OBC functionality in iProfiler is VERY BADLY programmed! how to bypass?

[Robert Ardill]

This is another problem, more like metameric failure. Paintings, especially aquarelles are a pain in ... to reproduce correctly. It takes a lot of tweaking to get it right, and you have to know under which light conditions the final print is going to be seen under. The different profiles in ImagePrint is a big help here.

Stefan, do you have some idea why the watercolors are more problematic?  After all, once you've photographed them and printed them, you're back to inkjet inks, so you would think they would be no different to photographs.  Or is it (as I suspect on the painting I posted) that the very limited palette with saturated colors is what makes the color shifts so noticeable?  In which case perhaps watercolors with more subdued colors should be easier to reproduce?

Robert

[Tim Lookingbill]

...When you say a combination of the Philips and GE tubes, do you mean to use both together?

Robert

Yes, I have both installed in a 2 tube desk lamp because the Philips has a noticeable magenta pigmented phosphor that aids in filtering the GE's noticeably greenish yellow spike on warm hues such as skin tone and oranges. IOW they balance each other out more or less. They're still not perfect but it's the best I've found in small T8's that install in available desk lamps and fixtures.

And thanks for going to the trouble of photographing and posting the OBA paper sampler comparison. I take it that non-OBA's don't look slightly yellow/beige like my Potlatch paper sampler which may be due to 20 years of aging.

Took some shots of a color print on Epson Ultra Prem Glossy next to a color print on the Potlatch sampler lit under both overcast and Alzo 5500K CFL. As you'll note the overcast light brings out the color distinctions between the different finishes in the paper where the Alzo CFL does not. I have no idea if the Potlatch paper has OBAs. I don't have a black light or measuring device to test.

But I find this demonstration points to another variable introduced by the type of light used that can bring out certain reflective characteristics that haven't been readily studied. Note that the Solux 4700K halogen (see photo below) exhibits the same color distinction between papers with different finishes as does the overcast light. This may be caused by the full spectrum qualities of both lights but I'ld think it would be hard to predict consistently whether this is the case considering the different paper finishes may have some part in it.

[Robert Ardill]

Took some shots of a color print on Epson Ultra Prem Glossy next to a color print on the Potlatch sampler lit under both overcast and Alzo 5500K CFL. As you'll note the overcast light brings out the color distinctions between the different finishes in the paper where the Alzo CFL does not. I have no idea if the Potlatch paper has OBAs. I don't have a black light or measuring device to test.

But I find this demonstration points to another variable introduced by the type of light used that can bring out certain reflective characteristics that haven't been readily studied. Note that the Solux 4700K halogen (see photo below) exhibits the same color distinction between papers with different finishes as does the overcast light. This may be caused by the full spectrum qualities of both lights but I'ld think it would be hard to predict consistently whether this is the case considering the different paper finishes may have some part in it.

There's certainly a big color shift between the Solux and the OTTLite.  I know that the Solux has very little UV and I think the OTTLite would have quite a lot as I understand that tubes for proofing have added UV (or perhaps it's that standard consumer-grade lights have UV filtered out).  The browns are particularly noticeable, but all colors are bluer under the OTTLite.  As both are supposed to be around 5000K it has to be down to UV and possibly the spikes in the OTTLite.

I'm beginning to think it may be quite important to target the illuminant when making a profile; perhaps more so than the OBAs.  The question is whether the illumination compensation is effective or not, which means more testing (on papers with no OBAs to remove that variable) .

Robert

[Tim Lookingbill]

There's certainly a big color shift between the Solux and the OTTLite.  I know that the Solux has very little UV and I think the OTTLite would have quite a lot as I understand that tubes for proofing have added UV (or perhaps it's that standard consumer-grade lights have UV filtered out).  The browns are particularly noticeable, but all colors are bluer under the OTTLite.  As both are supposed to be around 5000K it has to be down to UV and possibly the spikes in the OTTLite.

I'm beginning to think it may be quite important to target the illuminant when making a profile; perhaps more so than the OBAs.  The question is whether the illumination compensation is effective or not, which means more testing (on papers with no OBAs to remove that variable) .

Robert

Forgot to add that the OTTLite 100 watt HD label is a CFL I bought at Lowe's. Its blue spike is more from the transitional cyan to cerulean blue region rather than closer to the more optically dangerous UV cobalt blue violet spectrum. I included the comparison to the Solux only to show their affect on paper for this topic and to back up the similarities for the lack of color definition of paper white to the Alzo CFL on the Potlatch sampler comparison to overcast daylight.

