October 28, 2013
I want to make this as simple as possible, and it’s a subject that invites you to dive in to all manner of techno-vortices of Color Science. It’s really a simple question, though. Does it matter which light source I use to illuminate artwork for reproduction?
I’ve argued that the color and quality of the light source is crucial in reproducing the vision of the artist. I think I’ve demonstrated pretty well how the light quality affects the texture and surface of the canvas, but I’ve been struggling with a good way to demonstrate how the light color affects the perception of the various tones and values in a painting. I’ve been tempted to go into a deep, technical discussion of it, but then realized it’s really a very simple thing. Show how the colors are different with three basic light sources – tungsten, strobe and “full spectrum” fluorescent. The simplest way to show that is with a Colorchecker.
Basically, think of it in terms of throwing something at an object, and getting what bounces back. You can’t get back what you didn’t toss in the first place. If you’re not throwing red, for example (in the case of a fluorescent, specifically), you’re not going to get red bouncing back to the camera.
First, the video:
Now, the details.
The “Tungsten” version was shot using halogen gallery-type floods, the camera set to 3700K, and shooting RAW with the Nikon D800.
The “Strobe” version was simply changed to 5000K, and the “Fluorescent” version was 5000K as well. The fluorescent bulbs are so-called “continuous spectrum” 5000K bulbs, which is really a misnomer, a fact you can see by simply looking at a spectral response graph of any good bulb of this type, including those used on the Cruse Scanner and other similar devices.
The files were processed using Adobe Camera RAW, and a click-gray balance was made on the lighter of the two center gray patches. The shadows and highlights were adjusted slightly so the shadow and highlight points on the histograms would match up well. The files were cropped to the target, and processed with the default Adobe camera profile. The Working Color Space is Adobe1998.
Remember. The primary objective of the entire science and technology of CCD development and Color Management is to replicate the human visual experience of color. Color management tools’ job is to take these colors we see above and try to correct them to match the known colorimetric values of the target. They can do that a lot better and bring the colors closer to what we perceive if they have a starting point closer to where they’re trying to end up. If they don’t have the colors, they have to make them up, or stretch the colors they do have into the space they need to be.
The conclusions are pretty obvious to the eye, but even more so when you look at the histograms. Each light source is indeed different. The intensity of each of the color patches on the Colorchecker is rendered in a slightly different way in some cases, in others, the differences are pronounced.
So, yes, each is different. That begs a few questions.
Which one is more “accurate”? That question will send you down another vortex of Color Theory.
Which one is more faithful to what the artist saw? That question is simple. The light source that the artist used when creating the work can only be the most faithful to the artist’s vision and intent.
October 17, 2013
A painter’s view of light, color, and their importance in reproduction of paintings:
Warren worked closely with me in developing the technique I use for Fine Art Reproduction… inspiring me to develop and refine the process and the tools – the X-Y Easel.
May 22, 2013
We’ve seen some samples of the difference between standard copy-board lighting and what is pretty typical for an artist’s studio. Let’s take it a step further and look at what we can do using basic lighting techniques. If you’ve been the victim of one of my lighting classes, this is going to look familiar.
Painting by Nellie Ashford: “Best Friends”
This is an example of what you’d typically see in an artist’s studio or a gallery. It’s lit with a “Main” that’s a halogen spot from above, and has all the characteristics of that type of lighting – lots of texture, rich colors, deep shadows, bright highlights. There’s a very slight amount of cooler fill, spilling from the surrounding walls. This is “hard-edged closed shadows”, that is, the shadows have a hard edge, but are closed up, or dark.
This is the same light, but simply adding fill. “Hard-edged open shadows”. Take a good look, the shadows themselves still have a hard edge, but they’re now brighter, and show color and detail. This is pretty typical of what you’ll see from a modern artist’s studio, often a combination of North light and halogen spots. The fill in a studio like this is often far more cool that what we’re seeing here, though.
These last two examples are lit with a very soft, very diffuse light source. Typically a “North Light Studio” without any additional spots would look like this, but the first one has no fill in the shadows. Thus, it’s called “soft edged, closed shadows”. We still get a fair amount of texture and the appearance of relief, but the effect is less dramatic, more flat, with the overall contrast lower and less saturated colors. It’s more forgiving, but has far less impact.
Finally, we take soft, diffuse lighting and add fill. This almost completely flattens out the work, showing very little texture, very diffuse colors, and very low contrast. You’d use this if, for example, you had an original that had major surface flaws that you didn’t want to call attention to. This is how an artist’s studio would look if they had North light, and very bright walls, floors and even ceilings. It would be a fairly rare thing to see an artist working under these conditions.
