Color Comparison: Canon 5D Mark ll and Mark lll

As the next generation of Nikon and Canon cameras hit the street, one of the questions that always occurs to me is how these new bodies interpret color, in relation to the tried and true models they are replacing. I will be testing  more than one such pair, but lets begin with the newly released Canon 5D Mark lll, and its predecessor the Mark ll.

There are superficial changes between the cameras which remind you that they are not the same body, such as the on/off switch being moved to a new location, the “on but not adjustable” notch on the on/off switch being removed, grippy material being added where the heel of the hand rests on the body, and the larger LCD display. The change I will most appreciate, from a mechanical point of view, is that the mode dial can no longer be turned by accident, meaning I will not need to put a piece of black electrical tape on the top of my new Mark lll, as was needed on the Mark ll, to assure that the mode was not accidentally changed. Others will list the pros and cons of the various improvements, which appear to offer more for the video shooter than the still photographer. I will attempt to focus solely on their color reproduction.

In order to do this a copy of the Datacolor SpyderCheckr color target was set up and lit in a reasonable manner, with a single light from a 45 degree angle. It was shot at somewhat less than full frame to eliminate the corners of the image, where the lens is most challenged, from the target. In front of this a tripod was located and configured. Each camera was set, with the same lens, to full manual settings, using the same aperture, shutter speed, and ISO, at the same focal length on the lens. Both were set to shoot full size RAW images, and both produce similarly sized resulting files. So most factors are matched between the two cameras, so that differences in the resulting files should be representative of actual differences in the flavor of color each produces.

Multiple exposures were shot with each body, and the sharpest chosen from each. Sharpness has little effect on averaged color values from large patches, but its the habit of a lifetime to select the best files, so it was done here as well.

Since neither Lightroom 4, nor the Photoshop 6 beta, even with the latest ACR plugin from Adobe Labs will open the RAW files from the new Mark lll, it was necessary to use the Adobe DNG Converter, v 6.7 beta from Adobe Labs to process the files. Files from both cameras were processed this way for consistency. Both resulting DNG files were then opened in Lightrooom 4, and processed as any SpyderCheckr target shot is processed, by balancing on a light gray patch, adjusting the exposure to get appropriate, and similar white values from both shots, and adjusting blacks to get appropriate and similar black values as well.

The two resulting adjusted Lightroom files were then exported to the SpyderCheckr software, where a calibration set was produced using the Colorimetric option. Both resulting presets were then selected in Lightroom, and screenshots of the HSL adjustments they contained were screenshot. In the image below, the adjustment set on the left, as the title notes, is the 5D Mark ll, while the set on the right represents the Mark lll. While the HSL adjustment units in Lightroom are not as absolute as Delta-e comparisons, they are quite straightforward, and offer at least a relative sense of the color corrections required by each body, using the same lens.

Comparison of Color Adjustments Needed by 5D Mk ll vs. 5D Mk lll

Numerically, its possible to come up with some averages of the adjustments that SpyderCheckr made to correct the color of both bodies. The total of the Hue adjustments made to the eight color channels was 35 for the Mark ll, and 38 for the Mark lll. Saturation adjustments were 55 for the Mark ll, and 60 for the Mark lll. And Luminance adjustments were a total of 4 for both bodies. So the numerical route would tend to indicate quite similar color accuracy between the two cameras. Now what about the location and degree of those corrections?

The Mark ll scored the largest of all adjustments, a -19 in Green Hue. The Mark lll also scored its largest adjustment on the same setting, but only a -16, instead of -19. Similarly the second and third largest Hue adjustments were shared by both bodies as well, with the Mark ll requiring a +4 on Red and -4 on Aqua Hues, while the Mark lll scored +6 and -4 on the same two Hue channels. The outlier here is the Mark lll requiring 7 points more reduction in Magenta than the Mark ll.

The two bodies show similar flavor on Saturation results as well, with Saturation decreases on nearly all colors, reinforcing the theory that Canon’s produce more saturated color than Nikons, but you’ll need to wait until a further article in this series to see a cross-comparison that addresses this. The channels requiring the largest desaturation are similar in both bodies as well, with Red, Blue, and Aqua requiring larger adjustments with both, while the Mark lll reduced the size of the Green adjustment, but increased the size of the Magenta adjustment needed.

The Luminance variations in both cameras are very small, with a maximum of -3 in the Mark ll, and of +2 in the Mark lll. Overall, the luminance balance is excellent, barely requiring any tuning.

