Black levels

[egproductions]

being an event videographer, one of the biggest issues in my mind are black levels becasue of the poorly lit enviornments i want to retain every bit of detail i can especially when outputing to anolgue. I have read a few articles on black levels but still have some questions. When i output through firewire and then go anolgue out from my camera to a VCR the camera doesnt add a 7.5 IRE setup, is there any way to add it using the NLE instead of using a physical procamp or deck that can add 7.5 IRE. I know there is a procamp filter in Premiere but it just seems like it is adding noise rather than converting the black levels properly. I attempt to adjust the levels using the levels filter and monitoring using the NLE's waveform and color bars. When i see the 7.5 IRE black bar show up i know i have properly adjusted it however the picture still get noiser. i the levels filter you can choose a number from 1-255 so i set my black to star at 16 wich is the equvielent to 7.5IRE right? Why isnt it working properly. monitoring levels is one of the most convfusing topics i have personally come across so i would love to hear how people are handling their video.

 

[Walter_Graff]

Try going firewire and live to deck from there with a monitor so you can see what you are getting and make adjustments live. The waveform in the edit system has little to do with how it will look in the outside world. It's how you get it there that can alter what it looks like on the computer. Tell me more about your set up and I will help.

 

[egproductions]

while on a shoot i dont have monitoring equipemtn expet for zebras in my XL2, I have a firewire out from my computer to a crappy zr-100 that i use as a playback deck so i wont wear out my heads (hense the no 7.5 IRE setup) I monitor using a decent, but not professionl, 13inch Crt that is connected to the analog of the camera through a VCR. I cant totally elminate over exposure in the camera so in editing i clip it to 100IRE to be NTSC Safe. I just am a little confused on what is happening with my blacks (maybe the blakcs i record never go below code 16 so i dont have to worry about blkac levels but i know that the 7.5 ire black on the color bars that the camera generates shows up on the Zr-100 but not onthe televison. THe only way to make it show up on the telvison is to boost the brightness in the NLE for when i want ot make a VHS copy. However this creates noise. If my camera records below code 16 is there a way to retain that black information or is it inevitbalet hat is is going to get clipped

 

[Rush]

Hi eg, I think the problem may lie with the VCR. Try patching directly to the TV and see if it still does that. Most VCR's have AGC, Auto Gain Compensation, and ACC, Auto Contrast/Color Correction. The VCR might be fighting your 7.5 IRE, which it may interpret as being "milky black" and it corrects by making the 7.5 to 0 IRE. Most VCR's under $2500 will do that and will not allow you to turn it off. When you go to a pro dub house, they will have a rack of $2500 dub decks, each allowing you to set manual levels and audio gain. Unfortuantely, consumer VCR's don't allow this. Just do your best and understand that the VCR will do its

When you patch to your TV, turn off "Auto Picture". Most TV's, unlike VCR's, allow you to do that. Set your own settings as close to bars as possible, then play again.

Also, don't go by your computer monitor too much. Computer monitors have a much wider gamut than TV's and video, and will show gray values that won't show up in the final product.
Making DVD's from your computer will not suffer the same problems.

 

[egproductions]

are you saying that the anolog signal from my camera to my vcr has the proper black levels its just my television that isnt set properly. I would have set my television to the non default settings however i have read that unless you have a proc amp the black levels wont be correct comming out of you digital to anlogo source and if you adjust the television then your just fooling yourslef into thinking your levels are proper when really the vcr isnt getting teh correct 7.5IRE boost. Again very confusing topic.....

 

[Rush]

No, I said I think the problem is with the VCR not the TV. Setup the TV directly from the computer with Color Bars, then hookup the VCR. You will notice it looks different. The VCR changes the colors, gamma, contrast, and adds grain.