I want to duplicate some oil paintings on canvas. The surface is reflective, glossy, textured paints, and in places, the dimples of the canvas are visible. The oil paintings are coated with a gloss varnish of some sort. My tools are limited, but they'll have to do. I just want to get as close as I can using the tools I have. First, some background. I'm using a Canon 5Dmk2, 85mm prime lens with circular polarizer, two Alien Bee studio strobes on either side with polarizer gels (cross polarized to eliminate reflections and glare) aimed at 45°angles. I'm photographing the artwork with a small Color Checker and a Spyder Cube (for the light trap) to help me assess tone and color. I built a custom camera profile using XRite Color Checker Passport and I'm processing the images in LightRoom. I know, not perfect. In the past, I had a tough time getting even a lone color checker to reproduce fairly accurately until I forced the 6 neutral patches to match the L* values of my CC target (which I read with my Eye One with UV Cut filter). Once I got the L* values of the 6 neutral patches right, the 18 color patches measured fairly close to my spectro readings. Close enough for me. My conclusion is that the default LR settings are so contrasty, even with a "linear" Tone Curve, that it pumps everything way up and whacks the colors. In LR, I apply my custom camera profile, Click-WB on the 50% gray patch (which is the closest to dead neutral on my CC target), then manually adjust the Tone Curve to match the neutral L* values of my CC to match my spectro readings. My first photos of the artwork had some flare/glare/reflection due to the high gloss shine, so when I got the CC Target looking right, the paintings looked washed out and flat. I assumed this was the reason the CC looked right, but the painting did not. That's when I decided to try polarized light sources and a polarizer on the camera lens. It definitely helped and I am pleased with the improvement. However, even with the polarized images, if I force the L* values of the 6 neutral CC patches to match my spectro readings, the images still look a bit flat and washed out. The CC itself looks great and all the patches measure pretty close. I can adjust the image so it DOES look pretty accurate by eyeball, but then the contrast of the color checker ends up being high. Mainly, I have to darken the darken the black and Dark Gray patches so the painting looks right. I'm hoping to come up with a method that doesn't rely so much on memory and feel. I'm baffled as to why this would be? (unless I still have some flare). Any thoughts or suggestions? (additional equipment or software is not a consideration at this time). Thanks, Lou Dina
On Sep 17, 2015, at 8:14 AM, Louis Dina <lou@loudina.com> wrote:
In LR, I apply my custom camera profile, Click-WB on the 50% gray patch (which is the closest to dead neutral on my CC target), then manually adjust the Tone Curve to match the neutral L* values of my CC to match my spectro readings.
You may want to rethink this patch selection. ACR/LR is really designed for linear encoded (raw) data so one is advised to white balance on the 2nd white patch. Might help. You might look into the free DNG camera profile editor from Adobe. Some tweaking might be necessary. https://www.adobe.com/support/downloads/detail.jsp?ftpID=5493 Andrew Rodney http://www.digitaldog.net/
It isn't clear from your post that you made your custom camera profile using the identical cross-polarized setup that was used to capture the art, but assuming that was done, I'll just add that original art is different from a color checker in so many ways that it's a no brainer to me that one has to make final adjustments to the scan in order to best match the original. Some paintings require more tweaking than others, but they all need something and profiles alone can only get us very close to the optimal result. You also don't need to visit LR. Just assign your custom profile in Photoshop and then convert to a wide gamut working profile and go from there. Then I add a levels adjustment layer to set my black and white points and that gets me very close. You won't find a one size fits all for fine art reproduction though. It's always an interpretation. That said, your results are the opposite of what I'd expect. A cross polarized setup yields too much contrast rather than too little, so you might have too much flare or else you're not fully polarized. Maybe there's a lot of un-polarized spill light coming from flash units, so check that out. Also, you may discover that getting farther away from the original with a longer lens helps with reflections and minimizes the need for polarizers and get the lights closer to the wall than 45 degrees, but be sure to use gobos to prevent flare causing light from reaching the camera. john castronovo techphoto, llc -----Original Message----- From: