Mack
Mu-43 Hall of Famer
- Joined
- Jan 14, 2018
- Messages
- 3,728
They warp badly in the heat! Anything above 85 degrees (I'm in the desert and gets up to 110°F at times!) and they go into a bowl shape. I haven't had one separate from the glue holding them together yet when they bow out, but their extreme bowing bothers me and it might happen. Often I need to place them under books or try and reverse curl them back into being flat.
This one is pretty mild:
The glossy ones, i.e. their expensive ColorChecker Digital SG and their ColorChecker Video ones present surface glare and unevenness given the reflection oddities being bent. The calibration software, like Lumariver Profile Designer, wants the corners of the ColorChecker Digital SG White patches to be within one or two points maximum to keep the Delta E down so the color calibration and profiles made from them will be within tolerance. Calibrite has this one for their ColorChecker Digital SG card: "For optimum results when using the ColorChecker Digital SG 140 patch target in a studio environment. Check that exposure values of the white border patches on all sides are within +/- 3 of each other. When using a ColorChecker Classic 24 patch target, take two shots – rotating the chart 180° to check the white values are within +/- 3 of each other (or use two charts)." Not easy to do being all bent up and reflecting light differently. Sometimes I need to feather the studio flashes to the sides in to even out their lighting requirements. They really should have used a non-warping substrate, imho.
I use to clip them onto a board to keep them flat, but it was a hassle to find the clips and board and set it up. DataColor had a threaded hole in their color card's case which gave me an idea to somehow add one to some frame for the x-rite and Calibrite cards which are usually the same size.
So I met with a metal designer and he came up with some frame to slide the cards into to keep them flat along with a nut to mount it to a light stand. He recommended stainless steel given it cuts better than aluminum on their CAD operated laser cutter, plus he could laminate three pieces, the back, middle, and front as a unit with a spot welder. The middle needed to be the proper gauge for the card's thickness. Total laminated thickness is 1/4 inch. He could do it with aluminum as well as they had the capability, but the machining would be more costly than the laser cutter, and aluminum sheeting in sundry gauge sizes is sort of sparse for some reason.
Four weeks later I had a minimum run made for my use. However, the things do weigh a lot! Four pounds each (or 1,800 grams!) so I doubt they will be easy to blow over as has happened with my cards on a wooden easel. All four sides of the card are held flat against the back with the front frame. They added a notch on the end to grab onto the card to pull it out. The welded 1/4-20 nut on the bottom may be used on a tripod or a heavy duty ball head if it needs to be tilted, but given the weight the head needs to be strong.
I didn't know what do about a finish, maybe a flat black or some gray or white for the front? I thought I could even the lighting with a spot meter about one foot away from the frame in the studio with a light gray in the corners. Still undecided on the color options.
They did use some high grade stainless steel and it is non-magnetic so no iron in it to rust. Makes them washable I guess. There are two small holes near the entry side which were for some alignment jig when they spot-welded them together.
So here is a set of five with my cards. Top two are flat black. Middle and lower left are unpainted. Lower right has a gray auto primer coating on it, and I am still trying to decide what finish color to add to it, if any. I might have some cloth or fleece sleeves sewed up and keep them and the cards in them so I can access and set them up faster. I doubt dropping the things can damage the cards given the frame is strong being laminated.
This one is pretty mild:
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The glossy ones, i.e. their expensive ColorChecker Digital SG and their ColorChecker Video ones present surface glare and unevenness given the reflection oddities being bent. The calibration software, like Lumariver Profile Designer, wants the corners of the ColorChecker Digital SG White patches to be within one or two points maximum to keep the Delta E down so the color calibration and profiles made from them will be within tolerance. Calibrite has this one for their ColorChecker Digital SG card: "For optimum results when using the ColorChecker Digital SG 140 patch target in a studio environment. Check that exposure values of the white border patches on all sides are within +/- 3 of each other. When using a ColorChecker Classic 24 patch target, take two shots – rotating the chart 180° to check the white values are within +/- 3 of each other (or use two charts)." Not easy to do being all bent up and reflecting light differently. Sometimes I need to feather the studio flashes to the sides in to even out their lighting requirements. They really should have used a non-warping substrate, imho.
I use to clip them onto a board to keep them flat, but it was a hassle to find the clips and board and set it up. DataColor had a threaded hole in their color card's case which gave me an idea to somehow add one to some frame for the x-rite and Calibrite cards which are usually the same size.
So I met with a metal designer and he came up with some frame to slide the cards into to keep them flat along with a nut to mount it to a light stand. He recommended stainless steel given it cuts better than aluminum on their CAD operated laser cutter, plus he could laminate three pieces, the back, middle, and front as a unit with a spot welder. The middle needed to be the proper gauge for the card's thickness. Total laminated thickness is 1/4 inch. He could do it with aluminum as well as they had the capability, but the machining would be more costly than the laser cutter, and aluminum sheeting in sundry gauge sizes is sort of sparse for some reason.
Four weeks later I had a minimum run made for my use. However, the things do weigh a lot! Four pounds each (or 1,800 grams!) so I doubt they will be easy to blow over as has happened with my cards on a wooden easel. All four sides of the card are held flat against the back with the front frame. They added a notch on the end to grab onto the card to pull it out. The welded 1/4-20 nut on the bottom may be used on a tripod or a heavy duty ball head if it needs to be tilted, but given the weight the head needs to be strong.
I didn't know what do about a finish, maybe a flat black or some gray or white for the front? I thought I could even the lighting with a spot meter about one foot away from the frame in the studio with a light gray in the corners. Still undecided on the color options.
They did use some high grade stainless steel and it is non-magnetic so no iron in it to rust. Makes them washable I guess. There are two small holes near the entry side which were for some alignment jig when they spot-welded them together.
So here is a set of five with my cards. Top two are flat black. Middle and lower left are unpainted. Lower right has a gray auto primer coating on it, and I am still trying to decide what finish color to add to it, if any. I might have some cloth or fleece sleeves sewed up and keep them and the cards in them so I can access and set them up faster. I doubt dropping the things can damage the cards given the frame is strong being laminated.
Subscribe to see EXIF info for this image (if available)
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