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Author Topic: D800 clipping red channel ? Any possible solutions  (Read 7807 times)
Lorenzo Pierucci
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« Reply #40 on: February 07, 2014, 06:47:59 AM »
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Dear Luminous Lasndscapers,

at the end this topic and the experience i did for this had make me totally change my way of shooting. Now: i realize that i m not that good as the camera give me the exact linear raw and don't "cheat". It gave me the same impression of film, so that i have to adjust lighting in order to get a good raw.

Many thanks, that s is a turning point
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MarkM
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« Reply #41 on: February 09, 2014, 03:46:55 PM »
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Here's a video on correcting skin tones without having to resort to CMYK using Adobe raw converters:

Low Rez (YouTube)
http://www.youtube.com/watch?v=dWaFDKrNrwc

High Rez
http://digitaldog.net/files/SkinToneVideo.mov

Great videos, Andrew.

Maybe it's common knowledge by now, but just in case everyone hasn't figured it ou, you can now get LAB values in Lightroom 5 by right clicking the histogram in the develop module.

Also, I wish I lived somewhere where the a* and b* star values of skin tones where in the mid 20s. With no sun this time of year, everyone looks like vampires unless you cake them with makeup.
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G*
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« Reply #42 on: February 11, 2014, 11:02:20 AM »
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Just three more hints:
#1: You can copy the .icm profile that Capture NX2 generates when developing a .NEF file and put in CaptureOne (use linear tone curve then!). This way you get a NX2 color palette and CO demosaicing + GUI + performance. Just be careful with the camera’s settings: NX2 will interpret them and build its .icm profile accordingly. You might want to produce different profiles for different settings and lighting situations.
#2: It’s true that other converters than NX2 won’t understand the camera’s setting – exept for D-Lighting which directly affects exposure!
#3: Since now you understand that the in-camera preview file (that is shown on the rear LCD, is affected by in-camera settings, is the basis for the in-camera histogram) will not show the colors and the tone curve of your developed RAW file (and it’s limits/possibilities!), you might as well tweak it so that it’s at least a good indicator for exposure and clipping. Have a look at Jim Kasson’s take on that topic: http://blog.kasson.com/?page_id=2387
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D Fosse
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« Reply #43 on: February 11, 2014, 01:20:29 PM »
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You can copy the .icm profile that Capture NX2 generates when developing a .NEF file and put in CaptureOne

By now I've read this five times and it still makes no sense. What are you talking about?
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bjanes
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« Reply #44 on: February 11, 2014, 01:32:42 PM »
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PS: one Iliah Borg does not like moving close to clipping with D800(e), something like not within 1 stop of that...

I have not found that to be a problem with my D800e but greatly respect Iliah's opinion. Can you provide a link to reference Iliah's findings?

Thanks,

Bill
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« Reply #45 on: February 11, 2014, 02:27:57 PM »
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@ D Fosse:

I can tell you what I do on my Mac:

- Preparation: Make invisible folders and files in the finder visible: Start the Terminal app: Copy/paste "defaults write com.apple.finder AppleShowAllFiles TRUE;killall Finder": Push the return-button. Quit.
- Open a *.NEF file with Capture NX2
- Have a look at the folder *main volume*/private/temp in the Finder ("private" is one of the formerly "invisible" folders).
- Search for the folder "Nkn****" that has been created when you started Capture NX2. Look inside.
- You will find an *.icm file that has just been generated by Capture NX2. As much as I know it is uniquely tailored to the opened *.NEF file, its ISO, its WB, its picture control settings, whatever. Its name will be rather cryptic, but you might identify the name of your camera as part of the string. Anyway, copy that file.
- Paste it in the ColorSync/Profiles folder (*main volume*/*user*/*your user*/Library/ColorSync/Profiles).
- Name it according to CaptureOne’s rules, i.e. begin with the Name of your camera. For example "NikonD800-*********". Whatever comes after the "-" may be to your liking. You can quit Capture NX now, btw.
- Next time you start CaptureOne you will be able to choose the new profile from the drop-down menu "icc profile". Since a tone-curve is already part of the profile you better choose "linear response" instead of the CO film-curves.

That’s it. Sounds more complicated than it is.
Should work also with ViewNX software, which is free.
All information is provided without guarantee. Please be careful with your machine, get someone you trust to help you if you’re afraid to damage your computer. I have no idea what the steps would be on a Windows machine.
To hide the hidden folders and files again use the line "defaults write com.apple.finder AppleShowAllFiles FALSE;killall Finder" in Terminal.