Louis Dina Sent: Thursday, September 17, 2015 10:14 AM To: Colorsync Users List Subject: Art Duplication I want to duplicate some oil paintings on canvas. The surface is reflective, glossy, textured paints, and in places, the dimples of the canvas are visible. The oil paintings are coated with a gloss varnish of some sort. My tools are limited, but they'll have to do. I just want to get as close as I can using the tools I have. First, some background. I'm using a Canon 5Dmk2, 85mm prime lens with circular polarizer, two Alien Bee studio strobes on either side with polarizer gels (cross polarized to eliminate reflections and glare) aimed at 45°angles. I'm photographing the artwork with a small Color Checker and a Spyder Cube (for the light trap) to help me assess tone and color. I built a custom camera profile using XRite Color Checker Passport and I'm processing the images in LightRoom. I know, not perfect. In the past, I had a tough time getting even a lone color checker to reproduce fairly accurately until I forced the 6 neutral patches to match the L* values of my CC target (which I read with my Eye One with UV Cut filter). Once I got the L* values of the 6 neutral patches right, the 18 color patches measured fairly close to my spectro readings. Close enough for me. My conclusion is that the default LR settings are so contrasty, even with a "linear" Tone Curve, that it pumps everything way up and whacks the colors. In LR, I apply my custom camera profile, Click-WB on the 50% gray patch (which is the closest to dead neutral on my CC target), then manually adjust the Tone Curve to match the neutral L* values of my CC to match my spectro readings. My first photos of the artwork had some flare/glare/reflection due to the high gloss shine, so when I got the CC Target looking right, the paintings looked washed out and flat. I assumed this was the reason the CC looked right, but the painting did not. That's when I decided to try polarized light sources and a polarizer on the camera lens. It definitely helped and I am pleased with the improvement. However, even with the polarized images, if I force the L* values of the 6 neutral CC patches to match my spectro readings, the images still look a bit flat and washed out. The CC itself looks great and all the patches measure pretty close. I can adjust the image so it DOES look pretty accurate by eyeball, but then the contrast of the color checker ends up being high. Mainly, I have to darken the darken the black and Dark Gray patches so the painting looks right. I'm hoping to come up with a method that doesn't rely so much on memory and feel. I'm baffled as to why this would be? (unless I still have some flare). Any thoughts or suggestions? (additional equipment or software is not a consideration at this time). Thanks, Lou Dina _______________________________________________ Do not post admin requests to the list. They will be ignored. Colorsync-users mailing list (Colorsync-users@lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/colorsync-users/jc%40technicalphoto.... This email sent to jc@technicalphoto.com
The fact that the Color Checker reproduction appears OK argues against this problem being due to color appearance effects, but I would note that the deficiencies you see are of the type caused by color appearance changes due to viewing conditions. That is, a strict colorimetric reproduction of a scene as a print or monitor image usually appears to have less contrast and lower saturation than the source appeared to have. Viewing an image on a bright display with a dim surround in particular causes the lowlights to appear washed out, something that has been known since the early days of television. Again, your description of the correct-looking CC reproduction argues against this interpretation, but I just wanted to mention it for consideration. Wayne Bretl ----- Original Message ----- From: "John Castronovo" <jc@technicalphoto.com> To: "Louis Dina" <lou@loudina.com>, "Colorsync Users List" <colorsync-users@lists.apple.com> Sent: Thursday, September 17, 2015 9:49:10 AM Subject: Re: Art Duplication It isn't clear from your post that you made your custom camera profile using the identical cross-polarized setup that was used to capture the art, but assuming that was done, I'll just add that original art is different from a color checker in so many ways that it's a no brainer to me that one has to make final adjustments to the scan in order to best match the original. Some paintings require more tweaking than others, but they all need something and profiles alone can only get us very close to the optimal result. You also don't need to visit LR. Just assign your custom profile in Photoshop and then convert to a wide gamut working profile and go from there. Then I add a levels adjustment layer to set my black and white points and that gets me very close. You