Dark end of imported stills at DVinfo.net

Lauri Kettunen · September 26th, 2006, 11:36 AM

When importing still images --8-bit Photoshop document files converted from Canon raw files-- to a ProspectHD project in PPro 2.0, the black end of the images appear much darker in Premiere monitor window than in Photoshop CS2. This is not a serious problem, for the images can be rather easily adjusted. However, it still means the images have to be adjusted twice. First in Photoshop and then again in Premiere.

Is this a color space issue or something else, perhaps some mismatch with gamma adjustments? In any case, which color space matches best with CFHD projects in Premiere?

David Newman · September 26th, 2006, 01:10 PM

Likely a color profile/gamma issue. Premiere uses a pretty standard 2.2 gamma RGB.

Jay Hancock · September 26th, 2006, 02:55 PM

When you adjusted the image in PhotoShop, did you make it broadcast legal? Meaning the luminance ranges from 16 at the black end to 235 for brightest white. As you know, the range in the computer space is 0-255...

I don't know PPro (I use Vegas), but I am sure that if PPro is adjusting the image to make it broadcast legal, any blacks with luminance 16 and below will get crushed down to blackest black unless you had made this adjustment already in PhotoShop.

Since you are using PhotoShop CS2, you should be able to preview your still on an actual television using the firewire out through a A/D convertor box. If the TV is calibrated and the convertor sends correct IRE levels, you'll see what the image is going to look like on the video platform.

Lauri Kettunen · September 27th, 2006, 01:47 AM

Quote:

Originally Posted by Jay Hancock

When you adjusted the image in PhotoShop, did you make it broadcast legal? Meaning the luminance ranges from 16 at the black end to 235 for brightest white. As you know, the range in the computer space is 0-255...

Right, however, would sound plausible if the question was of a DV-project in Premiere. Does the same apply to CFHD projects? Does Premiere really assume every project is meant to be braodcasted? In fact, I've even never noticed that same with DV projects.

My monitor is calibrated to 2.2 gamme with a pro-level device. So the color profile should be in control. (Calibration of TVs is always bit questionable. So, I would not rely on them.) Besides, the question is, why the same images appear different on the same display.

Sounds like I should make tests with the color space.

David, is there any chance that the ProspectHD codec throwed away some small details of dark colors? The problem appears in images taken of stars and aurora borealis during the night. More precisely, if there is some ground in the image, the small variations of its dark tones cannot be recognized in PPro2. Instead the landscape appears like one single bulk in dark shadow.

Pete Bauer · September 27th, 2006, 02:53 AM

Lauri, I'm stretching my limited knowledge here but since Prospect is 10-bit, I doubt that it is truncating an 8-bit image. I'm at work right now so can't check but rather than using the default Adobe RGB, perhaps Photoshop has a color space that more closely matches the HD's 709? Worth a look anyway.

Myself, I haven't noticed any difficulties like that using *.psd files that originated as Canon 20D raw stills, and importing them into PPro/AspectHD timelines with XL H1 footage. But then, my projects probably weren't nearly as challenging as imaging auroras.

Also, have you tried a quick render to check that it isn't just a limitation of the monitor window that perhaps might not be a problem in a final render? PPro will throttle back on the program/monitor window image quality to attempt to keep playback smooth, so maybe it limits color rendition as well as resolution?

Jay Hancock · September 27th, 2006, 08:03 AM

Quote:

Originally Posted by Lauri Kettunen

Right, however, would sound plausible if the question was of a DV-project in Premiere. Does the same apply to CFHD projects? Does Premiere really assume every project is meant to be braodcasted? In fact, I've even never noticed that same with DV projects.

My monitor is calibrated to 2.2 gamme with a pro-level device. So the color profile should be in control. (Calibration of TVs is always bit questionable. So, I would not rely on them.) Besides, the question is, why the same images appear different on the same display.

The real question is, what's the target for this project? Will it be for viewing on a television or a computer?

Regardless of the fact that Photoshop and Premier are using the same display, if color management is turned on in PhotoShop it is altering the colors on that display.

If you are targeting television viewing for your Premier project, you should turn color management OFF in PhotoShop. I'm not the expert; I am taking that from Richard Harrington, author of many books about using PhotoShop for video productions. If your target is to view the project on a computer (only), this advice doesn't apply.

