Color Comparison: Canon 5D Mark lll and Nikon D800

This article compares the uncalibrated and calibrated color from Canon and Nikon’s recently released pro camera bodies: the Canon 5D Mark lll, and the Nikon D800. I recently spent two weeks in Tuscany shooting with other photographers. One of those was Kevin O’Connor, who was carrying the new Nikon D800, while I was carrying the Canon 5D Mark lll. It was interesting to compare the two cameras in terms of various types of shooting from sports to glamour, from food to landscape, not to mention low light and long lenses. But this article focusses on one factor of each camera: its native color, and its calibrated color.

The calibration tool used was Datacolor’s SpyderCheckr, which (in addition to the SpyderCube) we had with us on the trip. The SpyderCheckr target was shot with each body, and the resulting RAW file was cropped, white balanced, and exposure compensated in Lightroom before export to the SpyderCheckr utility, where a colorimetric calibration correction set was built for each. The image below shows the each of eight color channels, and the corrections to Hue, Saturation, and Lightness made to these channels for both bodies, with the 5D Mark lll on the left, and the D8oo on the right.

SpyderCheckr corrections for Canon 5D Mark lll (left) and Nikon D800 (right)

The first thing to notice in these corrections is that they are quite similar to one another. The 5D Hue adjustments tend to be a bit smaller than those for the D800, while the D800 Saturation are larger. The D800 Luminance adjustments are significantly larger than those for the 5D Mark lll. There is some variation in which colors need correction, but typically it is for a similar set of colors, and in a similar direction, for both cameras.

Shooting the same event with both Canon and Nikon bodies tends to produce images that are recognizably different, especially in bright reds and in sky blues. So the two sample images I have selected for comparison are ones containing those colors. First, lets look at similar shots of a musician from above. Here are the two images at Lightroom default import values, with exposure corrected for as close a match as possible.

Uncalibrated Image at Lightroom Defaults, Canon 5D Mark lll

Uncalibrated Image at Lightroom Defaults, Nnikon D800

Keep in mind that these images have been converted to sRGB for the web, and are viewed on your display; only you know how good your display is, whether it is calibrated, or how reasonable your ambient lighting conditions are. But the relative difference between the files should still be visible, unless your ambient lightings is so bright you can’t see the screen well. Both cameras produce a bright red for the shirt that the experienced eye sees as oversaturated, as well as problematic to print. Lets see what the files look like once the SpyderCheckr calibration has been applied to them.

SpyderCheckr Calibrated Image at Lightroom Defaults, Canon 5D Mark lll

SpyderCheckr Calibrated Image at Lightroom Defaults, Nikon D800

Both reds are now more believable, and more printable. There is still a minor white balance difference between the images, which ideally would be corrected with a SpyderCube, but once that is adjusted, it would be difficult to tell the calibrated results from the two cameras apart.

Now for the blue sky example. This is the most common Canon/Nikon mismatch issue, since the sky is such a common image element. First, the uncalibrated output from both cameras.

Uncalibrated Image at Lightroom Defaults, Canon 5D Mark lll

Uncalibrated Image at Lightroom Defaults, Nikon D800

Even on the web, its possible to spot the difference, with the Nikon producing a greener result, while the Canon produces a darker result. On a calibrated monitor I would say the Nikon hue is off, and the Canon luminance may be a bit dark; but its difficult to make a judgement on the web. Now the corrected versions.

SpyderCheckr Calibrated Image at Lightroom Defaults, Canon 5D Mark lll

SpyderCheckr Calibrated Image at Lightroom Defaults, Nikon D800

Here we are looking at an even smaller variation in camera white balance, and an even better match between the two cameras. I have complete confidence that, with these sets of HSL color corrections for each camera body, plus SpyderCube shots to adjust white balance and exposure for each lighting condition, that these two cameras would produce images with indistinguishable color, allowing them to be used side by side for even the most important of events.

All Nikon D800 images: Copyright Kevin O’Connor. Thanks Kevin, for your assistance in the preparation for this article.

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

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Video on Using SpyderCheckr with Hasselblad Phocus Now Available

I recently produced the English audio for this tutorial, which has now been integrated with the video. It covers how to use the Datacolor SpyderCheckr with Hasselbad’s Phocus RAW conversion software. So those of you with an interest in the SpyderCheckr for camera calibration, or who use Phocus for your RAW conversion, should take a look. There is a German version available as well. SpyderCheckr can be used with Adobe Camera Raw and Lightroom as well as with Phocus. Thanks to all who were involved in producing this video!

