Ad
Ad
Ad
Pages: [1] 2 »   Bottom of Page
Print
Author Topic: What is the purpose of the Leaf Prophoto RGB profile?  (Read 1979 times)
torger
Sr. Member
****
Offline Offline

Posts: 1588


« on: December 16, 2013, 02:49:25 AM »
ReplyReply

I've read the Leaf Technical Bulletin on image profiles which covers all profiles except the "LeafLF2/3-Prophoto RGB.icm" profile. Anyone who knows what that the properties of that profile is and the intended use? I've noted that unlike the other profiles it has an exact linear curve (which is gamma 1.8 for Capture One, the others are closer to gamma 1.9 or 2.0) so I'm thinking that maybe it's some sort of repro copy type of profile, ie as neutral as possible. What's the calibration illuminant?
Logged
JerryReed
Sr. Member
****
Offline Offline

Posts: 276


jerry@jerryreed.net


WWW
« Reply #1 on: December 16, 2013, 03:32:47 AM »
ReplyReply

Usually D50.
Logged

yaya
Sr. Member
****
Offline Offline

Posts: 1137



WWW
« Reply #2 on: December 16, 2013, 04:08:03 AM »
ReplyReply

Hi Torger,

We've added this profile some years ago, if you look in its properties you'll find that it says "Copyright (c) Eastman Kodak Company, 1999"

It is meant to provide a fairly wide gamut that more or less presents what Kodak and Dalsa CCDs can capture. It is not a linear profile however but at the time many customers a retouchers liked it as it gave them a fairly neutral starting point when going into photoshop

Hope this helps

Yair
Logged

Yair Shahar | Product Manager | Mamiya Leaf |
e: ysh@mamiyaleaf.com | m: +44(0)77 8992 8199 | www.mamiyaleaf.com | yaya's blog
torger
Sr. Member
****
Offline Offline

Posts: 1588


« Reply #3 on: December 16, 2013, 05:24:45 AM »
ReplyReply

Thanks Yair, that was what I wanted to know.

The copyright actually says "Copyright (c) 2010 Phase One A/S. All rights reserved", but I guess that's since they got bundled with Capture One. The other Leaf profiles have the expected copyright (Leaf/Kodak/Creo depending on age).

On visual inspection when applying the profile on my Aptus 75 it's hard to see any difference between using it and only applying the color matrix. There probably is a little difference but says something about the natural color this sensor is capable of, very little correction is required. This is also the experience I have from making own custom profiles with daylight illuminant.
« Last Edit: December 16, 2013, 05:58:19 AM by torger » Logged
yaya
Sr. Member
****
Offline Offline

Posts: 1137



WWW
« Reply #4 on: December 16, 2013, 06:32:53 AM »
ReplyReply

Regarding the various copyrights I was looking at an older version but they are all the same profile, just different licensing etc....

In general the ProfotoRGB is a bit flatter and less saturated than the LF1/2/3 product profiles. It tends to warm up some of the Red and Magenta tones though

Yair
Logged

Yair Shahar | Product Manager | Mamiya Leaf |
e: ysh@mamiyaleaf.com | m: +44(0)77 8992 8199 | www.mamiyaleaf.com | yaya's blog
digitaldog
Sr. Member
****
Offline Offline

Posts: 9191



WWW
« Reply #5 on: December 16, 2013, 11:50:03 AM »
ReplyReply

It is meant to provide a fairly wide gamut that more or less presents what Kodak and Dalsa CCDs can capture.
Then I doubt it's actually ProPhoto (or ROMM RGB). Like to take a look at it in ColorThink.
Logged

Andrew Rodney
Author “Color Management for Photographers”
http://digitaldog.net/
yaya
Sr. Member
****
Offline Offline

Posts: 1137



WWW
« Reply #6 on: December 16, 2013, 12:25:09 PM »
ReplyReply

Like to take a look at it in ColorThink.