Does it make sense? That depends. I like the colors I get using the NX2-profiles in CaptureOne. To my eye they’re better than CaptureOne’s generic profiles. And I don’t have the means to make really good profiles on my own. YMMV
« Last Edit: February 11, 2014, 02:31:26 PM by G* » Logged
D Fosse
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« Reply #46 on: February 11, 2014, 04:39:57 PM »
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Does it make sense?

Disclaimer: I only use Lightroom and I'm not familiar with Capture NX or Capture One.

But here's the part I still don't understand: Why would a raw converter use .icc/.icm profiles at all - aside from the direct chain from the converter's internal working space to the display profile? There are no other profiles or color spaces in the loop, not that I know of, not in Lightroom. The camera profiles are not icc profiles.

So the only way I can make sense of what you wrote is to conclude that you somehow manage to dissect and extract an icc profile that describes the converter's internal working color space. But why would that be "individually tailored to each file"?

I still don't get this. This is contrary to everything I (thought I) knew about raw converters. Maybe I'm missing something. Andrew? Jeff?

BTW I've never had any problems with red clipping or skin tones in my D800, so I'm just watching this thread out of curiosity.
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digitaldog
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« Reply #47 on: February 11, 2014, 04:56:55 PM »
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But here's the part I still don't understand: Why would a raw converter use .icc/.icm profiles at all - aside from the direct chain from the converter's internal working space to the display profile? There are no other profiles or color spaces in the loop, not that I know of, not in Lightroom. The camera profiles are not icc profiles.
There are (presumably) no other color profiles in the loop but there are color space assumptions along the line. And some internal color processing space (ProPhoto primaries in the one converter I can speak about, ACR/LR).
As for as other converters that use ICC profiles, ICC profiles are output referred. That means this profile 'defines' a rendered and processed data. Something LR/ACR doesn't do with it's profiles. Just to build an  ICC profile, you have to hand off a processed TIFF or similar to the profile building application. A lot of the cake has been baked so to speak, a lot of the ingredients are undefined. I don't know what G* is referring to as I like you only work with LR/ACR. But if this is an ICC profile, it's defining the entire process or a lot of it, up to the point you've got some data you can send as a rendered image to a profile creator. That means a lot of what happens in the converter isn't 'defined' but the final data is supposed to be.

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Andrew Rodney
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« Reply #48 on: February 11, 2014, 06:25:08 PM »
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...
I can tell you what I do on my Mac:
....
- Next time you start CaptureOne you will be able to choose the new profile from the drop-down menu "icc profile". Since a tone-curve is already part of the profile you better choose "linear response" instead of the CO film-curves.
....

hello G*,

interesting to read something about how Nikon deals with their NEF's .
I suppose you can use this method ony with CaptureOne ?  for i did not manage to load it in ACR , or another raw converter..

and speaking about NEFS; do you happen to have a methode to quickly set free the jpeg's from the NEFS?

i did have a programm that did it very well but it stopped working in 10.9 mavericks, alas

(that program is called IJFR by Micheal Tapes  -http://michaeltapesdesign.com/instant-jpeg-from-raw.html)

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Pieter Kers
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« Reply #49 on: February 12, 2014, 01:42:13 AM »
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Just to build an  ICC profile, you have to hand off a processed TIFF or similar to the profile building application.
no, you don't... why spread FUD ? for example use RawDigger CGATS output and so on...
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D Fosse
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« Reply #50 on: February 12, 2014, 03:14:28 AM »
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All right, now I had to google CGATS, just to show how much I know...but as far as I can tell, CGATS is just a protocol for exchanging color data. It doesn't alter the basic fact:

Quote
ICC profiles are output referred

So as I see it, an icc profile requires rendered data. And in Lightroom/ACR at least, this doesn't happen until the raw file is encoded into linear ProPhoto - after the raw file has been demosaiced, and after the camera profiles.

From linear ProPhoto, it's a single step to the display profile, or the printer profile, or the export color space. These are all (output referred) icc profiles.

Or is this just FUD?
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G*
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« Reply #51 on: February 12, 2014, 05:40:23 AM »
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I am the last person to ask for what’s going on under the hood of NX2 or CO, really. I did not invent this method, either. I picked it up somewhere on the web during my search for alternative color palettes out of CO. All I can say is that my experience is quite positive, so far I have not encountered major problems. But I’m no pro, my time for photography is pretty limited. It would be interesting for me to hear what others think of this method, too.

As for the LR/ACR users: My understanding is that Adobe has chosen a completely different path to incorporate profiles, probably because their rendering engine follows a different path, too. They use DNG profiles which you can build quite easily by yourself on the basis of ColorChecker shots. Since I’m not overly familiar with LR/ACR I will leave further comments on this system and how it compares with other methods to the more versed.