Why turn off color management? Mainly because you can't load an ICC profile on your television. Photoshop shouldn't either, or else they are guaranteed to look different.

Back to your original question why they look different on the same display. While Premier may not always assume you are going to broadcast your video, it also doesn't know or care what ICC profile you use in PhotoShop. Or it shouldn't, anyway. I'm not a Premier user. Does Premier color manage preview displays with ICC profiles? If it does, think carefully about the real target environment of the project. Adobe RGB is primarily for print. Most video isn't for print. And most computer monitors don't use Adobe RGB for normal display. And certainly TV's don't either. Assuming your target is only for viewing on a computer, PhotoShop and Premier must use exactly the same ICC profile for previewing or else they'll look different. If Premier isn't using a color profile, turn off color management in PhotoShop.

David Newman · September 27th, 2006, 12:32 PM

First off Premiere uses CG RGB 0-255, not video systems RGB 16-235. So 0,0,0 is black in Premiere and that is how Prospect HD interprets black from graphics sources (BMP, TIFFs, etc.) Only YUV sources have black at 16 (or 64 in 10-bit.) Prospect HD will not clip the data as we have plenty of film customers who want the extended color range.

Can I see the frame in question? Please email me a download link.

Jay Hancock · September 27th, 2006, 05:58 PM

Quote:

Originally Posted by David Newman

First off Premiere uses CG RGB 0-255, not video systems RGB 16-235. So 0,0,0 is black in Premiere and that is how Prospect HD interprets black from graphics sources (BMP, TIFFs, etc.) Only YUV sources have black at 16 (or 64 in 10-bit.) Prospect HD will not clip the data as we have plenty of film customers who want the extended color range.

Can I see the frame in question? Please email me a download link.

David - I think we're not contradicting each other, but maybe on the surface it sounds like it. I know that all NLE's take 0-255. And I certainly wasn't suggesting that Cineform's product differs. Regarding the 16-235 part, I was only referring to what the output will look like on a video out (like to a television) or to a preview window if Premiere has settings to do it that way.

And my other comment (which I think is exactly the issue) was that using an ICC profile in PhotoShop will make colors look different than if they are shown in Premiere without any such profile in use. I think (hope) that my last post made that point well enough (and I didn't mention the 16-235 point in that post).

I think none of this has anything to do with Cineform. It's all a question of using color management in PhotoShop. If the posts are read carefully, hopefully I didn't inject any confusion regarding CF.

Lauri Kettunen · September 28th, 2006, 04:11 AM

Jay, Pete, Thanks for sharing your thoughts. David checked the situation and it seems the problem is local and related to my computer. However, will get a new one in couple days, so hopefully the problem also disappears.

Lauri Kettunen · October 11th, 2006, 11:56 AM

Have now a new machine, including display, and the problem with still images disappeared. However, now I see for the first time this issue mentioned at Cineform webpages: There is a slight color shift in colors when viewing the rendered video in ProspectHD Premiere project. More precisely, the colors of of the stills are right in the monitor window. Then, after rendering the timeline, there is a small but clearly observable shift in colors.

Is it possible to calibrate the colors of the video overlay? My display adapter is Nvidia GeForce 7600GS, and it seems to enable one to import a color profile *for the overlay*. But, how can one create such a profile? Or, is it that the color profile will not affect the overlay colors? (This setting is under 'color correction', where one has 'overlay', below that one is 'all channels' and below this one has 'color profile' with an option 'import'.)

I have calibrated my monitor with Colorvision software (Spyder2Pro), but at least this software does not seem to have anything for creating a profile for the overlay.

September 26th, 2006, 11:36 AM	#1
Lauri Kettunen Major Player Join Date: Aug 2004 Location: Kangasala, Finland Posts: 445	Dark end of imported stills When importing still images --8-bit Photoshop document files converted from Canon raw files-- to a ProspectHD project in PPro 2.0, the black end of the images appear much darker in Premiere monitor window than in Photoshop CS2. This is not a serious problem, for the images can be rather easily adjusted. However, it still means the images have to be adjusted twice. First in Photoshop and then again in Premiere. Is this a color space issue or something else, perhaps some mismatch with gamma adjustments? In any case, which color space matches best with CFHD projects in Premiere?