By all means....
Logged

Yair Shahar | Product Manager | Mamiya Leaf |
e: ysh@mamiyaleaf.com | m: +44(0)77 8992 8199 | www.mamiyaleaf.com | yaya's blog
digitaldog
Sr. Member
****
Offline Offline

Posts: 9191



WWW
« Reply #7 on: December 16, 2013, 12:37:33 PM »
ReplyReply

Thanks. It IS ProPhoto RGB. It probably isn't in any way related to some chip or capture device (ProPhoto RGB was designed as an editing space). So this is a good profile to convert TO from some native camera color space for editing.
Logged

Andrew Rodney
Author “Color Management for Photographers”
http://digitaldog.net/
eronald
Sr. Member
****
Offline Offline

Posts: 4121



« Reply #8 on: December 16, 2013, 12:45:43 PM »
ReplyReply

Thanks. It IS ProPhoto RGB. It probably isn't in any way related to some chip or capture device (ProPhoto RGB was designed as an editing space). So this is a good profile to convert TO from some native camera color space for editing.

ProPhotoRGB is a huge space. I think it was proposed for storing images in a colorimetrically well defined space without clipping any real-world colors; sRGB is or rather was a convenient display and edit space but it destructively clips quite a bit of the colors we encounter. This means that it is better to keep the originals in a wide-gamut space.

Editing in 8 bit mode in ProphotoRGB is not a good idea, steps will be too large, 16 bit editors are mandatory. Andrew knows this much better than I do of course.

As to the strange name, I guess that redefining the space by primaries and gamma takes about 5 minutes, in fact Photoshop does it for you in the custom profile conversion dialog, and that solves all painful copyright issues that may arise from copying a standard file. These days I expect US copyright law criminalizes the inclusion of a profile in an image if you cannot prove you are licensed, and rendition teams are standing by ...

Edmund
« Last Edit: December 16, 2013, 02:03:29 PM by eronald » Logged
torger
Sr. Member
****
Offline Offline

Posts: 1588


« Reply #9 on: December 18, 2013, 10:10:09 AM »
ReplyReply

Thanks. It IS ProPhoto RGB. It probably isn't in any way related to some chip or capture device (ProPhoto RGB was designed as an editing space). So this is a good profile to convert TO from some native camera color space for editing.

All Leaf Aptus ICC profiles are in Prophoto space, and is in that way different from the other profiles bundled with Capture One. The Aptus raw format (.mos) has a Camera RGB to Prophoto RGB color matrix built-in, so what you do is that you convert the demosaiced and white-balanced demosaiced raw data into prophoto by matrixing, apply inverse gamma (1/1.Cool and your desired tone-curve (the profiles seem to be calibrated for a their standard curves, ie color is not as good if you feed it with linear data), and then you put it through the Leaf ICC profile, and out comes wonderful color :-)
Logged
digitaldog
Sr. Member
****
Offline Offline

Posts: 9191



WWW
« Reply #10 on: December 18, 2013, 10:16:05 AM »
ReplyReply

All Leaf Aptus ICC profiles are in Prophoto space, and is in that way different from the other profiles bundled with Capture One. The Aptus raw format (.mos) has a Camera RGB to Prophoto RGB color matrix built-in, so what you do is that you convert the demosaiced and white-balanced demosaiced raw data into prophoto by matrixing, apply inverse gamma (1/1.Cool and your desired tone-curve (the profiles seem to be calibrated for a their standard curves, ie color is not as good if you feed it with linear data), and then you put it through the Leaf ICC profile, and out comes wonderful color :-)

Not sure I fully understand this. Perhaps you are saying, much like Adobe's raw converters, the processing color space is ProPhoto RGB or a variant (alteration of TRC). But the camera isn't producing ProPhoto RGB. The source color space isn't ProPhoto RGB. And when you say: All Leaf Aptus ICC profiles are in Prophoto space that doesn't make sense to me (all?, why would there need to be more than one such profile? ProPhoto is ProPhoto). Camera RGB to Prophoto RGB color matrix built-in sounds like there's some assumed camera color space which is then converted to ProPhoto RGB while processing the data. Is that correct? That's how LR and ACR operate.
Logged

Andrew Rodney
Author “Color Management for Photographers”
http://digitaldog.net/
torger
Sr. Member
****
Offline Offline

Posts: 1588


« Reply #11 on: December 18, 2013, 10:28:40 AM »
ReplyReply

Not sure I fully understand this. Perhaps you are saying, much like Adobe's raw converters, the processing color space is ProPhoto RGB or a variant (alteration of TRC). But the camera isn't producing ProPhoto RGB. The source color space isn't ProPhoto RGB. And when you say: All Leaf Aptus ICC profiles are in Prophoto space that doesn't make sense to me (all?, why would there need to be more than one such profile? ProPhoto is ProPhoto). Camera RGB to Prophoto RGB color matrix built-in sounds like there's some assumed camera color space which is then converted to ProPhoto RGB while processing the data. Is that correct? That's how LR and ACR operate.

