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Author Topic: Colorchecker Passport and Fine Art Reproduction  (Read 19991 times)
Roscolo
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« Reply #20 on: January 12, 2012, 11:19:25 PM »
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Thank you, thank you, thank you. I just saw the chart you are referring to on their site. Ron, can I ask you where you bought yours? All the pricing on their site is in Euros.

EDIT: Never mind. I see that you bought it from Europe. Sounds much more appropriate for the work I'm doing, so I'll do some digging and order from there if I can't find a stateside source.

« Last Edit: January 12, 2012, 11:21:29 PM by Roscolo » Logged
Colorwave
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« Reply #21 on: January 12, 2012, 11:37:50 PM »
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They normally cary it at B&H, but they were out of stock when I ordered mine.  As best I recall, it was slightly cheaper ordering it from the manufacturer, also, because B&H charges a premium to ship to Hawaii, and Qp sends it via mail with no surcharge.
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Huelight
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« Reply #22 on: January 13, 2012, 03:41:57 AM »
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I work as a consultant in fine art reproduction, they goal for my customers has always been to reproduce colours exactly as they appear in the original painting, I can offer the following advice:-

1. Forgot Passport it does not have enough colours to be useful for this application, I use a chart with a palette of over 1000 patches that are tuned to the gamut of art medium being photographed ie  oil, water colour etc. If producing and measuring your own chart is out of the question use a colorchecker SG or Kodak IT8 not ideal by any means but a step up from Passport.
 
2. Shoot RAW but do not use ACR for RAW conversion it does not have a wide enough gamut to accommodate all the colours you may need to preserve, it is also built for speed not accuracy detail smoothing and demosaic errors will appear.  I use a heavily modified version of Rawtherapee that includes slow but accurate demosaicing my own input and output spaces tuned to fine art and is floating point for greater accuracy and detail.

3. Use a high quality balanced light source around D50, and set white-balance in the camera, you should not have to play with the white balance after the image is taken.

4. A good LUT based input ICC profile is critical to reproduce colours such as Cobalt Blue accurately.

I hope this is of some help!



« Last Edit: February 16, 2012, 04:50:57 AM by Huelight » Logged
jeremypayne
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« Reply #23 on: January 13, 2012, 04:59:46 AM »
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2. Shoot RAW but do not use ACR for RAW conversion it does not have a wide enough gamut to accommodate all the colours you may need to preserve

Could you elaborate on this?   
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Paz
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« Reply #24 on: January 14, 2012, 05:22:37 PM »
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Quote
3. Use a high quality balanced light source around D50, and set white-balance in the camera, you should not have to play with the white balance after the image is taken.

Set the camera's white balance where?

I paint under a combination of fluorescent lights that give off D50.  At least the color band - or no band - checker from Bruce Fraser's Real World Color Management doesn't show bands... but I photograph with my camera set at Auto White Balance, not D50.

I've tried various other settings, Standard, Portrait, Landscape, etc., and believe Neutral gives me best results.  Anyone's thoughts?
...

Is this 30 color card the B&H QP card in question?

http://www.bhphotovideo.com/c/product/286652-REG/QP_Card_GQP201.html

...

I once had a giclee made on Epson 'watercolor' paper that was such a close match to my original watercolor that with both images matted, most people could tell which was the print and which was the original.  I could tell, but I had to look closely.  It wasn't color so much as I knew the difference in the texture of the papers.   I believe that's exactly what artists who make limited edition prints want.

Paz
« Last Edit: January 14, 2012, 05:25:33 PM by Paz » Logged
Colorwave
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« Reply #25 on: January 14, 2012, 06:00:30 PM »
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Is this 30 color card the B&H QP card in question?

http://www.bhphotovideo.com/c/product/286652-REG/QP_Card_GQP201.html
This is their current offering for the larger size card that I think the profiling software is built for.  It doesn't look like B&H carries this card anymore.

http://www.qpcard.com/en_b2c/products-on-index/qpcard-203-book-colorcard-profile.html
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Huelight
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« Reply #26 on: January 15, 2012, 04:19:08 AM »
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Take a custom white balance with your camera, this will set the optimum white balance for your light source.