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

Using Datacolor’s SpyderCube with Lightroom 4’s Process 2012

Datacolor’s SpyderCube can be used to set white balance and exposure settings by shooting it in an initial image under a given lighting condition, correcting basic settings in RAW converters such as Adobe Lightroom, and then applying those corrections to all other images shot under the same conditions. Adobe’s new Lightroom 4 defaults to a new set of RAW import controls called Process 2012, which function differently than previous Lightroom controls. This article outlines the differences between the previous Process 2010 and the new Process 2012, and how to achieve similar results from the two different processes when adjusting images using the SpyderCube.

The controls and their default settings for the Basic tools in the Develop Mode of Lightroom under Process 2010 are shown below on the left, with the Process 2012 equivalent controls, also at default settings on the right.

Process 2010 and Process 2012 default settings for the Basic controls

Images which were previously imported through Lightroom 3 will appear in Lightroom 4 using Process 2010; older images imported using Lightroom versions 1 or 2 will show as Process 2003. New imports in Lightroom 4 will appear as Process 2012 images. This brings two questions to mind; can images be converted from Process 2003 and 2010 to Process 2012 without visible changes? Not automatically, as explained in an earlier article. But with careful tweaking, the results can be very close, as we will demonstrate here.

Below are the copies of the same RAW file, one opened at defaults in Process 2010, the other opened at the default settings in Process 2012. Clipping warnings or white and black ends are turned on in both images, to show the relative clipping the two defaults produce.

Image opened using Process 2010 and Process 2012 defaults, with black and white clipping warnings

There are some differences in the densities and clipping, due to the differences in the defaults, and the different default Tone Curves in the two Processes. Next I use the SpyderCube to correct the p2010 image in the manner that the Cube has been used to correct images with Lightroom previously. The resulting adjustments are shown on the left below. I then adjusted the p2012 version of the file to as close to identical as the rather different controls in p2012 allowed. These adjustments are on the right below.

Process 2010 and Process 2012 adjusted settings

These adjustments resulted in the pair of corrected images shown below. As you can see, there is not much difference to the eye. However, the new controls in Process 2012 have other advantages not apparent here that are well worth the upgrade.

Images adjusted in Process 2010 and Process 2012

Below are the same two corrected images, with black and white clipping warnings turned on.

Adjusted images with black and white clipping warnings turned on

As you can see, the black clipping areas are nearly identical. The white clipping is somewhat reduced under Process 2012, due to changes in how the controls function.

Under any Process, the first adjustment is to set the White Balance by using its eyedropper to sample from the center of the lighter of the two gray faces, which represents the primary light source’s color temperature and tint. Under Process 2003 and 2010, the lighter white face was then adjusted to a value of about 90%, using the Exposure control. Then the lighter gray face was adjusted to a value ranging from 50% for shots in direct sunlight to higher values in lower light conditions. This was done with the Brightness control. Further fine tuning of Exposure and Brightness are often necessary, to compensate for each other, until the target percents are shown in both the primary gray and primary white samples. Finally the blacks were adjusted until an appropriate visual distinction was visible on a calibrated monitor in proper editing conditions (dim ambient lighting), resulting in a black value usually in the range of 10%, if there was splash lighting hitting the black face, or as low as 5% if there was not. White and gray values are rechecked if there is significant adjustment for the blacks, and adjusted if necessary.

Under Process 2012, it would seem that the nearest equivalent to this method would use Exposure to set whites, Whites to set grays, and Blacks to set blacks. But this does not produce the expected results with the new controls.

Instead a significantly different method can be used to obtain similar results. Once the image is white balanced, the Exposure control is used next to set the lighter gray face to the desired level. Then the Whites control is used to set the lighter white face to the appropriate level, with minor adjustments to the Highlights control if needed for optimal results. Again, these are tuned until gray and white levels are appropriate. Now the Blacks control can be adjusted to control black clipping in the SpyderCube’s black trap, while the black face surrounding the trap can be adjusted using the Shadows control. Finally, checks of white and gray are done again, once black adjustments are complete. This method now has five controls which can be brought into play, instead of the three used in earlier Processes, offering finer control of shadow to black ratios and black clipping, and highlight to whites ratios and white clipping.