@kers:
I really can’t say if there are other converters than CaptureOne with which this method works – I am only guessing that there should be some. But I’m pretty sure that there is a profound difference between CO and ACR/LR that precludes from using this method with Adobe software.
I have never tried to unhinge the preview JPGs from a NEF file. I was thinking that they were probably pretty small anyway.

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D Fosse
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« Reply #52 on: February 12, 2014, 05:58:24 AM »
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Well, you obviously found something. I'm just trying to figure out what it can be.

Maybe what you found is what Andrew calls "color space assumptions along the line". Something similar to Lightroom's camera profiles, but using a different framework.

And of course we're talking about different converters. Perhaps someone more familiar with the inner workings of NX or C1 can shed some more light on it.
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kers
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« Reply #53 on: February 12, 2014, 08:08:01 AM »
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@kers:
...
I have never tried to unhinge the preview JPGs from a NEF file. I was thinking that they were probably pretty small anyway.
...

No, as you can imagine they are full size ( otherwise you could not zoom in@100% using RAW ) but are compressed to about 2-3 MB size.
And with IJFR releasing them takes no time at all. So you can make more pictures on your card.(Now i shoot RAW + small fine jpeg )
« Last Edit: February 12, 2014, 08:10:09 AM by kers » Logged

Pieter Kers
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« Reply #54 on: February 12, 2014, 08:39:49 AM »
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As for as other converters that use ICC profiles, ICC profiles are output referred. That means this profile 'defines' a rendered and processed data. Something LR/ACR doesn't do with it's profiles. Just to build an  ICC profile, you have to hand off a processed TIFF or similar to the profile building application. A lot of the cake has been baked so to speak, a lot of the ingredients are undefined. I don't know what G* is referring to as I like you only work with LR/ACR. But if this is an ICC profile, it's defining the entire process or a lot of it, up to the point you've got some data you can send as a rendered image to a profile creator. That means a lot of what happens in the converter isn't 'defined' but the final data is supposed to be.

I don't understand why you make such a sharp distinction between scene and output referred files. The output referred file is tone mapped, usually with a compression of the dynamic range, and gamma encoded. The scene referred file is a linear representation of the actual scene. I can render a Colorchecker into LinearRIMM Ver 4 as outlined by this ICC paper as scene referred. The graph shown below is a plot of the bottom row of the monochrome patches, and confirms linearity. Viewed in a non color managed application, it looks dark but it appears normal when viewed in Photoshop. I can hand off this scene referred file to any ICC profile for output.

Regards,

Bill

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digitaldog
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« Reply #55 on: February 12, 2014, 09:32:50 AM »
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no, you don't... why spread FUD ? for example use RawDigger CGATS output and so on...

FUD? What got you panties tied in a knot?  Undecided
And I could build a CGATs file from rendered data too, the point is, you are not sending raw data to an ICC profile creator, you're sending some "processed" RGB data to the profile creator. Forgive me for specifying one has to send a rendered TIFF or similar to a profile creator. OK, you can send what is basically a text file too (which defines processed RGB data).

I don't understand why you make such a sharp distinction between scene and output referred files. The output referred file is tone mapped, usually with a compression of the dynamic range, and gamma encoded. The scene referred file is a linear representation of the actual scene. I can render a Colorchecker into LinearRIMM Ver 4 as outlined by this ICC paper as scene referred. The graph shown below is a plot of the bottom row of the monochrome patches, and confirms linearity. Viewed in a non color managed application, it looks dark but it appears normal when viewed in Photoshop. I can hand off this scene referred file to any ICC profile for output.

I agree, I'm simply pointing out the vast differences between actual raw data, what may be scene referred data and output referred data, the later more heavily processed data and for some, easier to get at (scene referred more difficult to get to).