Set the camera's white balance where?

I paint under a combination of fluorescent lights that give off D50.  At least the color band - or no band - checker from Bruce Fraser's Real World Color Management doesn't show bands... but I photograph with my camera set at Auto White Balance, not D50.

I've tried various other settings, Standard, Portrait, Landscape, etc., and believe Neutral gives me best results.  Anyone's thoughts?
...

Is this 30 color card the B&H QP card in question?

http://www.bhphotovideo.com/c/product/286652-REG/QP_Card_GQP201.html

...

I once had a giclee made on Epson 'watercolor' paper that was such a close match to my original watercolor that with both images matted, most people could tell which was the print and which was the original.  I could tell, but I had to look closely.  It wasn't color so much as I knew the difference in the texture of the papers.   I believe that's exactly what artists who make limited edition prints want.

Paz
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shewhorn
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« Reply #27 on: January 15, 2012, 10:05:31 AM »
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2. Shoot RAW but do not use ACR for RAW conversion it does not have a wide enough gamut to accommodate all the colours you may need to preserve,

ACR doesn't have a "gamut". It uses a working space which is defined by the user and the working space is what defines the gamut that it is capable of representing when the final image is output. ACR is capable of using ProPhoto RGB at 16 bits. If this can't accommodate "all the colors you may need to preserve", ACR isn't what I'd be worried about, it's your choice of printers because I'm not aware of any printer than can reproduce all of ProPhoto RGB.

It certainly would be nice if ACR and Lightroom supported ICC profiles for various cameras but they don't. Capture One does.

Cheers, Joe
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Tim Lookingbill
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« Reply #28 on: January 15, 2012, 11:40:16 AM »
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It would be really helpful if HueLight posted some 100% crop comparisons to show what's not captured in ACR over what can be pulled out of the scene gamut using his Rawtherapee method.

From my experience getting dead to nuts accurate scene captures on a wide range of objects made of acrylic to dyed wool processing with ACR, the quality and amount of light used to light the subject does most of the heavy lifting in getting the most accurate reproduction shooting Raw with a DSLR.
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ErikKaffehr
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« Reply #29 on: January 15, 2012, 11:47:20 AM »
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Hi,

My impression is that ICC profiles are not really appropriate for capture devices. I may be wrong on this, of course.

Best regards
Erik

ACR doesn't have a "gamut". It uses a working space which is defined by the user and the working space is what defines the gamut that it is capable of representing when the final image is output. ACR is capable of using ProPhoto RGB at 16 bits. If this can't accommodate "all the colors you may need to preserve", ACR isn't what I'd be worried about, it's your choice of printers because I'm not aware of any printer than can reproduce all of ProPhoto RGB.

It certainly would be nice if ACR and Lightroom supported ICC profiles for various cameras but they don't. Capture One does.

Cheers, Joe
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Colorwave
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« Reply #30 on: January 15, 2012, 11:56:20 AM »
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Huelight-
Could you be more specific about which 1000+ patch color chart you use?
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shewhorn
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« Reply #31 on: January 15, 2012, 12:57:22 PM »
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Hi,

My impression is that ICC profiles are not really appropriate for capture devices. I may be wrong on this, of course.

Best regards
Erik


I think they're quite appropriate. The question is, are they practical? For a controlled environment with controlled lighting that is the same for every single shot... sure. Capture One uses ICC profiles for every camera they support. Exactly how they build those profiles, and how they tweak them to work across a range of different lighting conditions (not only different color temperatures but different spectral power distributions) I'm not entirely sure. They weren't always great though. Back when I shot Canon I had a 1DMkII. I was using Capture 1 at the time and the Phase One provided profiles were not very good at all. The Magne Etc. profiles however were fantastic. Unfortunately he stopped developing them for newer cameras due to piracy issues, it just wasn't profitable for him anymore.

The same applies to DNG profiles, they're not terribly useful for lighting conditions, other than those that you shot the target in. Fortunately the Passport Color Checker target is small enough that it fits in a shirt pocket and can be whipped out for a quick shot if you think the lighting might pose some challenges.