Notice in the adjusted settings image above that Process 2010 editing increased the Exposure significantly, while reducing the Brightness (which started at a default of +50). Under Process 2012, Exposure is increased only fractionally, while Whites are increased significantly. Lightening an image using the Whites control increases the brightness of the dark areas less than the Exposure control, so effects the grays of the SpyderCube less, for a similar change in the Cube’s whites than the Exposure control. It is the differential between these two controls that is being used to control highlight values versus midtone values, and produce some, but not too much, white clipping in the chrome ball on top of the Cube to assure specular highlights are correctly set. Similarly the Blacks control, which clips, and the Shadows control, which does not, are played against one another for clean blacks in the black trap, and appropriate shadow detail in the black face.

Opposing Adjustments to Blacks and Shadows can be used under Process 2012

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

Lightroom 4: Analyzing the New Process 2012 Controls

There are some fundamental changes between the controls and settings in Lightroom 3’s Process 2010, and Lightroom 4’s Process 2012. I have described these differences, and shown some of the value of the new controls, in previous articles, as well as the weaknesses inherent in the older process. It has been pointed out to me that none of these articles actually analyze the differences in the controls, and describe how they effect images; so that is what I will do here. Those of you who are determined to understand the new process fully may find some answers in the testing notes below.

Both Process 2010 and 2012 are available in Lightroom 4, with previously imported images defaulting to Process 2010 (or if they are of Lightroom 2 or earlier, to Proces 2003), while newly imported images will be in Process 2012. It is possible to change between these processes, but there is not exact equivalency, as you will see in this article. The illustration below compares the Basic Controls in the Develop module of Lightroom 3, on the left, and Lightroom 4, on the right.

Lightroom 3 and 4 Basic Controls, AKA: Process 2010, and Process 2012

Testing Methodology

In order to analyze changes caused by the various controls, test images where shot of the Datacolor SpyderCheckr target, where the ten percent gray ramp patches, and the additional 5% and 95% gray patches, were used to determine how adjustments were effecting the image tonal range. These numerical changes were compared to the visual changes in the image itself, and the graphical changes in the RGB histogram of the image at the top of the Lightroom Develop Mode’s right panel. Shots of the Datacolor SpyderCube were similarly tested, in part to help analyze the Lightroom Processes, and in part to determine how best to use the SpyderCube with these new controls, which I will document in a future article. Checks were done between Lightroom 3, and Lightrooom 4’s implementation of Process 2010, to be sure that the two were equivalent. Further testing was done in Lightroom 4.1, using the p2010 and p2012 settings, which is much more convenient than running two versions of Lightroom simultaneously.

White Balance (graphical change)

While the Color Temperature and Tint controls in the White Balance section display differently between the versions, this is simply a matter of Process 2012 now displaying the actual Color Temperature value in Degrees Kelvin even at the “As Shot” setting, instead of defaulting to zero, and not offering any useful Color Temp info until the slider had been moved from that location in Process 2010. The functionality of the controls in this section is unchanged, so will not be discussed further.

Exposure (range change)

The Tone Controls section has the same number of controls as before, but their names, groupings, and some cases their control types have been changed, between p2010 and p2012.  The first control to analyze is the Exposure slider. It now has a range of negative five to positive five in Process 2012, increased from four units in each direction in the previous version. This extra range may come in handy for some extreme situation, but the functionality of the control in its usual range appears unchanged. Exposure stretches (positive move) or compresses (negative move) all tones. No clipping of values at the black end occurs when compressing the Exposure downward, but significant blow-out of highlights occurs when increasing the Exposure in either Process.

Contrast (location change)

Contrast functions by stretching all values out from the center with a positive adjustment, or compressing them towards the center with a negative adjustment. The effect is not symmetrical with much more change taking place in the darker end of the range than in the lighter end. Contrast adjustments do not clip either near whites or near blacks, compressing them towards the ends instead. This behavior appears identical in Process 2010 and Process 2012. So while the Contrast control has a new location, now paired with the Exposure control at the top of the Tone section, its functionality can be considered unchanged.

Recovery (removed)

This Process 2010 control no longer exists in Process 2012. It is a single directional slider, with the default position at the zero end. Moving the slider away from zero does not darken white, but darkens near whites and highlights, while having little effect at the dark end of the range. This is a “gamma-like” adjustment, where both ends are fixed, and the adjustment centers in the highlight zone, moving only in the direction that reduces the brightness of tones from their default values.

