View Full Version : Ugly Screengrabs


Adam Reuter
October 20th, 2008, 03:52 PM
Last year when working on a movie and part of a documentary I exported some screengrabs from Final Cut Pro. I've attached screen grabs.

Those stills look the same to me on my computer monitor as they do on my HDTV. They were shot with a Panasonic HVX200.

Now, when I export stills that were shot with the EX1 using the Clip Browser software my images look bleh. Desaturated, soft and washed out are the ways I describe them. NOTHING like what they look like on my TV screen. Are all stills exporters not created equal?

Funnily enough the only good results I've had when outputting for web video is with Quicktime...which of course is Apple owned/supported. So there MUST be some Apple colorspace/gamma mojo happening to get this quality.

I saw a recent post with EX1 stills that look fantastic. I've PMed the forum member but am wondering about EX users who have access to FCP (I don't, I was editing the movie/documentary at a rental house.) How do your screengrabs look? Even when using "punchy" or "HVX look" picture profiles in the EX1 the stills look washed out/soft in comparison.

Adam Reuter
October 20th, 2008, 04:06 PM
Here's a much better example. This is from my Windows-based NLE software...using the exact same footage from the HVX200 but exported as a still from the timeline. The NLE's still export looks the same as Clip Browser's export.

Noah Kadner
October 20th, 2008, 04:36 PM
Not sure to suggest what as you don't say which NLE is making these grabs not look good. But it's fixable in about four seconds in Photoshop, simply open there and do auto-color, auto-contrast and then correct additionally as needed. As I'm sure you've discovered printing stills off a timeline is not the best way to get good stills but sometimes it's the only way. If you need to tweak them a little bit due to gamma shifts or whatever, not the end of the world. Also don't forget Macs and PCs do not have the same basic gamma characteristics:

http://www.kenstone.net/fcp_homepage/gamma_mac_pc.html

Noah

Tom Roper
October 21st, 2008, 01:43 PM
Could it be PC (RGB) space 0-255 versus HDTV 16-235?

Videos viewed on Windows Media Player have the same washed out appearance for me. Shouldn't there be a Windows Color System profile for 16-235?

Phil Bloom
October 22nd, 2008, 05:45 AM
I use quicktime to export my screen grabs and they are identical.

Barry J. Anwender
October 22nd, 2008, 08:45 AM
Could it be PC (RGB) space 0-255 versus HDTV 16-235?


The EXn generates video in the component color space (i.e YPbPr) which is Sony's designation for digital YUV. So yes if your moving a frame grab to an RGB application then the result will be off.

I can confirm this with repeatable results when capturing frames from EX3 HD-SDI port directly into Photoshop or into FCP via my Blackmagic Multibridge Extreme. The DeckLink Photoshop plugin has options to capture 16bit frame grabs either as YUV or as RGB. So I can see the shifts between these two color spaces. The DeckLink-Photoshop frame grabs are crisp and clear, noticeably better results than extracting a FCP frame.

Barry J. Anwender
October 22nd, 2008, 11:21 AM
It took me a while to dig this out again and as usual Adam Wilt has a very thorough and detailed explanation of what happens when exporting stills from FCP. He clearly explains the digital YUV and RGB scaling differences. Chris, I hope it's alright to post this link to Adam's article.

ProVideo Coalition.com: Camera Log by Adam Wilt | Founder | Pro Cameras, HDV Camera, HD Camera, Sony, Panasonic, JVC, RED, Video Camera Reviews (http://provideocoalition.com/index.php/awilt/story/exporting_stills_from_fcp/)

Bob Jackson
October 22nd, 2008, 03:37 PM
i have used snap x pro with xdcam transfer and it works great.