The poly fiber glove seen as red brown from the Solux and bluish green from the OTTLite is a metameric error by a combination of both the illuminant and how my camera recorded it. A rare piece of reflective fabric which is why I included it in that test comparison. It's similar to what Stefan mentioned about certain paints. Again its hard to distinguish whether it's the limits of the camera or the illuminant as an example of another rare and odd variable with light and color. The color of the glove under sunlight is a yellowish, grayish umber like this...

http://3.bp.blogspot.com/-rgxrh5Czc1I/TXz6hFLYhyI/AAAAAAAAANc/qD1ytI2o5LA/s320/a%2Bumber.gif


The red spectrum from the Solux halogen throws off my camera to record it as more red brown which can't be fixed using HSL adjusts without throwing off other colors in the image. Visually the Solux renders the glove quite accurate to how it appears in direct sunlight.

The OTTLite was easy for the camera to record the glove's color inaccuracy which is how it actually looked visually but not how it looks under sunlight. Just more variables to consider with light, camera and color.

[Robert Ardill]

Forgot to add that the OTTLite 100 watt HD label is a CFL I bought at Lowe's. Its blue spike is more from the transitional cyan to cerulean blue region rather than closer to the more optically dangerous UV cobalt blue violet spectrum. I included the comparison to the Solux only to show their affect on paper for this topic and to back up the similarities for the lack of color definition of paper white to the Alzo CFL on the Potlatch sampler comparison to overcast daylight.

The poly fiber glove seen as red brown from the Solux and bluish green from the OTTLite is a metameric error by a combination of both the illuminant and how my camera recorded it. A rare piece of reflective fabric which is why I included it in that test comparison. It's similar to what Stefan mentioned about certain paints. Again its hard to distinguish whether it's the limits of the camera or the illuminant as an example of another rare and odd variable with light and color. The color of the glove under sunlight is a yellowish, grayish umber like this...

http://3.bp.blogspot.com/-rgxrh5Czc1I/TXz6hFLYhyI/AAAAAAAAANc/qD1ytI2o5LA/s320/a%2Bumber.gif


The red spectrum from the Solux halogen throws off my camera to record it as more red brown which can't be fixed using HSL adjusts without throwing off other colors in the image. Visually the Solux renders the glove quite accurate to how it appears in direct sunlight.

The OTTLite was easy for the camera to record the glove's color inaccuracy which is how it actually looked visually but not how it looks under sunlight. Just more variables to consider with light, camera and color.

Interesting!  Could you try again, but this time 'profile' the camera for Lightroom.  That should at least to some extent fix the problems I would have thought.

Robert

[Tim Lookingbill]

Interesting!  Could you try again, but this time 'profile' the camera for Lightroom.  That should at least to some extent fix the problems I would have thought.

Robert

I'm assuming you're referring to trying again to correct for the Solux/OTTLite glove metamerism. What is different about Lightroom in how it deals with DNG profiles? I don't see the point.

I already built an OTTLite CFL camera profile but did not build one specifically for the Solux. The OTTLite CFL profile didn't fix the issue but I made the profile converting the Raw to DNG CCchart target in ACR PV2003. I apply that same profile in Lightroom and get the same results.

And besides from watching Andrew Rodney's video on building camera profiles whether for use in Lightroom or ACR I saw the same subtle fixes to color that wouldn't have made a dent in fixing metameric color errors shown in the glove.

[Robert Ardill]

I'm assuming you're referring to trying again to correct for the Solux/OTTLite glove metamerism. What is different about Lightroom in how it deals with DNG profiles? I don't see the point.

I already built an OTTLite CFL camera profile but did not build one specifically for the Solux. The OTTLite CFL profile didn't fix the issue but I made the profile converting the Raw to DNG CCchart target in ACR PV2003. I apply that same profile in Lightroom and get the same results.

And besides from watching Andrew Rodney's video on building camera profiles whether for use in Lightroom or ACR I saw the same subtle fixes to color that wouldn't have made a dent in fixing metameric color errors shown in the glove.

OK, I didn't realize you already had built a profile for the OTTLite.  The glove's fabric must have some strange stuff in it!

Robert