Cheers, Joe
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digitaldog
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« Reply #32 on: January 15, 2012, 01:02:54 PM »
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The really big difference between an ICC profile and a DNG profile is one is output referred and the other is scene referred. Now if you don’t think all the rendering in a raw converter plays much a role in the entire process of profiling, then an ICC profile is fine and as shewhorn points out, that means treating the camera a lot like a scanner. Lock stuff down in a very tight shooting condition.

The other issue is that when you are dealing with an output referred profile process, the target plays a big role. You can’t build an ICC camera profile who’s gamut is larger than the gamut of the target used to build said profile. They are a bitch to shoot properly too. Look at the original ColorChecker DC target, created when GMB tried to provide camera profiles. Lots of colors but many on a very glossy material to extend the gamut. Only issue was, a tiny amount of flar or reflection off the target and a butt ugly profile. The next target they built, no shiny patches. Easier to shoot, lower gamut profiles. They finally gave up on the process.
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Andrew Rodney
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deejjjaaaa
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« Reply #33 on: January 15, 2012, 03:54:45 PM »
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ACR doesn't have a "gamut". It uses a working space which is defined by the user

Quote from: Eric Chan
...The internal working space of ACR and LR is Referred Input Medium Metric (RIMM), which has ProPhoto RGB primaries with linear gamma.  Temporary excursions are made to other color spaces and image decompositions, as needed, to suit the image processing.

In ACR, there are additional options to set the desired output color space (which is used to drive the histogram and on-screen preview image).  These color conversions are done at the end of the image processing pipeline, after the UI-driven controls (e.g., Exposure) are done.  In LR, there are also such options (e.g., in Export and Web), though they do not drive the displayed histogram, nor the on-screen preview image.  The color conversions are handled in exactly the same way...
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deejjjaaaa
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« Reply #34 on: January 15, 2012, 03:57:16 PM »
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I think they're quite appropriate. The question is, are they practical?

somehow all other ( != LR/ACR ) raw converters are using ICC profiles as a starting point (and whatever code they need to make it work).
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K.C.
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« Reply #35 on: January 18, 2012, 02:11:27 AM »
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I shot fine art for reproduction for 15+ years. I used a SINAR 4X5 (vacumn back) with AM ED Nikon APO lenses. Voltage stabilized tungsten lighting, cross polarized in a blacked out studio and I used the standard GMB color checker. I ran the Sitte Tischer line myself and could tweek a bit there if needed. Large drum scans were run in L.A. by the best and presses were profiled. We got really, really close, but certain colors were never really true.

Pastels - tuff
Water colors - pretty easy
Acylics - artist seldom cared
Oil - a bitch

Today I use a SONY A850 and CZ glass with the same lighting setup. We start much closer to the end result we're looking for and the time saved in the camera is now used in PS. Capture 1 does the best for most everything. I still run through ACR and a couple others when I get a new client but it's rare that we use anything but C1.

In the end it's still all subjective.
« Last Edit: January 18, 2012, 02:12:59 AM by K.C. » Logged
elolaugesen
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« Reply #36 on: January 18, 2012, 05:57:08 AM »
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Re: Bill T's comment
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 I like to use the third grey patch down underneath the letters "ecker."  Then go on and adjust exposure, brightness, contrast, and then go on to color tweaks.  Incidentally the black textured case of the Passport is very nice for getting the shadow areas and overall contrast right.
I use Passport too   not always happy with colours too saturated.
I was told to use the second grey from the bottom ..  Why do you use third grey patch from the top???

This is one of the most interesting discussions for me in a long time as I only work with original art of all types for my wife and partner and many other artists, oil, pastels, material, rock dirt and whatever else artist find.  They want prints to look the same ...  not improved (unless it helps sales)

Would love a permanent category on this discussion forum for original art issues.
cheers elo
« Last Edit: January 18, 2012, 06:58:13 AM by elolaugesen » Logged
elolaugesen
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« Reply #37 on: January 18, 2012, 07:03:35 AM »
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Elo Laugesen.
Of interest to me is what software do you use for printing original art reproductions? 

