Underexposed Footage & AE 32bit Mode Question at DVinfo.net

Devon Lyon · June 21st, 2007, 09:01 PM

David:

We recently shot part of a short film with a A1 and Brevis 35mm adaptor to tape. The footage at issue was shot at night (with lights) but is still pretty dark. When we watch the footage piped out of the camera directly to a HD monitor there is sufficient light and detail. We then captured the footage via Prospect HD to 1920x1080 (at either High or Film Scan 1, don't remember).

After capture the footage sure seems darker. Here is something I don't understand. I looks the least dark in AE 7.0 at 8bits and is almost totally dark in AE at 32bits. Why is that?

Also, when dealing with the Cineform codec, is there any particular tricks to help bring some of the detail out without ruining the picture? Remember that when we watch the tape directly to HD Monitor there is sufficient light/detail.

Would love to hear your thoughts. Thanks buddy!

David Newman · June 21st, 2007, 09:46 PM

The darkness in 8-bit and 16-bit mode of AE just reflects the characteristic your computer monitor vs the display you previewed on. If you output via an AJA card to that preview monitor it will look the same. Just clearing up that the image is not darker as a result on CineForm compression.

32-bit -- great the you are using this -- in this mode the image is converted from the display gamma to photometrically linear, we is much more suitable of enhancing the image. It is darker because it is now linear data being displayed on a 2.2 gamma monitor (or similar.) Add a adjustment layer to restore the viewing gamma so that is look the same as 8/16-bit modes -- but only apply monitor calibrations to the adjustment layer, preserving your linear source. Now if you add gain to the source clip in linear space, you have a mathematically correct exposure control. Gain of 2.0 is the same adding a stop. As for more hint for dark footage enhancement, sorry I'm not a color correction expert, so I hope others can jump in.

Sergio Sanchez · June 22nd, 2007, 12:59 AM

I`ve found this link in wich is explained how to set up a 32bit workflow in AE, maybe its useful to you

http://www.fxguide.com/article336.html

Devon Lyon · June 22nd, 2007, 06:04 PM

Thanks Sergio, I will check it out. Also, if anyone does have any extra tidbits of info on making dark, underexposed footage look better - we would appreciate it (as this is the first time we've really had this issue). Thanks!

June 21st, 2007, 09:01 PM	#1
Devon Lyon Major Player Join Date: May 2005 Location: Oregon Posts: 213	Underexposed Footage & AE 32bit Mode Question David: We recently shot part of a short film with a A1 and Brevis 35mm adaptor to tape. The footage at issue was shot at night (with lights) but is still pretty dark. When we watch the footage piped out of the camera directly to a HD monitor there is sufficient light and detail. We then captured the footage via Prospect HD to 1920x1080 (at either High or Film Scan 1, don't remember). After capture the footage sure seems darker. Here is something I don't understand. I looks the least dark in AE 7.0 at 8bits and is almost totally dark in AE at 32bits. Why is that? Also, when dealing with the Cineform codec, is there any particular tricks to help bring some of the detail out without ruining the picture? Remember that when we watch the tape directly to HD Monitor there is sufficient light/detail. Would love to hear your thoughts. Thanks buddy! __________________ Lyon Films www.LyonFilms.com;

June 21st, 2007, 09:46 PM	#2
David Newman CTO, CineForm Inc. Join Date: Jul 2003 Location: Cardiff-by-the-Sea, California Posts: 8,095	The darkness in 8-bit and 16-bit mode of AE just reflects the characteristic your computer monitor vs the display you previewed on. If you output via an AJA card to that preview monitor it will look the same. Just clearing up that the image is not darker as a result on CineForm compression. 32-bit -- great the you are using this -- in this mode the image is converted from the display gamma to photometrically linear, we is much more suitable of enhancing the image. It is darker because it is now linear data being displayed on a 2.2 gamma monitor (or similar.) Add a adjustment layer to restore the viewing gamma so that is look the same as 8/16-bit modes -- but only apply monitor calibrations to the adjustment layer, preserving your linear source. Now if you add gain to the source clip in linear space, you have a mathematically correct exposure control. Gain of 2.0 is the same adding a stop. As for more hint for dark footage enhancement, sorry I'm not a color correction expert, so I hope others can jump in. __________________ David Newman -- web: www.gopro.com blog: cineform.blogspot.com -- twitter: twitter.com/David_Newman

June 22nd, 2007, 06:04 PM	#4
Devon Lyon Major Player Join Date: May 2005 Location: Oregon Posts: 213	Thanks Sergio, I will check it out. Also, if anyone does have any extra tidbits of info on making dark, underexposed footage look better - we would appreciate it (as this is the first time we've really had this issue). Thanks! __________________ Lyon Films www.LyonFilms.com;

June 22nd, 2007, 12:59 AM	#3
Sergio Sanchez Regular Crew Join Date: Feb 2007 Location: Mexico Posts: 176	I`ve found this link in wich is explained how to set up a 32bit workflow in AE, maybe its useful to you http://www.fxguide.com/article336.html