Fill Light (removed)

This is another Process 2010 control that no longer exists in Process 2012. It is also a single directional slider, with the default position at the zero end. Moving the slider away from zero does not lighten black, but lightens near backs and shadows, while having little effect at the light end of the range. This is another “gamma-like” adjustment, where both ends are fixed, while the adjustment centers in the shadow zone, moving only in the direction that increases the brightness of tones from their default values. The functionality of the Fill control appears to be a symmetrical opposite of the Recovery control.

Blacks (range and location change)

The blacks control in Process 2010 is a single directional control, but the default value was not zero. Offset from zero varies, but for all cameras I checked it was at 5, while for non-RAW images, it was at zero. Adjusting the control back towards zero decreases the default clipping of blacks. Increasing the slider value clips an increasing number of near blacks to black. In Process 2012, the Blacks slider is now a bidirectional slider, with a default of zero. The lack of a default offset here is compensated for elsewhere in p2012; partially with changes in the Tone Curve default and engine (more on that below).

Brightness (removed)

This p2010 control has no equivalent in p2012. The Brightness control is a bidirectional slider, which defaults to zero for non-RAW images, but defaults to a value of +50 with all tested cameras.  The Brightness control runs to positive and negative 150, and compresses but does not clip at the black end with negative values. It clips significantly at white with positive adjustments. The control has a similar function, when moved in the positive direction, to the Exposure slider, but does not have as much range.

Highlights (added)

This new Process 2012 control is bidirectional, and defaults to zero, as do all the new/replacement controls. Positive adjustments stretch highlights towards white, compressing near whites to white without clipping them, and stretching highlights in the midtone end of the affected zone. Negative adjustments are more in line with previous Recovery adjustments. They compress highlights into the midtone zone, while stretching them in the near whites. There is also a parametric Tone Curve function of the same name. Both Highlights controls have very similar effects, though they are applied separately. It makes sense not to raise one of these controls while lowering the other, as it would be counterproductive, but there might be cases in which minor adjustments in the same direction are made in both.

Shadows (added)

This new p2012 control, like the others, is bidirectional and defaulted to zero. It is an mirror of the Highlight control, used to control shadow detail versus image punch. Again there is a control of the same name in the Tone Curve section, but here the effect of the Tone section’s slider has a broader effect than the similarly named control under the Tone Curve section, so one or the other may be selected depending on whether a more localized or more broad effect is desired.

Whites (added)

This new bidirectional, zeroed p2012 control is somewhat analogous to the now older Brightness control, but with much less range in the negative direction. It does not have the Highlight control’s protection against clipping, if moved in a positive direction. It raised all tones, and clips those near white progressively as stronger positive adjustments occur. Whites are also not held when negative adjustments occur, so lowering the Whites control will darken whites along with other values.

Blacks (again)

This new p2012 control is the mirror of the White control, producing the same results, from the other end of the tonal range. Its described above, and included here only to round out the “new four” as this is the only control of the four to retain its name, though it has changed its function considerably.

The Other Change: Tone Curve Default

The Tone Curve defaulted to Medium Contrast in Process 2010. It defaults to Linear in Process 2012. Moving an image from p2010 to p2012 forces a change in Tone Curve, rather than retaining the previous setting; since apparently retaining the setting does not retain the tone densities anyways. Medium Contrast in p2010 and Medium Contrast in p2012 mean different things, so aligning them would not be appropriate. This would indicate changes to the tone engine in Process 2012, and not clear equivalency for older images, which had been processed previously in either Process 2003 (Lightroom 1 or 2) or Process 2010 (Lightroom 3). This means that you should not automatically update the Process for pre-corrected images and expect matching tonalities. If you choose to move the Process version of an image to p2012, be prepared to readjust the tonality.

Opposing Adjustments to Blacks and Shadows

Interactions and Improvements

The new, centered, bidirectional controls offer a few advantages over the older versions. Control of black clipping against shadow detail is the clearest example. It is now possible to use the Blacks control to clip noise from the levels nearest to black by moving it in a negative direction, while independently opening the shadow area by moving the Shadows control in a positive direction, as illustrated above. Interaction between the new, and more symmetrical, controls is clearer, as well as more effective. Its now possible to adjust highlight and shadow areas without unintended clipping of whites or blacks, while it is also possible to make powerful adjustments to images from either end, both without clipping, if the end adjustment is inward, or with the inevitable clipping if the adjustment is outward. The engine underneath the new Process is improved, and more drastic adjustments to images can now be made without the the kinds of artifacts that the older, less linear, process produced.