There are "portrait", "product" profiles with LUTs that provide different looks. All of them expect an input which is in prophoto working space. Probably the processing/working color space was prophoto in Leaf Capture, the profiles are from that time. Nowadays Leaf is processed in Capture One, and I don't know what they use as working space, so there could be some additional conversion.

Yes the processing pipeline is very similar to Adobe's DCP, ie first you use a matrix conversion from camera RGB to get into some-close-to-target color rendition in the Prophoto color space (with the use of ForwardMatrices Adobe's DCP has stopped producing sane color with matrices though for some reason I don't understand, color look way off until you apply the LUT), and then you apply a LUT for further color adjustments. A difference is that with Leaf's profiles you apply the tone-curve before the LUT, while with DCP you apply it after.

So yes, the colors coming from the sensor and stored in the raw file is not in Prophoto RGB.
« Last Edit: December 18, 2013, 10:30:28 AM by torger » Logged
digitaldog
Sr. Member
****
Offline Offline

Posts: 9191



WWW
« Reply #12 on: December 18, 2013, 10:36:14 AM »
ReplyReply

There are "portrait", "product" profiles with LUTs that provide different looks.
What's that got to do with ProPhoto RGB?
Something is happening behinds the scenes here as in most raw converters. Few of it has anything to do with ProPhoto RGB I suspect. Pretty clear the colors coming from the sensor and stored in the raw file is not in Prophoto RGB, that's not possible.

Here's the deal though. There's only one ProPhtot RGB. It was designed by Kodak with a non ambiguous set of parameters. Change a single value, it's no longer ProPhoto RGB. It's a synthetic color space that defines 'colors' we can't see (so I submit they are not colors). It's not based on any capture or output device. There is no such thing as LeafLF2/3-Prophoto RGB.icm. It may or may not be ProPhoto RGB and if the chromaticity, white point and TRC match ProPhoto, let's just forget anything to do with LEAF.  Nikon did the same silly thing with sRGB, another example of companies making color management even more confusing than it is and for no reason.
Logged

Andrew Rodney
Author “Color Management for Photographers”
http://digitaldog.net/
torger
Sr. Member
****
Offline Offline

Posts: 1588


« Reply #13 on: December 18, 2013, 11:33:42 AM »
ReplyReply

Color management is complex enough so you need to take into account that non-experts like me may not be using the terminology as exact Smiley Note that I'm just a Leaf owner (I have no association with Leaf) and my knowledge of these profiles comes from reverse engineering as I want to be able to use those profiles in other software than just Capture One. Closed up formats and systems just suck for the users, so I try to make it a bit more open. Hopefully Leaf won't hate me for that Smiley.

A more suitable name for "Leaf Prophoto RGB" would probably be "Leaf Neutral" so it's put in relation to "Leaf Portrait", "Leaf Product" etc, then I would not have needed to ask the question in first place, but it is as it is. I would guess that the profile has been made through the same calibration process as the product and portrait profiles, but no additional "look tweaks" have been applied.
Logged
digitaldog
Sr. Member
****
Offline Offline

Posts: 9191



WWW
« Reply #14 on: December 18, 2013, 11:35:37 AM »
ReplyReply

A more suitable name for "Leaf Prophoto RGB" would probably be "Leaf Neutral" so it's put in relation to "Leaf Portrait", "Leaf Product" etc, then I would not have needed to ask the question in first place, but it is as it is.

