Crushed blacks and levels

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Hi everyone, many moons ago I saw a discussion concerning black levels on the DVX100... someone even provided a link to a JVC QuickTime video that explained the whole process. I just produced a little interview that looks great on my DVX100, but looks terrible (crushed blacks) on my television monitor. I did some searching on this site to find the previous discussion, but to no avail. Does anyone know where I can find this discussion thread?
Thanks in advance for your help
Jean
;D
 
Re: Crushed blacks and levels

... by the way I'm not a guest here (regarding the above post)... it's just that I forgot to logon

:o :o :o :P
 
Re: Crushed blacks and levels

JVC had a link to an animation about "setup" and the 0 IRE and 7.5 IRE conundrum. However, I doubt that's what's happening with your footage, I would rather suspect that the TV has the contrast adjusted too high, which is crushing the dark areas. If the footage looks good on the DVX, and looks proper in the computer, then it's the TV that's at fault.
 
Re: Crushed blacks and levels

What is the typical level that the dvdx should be set at for levels 7.5% or 0%. I use a PC and NTSC.
 
Re: Crushed blacks and levels

Jean,

Where's Preston when you need him? Here goes, I hope. The DVX analog and DV output is at 0 IRE. Most NTSC monitors expect a 7.5 IRE signal. So, you need a procamp to step it up to your monitor, or as Barry suggests, fudge with the contrast and brightness to get it to 'look" OK.
 
Re: Crushed blacks and levels

...my ears were burning. Yup, you're most likely sending your 0 IRE signal to a TV or monitor expecting 7.5. If your monitor isn't switchable, like Scott and Barry said, adjust the brightness and contrast using color bars the best you can. Or, use something like this Canopus product between your NLE and TV to get the correct levels for monitoring (which would be more versatile than a proc amp in your case).

http://www.canopus.us/US/products/advc-100/pm_advc-100.asp

BTW, I've got a Sony field monitor that has no switch and I can adjust it well enough for field use with just the brightness control.
 
Re: Crushed blacks and levels

OK Preston, how does the ADVC-100 work? It appears as though there is only one IRE dip switch. So you cannot control analog inputs and outputs separately? I assume it controls the analog out only, and maybe the DV out as well.

If so, how does it differentiate between a VHS deck in vs. a DVX100 analog signal coming in?

Thanks,

Scott
 
Re: Crushed blacks and levels

Hi Scott. I don't own a ADVC100 so I can't comment on how it works exactly. I presume you were looking at the downloadable user manual though. I know others have used it to accomplish what were talking about - and does look pretty slick.

My best guess is: The IRE dip switch controls both analog in and out at the same time - which is what you'd want it to do. I doubt it has any affect on the DV i/o - which is also what you'd want so that it stays within the spec. Just the like DVStorm, you would want to set the switch to match whatever your analog source is. VHS? Set it to 7.5. DVX analog? Depends on what you have the camera set to (should be 0). In that case you'd switch the dip to 0. Of course, I don't know why someone would want to use the analog out of the DVX though in this case. Depending on how the dip switch is set, the device then remaps the luminance values in accordance to the DV spec.

For example: If you have a VHS source which most likely has setup and the dip switch is set to 7.5, then it remaps the values so that your blacks exit the DV connector to your NLE at 0 IRE like it should. If you accidently left the switch at 0, then your levels will be messed up in your NLE.

If you had an analog source that you knew was not recorded with setup, then you would switch it to 0 and the device would do nothing to the signal other than convert it to DV.

Works the same way in reverse and would be easier than a proc amp and maybe cheaper. On the set you'd simply connect a firewire cable from the DVX or other camera to the DV connector on the device - and the analog outs of the device to your monitor with the dip set to 7.5.
 
Re: Crushed blacks and levels

[quote author=PrestonH link=board=Events;num=1095227858;start=0#9 date=09/15/04 at 17:29:24] On the set you'd simply connect a firewire cable from the DVX or other camera to the DV connector on the device - and the analog outs of the device to your monitor with the dip set to 7.5.[/quote]

Hi Preston,

OK..my tunnel vision was focused on my application. Camera firewire connected to MCE QuickStream, leaving only analog out for the monitor, and a proc amp would be my only option (perhaps). I figure the setup on the ADVC-100 affects only analog and that both input and output are set the same.
 
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