won't find a one size fits all for fine art reproduction though. It's always an interpretation. That said, your results are the opposite of what I'd expect. A cross polarized setup yields too much contrast rather than too little, so you might have too much flare or else you're not fully polarized. Maybe there's a lot of un-polarized spill light coming from flash units, so check that out. Also, you may discover that getting farther away from the original with a longer lens helps with reflections and minimizes the need for polarizers and get the lights closer to the wall than 45 degrees, but be sure to use gobos to prevent flare causing light from reaching the camera. john castronovo techphoto, llc -----Original Message----- From: Louis Dina Sent: Thursday, September 17, 2015 10:14 AM To: Colorsync Users List Subject: Art Duplication I want to duplicate some oil paintings on canvas. The surface is reflective, glossy, textured paints, and in places, the dimples of the canvas are visible. The oil paintings are coated with a gloss varnish of some sort. My tools are limited, but they'll have to do. I just want to get as close as I can using the tools I have. First, some background. I'm using a Canon 5Dmk2, 85mm prime lens with circular polarizer, two Alien Bee studio strobes on either side with polarizer gels (cross polarized to eliminate reflections and glare) aimed at 45°angles. I'm photographing the artwork with a small Color Checker and a Spyder Cube (for the light trap) to help me assess tone and color. I built a custom camera profile using XRite Color Checker Passport and I'm processing the images in LightRoom. I know, not perfect. In the past, I had a tough time getting even a lone color checker to reproduce fairly accurately until I forced the 6 neutral patches to match the L* values of my CC target (which I read with my Eye One with UV Cut filter). Once I got the L* values of the 6 neutral patches right, the 18 color patches measured fairly close to my spectro readings. Close enough for me. My conclusion is that the default LR settings are so contrasty, even with a "linear" Tone Curve, that it pumps everything way up and whacks the colors. In LR, I apply my custom camera profile, Click-WB on the 50% gray patch (which is the closest to dead neutral on my CC target), then manually adjust the Tone Curve to match the neutral L* values of my CC to match my spectro readings. My first photos of the artwork had some flare/glare/reflection due to the high gloss shine, so when I got the CC Target looking right, the paintings looked washed out and flat. I assumed this was the reason the CC looked right, but the painting did not. That's when I decided to try polarized light sources and a polarizer on the camera lens. It definitely helped and I am pleased with the improvement. However, even with the polarized images, if I force the L* values of the 6 neutral CC patches to match my spectro readings, the images still look a bit flat and washed out. The CC itself looks great and all the patches measure pretty close. I can adjust the image so it DOES look pretty accurate by eyeball, but then the contrast of the color checker ends up being high. Mainly, I have to darken the darken the black and Dark Gray patches so the painting looks right. I'm hoping to come up with a method that doesn't rely so much on memory and feel. I'm baffled as to why this would be? (unless I still have some flare). Any thoughts or suggestions? (additional equipment or software is not a consideration at this time). Thanks, Lou Dina _______________________________________________ Do not post admin requests to the list. They will be ignored. Colorsync-users mailing list (Colorsync-users@lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/colorsync-users/jc%40technicalphoto.... This email sent to jc@technicalphoto.com _______________________________________________ Do not post admin requests to the list. They will be ignored. Colorsync-users mailing list (Colorsync-users@lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/colorsync-users/waynebretl%40comcast... This email sent to waynebretl@comcast.net
Lou, FWIW, have you ever experimented with shooting under direct "noon" kind of sunlight? / Roger -----Original Message----- From: colorsync-users-bounces+graxx=videotron.ca@lists.apple.com [mailto:colorsync-users-bounces+graxx=videotron.ca@lists.apple.com] On Behalf Of Louis Dina Sent: 17 septembre 2015 10:15 To: Colorsync Users List <colorsync-users@lists.apple.com> Subject: Art Duplication I want to duplicate some oil paintings on canvas. The surface is reflective, glossy, textured paints, and in places, the dimples of the canvas are visible. The oil paintings are coated with a gloss varnish of some sort. My tools are limited, but they'll have to do. I just want to get as close as I can using the tools I have. First, some background. I'm