This is explained by the ICC in the following paper:

Using ICC profiles with digital camera images:

There is also the case where a camera puts out files containing raw or scene- referred image data. If the raw image data results from capture using a color filter array (e.g. the red, green and blue color values are captured by different pixels), a special camera raw processing application is needed to create a viewable color image. In most cases, these applications (for example Adobe Photoshop camera raw) create standard output referred images, as would the camera.


http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CDIQFjAB&url=http%3A%2F%2Fwww.color.org%2Ficc_white_paper_17_icc_profiles_with_camera_images.pdf&ei=eYv7UrWzMsiErQHDiYDwDg&usg=AFQjCNG7OE45m9ZbE6bGh1iiAYWtWcyqqg&sig2=Y1TFJYW2luEFGze9eZzhaA&bvm=bv.61190604,d.aWM

Here's some further data to chew on from Erick Walowit (this is from the ColorSync list way back in 1998, has anything changed?):

Quote
All v2 ICC colorimetry is picture-referred and may assumed to be
output-referred. This means that all v2 ICC rendering intents represent the colorimetry
of the desired reproduction, not the scene. Yep, even for the colorimetric
rendering intent.
B) v4 was silent on image state so most assume that v4 also represents
output-referred colorimetry.
C) In v2, v4, and many other non-ICC profiling methods, there is no way that
I knew of to commmunicate weather the colorimetry is scene-referred or
output-referred. This means you have to assume its output-referred, the colorimetry
of the reproduction, not the scene.
D) For this reason, I introduced the "colorimetric intent image state" tag
for v4 profiles. It was approved by the ICC last year and will hopefully start
showing up in camera profiles in the future. If you have a v4 profile with the
image state tag set to one of the scene-referred values, then you know the
profile represents the colorimetry of the scene instead of the desired
reproduction. Otherwise you have to assume the colorimetry is output-referred.
E) It is perfectly understandable that v2, v4, and non-ICC profiles produce
output-referred colorimetry: most workflow demands it. Is only been relatively
recently (RAW) that applications are starting to understand the value of
scene-referred colorimetry. But many RAW workflows also use output-referred
profiles for the sake of productivity.
F) So, in the general case, you have no way of knowing if a given profile
(ICC or otherwise) is intended to produce scene-referred or output-referred
colorimetry.
G) But lets suppose you have a given profile and you know it is
scene-referred, then you are good to go, right? Wrong, for many reasons. Here is just one
example: No shipping camera that I know of meets the Luther-Ives condition. The
means that cameras exhibit significant observer metamerism with respect to
humans. So the scene-referred profile designer must decide how to optimize the
profile. Two possible extremes: i) minimize the color differences of a color
chart, or ii) minimize the color differences of representative scene spectra. If
i) is chosen then the profile will perform optimally on the chart but
suboptimally (not necessarily poorly) on real scenes. Poor choice. If ii) is chosen
then the profile will perform optimally on the scene but suboptimally (and
frequently quite poorly) on color charts. Better choice. If you have any doubt
about this, derive and compare the basis functions for color charts and scene
spectra. ISO 17321 is a good place to start. There is a third possibility
somewhere in the middle. Use a photograph of a color chart to learn something about
the camera colorimetry but influence the profile based on scene-spectra consi
derations. OK choice.

Maybe since 2008, this is changed (Eric's update to the V4 spec, cameras that meet Luther-Ives condition?).
« Last Edit: February 12, 2014, 09:40:54 AM by digitaldog » Logged

Andrew Rodney
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« Reply #56 on: February 12, 2014, 10:03:01 AM »
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FUD?

yes, you are with vested interests in Adobe's suite of tools

And I could build a CGATs file from rendered data too

yes, but you can do it w/o rendered output of raw converter - that is the point that you try to hide

, the point is, you are not sending raw data to an ICC profile creator, you're sending some "processed" RGB data to the profile creator.

and so you can say about "dcp" (Adobe DNG profiles) profiling :-) ...  Adobe DNG PE does work with no less rendered data than rawdigger - so ?
« Last Edit: February 12, 2014, 10:04:55 AM by Vladimirovich » Logged
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« Reply #57 on: February 12, 2014, 10:06:57 AM »
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This is explained by the ICC in the following paper
using ICC as a data container for input profiles does not mean everybody does them like ICC (organization) says so
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digitaldog
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« Reply #58 on: February 12, 2014, 10:15:20 AM »
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yes, you are with vested interests in Adobe's suite of tool
Please elaborate. Because you don't know WTF you're talking about. What vested interest?
Quote
yes, but you can do it w/o rendered output of raw converter - that is the point that you try to hide
I'm not trying to hide anything. You on the other hand seem to be hiding (here) behind an anonymous alias while my transparency is pretty clear. Pot calling the kettle black!
Quote
and so you can say about "dcp" (Adobe DNG profiles) profiling :-)
Absolutely I never said otherwise. The data is quite different, as is the processing.
« Last Edit: February 12, 2014, 10:17:46 AM by digitaldog » Logged

Andrew Rodney
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« Reply #59 on: February 12, 2014, 10:16:22 AM »
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using ICC as a data container for input profiles does not mean everybody does them like ICC (organization) says so
Sure, what do they know.
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Andrew Rodney
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