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

Color Calibration Comparison: Canon 5D Mark lll from Different Profiles

In my recent article comparing the color response of the Canon 5D Mark lll in Lightroom 4.1 with and without SpyderCheckr calibration received a lot of interesting responses. The most frequent questions were: what profile did you use (answer: Adobe Standard, for reasons that will become apparent below), and what effect would changing that profile have on the color? That seemed like a valid line of enquiry. I also thought it appropriate to also show what would happen if I build a calibration on top of each of these profiles, and applied these calibrations for comparison. The usual caveats about what you see on your (possibly uncalibrated) monitor through your (possibly non-color managed) browser apply.

First its necessary to understand the importance of defaults in such settings as Tone Curves and Profiles. Images are imported into Lightroom, and unless  you build a special Preset, and specifically include things like a Tone Curve and a Profile into that preset, and remember to import all images through that Preset, then you (like 99% of Lightroom users) will end up processing your images on top of the default settings. So my standard recommendation is to leave the Tone Curve and the Profile at the default, and to build your custom SpyderCheckr camera calibration (and your SpyderCube white balance and exposure adjustments) on top of those settings. That way you won’t have to remember what settings were in place when you created the calibration, and the chance of you having the wrong settings in place when you apply the calibration are minimized.

Also note that pushing the Reset button in Lightroom’s Develop Mode will reset the Tone Curve in Process2012 to Linear, and the Profile to Adobe Standard, even though you might not have intended either of those actions. One more reason its safest to build on top of the defaults, to ensure consistency, and minimize errors.

Next, I built three different calibrations in the SpyderCheckr software, all from the same shot of the SpyderCheckr target, taken with the Canon 5D Mark lll camera. In all cases I left the Tone Curve set at the new default of Linear. In all cases I left the intent in the SpyderCheckr application set to Colorimetric, the most literal setting. For one calibration, I left the Lightroom 4.1 Profile set at the default profile of Adobe Standard. For another I set the Profile to Camera Standard. And, to test one of the “flavored” choices, I also build a calibration with the Profile set to Camera Portrait.

I then opened the same 5D Mark lll test image I used in my previous articles in Lightroom 4.1, at its default Profile setting of Adobe Standard, and captured what the color from that looked like. I then applied the Lightroom Preset I had build for the Mark lll at Adobe Standard, and captured that as well. These two images were combined side by side into an Uncalibrated/Calibrated image. That image is below. Click on it to see the results at 100%.

Results using Adobe Standard, Uncalibrated, then Calibrated

These results, though I created a new calibration, and newly applied it to the image, are similar to the results in the previous article, as the same configurations are used. Next I repeated the same test, with Lightrooom 4.1 now set to the Camera Standard Profile. The results for this pair of images are below.

Results using Camera Standard, Uncalibrated, then Calibrated

These results are quite similar to the first pair. Camera Standard is not quite as oversaturated to Adobe Standard, showing a bit better color detail since it is not as bleary, and with a somewhat different hue. Calibration, starting from these two different hues and levels of oversaturation, is satisfyingly similar. This is what calibration is supposed to do. Calibration takes two inaccurate and dissimilar monitors, and makes them both correct and similar by calibrating them. Camera calibration similarly corrects both versions of the image, and as a result makes them a closer match as well. This is very reassuring.

Now to test with a “flavored” Profile. One intended for Portraits is shown below.

Results using Camera Portrait, Uncalibrated, then Calibrated

Here the  reds are less oversaturated then either of the previous cases, but the near whites show much pinker and more saturated. Note that the calibrated result on the right adds a bit more color detail in the reds, and reduces the over saturation and excess density in the near whites considerably. As a calibration can’t fix everything, there are compromises required. The worse starting point of this Profile resulted in less accurate reds than the other calibrations, in the process of curing the heavily over saturated and too-dark near white zone. This result would indicate to me that one of the other Profiles would be a better starting point for calibration, much as it is possible to choose a better media setting in a printer driver before profiling the printer.

It makes sense that avoiding intentional flavorings and non-linear Profiles in advance of creating a Camera Calibration is a good idea. The fact that the default (Adobe Standard) Profile offers good results in convenient, as it allows users to feel comfortable doing what is easiest: calibrating on top of the default, for the least chance of later errors in applying the calibration to future images as they are imported.