September 26th, 2006, 01:10 PM	#2
David Newman CTO, CineForm Inc. Join Date: Jul 2003 Location: Cardiff-by-the-Sea, California Posts: 8,095	Likely a color profile/gamma issue. Premiere uses a pretty standard 2.2 gamma RGB. __________________ David Newman -- web: www.gopro.com blog: cineform.blogspot.com -- twitter: twitter.com/David_Newman

September 26th, 2006, 02:55 PM	#3
Jay Hancock Regular Crew Join Date: Jan 2005 Location: Dallas, TX Posts: 40	Jay Hancock When you adjusted the image in PhotoShop, did you make it broadcast legal? Meaning the luminance ranges from 16 at the black end to 235 for brightest white. As you know, the range in the computer space is 0-255... I don't know PPro (I use Vegas), but I am sure that if PPro is adjusting the image to make it broadcast legal, any blacks with luminance 16 and below will get crushed down to blackest black unless you had made this adjustment already in PhotoShop. Since you are using PhotoShop CS2, you should be able to preview your still on an actual television using the firewire out through a A/D convertor box. If the TV is calibrated and the convertor sends correct IRE levels, you'll see what the image is going to look like on the video platform.

September 27th, 2006, 02:53 AM	#5
Pete Bauer Wrangler Join Date: May 2003 Location: Eagle River, AK Posts: 4,100	Lauri, I'm stretching my limited knowledge here but since Prospect is 10-bit, I doubt that it is truncating an 8-bit image. I'm at work right now so can't check but rather than using the default Adobe RGB, perhaps Photoshop has a color space that more closely matches the HD's 709? Worth a look anyway. Myself, I haven't noticed any difficulties like that using .psd files that originated as Canon 20D raw stills, and importing them into PPro/AspectHD timelines with XL H1 footage. But then, my projects probably weren't nearly as challenging as imaging auroras. Also, have you tried a quick render to check that it isn't just a limitation of the monitor window that perhaps might not be a problem in a final render? PPro will throttle back on the program/monitor window image quality to attempt to keep playback smooth, so maybe it limits color rendition as well as resolution? __________________ Pete Bauer* The most beautiful thing we can experience is the mysterious. It is the source of all true art and science. Albert Einstein Trying to solve a DV mystery? You may find the answer behind the SEARCH function ... or be able to join a discussion already in progress!

September 27th, 2006, 12:32 PM	#7
David Newman CTO, CineForm Inc. Join Date: Jul 2003 Location: Cardiff-by-the-Sea, California Posts: 8,095	First off Premiere uses CG RGB 0-255, not video systems RGB 16-235. So 0,0,0 is black in Premiere and that is how Prospect HD interprets black from graphics sources (BMP, TIFFs, etc.) Only YUV sources have black at 16 (or 64 in 10-bit.) Prospect HD will not clip the data as we have plenty of film customers who want the extended color range. Can I see the frame in question? Please email me a download link. __________________ David Newman -- web: www.gopro.com blog: cineform.blogspot.com -- twitter: twitter.com/David_Newman

September 28th, 2006, 04:11 AM	#9
Lauri Kettunen Major Player Join Date: Aug 2004 Location: Kangasala, Finland Posts: 445	Jay, Pete, Thanks for sharing your thoughts. David checked the situation and it seems the problem is local and related to my computer. However, will get a new one in couple days, so hopefully the problem also disappears.

October 11th, 2006, 11:56 AM	#10
Lauri Kettunen Major Player Join Date: Aug 2004 Location: Kangasala, Finland Posts: 445	Have now a new machine, including display, and the problem with still images disappeared. However, now I see for the first time this issue mentioned at Cineform webpages: There is a slight color shift in colors when viewing the rendered video in ProspectHD Premiere project. More precisely, the colors of of the stills are right in the monitor window. Then, after rendering the timeline, there is a small but clearly observable shift in colors. Is it possible to calibrate the colors of the video overlay? My display adapter is Nvidia GeForce 7600GS, and it seems to enable one to import a color profile for the overlay. But, how can one create such a profile? Or, is it that the color profile will not affect the overlay colors? (This setting is under 'color correction', where one has 'overlay', below that one is 'all channels' and below this one has 'color profile' with an option 'import'.) I have calibrated my monitor with Colorvision software (Spyder2Pro), but at least this software does not seem to have anything for creating a profile for the overlay.