Go ahead and click on each image to take a good close enlarged look.
These are what I consider to be the four basic building blocks of lighting. What gets interesting is where you start working with degrees of these techniques – starting with hard-edged closed lighting and adding just a little fill… controlling the degree of softness in soft-edged closed shadows – or any combination of types. Not only do I get 4 basic flavors, but I can mix and match and hit somewhere in between.
This is true photographic lighting, and why it’s so powerful in redering artwork in a way that’s faithful to the artist’s vision. It’s possible through no other process – no scan system or copyboard lighting can achieve these kinds of basic results, and certainly not in any combination.
December 15, 2012
I’ve been doing a lot of Color Management work lately, and it’s been on some pretty interesting projects. …so I decided to give it it’s own site. Have a look: www.colorv2.com
Along with the usual contact information and stuff, there are also some stories of the projects I’ve been involved with… including how landing one $2 million dollar contract hinged on matching (and surpassing the competition’s “match”) of a single color.
I’ve also been able to incorporate something I’ve wanted to do for years: the Complete Color Survey. A simple, easy to fill form that gives me most of what I need to understand your color issues and work on some solutions. See that here: The Complete Color Survey
Not only do Color Management tools work now, (they haven’t always worked well, if at all) but as they become more reliable and sophisticated they can be applied in many surprising ways. Read more at www.colorv2.com.
November 18, 2012
Want some fun with your CD/DVD printer? Download these targets to make a nice profile for it.
They’re based on the standard i1 RGB 1.5 and CMYK 1.1 targets, and I’ve used them on several types of printers that handle CD/DVD printing, even commercial thermal printers. Here’s how to use them.
Print them from Photoshop using “No Color Management”, and turn all the printer color controls off, just like you’d do with any other profiling target. I’d suggest using the RGB target for an inkjet printer and the CMYK target for thermal printers as a starting point.
When you start up your software, (I’m using XRite i1 Match), select the i1 RGB 1.5 or CMYK 1.1 target (reference file) option.
Put the disk on an empty spindle, and place your Eye-One plastic guide on the first strip. I find it helpful to prop up the rear of the guide to make it level, but that depends on your spindle design. Click, and read the strips in the same way you would a page, except by rotating the disk on the spindle instead of sliding the Eye-One. (Update: see below for a better way.)
BAM! Awesome profile for your CD and DVD printing!
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Here are the RGB targets:
I found that it was pretty difficult to consistently hold the Eye-One in place… my first few tries were beginner’s luck I guess, so I made this little bracket. Just slip the disk on to a spindle, and slip this on top. The holes locate the Eye-One precisely, as well as at the exact depth you need for a good reading.
I’ve tried it a few times and it’s a 100% good profile read.
Here’s a quick little down-‘n-dirty video showing how to read it:
October 11, 2012
Answer: Not hard at all. Really.
There was a time, not long ago, when Color Management was the Next Big Frontier, and using good Color Management was pretty difficult… simply because, honestly, it didn’t work that well yet. Besides that, the tools were simply out of reach, from a cost standpoint. That, thankfully, is no longer the case. Understanding everything that goes on “under the hood” may still be a challenge for most, but implementing good Color Management and getting predictable results? It’s a piece of cake.
Here’s how it works.
There are five steps.
- Accurate Display.
- Color Settings in Photoshop.
- Color managing in Photoshop.
- Turning off Printer Color Controls.
- Viewing light.
First, you need a good, “color accurate” monitor. Simply, if your monitor can’t display a color, you aren’t going to be able to see it. Make sense? If you’re trying to hear the subtle tones of a Cello on your boom-box, it ain’t gonna happen. You need good speakers. Likewise, if you’re trying to see all the colors in that sunset you just shot on an personal or office-level computer screen, you’re not going to. It’s simply not able to “shoot” that kind of color fidelity. Here’s our favorite line of Color Accurate displays: the Eizo ColorEdge, for one example.
Second. You need to calibrate it. With a good device.
Calibrating a monitor with a good device like the i1 Display, shown here, ensures you’re working with the same standards as every other Graphics or Printing professional out there, if you calibrate it to the common industry standards. Cheaper devices (and frankly, the i1 Display is not a lot of money) will give you inferior results. Calibrating to your own personal preferences will give you unpredictable results. Calibrating it to industry standards with a good device like the i1 Display will guarantee your color-accurate display is, in fact, accurate. (The standards for the printing/photo industry are a Gamma of 2.2, a White Point of 6500K or D65, and a Luminance of 120.)