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

Color Calibration: Canon 5D Mark lll

Calibration Corrections for the 5D Mark lll

In my recent article comparing the color response of the Canon 5D Mark ll to the 5D Mark lll, I showed the calibration adjustments from Datacolor’s SpyderCheckr for both cameras. Today I am focussing on the Mark lll, and what calibration does to improve its color response, so I will limit myself to the Mark lll correction chart only.

Color Corrections for Canon 5D Mark lll from SpyderCheckr

While there are several colors where the combination of hue and saturation adjustments are fairly significant, I will limit my examples to the primary color channels with the largest Hue shift (Green, with Hue -16, and Saturation -4) and the largest Saturation Shift (Red, with Hue +6, and Saturation -15). The first question is: are these adjustments visible in real world images? And the second is: do they actually improve the results in images where they are visible? I selected images from my first test shoot with the 5D Mark lll that showed these adjustments clearly, and which can be used to judge the value of these calibration adjustments.

Limitations of Web Color

The images you will see below were color accurate on a calibrated display. On an uncalibrated screen, or with a non-color managed browser, the results may not be as accurate. However they should still show the degree of difference, even if the colors are not exactly as they would be under color management. So try to visualize what the text describes for color and saturation, and use the images to compare the degree of change, if the actual changes described are not reflected on your screen.

First the Reds

To judge the effect of red adjustments, I selected am image with saturated red flowers, and cropped a section at 100 percent. The red flower petal in the center of the image moves forward from the point of focus, and becomes less focussed in the lower regions. The reds are extremely saturated, and the trained eye sees a color that will be problematic to print as well as having the bleary quality that over saturated colors often exhibit.

5D Mark lll Reds, Uncalibrated

Next we’ll examine a similar closeup from the same image after the SpyderCheckr calibration has been applied to the image. Here the colors look more believable, and show a good deal more color detail, that was lost the the bleariness of the uncalibrated version. The Hue Shift, while far smaller then at the Saturation reduction, also improves the realism of the image, accurately reflecting the transition from magentas to a more orangey red in this type of flower. Its often surprising to see that color correction does not just improve the colors; it improves the color detail, which results in a more detailed image; something we tend to associate with focus and lens quality, when it can actually be an artifact of incorrect color.

5D Mark lll Reds, Calibrated

Now the Greens

Next we’ll move on to the greens, which are a subtler situation, since it is the Hue, not the Saturation, that has the largest adjustment. Here the issue is less one of lost detail, than one of lost color richness. Leaf greens must contain an appropriate yellow component to read correctly to the eye; an emerald green leaf looks as false as the Emerald City, painted onto the Wizard of Oz backdrop.

5D Mark lll Greens, Uncalibrated

Now we’ll compare this with the calibrated green, which has a 16 point Hue shift towards Yellow, and a 4 point Saturation reduction. Here the greens read as much more realistic, with the necessary yellow component, and the slight reduction in saturation to produce photo-realistic foliage. This will be a much more printable green, and much more satisfying in print, as well as the improvement shown on screen.

5D Mark lll Greens, Calibrated

And the Rest

Other calibration corrections for the 5D Mark lll follow a similar pattern, but the effect is reduced for those channels requiring less adjustment. Overall, native color on the 5D Mark lll is very good, but calibrated results are truly excellent.

Personal Preference 

The color corrections shown above are aimed at accurate color portrayal. They are from the Colorimetric option in SpyderCheckr. Personal preference may lean towards emerald green leaves and over saturated flowers; thats fine as artistic intent, but it should occur by intentional adjustment, not by incorrect original coloration.

A Note to Nikon Shooters

Vincent Versace recently requested that I do a color comparison of the latest Canon and Nikon models. As a Nikon shooter, he as always felt that the Canon results were more saturated; perhaps too saturated. The calibration corrections above do tend to lean towards desaturation of the RAW file’s color; in fact there is not a single channel where calibration increases the saturation. I plan to analyze the color of the new Nikon D4 against its predecessor, the D3, and similarly the D800 against the D700. Once I have completed those results, I will be in a position to compare the 5D’s color saturation, and other color characteristics, to those of the D4 and D800. Perhaps the results will reinforce Vincent’s personal impressions. It will be interesting to find out.

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.

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

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