MiniDV Versus Beta

Alessandro Machi · May 13th, 2004, 01:09 PM

My ENG camera has both 7.5 and black level adjustment. When I lift the adjustment to a +1 or +2, I definitely gain lower black sensitivity and it's no longer at a lower than 7.5 IRE. The black level adjustment lifts the darker parts of the scene without raising the brighter parts of the scene.

Then when I edit I choose what I want to crush and what I don't want to crush.

Graeme Nattress · May 13th, 2004, 01:33 PM

I think that's a strictly analogue camera phenonema, and is really a black level ("brightness") adjustment. Although, there was talk of something like this on the Canon XL1 with a similar control. I use an ultra contrast filter to give me more control over crushing blacks in post and this looks great.

Graeme

Alessandro Machi · May 13th, 2004, 01:55 PM

I was adjusting the black level once and I accidentally left the camera running while I was shifting the black level adjust, when I viewed the footage later I was shocked to see detail emerge on the persons dark suit right at the moment that I lifted the black from the default setting of zero up to one, then to two. The additional gain in detail in the dark areas was significant, so even though I was at 7.5 the additional adjustment of the pedestal was necessary.

The Canon XLS-1 that I reviewed for camcorder magazine two years ago was most definitely too contrasty for camera acquisition. The brights were over 115 and the darks were almost to zero IRE, this will cause one to lose precious data in the dark areas of the scene. The good news is the Canon XL1-S allows you to save different settings that allow one to lift the black level.

In my opinion Video acquistion should always be about getting as much of the visual information as possible by reducing the contrast. Contrast reduction is achieved by lifting the black levels when shooting, then reducing or redefining contrast when one is editing.

Graeme Nattress · May 13th, 2004, 02:05 PM

Agreed - as I say, that's why I use the ultra contrast filter as it gives me more room in post.

The comments on the Canon are interesting - DV should have black at IRE 0 - that's digital video for you. Was it peaking at 115 even if you're just hitting zebras at 100? If it records accurately, although illegally in that range, can it not give you more room in post if you've managed to record a wider dynamic range? As long as you don't just clip the whites, it could be advantageous, and indeed is this not what the cine-gamma on the DVX100 does?

I sounds like having a pre-tape brightness control would be a useful addition to any camera to help with difficult shots. I wish the affordable cameras had a lot of more controls in this area as it would really allow you to get the most out of filters and difficult lighting, and as you say, expanding the contrast range that is shootable without clipping.

Graeme

Alessandro Machi · May 13th, 2004, 10:07 PM

<<<-- Originally posted by Graeme Nattress : can it not give you more room in post if you've managed to record a wider dynamic range? As long as you don't just clip the whites, it could be advantageous, and indeed is this not what the cine-gamma on the DVX100 does?
Graeme -->>>

I think it may work the opposite way. Pull the darker parts of the scene up when actually videotaping, then readjust the final contrast values when editing.

The key is as you said, don't clip the whites and don't excessively crush the darker part of the scene when actually videotaping.

May 13th, 2004, 01:09 PM	#16
Alessandro Machi Major Player Join Date: Oct 2003 Location: Los Angeles, Ca USA Posts: 553	My ENG camera has both 7.5 and black level adjustment. When I lift the adjustment to a +1 or +2, I definitely gain lower black sensitivity and it's no longer at a lower than 7.5 IRE. The black level adjustment lifts the darker parts of the scene without raising the brighter parts of the scene. Then when I edit I choose what I want to crush and what I don't want to crush. __________________ https://alexlogic.blogspot.com/ Los Angeles Emmy Winner (yes, used a video edit controller and loved doing so.)

May 13th, 2004, 01:33 PM	#17
Graeme Nattress RED Problem Solver Join Date: Sep 2003 Location: Ottawa, Canada Posts: 1,365	I think that's a strictly analogue camera phenonema, and is really a black level ("brightness") adjustment. Although, there was talk of something like this on the Canon XL1 with a similar control. I use an ultra contrast filter to give me more control over crushing blacks in post and this looks great. Graeme __________________ www.nattress.com - filters for FCP

May 13th, 2004, 01:55 PM	#18
Alessandro Machi Major Player Join Date: Oct 2003 Location: Los Angeles, Ca USA Posts: 553	I was adjusting the black level once and I accidentally left the camera running while I was shifting the black level adjust, when I viewed the footage later I was shocked to see detail emerge on the persons dark suit right at the moment that I lifted the black from the default setting of zero up to one, then to two. The additional gain in detail in the dark areas was significant, so even though I was at 7.5 the additional adjustment of the pedestal was necessary. The Canon XLS-1 that I reviewed for camcorder magazine two years ago was most definitely too contrasty for camera acquisition. The brights were over 115 and the darks were almost to zero IRE, this will cause one to lose precious data in the dark areas of the scene. The good news is the Canon XL1-S allows you to save different settings that allow one to lift the black level. In my opinion Video acquistion should always be about getting as much of the visual information as possible by reducing the contrast. Contrast reduction is achieved by lifting the black levels when shooting, then reducing or redefining contrast when one is editing. __________________ https://alexlogic.blogspot.com/ Los Angeles Emmy Winner (yes, used a video edit controller and loved doing so.)

May 13th, 2004, 02:05 PM	#19
Graeme Nattress RED Problem Solver Join Date: Sep 2003 Location: Ottawa, Canada Posts: 1,365	Agreed - as I say, that's why I use the ultra contrast filter as it gives me more room in post. The comments on the Canon are interesting - DV should have black at IRE 0 - that's digital video for you. Was it peaking at 115 even if you're just hitting zebras at 100? If it records accurately, although illegally in that range, can it not give you more room in post if you've managed to record a wider dynamic range? As long as you don't just clip the whites, it could be advantageous, and indeed is this not what the cine-gamma on the DVX100 does? I sounds like having a pre-tape brightness control would be a useful addition to any camera to help with difficult shots. I wish the affordable cameras had a lot of more controls in this area as it would really allow you to get the most out of filters and difficult lighting, and as you say, expanding the contrast range that is shootable without clipping. Graeme __________________ www.nattress.com - filters for FCP

May 13th, 2004, 10:07 PM	#20
Alessandro Machi Major Player Join Date: Oct 2003 Location: Los Angeles, Ca USA Posts: 553	<<<-- Originally posted by Graeme Nattress : can it not give you more room in post if you've managed to record a wider dynamic range? As long as you don't just clip the whites, it could be advantageous, and indeed is this not what the cine-gamma on the DVX100 does? Graeme -->>> I think it may work the opposite way. Pull the darker parts of the scene up when actually videotaping, then readjust the final contrast values when editing. The key is as you said, don't clip the whites and don't excessively crush the darker part of the scene when actually videotaping. __________________ https://alexlogic.blogspot.com/ Los Angeles Emmy Winner (yes, used a video edit controller and loved doing so.)