In general, what color effects should one expect to see from these two cameras, when uncalibrated? By the numbers the over-saturation in Reds and Greens would be the most obvious in the Mark ll, and the over-saturation in Red and Magenta in the Mark lll. Perhaps the easiest way to tell them apart would be the Green Saturation levels, with ten points more saturation in the Mark ll than the Mark lll. Keep in mind that building a calibration for each body, and applying it to all the images shot with that camera should go a long way towards removing any visible color errors in either case, and should allow excellent matching between their files, in case you now use your Mark ll as your second body, and need to mix images shot with both.

The image below is an animated GIF showing the normalized, but not color corrected, results from each camera. The areas of difference noted above do stand out, but the blues appear, visually, to have more variation than any other color. 

Color Differences Between Canon 5D Mk ll and Mk lll

It may be necessary to click on this illustration to bring it up in its own window in order for the GIF animation to occur.

A Note on Camera Color

What cabbage leave does camera color come out from under? It has two parents: the camera manufacturer, who is responsible for the hardware, and for the firmware that produces the proprietary file, and the RAW converter developer, who uses their own form of camera profiles to convert that proprietary camera format to a RAW file on screen. At one time, both these were the same parent; and we felt obliged to use the manufacturer’s RAW converter when testing the camera. But today the majority of RAW files, at least those from DSLR and subDSLR cameras, are processed in third party software. And by far the most common of those third party products is the Adobe engine used in Lightroom, ACR, and therefore Photoshop. So when I talk about camera color, I’m speaking of the camera color we are going to get in the real world, where we process our images in Lightroom or ACR. Using another third party RAW converter, or a camera manufacturer’s conversion utility, may produce different results. But given the success I have been having with the Adobe engine and a SpyderCheckr HSL correction set, I am quite comfortable with the color from this workflow, and don’t see any significant reason to be looking at less common or more complex workflows in order to achieve the results I need; especially with Lightroom 4’s much improved capabilities.

Please read my additional article on Canon 5D Mark lll color.

Credits: C. David Tobie, Copyright 2012. Website: CDTobie.com Return to Blog’s Main Page

Datacolor Releases Spyder4TV HD

Datacolor’s line of new Spyder4 products has been available since the first of the year. But one obvious component has been missing: there has been no Spyder4-based Home Theater and Video Reference Display calibration tool. Now that remaining gap in the Spyder4 line as been filled with the release of Spyder4TV HD. I’ve been waiting less-than-patiently for this release, so that I would be able to write about this product here.

Spyder4TV HD Retail Package

Three Types of Users

Most users of Datacolor’s SpyderTV products are calibrating their own Home Theater TVs with the product. But some users are calibrating home theaters and TVs for clients, either as part of the purchase and configuration of the system, or as a standalone service for existing Home Theaters and Office Systems. A third category of SpyderTV users is photographers and videographers who shoot video, and need to calibrate a video reference display, to be sure that the footage they are editing will look as intended once it is viewed as a video stream, rather then on a computer display. Since many photographers are now also shooting motion, the need for affordable video reference displays, and affordable ways to calibrate these displays, is growing.

What Spyder4TV HD Includes

Spyder4TV HD includes the new Spyder4 sensor, with its increased accuracy and stability over time, as well as improvements in the Spyder TV software. The addition of “HD” to the title reflects another change as well: In addition to reference discs in PAL/SECAM and NTSC formats, Spyder4TV HD now includes a Blu-ray reference disc, for calibrating Blu-ray sources. One last improvement in Spyder4TV HD, is the inclusion of the SpyderWeb; a convenient tool for supporting the Spyder on large displays such as plasma and LCD television screens.

How Spyder4TV HD Works

Spyder4TV HD is used by installing the included software on a Mac or Windows laptop or computer, attaching the Spyder to the TV screen, running one of the included reference discs from the TV system’s disc player, and following the on-screen directions to adjust Brightness, Contrast, Color, Tint, and White Balance to optimal levels.

TV Calibration Versus Computer Display Calibration

One common question is whether a TV can be calibrated with Datacolor’s Spyder4Express, Pro, or Elite products. The answer is that a “TV” that is actually running as a monitor attached to a computer can be calibrated by these monitor calibration products. But that a “TV” which are not computer driven require a totally different TV calibration process, as described above. So the same display can be a video display when connected directly to a video source, or a computer display, when connected to a computer source, and will require different methods of calibration for those two sources.

Future Spyder4 Cross-grades

Datacolor plans to release a cross-grade for existing Spyder4Pro and Spyder4Elite owners supplying the video reference discs, software installer disc, and SpyderWeb, with a Spyder4TV HD serial number in a few weeks, allowing existing owners of these Spyder4 products to calibrate TVs without having to purchase a second Spyder4 device. Spyder4Express is not upgradable to Spyder4Pro, Elite, or TV HD versions, due to differences in the hardware device. So Spyder4Express owners would need to purchase the full Spyder4TV HD product, instead of the future upgrade version. The pricing of the full Spyder4TV HD package is low enough ($129US) to be tempting even to Spyder4Pro and Elite users, who might not mind having a second Spyder.