using a Canon 5Dmk2, 85mm prime lens with circular polarizer, two Alien Bee studio strobes on either side with polarizer gels (cross polarized to eliminate reflections and glare) aimed at 45°angles. I'm photographing the artwork with a small Color Checker and a Spyder Cube (for the light trap) to help me assess tone and color. I built a custom camera profile using XRite Color Checker Passport and I'm processing the images in LightRoom. I know, not perfect. In the past, I had a tough time getting even a lone color checker to reproduce fairly accurately until I forced the 6 neutral patches to match the L* values of my CC target (which I read with my Eye One with UV Cut filter). Once I got the L* values of the 6 neutral patches right, the 18 color patches measured fairly close to my spectro readings. Close enough for me. My conclusion is that the default LR settings are so contrasty, even with a "linear" Tone Curve, that it pumps everything way up and whacks the colors. In LR, I apply my custom camera profile, Click-WB on the 50% gray patch (which is the closest to dead neutral on my CC target), then manually adjust the Tone Curve to match the neutral L* values of my CC to match my spectro readings. My first photos of the artwork had some flare/glare/reflection due to the high gloss shine, so when I got the CC Target looking right, the paintings looked washed out and flat. I assumed this was the reason the CC looked right, but the painting did not. That's when I decided to try polarized light sources and a polarizer on the camera lens. It definitely helped and I am pleased with the improvement. However, even with the polarized images, if I force the L* values of the 6 neutral CC patches to match my spectro readings, the images still look a bit flat and washed out. The CC itself looks great and all the patches measure pretty close. I can adjust the image so it DOES look pretty accurate by eyeball, but then the contrast of the color checker ends up being high. Mainly, I have to darken the darken the black and Dark Gray patches so the painting looks right. I'm hoping to come up with a method that doesn't rely so much on memory and feel. I'm baffled as to why this would be? (unless I still have some flare). Any thoughts or suggestions? (additional equipment or software is not a consideration at this time). Thanks, Lou Dina _______________________________________________ Do not post admin requests to the list. They will be ignored. Colorsync-users mailing list (Colorsync-users@lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/colorsync-users/graxx%40videotron.ca This email sent to graxx@videotron.ca
Lou, you're probably getting results about as good as you're going to get with your workflow. Colorimetric accuracy with no manual tweaking is possible, and even possible with the equipment you have at hand. But Adobe products are designed not for accuracy but "pleasing" color, so you'll have to use a different RAW processor. And 24- or 50- or even 500-patch printed charts cannot sample the camera's response to the degree needed; you need to build a model of the camera's spectral properties and create synthetic test sets to build ICC profiles from. This, obviously, is a significant departure from the workflow you're familiar with. To photograph the work itself, you'll need a completely blackened room; I've got black flock velvet drapes I made that I can put up and move around wherever, including over the ceiling, plus a black backdrop (from Savage, vinyl) on the floor. Put a mirror in place of the artwork and arrange the camera and lighting until both the camera is evenly lit and you can't see the lights from the camera; the lights will be much closer to the plane of the artwork than 45°, due to the fact that camera's field of view expands beyond the central point. Get this right and you likely won't need polarizers, unless the texture is dramatic -- and, in that case, a piece of clear acrylic over the art might be a better solution. Make sure no light is directly falling on the camera from the lights, even if they're not visible in the viewfinder; you might need to use flags or the like. You can use the mirror to align the camera: when the center of the lens is centered in the viewfinder, the camera's plane is parallel to that of the mirror. As a last step, drape the camera, save for the lens, in black cloth. Obviously, you'll need a remote release with you nowhere near the scene. Good luck.... Cheers, b& On Sep 17, 2015, at 7:14 AM, Louis Dina <lou@loudina.com> wrote:
I want to duplicate some oil paintings on canvas. The surface is reflective, glossy, textured paints, and in places, the dimples of the canvas are visible. The oil paintings are coated with a gloss varnish of some sort. My tools are limited, but they'll have to do. I just want to get as close as I can using the tools I have. First, some background.