Exactly. This discussion really has nothing to do with ProPhoto RGB despite Leaf putting their name in front of it. They've just confused the issue (hence your question).
Logged

Andrew Rodney
Author “Color Management for Photographers”
http://digitaldog.net/
yaya
Sr. Member
****
Offline Offline

Posts: 1137



WWW
« Reply #15 on: December 18, 2013, 01:47:22 PM »
ReplyReply

FWIW and to clear up the conspiracy theory...In Leaf Capture the profile is called Profoto RGB (the one I've attached a few posts up) and it was added many moons ago following requests from users (catalogue and repro houses) and some 3rd party developers to have the ability to export the RAW files in a space as wide as possible or as close as possible to the camera's RGB space (without looking too "ugly"). In Leaf Capture you can set it as either Input or Output profile or you can switch colour management off and choose the profile when you open the image in e.g. Photoshop (depends on your colour settings)

Capture One supports many cameras and the input profiles there are organised into groups with the vendor's name on them, so adding "Leaf" in front of "Profoto RGB" made (and still makes) a lot of sense to any Leaf users coming from Leaf Capture.

Yair
Logged

Yair Shahar | Product Manager | Mamiya Leaf |
e: ysh@mamiyaleaf.com | m: +44(0)77 8992 8199 | www.mamiyaleaf.com | yaya's blog
eronald
Sr. Member
****
Offline Offline

Posts: 4121



« Reply #16 on: December 18, 2013, 01:49:27 PM »
ReplyReply

Exactly. This discussion really has nothing to do with ProPhoto RGB despite Leaf putting their name in front of it. They've just confused the issue (hence your question).

color mismanagement Smiley
Edmund
Logged
digitaldog
Sr. Member
****
Offline Offline

Posts: 9191



WWW
« Reply #17 on: December 18, 2013, 01:54:35 PM »
ReplyReply

FWIW and to clear up the conspiracy theory...In Leaf Capture the profile is called Profoto RGB (the one I've attached a few posts up) and it was added many moons ago following requests from users (catalogue and repro houses) and some 3rd party developers to have the ability to export the RAW files in a space as wide as possible or as close as possible to the camera's RGB space (without looking too "ugly").

And that profile IS ProPhoto RGB so if named, no issue, no conspiracy theory. If it was ProPhoto RGB and named anything but, again not a conspiracy theory, a rant about a stupid name that just confuses customers.

Quote
Capture One supports many cameras and the input profiles there are organised into groups with the vendor's name on them, so adding "Leaf" in front of "Profoto RGB" made (and still makes) a lot of sense to any Leaf users coming from Leaf Capture.

I disagree and the OP proves my point. It's like me calling your camera Rodney instead of what it is, Leaf.

As the Chinese proverb says: The first step towards genius is calling things by their proper name. What Leaf did wasn't a good idea and as we've seen here, added confusion that isn't necessary.
Logged

Andrew Rodney
Author “Color Management for Photographers”
http://digitaldog.net/
HarperPhotos
Sr. Member
****
Offline Offline

Posts: 1249



WWW
« Reply #18 on: December 18, 2013, 02:01:03 PM »
ReplyReply

Hello,

When I use to use a Leaf Aptus 75 I always set the colour profile to Prophoto RGB.

I miss using Leaf Capture as it was always rock solid, reliable and I liked the layout.

I just wished my Nikon D800’s could have worked with it as I would keep on using it.  

Maybe the techs at Leaf could make it work with Canon, Nikon as well as Fuji and Sony

Cheers

Simon
« Last Edit: December 18, 2013, 06:44:45 PM by HarperPhotos » Logged

Simon Harper
Harper Photographics Ltd
http://www.harperphoto.com
http://www.facebook.com/harper.photographics

Auckland, New Zealand
digitaldog
Sr. Member
****
Offline Offline

Posts: 9191



WWW
« Reply #19 on: December 18, 2013, 02:02:21 PM »
ReplyReply

Capture One supports many cameras and the input profiles...
But ProPhoto RGB is not an input profile. It's a very specific class of profiles (working space) and a matrix profile at that. It doesn't define a capture device and no capture device can produce ProPhoto RGB. So again I'm confused by what Leaf's trying to tell us.

FWIW, I am a Leaf fan (well I owned both a Leaf 45 and 35mm scanner and knew the great Bob Caspe).
Logged

Andrew Rodney
Author “Color Management for Photographers”
http://digitaldog.net/
Pages: [1] 2 »   Top of Page
Print
Jump to:  

Ad
Ad
Ad