#1
Eugene Kosarovich Taken away too young... rest in peace Eugene Join Date: Mar 2008 Location: Albany, NY Posts: 161	Master Black Setting I want to make sure I'm setting the Master Black correctly. With previous cameras, I've always adjusted the Master Black so that with my iris closed, at 0dB gain, I'll see 7.5 IRE on my waveform monitor here in my NTSC country. I would do that and that was it, and I'd never adjust it again. For my scene file, I normally use the Australian settings that Uli posted, and I am quite happy with them. I also sometimes use some of the Sony scene files. The point being, the Australian settings have the Master Black at -3, which is where it should be based on what I see on my waveform monitor, using my method described above. But a lot of the other scene files have many different negative Master Black levels. I thought that making it match 7.5 IRE is what one had to do to stay legal, since anything lower goes into super black, which shouldn't be legal in a NTSC country with 7.5 IRE setup level. Also, in Greg Boston's excellent F330/F350 training DVD, he mentions that a Master Black of 0 corresponds to 3 IRE in a F350. But again, based on my tests in my F335, a Master Black of 0 would put my setup level above 7.5 IRE. But then I have my other test finding that a B&W checkerboard pattern will show spikes below 7.5 IRE at each contrast change to black, getting down right about to 0 IRE. This is with Detail turned on but set at 0. (Of course, it can be set lower than 0 or turned off entirely, though I haven't tested that setting on the waveform monitor yet to see if the spikes go away.) So am I correct in how I set my Master Black? Or is there more creative freedom with it than I've been using? My camera doesn't have a limiter to clip me to legal, but my NLE can if I need it to, effectively crushing extreme black. __________________ Scorpio Productions PDW-F335, PDW-U1, Vegas Pro 9.0b

May 22nd, 2008, 08:24 PM	#2
Dan Brazda Regular Crew Join Date: Oct 2006 Location: Richmond, VA Posts: 165	Sorry in advance if I'm over-simplifying this but... Digital black is 0 and analog NTSC black is 7.5. If you are shooting digital- whether it be standard or HiDef, black should be set at 0. It is only when you have to transfer to an NTSC format that you need to add pedestal or 7.5 ire black (which the machine you are transferring to normally does automatically). I'm sure others will chime in...

May 23rd, 2008, 09:21 AM	#3
Greg Boston Wrangler Join Date: Oct 2003 Location: DFW area, TX Posts: 6,117 Images: 1	To echo Dan's comments, it's okay to 'acquire' the image with wider settings than would be legal for broadcast, as that gives you flexibility in post to manipulate the image to your liking, then clamp it to legal values for broadcast if that's where it's headed. Setting up the camera for legal NTSC values is necessary if you're doing a live shot, or predominately work in news where you don't have time to clamp it down in post. Some people purposely drop the master black level to widen the range in the image. -gb- p.s. Thank you for the kind words, Eugene.