I'm using a Canon 5Dmk2, 85mm prime lens with circular polarizer, two Alien Bee studio strobes on either side with polarizer gels (cross polarized to eliminate reflections and glare) aimed at 45°angles. I'm photographing the artwork with a small Color Checker and a Spyder Cube (for the light trap) to help me assess tone and color.
I built a custom camera profile using XRite Color Checker Passport and I'm processing the images in LightRoom. I know, not perfect.
In the past, I had a tough time getting even a lone color checker to reproduce fairly accurately until I forced the 6 neutral patches to match the L* values of my CC target (which I read with my Eye One with UV Cut filter). Once I got the L* values of the 6 neutral patches right, the 18 color patches measured fairly close to my spectro readings. Close enough for me. My conclusion is that the default LR settings are so contrasty, even with a "linear" Tone Curve, that it pumps everything way up and whacks the colors.
In LR, I apply my custom camera profile, Click-WB on the 50% gray patch (which is the closest to dead neutral on my CC target), then manually adjust the Tone Curve to match the neutral L* values of my CC to match my spectro readings. My first photos of the artwork had some flare/glare/reflection due to the high gloss shine, so when I got the CC Target looking right, the paintings looked washed out and flat. I assumed this was the reason the CC looked right, but the painting did not. That's when I decided to try polarized light sources and a polarizer on the camera lens. It definitely helped and I am pleased with the improvement.
However, even with the polarized images, if I force the L* values of the 6 neutral CC patches to match my spectro readings, the images still look a bit flat and washed out. The CC itself looks great and all the patches measure pretty close.
I can adjust the image so it DOES look pretty accurate by eyeball, but then the contrast of the color checker ends up being high. Mainly, I have to darken the darken the black and Dark Gray patches so the painting looks right. I'm hoping to come up with a method that doesn't rely so much on memory and feel.
I'm baffled as to why this would be? (unless I still have some flare). Any thoughts or suggestions? (additional equipment or software is not a consideration at this time).
Thanks,
Lou Dina _______________________________________________ Do not post admin requests to the list. They will be ignored. Colorsync-users mailing list (Colorsync-users@lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/colorsync-users/ben%40trumpetpower.c...
This email sent to ben@trumpetpower.com
Hey Lou! Fun to hear that you’re doing this. I just spent the last two days tweaking out a Betterlight based reproduction system on CO. As for polarization I like to make at least three profiles, CrossPolarized, HalfPolarized and no polarization. I think there is no one way of doing it and different situations call for different lighting and polarization configurations.
My conclusion is that the default LR settings are so contrasty, even with a "linear" Tone Curve, that it pumps everything way up and whacks the colors.
My first thought here is that it’s your cross polarization that's wacking up the contrast and colors. LR’s tools are designed for an entirely different situation. Make sure you’re working with profiles for your polarization configuration. Still, cross polarized images will be quite contrasty. Play with al three configurations. I know we share enthusiasm for extensive testing :-] IMO, the big variable in this kind of workflow is the lighting. Think outside the box. Go beyond 45° degree lighting. I tend to prefer oblique angles that bring out texture. Of course 3D objects require a lot more lighting creativity than 2D work… Have fun - that’s great exercise! Scott Martin www.on-sight.com www.martinphoto.com
participants (7)
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Andrew Rodney
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Ben Goren
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John Castronovo
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Louis Dina
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Roger Breton
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Scott Martin
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