Full Product Overview, with Screen-shots

A complete product review of Datacolor Spyder products is usually posted at Northlight Images shortly after products ship. So let Keith know that you are looking for a Spyder4TV HD review, and I expect he will produce one to meet the demand. You can tell him I sent you.

Credits: C. David Tobie, Copyright 2012. Website: CDTobie.com Return to Blog’s Main Page

New Portfolio of iPhone Landscape & Arch. Images

Landscape and Archtectural photos are usually taken with DSLR or Medium Format cameras. But its possible to shoot very effective images with the iPhone, as long as high resolution is not required. If such images are thought of as small images of larger things, they can be quite pleasing. As iPhone camera resolution increases, “small” may now mean “small to medium”. To view the full portfolio of images please go to CDTobie’s Portfolios.

Palm Silhouettes

Saint Mark's Fisheye

Maine Barn

Credits: C. David Tobie, Copyright 2012. Website: CDTobie.com Return to Blog’s Main Page

New Portfolio of iPhone Macro Images

The iPhone camera lends itself to macro and closeup photos. The more recent models are particularly good at this type of imaging. This portfolio explores some of the types of macros possible with the iPhone. To see the entire portfolio go to CDTobie’s Portfolios.

Pink Ash

Umbrella

Abstract

Credits: C. David Tobie, Copyright 2012. Website: CDTobie.com Return to Blog’s Main Page

Photoshop World DC, Coming Right Up

Its that time of year again, cherry blossoms in the Nation’s Capital, and Photoshop World DC. Well, with this year’s weather I won’t be surprised if the cherry blossoms have come and gone, but Photoshop World will make up for it.

Any of you wishing to meet up with me will find me speaking at Forensics Day on Friday (thats right, color management for CSI!) and on the tradeshow floor most of the rest of the show. Try the Datacolor booth first, thats always my base of operations. Hope to see a few of you there, and I hope the spate of articles I’ve published in the last couple of hours will keep the rest of you happy until I return. If there  are items of interest at the show, I just might make a blog post or two from there. Otherwise, I’ll be back next week.

Credits: C. David Tobie, Copyright 2012.   Website: CDTobie.com   Return to Blog’s Main Page

More Answers about the new iPad and Color

iPad2 gamut over iPad3 gamut

Please see the previous articles in this series:

Color Management and the iPad

Questions about the new iPad and Color

Answers about the new iPad and Color

The graph above compares the color gamut of earlier iPads to the new iPad. The difference is quite apparent. Ever since the days of the early color screen iPods, Apple’s iTunes app has been doing color conversion before creating down sampled images for sending to what are now called iOS devices. This could be tested by tagging the same image with a larger and a smaller color space, while not changing the actual image colors. If iTunes was ignoring incoming color profiles, the images would be identical on the iOS device. If images were being converted, then they would end up being different, as they would be converted from different source spaces. The latter was true, showing that images were converted on the way to the device. But converted to what? We jokingly called it iPodRGB, then later iPhoneRGB, and later still iPadRGB.

Now that Apple has created its first iOS device with a noticeably different color gamut, are they converting files differentially for the different device gamuts? Certainly they are creating different file sizes and resolution for different devices; the same file is larger, when rendered through iTunes to a new iPad, then it is when rendered to an earlier iPad. But more to our point: the color is different as well. E-mailing the same image “back to the Mac” from the new and an older iPad results in versions which are both different in size, and different in color. Resizing them to an approximate match, and overlaying them in an animated GIF results in the image below.

The same image, returned from older and new iPads

I apologize for the blinking image, but it is the most efficient way to show the changes. “What changes?” you may ask. And its true: the number flashes from 2 (older iPad) to 3 (new iPad) and the grid move a pixel or two, but the colors really don’t seem any different. In order to produce an animated image, its necessary to use the GIF format, which offers lower color bit depth than newer format. So for the most part, the minor differences in color are lost. But even in Photoshop at full color depth, the difference tended to be indistinguishable to the eye. However the RGB values of many patches were as much as several points different. So this may not be as big a deal as the headline “Images sent to New iPad are Color Converted Differently” could make it seem.

In a practical sense, how does this matter to the end user who cares about color? The same way it did in the past: Apple’s secret iTunes conversion to unknown colorspaces for iOS devices was apparent to those serious about color long ago, and has not really changed. Sending the same image to any iOS device through iTunes does not end up with the same result as emailing the image, or otherwise transporting it to the iPad outside of the iTunes process. Images imported outside of iTunes are not downsampled to what Apple considers an optimal level, so your iPad may get full much faster. And then there is Apple’s unmentioned color conversion. But now, there are multiple, slightly different, iTunes color conversions; the plot, as they say, thickens.