       Photoshop, lightroom, Photoshop Elements, Aperture, etc?

I have for years used Photoshop Elements as I did not need all the options and features.  However the latest versions of Elements have been consumerised  all the printing options eliminated, downgraded and I must now move on.....
« Last Edit: January 18, 2012, 08:15:17 AM by elolaugesen » Logged
WombatHorror
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« Reply #38 on: January 18, 2012, 08:23:37 PM »
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Well, bought the Passport Colorchecker and just tried it out. Picked a painting with a lot of purples / magentas. Shot the chart, shot artwork under exact same conditions, built profile, applied profile, applied white balance.

On the training video the lady on the videos builds a profile and then applies it and says, "when you apply the profile you'll see THOSE COLORS ARE JUST POPPING RIGHT OUT!" Then she goes on to say, "You'll see it gives you a much richer, much more elegant look to your images." lol...what the hell is she talking about?!?  The purpose of color management is to get accurate repro of colors in a scene, not to "make colors pop out" or appear "richer, more elegant." Good luck communicating color management using those terms.

So, I was a little harsh on my first review, so I've edited this. I've played with with the Colorchecker Passport. It's OK. Maybe a slight advantage, but I can't say it's any huge advantage over Adobe's presets for repro of artwork.

Are you using ACR set to ProPhotoRGB 16bits (and same for Photoshop working space)? If you happen to be using it in sRGB space, sRGB space might be clipping away the deep purples and magentas. Deep purples can be tricky, even AdobeRGB may clip them. I think you 221W display is 96% AdobeRGB those types of wide gamuts often both fall a little short of AdobeRGB and don't add all that much beyond the 98-100% AdobeRGB screens tend to add a good chunk of extras colors down in the purples and magentas and reds. If the painting has way intense magentas and purples they might be beyond even what your screen can show. Do you get any sort of image out of gamut warnings if you proof to your monitor space?

Sometimes CC makes a big difference but plenty of times it is more subtle. For the canned profiles from Adobe and Canon I find that Faithful is often the best (but CC is almost always at least a trace better and sometimes much better).

Sometimes monitor calibration probes are a touch off too. And then there is the issue of metamerism where a probe may measure same on two different things and they eye sees them differently. You'd need spectral distribution color management to avoid that and nobody inthe consumer world does that, at least not yet.
« Last Edit: January 18, 2012, 09:19:40 PM by LarryBaum » Logged
WombatHorror
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« Reply #39 on: January 18, 2012, 08:27:31 PM »
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The painting I have chosen is watercolor landscape with lots of hues of magentas and blues. I shoot with two 3200K lamps on either side of the artwork in a blacked out studio, as I have for years. Shot the painting. Then shot the colorchecker. Built my profile per instructions. Did it again just to be sure. Then white balanced and saved as an Adobe Raw Preset. Applied to painting. Everything was too magenta. So I built another preset and white balanced using the white balance squares for color adjustment on the Colorchecker, essentially making the next preset I built "cooler." But, nay, now a little too cool. The blues are overtaking the magentas. So, I'm getting close, but already at this point the passport colorchecker offers no real savings in accuracy or time over just using the Adobe raw present for Camera Neutral or sometimes Camera Standard. I usually get them right after this many proofs anyway.

I'm probably going to return this. Honestly, if it was priced where it should be, I don't know, $20-$30, I might keep it for general use on portraits or something. Not sure if it would offer any big advantage there over Adobe's presets either. For painting repro, $100 for ballpark color accuracy is too much...I can do ballpark color with my eyes as fast as this.

Glad it works for you. If it doesn't help me match color in 3-4 tries or less, it's useless for me because I can usually get my colors right in 3-4 tries just using my eyes. I'll give it a try on a less challenging painting, but honestly, it's the challenging paintings I bought it for.


One thing is also that when you are white balancing it you are making it look as it would under D65 but in your studio you were looking at the painting under 3200K which is quite a long ways off from D65 and too far for vision to fully adapt to so I'm not sure a WB to D65 would be expected to match your view of the painting under 3200K.
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