There are, of course, more sophisticated devices. Do you need a really expensive device like the i1 Pro? Well, it does a better job, certainly. It’s more accurate, but for most people it’s a lot to spend – around $1500 – and possibly worth it to hire a consultant with the equipment and the expertise. See my post, here, for a little discussion of that.
Finally, you have to make sure that when you send the file to the printer, you’re controlling where the color is managed. This is where things have gotten a lot simpler… Photoshop and your Operating System, especially on the Apple side, are now talking together. Here’s how that works.
First, make sure your Adobe applications are handling color correctly. Go to Edit>Color Settings and set it to North American Prepress 2. This will get you 98% of the way there. If you want to go the last 2%, open up “More Options” ans select “Perceptual Rendering” as your Intent.
Now, open a file.
Since you’ve set your color settings in Photoshop correctly, you’re working in Adobe RGB (1998) as a Working Color Space. You hit Print. (File > Print)
You get this screen:
Make sure you’ve selected “Photoshop Manages Color”.
You select the printer/paper/ink profile in the pulldown that says “Printer Profile”. This is not a “close enough” or near-guess case. Your printer profile has to match your printer, your paper, and your inksexactly. 90% of the issues we here from printers stem from using a profile they thought was “close”.
Now you’ve Color Managed your file. You have to let the printer driver know it needs to lay off any additional color adjustments.
When you hit “Print”, in the more recent versions of software like Photoshop CS5 and Apple Snow Leopard, the setting you just made will turn the Printer Color Management to “Off”. That’s of crucial importance, and where most people goof. Here’s what it should look like. In CS5, the button that says “Page Setup” is different, it will say “Print Settings”. In previous versions you just hit “Print” and, in either case, it takes you to this screen:
Hit the button that says “Layout” and you’ll get this, where you select “Color Options”:
From there, select, for Color Management, “Application”. Hit “Print”, you’re done.
This is shown for the HP Printers, if you’re using Epson, it’s the same process, except you have to make sure that the correct media is set in the Epson Driver. The first selection is called “Print Settings”.
Select that, and set your paper type. Here we’re printing to Premium Luster. Now make sure your Epson Color Controls are set to “Off”, as shown.
The single piece of the puzzle that goes ignored most often is the viewing light. If you take your nice print and go into your bathroom or kitchen and try to evaluate it there, it’s going to look green. The cool-white fluorescent lights are not white, they’re slightly greenish. If you put it under your halogen desk lamp, it’s going to look brownish-red. If you hold it up to the window, you’re going to get the blue sky lighting the print. Think you don’t need a standard viewing light? Think again, it may well be the single most important part of your workflow.
This is a GTI PDV-e Desktop viewing light. There are several models, of varying sizes, features and prices. You can have all the Color Management in the world at your fingertips, but if you can’t evaluate your prints under some sort of standardized light source, you’re essentially working blind. If you don’t believe it, do this little test. Make a print. Look at it with window light. Now fluorescent lights. And finally, look at it under a halogen track light or desk lamp. The more subtle and neutral the print is, the more dramatically you’re going to see the color shifts.
It really is just that simple. If you’re interested in learning all the whys and wherefores of how a Color Management system works under the hood and how you can tamper with the controls, there are countless groups, forums, webinars are resources that can lead you down that tortured path. Better yet, you can buy my book. If, however, you just want your prints to come close to what your screen is showing you, then this is all you need to do.
June 20, 2012
In my previous post I argued that your light source dictates the range of color you have to work with. The simplest way to prove that is to show you, so I’m using a tool called ColorThink, which maps the colors in an image on a conventional gamut map.
I shot a ColorChecker under mixed lighting with North light and tungsten, as I would a painting in my client’s studio. I also shot it under so-called “full-spectrum” fluorescent. Here’s how they compare:
Think “boxes of crayons” here. These gamut maps show how many crayons you have to work with after all’s said and done, once the file is processed and in Photoshop format. Even with the small range of 24 color patches in the ColorChecker you can see that “full spectrum fluorescent” doesn’t give you as many colors to work with as daylight, or daylight with tungsten.
Imagine what this would look like when you’re looking at the full range of colors in a painting.
These were shot RAW, processed in Adobe Camera Raw using the X-Rite Passport profiling system to achieve optimal color rendering. They were shot with the Nikon D5000 and the 55mm Micro Nikkor 3.5.