Apple is attempting to make this all invisible and automatic, to simplify the end user experience. Those with more advanced needs are left to deal with these simplifications as best they can. The first conclusion you can draw is that importing images through iTunes to your iOS devices, then sending them on for other uses is not a good idea. Images you wish to have retain known colors should be emailed or otherwise sent to the device instead. On the other hand images in color spaces other than sRGB, such as AdobeRGB, will be more appropriate if converted though iTunes, though the best solution is to convert such images to sRGB before outputting them to any mobile or web usage. A further conclusion is that those concerned about color should use the consistent method of their choice for importing files to their iOS device, and avoid mixing and matching files from iTunes and other sources. And the final observation would be that using SpyderGallery for color managed display is still the best choice for controlled iOS color.

Credits: C. David Tobie, Copyright 2012. Website: CDTobie.com Return to Blog’s Main Page

RAW Formats and Converters – Part 4: Which Apps to Update?

Please read the FirstSecond, and Third articles of this Series.

Our previous analysis has helped us understand the formats and conversions involved in RAW workflows. But it hasn’t come down to the questions that cost us the money: Which apps do we have to keep updated, for compatibility with new cameras, and other new apps?

The simplest workflow for the photographer is to store images in a Lightroom library as RAW files, and export from Lightroom to a recent version of Photoshop, which will open these RAW files in ACR, respecting all edits applied in Lightroom. This version can then be saved as a high bit TIF file back into Lightroom where it will be stored with the original file.  Simple process, minimal steps, convenient, and leaves rendering to the last possible point in the workflow. However this workflow requires anyone who purchased new cameras to continuously upgrade Lightroom, which is moderately priced app, and getting more affordable over time, and to similarly upgrade Photoshop, for continuous access to the latest camera formats and compatibility with the the latest versions of Lightroom (explained below). Photoshop is not a low cost app, and not as low priced as Lightroom even for upgrades; plus there are now two applications which need to be upgraded with each new generation. So this is simplest and most flexible workflow, but also the most costly.

The way that Adobe deals with the need for inter-application compatibility is through defining “Processes”. For instance Photoshop CS5, and Lightroom 3, used Process 2010, which was developed in (you guessed it) 2010. Any other app can also adopt that standard. The problem happens when you have newer images processed in Lightroom4, or another Process 2012 app (though I doubt that there are many other Process 2012 apps out there yet), and try to open it into Photoshop CS4 or CS5. In those older apps (yes, I just called the current version of Photoshop “older”… get your wallet ready) you’ll see a warning dialog that this version of Photoshop does not support the more recent features used on this image.

However, there is a workaround. At least when importing from Lightroom, you will see an option to render the file from Lightroom, to retain the edits made with the newer functions. Since you are going to have to render the file shortly, the fact that Lightroom instead of ACR in Photoshop performs this function is not a big deal. It might, in some instances, mean one more saved interim copy of the image, if your workflow isn’t optimized to avoid that, costing you disc space, but not really any extra effort.

So perhaps you have already noticed what this change in workflow could mean to your wallet: you don’t have to update Photoshop every time you update Lightrooom, (or your camera) to retain compatibility. In fact, you won’t ever need to update Photoshop at all, unless there are new features in it that you decide you need, or other critical changes (such as support for newer OS versions) occur. There are similar workflows for rendering from Aperture and other applications using their latest “Process” version, then opening in Photoshop, though they may be a bit less automatic, since they are not handing off between two Adobe apps. Be sure to render out using a file, type, compression type, and bit depth that your receiving application can handle.

There are a few warnings that go with this suggestion. You will lose your ability to open images from newer cameras directly into Photoshop, and will have to launder them through Lightroom or your other app that contains the latest camera RAW format definitions. But you will have to render out any images to TIF  before opening them with Photoshop, so these two processes will occur seamlessly in the same workflow.

Another warning would be that Adobe may not honor your copy of Photoshop for upgrade, if you have not kept up with all the interim versions. But unless you intend to purchase upgrades for both Lightroom and Photoshop with each generation (which is looking like every two years) then you will have to become familiar with these other workflow options, and act accordingly. Those using other RAW conversion and image management apps will similarly need to decide if they will update that app for new camera compatibility, and recent “Process” versions, plus update Photoshop as well; or develop a lower cost workflow that only sends TIF and JPG files to Photoshop, and does not use Photoshop’s ACR plugin for opening and rendering RAW files.

Credits: C. David Tobie, Copyright 2012. Website: CDTobie.com Return to Blog’s Main Page