Archive for October, 2016
Can You Really Use One Billion Colors?
Some days, I get my exercise by jumping to conclusions, running off at the mouth and pushing the limits of my technical understanding. To wit, buying a wide gamut monitor that encompass 98% of Adobe RGB 1998 as opposed to a “conventional” monitor that typically displays ~95% of sRGB. I thought I understood the considerations needed to make a clear decision on the purchase of a wide gamut monitor. Oops!
About 99.99% of all monitors are “conventional” displays that can show approximately 16.7 million colors. They have 8-bits per channel. Eight bits is equal to 28 (2 x 2 x 2 x 2 x 2 x 2 x 2 x 2) or 256 levels (colors.) Since there are three channels (RGB or red, green, blue,) multiplying 256 x 256 x 256 gets you 16,777,216 different combinations (colors.)
Wide gamut monitors, on the other hand, have 10-bits per channel or 1024 x 1024 x 1024. That means they display 1,073,741,824 (~1.07 billion) colors, 64 times more than conventional monitors. So, that must mean wide gamut monitors are 64 times better than conventional monitors, right? Well, it all depends.
During my 4 days at Stephen Johnson’s Fine Art Digital Printing Workshop, one thing that dazzled me were the wide gamut Eizo monitors in Stephen’s lab. I’d been thinking a wide gamut monitor might help me with some photos that had caused me consternation. For the rest of my summer road trip, I researched monitors and had pretty well decided to spring for an Eizo CS2420 24″ wide gamut monitor. Still, there were some doubts that I couldn’t completely stifle. When B&H raised its price by $45, that was enough to cause me to step back and delve further into the wide gamut question. (nb, B&H has now reduced the price from $861 to $719)
Buying a wide gamut monitor isn’t just a matter of ponying up the bucks, there’s more to consider. For most of my readers, there’s the matter of the software they’re using. I do 90% of my post processing in Lightroom 6 and, it just so happens, LR6 doesn’t support 10-bit color. In other words, I would have to revert to Adobe Photoshop (CS4 or newer) which are the only versions that support 10-bit color. I like Photoshop but not enough to totally revamp my workflow.
Keep in mind that many of the colors are simply finer shades between existing colors. Let’s say we have two shades of red in sRGB with numbers 254,0,0 and 255,0,0. In aRGB 1998, there are 64 additional shades of red between those two sRGB shades. This is useful in producing smoother transitions for prints but may not make a lot of difference for 0nline images.
Bottom line, wide gamut monitors can be useful and helpful in situations where you’re using compatible software to process photos that need more colors in the blue-green space. Obviously, some purists will say a wide gamut monitor is necessary in all cases but, for most photographers, a conventional monitor could be the best current compromise.
For those looking for specific recommendations, unless you’re sure you want and need wide gamut, buy a good IPS (in-plane switching) monitor in the 24″ to 26″ size as a second monitor, especially if you’re editing on a laptop. At a minimum, the monitor should have OSD controls for color temperature in Kelvin, custom RGB adjustments, gamma settings and digital inputs. At B&H, monitors fitting these requirements can be had for $300-$500. A low cost option is a Dell U2515H for $339. On the high end, an Eizo FlexScan EV2455 will set you back about $536 but should last forever. Lower-cost options are plentiful but require careful study of the specs to ensure they can be accurately calibrated. Also, if you don’t already own one, buy a good monitor calibration device such as an X-Rite Color Munki to ensure you get the best images out of the monitor.
This Got Messy in a Hurry!
I started to write a short article on different methods of using Adobe DNG Profile Editor (DNG-PE) and quickly bogged down into a mini-thesis. This is one of those tools where it seems everyone has a different take on its efficacy and benefits. So, I decided to back up and reduce this first article to “just the facts.”
Fact: No less a luminary than John Nack invited Eric Chan, a really smart MIT scientist and Camera RAW developer, to explain the advantages of custom camera profiles via a blog post back in 2008. (Unfortunately, for Photoshop and Lightroom fans, John moved to Google in 2014. His current blog is HERE.)
Fact: Camera sensors have huge gamuts that far exceed any standard color space (below,) The horseshoe shape underneath represents CIE1931, virtually the entire visible spectrum. 2200 Matte Paper represents the ICC profile for an Epson Stylus Photo 2200 using matte paper. A camera sensor can “produce” (mathematically calculate) colors way outside even CIE1931. The color within a gamut are what can be “seen” with devices that use that gamut. For example, sRGB contains all the colors that most consumer monitors can display while Adobe RGB 1998 is the range of colors that can be displayed in a high-end, wide gamut monitor such as an Eizo or NEC. ICC profiles like 2200 Matte Paper show colors that can be printed using a specific printer, ink and paper combination, e.g. Epson 2200 Stylus Photo printer using Epson inks and Epson matte paper.
Fact: Color IS subjective. The word red means different hues to different people.
Fact: Camera manufacturers have their own interpretation of colors. Some manufacturers even provide different interpretations (e.g. Canon Picture Styles.) The three photos (below) were processed using different camera profiles in Adobe Lightroom 6. The first uses Adobe Standard, the default. The second photo uses Camera Landscape and the third is Camera Neutral. Camera profiles (in PS & LR) are Adobe’s interpretation of the camera manufacturer’s JPEG rendition on the LCD. The camera’s JPEG rendition is discarded as soon as the file is brought into any software other than the camera manufacturer’s programs. For Canon, that would be Canon Digital Photo Professional (DPP) which is included with just about every Canon digital camera.
Fact: If camera manufacturers can offer different profiles (interpretations,) users can create their own profiles as well or “tweak” existing profiles to suit their own interpretation. Adobe DNG Profile Editor is the tool for doing this.
Fact: No one has perfect color memory. Some people are very good but NO ONE is perfect. Photographers only think they remember what they saw at the moment they released the shutter. By my calculations, in Photoshop, there are about unquadragintillion (give or take a few septendecillion) combinations and permutations of colors. Trying to reproduce an exact color from memory is not a useful exercise.
Summary: Adobe DNG Profile Editor produces profiles for PS, PSE and LR that replicate the look you saw on your camera’s LCD which is a JPEG rendition using the manufacturer’s “secret sauce” of JPEG adjustments.
The manufacturer’s JPEG adjustments are discarded when a RAW file is imported into an Adobe product because Adobe can’t decode the manufacturer’s “secret sauce.” Instead, Adobe applies “Adobe Standard” which probably doesn’t look the same as the in-camera JPEG.
In Adobe Camera RAW and LR, Adobe supplies camera profiles such as Camera Faithful, Landscape, Neutral, Portrait and Standard. Different cameras may have different profiles. These try to replicate what Adobe engineers see when they look at the JPEG on the camera’s LCD. Camera owners may or may not be satisfied with these camera specific profiles. In that case, Adobe DNG-PE can be used to “tweak” the supplied profiles or, in extreme cases, create whole new profiles.
The advantage to doing this is less post-processing but, more importantly, freedom to “roll your own” camera profiles. This probably isn’t of interest to most photographers but, if you’re serious about getting as close to perfect as possible, this is one way to get there.
My next article will show how to use Adobe DNG-PE, step-by-step, the “normal” way. Finally, in a wrap-up article, I’ll demonstrate how you can use Adobe DNG-PE to “wing it” after the fact when you want to adjust colors without a Color Checker based camera profile.