Soft Proofing and Printing with Lightroom

In my previous blog on exposing to the right with Olympus OM-D I mentioned shortly the Soft Proofing capabilities of Adobe Lightroom 4.

Here I take another look at Soft Proofing and why this tool in Lightroom is so powerful and important, especially for anyone printing images.

I like to tweak my images to have strong colors. With well calibrated and profiled monitor, reading color picker values and having lots of experience on printing I can forecast quite closely where the limit goes. But not always. One thing to notice is, like here, that Lightroom´s warning colors do not give any advice on how colors would behave in any lesser color space than ProPhoto RGB. Red on bike´s fender and blue on shadows give only a promise of a nicely contrasty image. However, my experience tells that those strong blue and cyan colors are now at least on the verge of being too saturated to be printed.

Enter Soft Proofing

To get a more precise and explicit view on how things really are, I have turned on Soft Proofing. I am going to print this image on Canson Infinity Rag Photographique 310g paper. That´s why I have chosen as Profile: cifa_3800_ragphot310_M... Here "cifa" is short of Canson Infinity Fine Art, "3800" stands for Epson 3800 printer and "ragphot310" is the just mentioned printing paper. Profile name goes on to say that I should use Matte Black ink. This profile is supplied by Canson and is downloadable from their web site at canson-infinity.com. Furthermore the instructions on their web site tell me which Epson 3800 printer driver settings should be used with this paper. I have chosen Perceptual as Intent. There´s a slight difference between how intents Perceptual and Relative render the image with this profile and I like Perceptual better. The choice here is just a matter of taste, and with many images the difference is quite small. 

As you can see, there is now a red warning color over most of blue and cyan surfaces and also on some areas having red color, although reds are naturally more difficult to notice here. The histogram has also a very different shape as it shows how the tones are mapped into color gamut of Rag Photographique. Red warning color is gamut warning color and it shows which colors from my image can not be properly mapped into my desired target. The warning goes on if any channel loses definition. While printing with inkjet printers it is not necessarily a disaster if one channel is clipped IF the other two have lots of variation inside the same area. But you are being warned and you need to check what is going on and you must make a decision on what to do.

To illustrate two exmples of possible corrective actions, here I have tweaked the blue range of colors in my image. A drop in saturation, small change in hue and slight lowering of luminance brings blues and cyans quite well inside of gamut. This is done in HSL window. Red colors are of course not affected but let´s forget them now as any correction there would be analogous.

Previous correction affects all blue colors globally in this image. Also those areas which are not at the edge and as a result some predominantly blue areas might turn too pale. By using Adjustment Brush tool you can tweak separate areas. Here I have painted Saturation -35 on the middle of cyan poster. Working with brush tool you can be very subtle and work gradually, and you can combine Saturation, change of color (Temp and Tint), Exposure and all the other sliders with so many ways. Each separate area can have its own correction as needed.

Let´s Print

After corrections it is time to print. I printed the above image both as it was and corrected with the above shown HSL tweak. Then I scanned both prints with a flatbed scanner. Here are details from both scans. On the left from the uncorrected and on the right from the corrected print. As can be seen, you can trust quite well the combination of Lightroom Soft Proofing and properly made profiles, like Canson profiles are. The cyan poster was bulging and reflecting the sky. Blue cardboard of kiosk was also bulging, torn and dirty and the fence must have highlights and shadows. The corrected print is a lot more life like.

At first I was quite disappointed with Lightroom 4´s Soft Proofing because CMYK Soft Proofing is not possible there. Now when I have used Soft Proofing habitually with every ink jet print I make, I couldn´t live without. It is one more tool which takes quessing out of equation. I can previsualize even better, actually quite perfectly, how my prints will look like when they come out of the printer. And like I wrote above, it is not a must to force every color always inside the paper´s gamut. Soft Proofing is a tool, not a dictator. It is not forbidden to use overly saturated or clipped colors in prints. Soft Proofing helps you to achieve even that in a controlled manner.

-p-

My Lightroom 4 book is out

Just when I'm slowly coming back from summer break, also my new book on Lightroom 4 comes out from printing. Previous versions covered Lightroom versions 1 and 3. This is a 360 page book covering all aspects of Lightroom. It is not a re-write of manual and menus but concentrates on real life use of Lightroom and workflows with images. For now it is only in Finnish. Naturally I would hope that publishers, Docendo, has it published also in some other languages! 

-p-

Olympus E-M5: Exposing (to the right) and Lightroom 4.1

I posted previously an article on "Exposing to the Right" (ETTR) with Olympus E-P3 RAW images. You can read it here. This blog is based on the same fundamental idea. My previous article was both praised and scorned. The latter came mostly from people who believe in a method to do ETTR known as UniWB. UniWB is a clever method of addressing limitations you encounter with practically every digital camera if you want to expose to the right. With it you have to endure either a green or a black and white live view viewfinder, and I am not too happy with either. Also it is based on using histogram which I´m not happy with either. This method I am using is based on using highlight warning blinkies as exposure meter: they are both easy to see, very graphical, and show what´s actually happening in your image, spot by spot if you want to. This method applies for Olympus PEN cameras since E-P3 (plus E-PL3 and E-PM1) and OM-D E-M5.

Since I got Olympus E-M5 I have practiced it quite happily with the same settings as with E-P3. Lots of people have written to me to write about ETTR with E-M5. I wanted to wait until Lightroom is ready for it because this method is set to be used with Lightroom. Of course you can tweak it for other RAW converters by varying camera configuration settings. At first Lightroom 4.0 was a pile of bugs. There were two Release Candidates for Lightroom 4.1, and now we have a quite satisfactory final version of Lightroom 4.1. It still has some instability issues left (and a few shortcomings with Photoshop integration if you have not updated to Photoshop CS6) but they are no more important here. What´s more important is that Lightroom 4.1 gives you more control on your image relative to its final use.

E-M5 configuration

Lets start with Olympus E-M5 configured like this:

Shooting Menu 1 > Picture Mode > 4 Muted > Contrast -2, Saturation, -2, gradation: Normal

Custom Menu D > Info Settings > LV-info > Highlight&Shadow:On, Histogram: Off

Custom Menu D > Histogram Settings > Highlight: 245

Custom Menu D > Live View Boost: Off

Custom Menu G > Color Space: Adobe RGB

Auto white balance, if used, must be set to neutral: Custom Menu G > Auto WB, Keep Warm Color: Off

Exposure

I adjust my exposure until the red warning color just appears on my chosen critical tone area. By critical tone I mean the brightest area in my image where I want to have definition of tones if the image is printed. In principle, this allows a 1/6-stop accuracy at best, but in practice, the reference tone is very close to the value of 96% almost always when the image opens in Lightroom Develop module. Same critical area will be at RGB value 245 (Adobe RGB or sRGB) in the final image with very little need to adjust as seen below. I do not need to use histogram while shooting, I do not need to check captured images, at least not because of the exposure. 

I exposed this target (right half of Spyder Checkr) with E-M5 so that red highlight warning color started to blink on the lightest area, which is the white patch, up left. This how it looks like imported in Lightroom 4.1 with Lightroom default settings. The only thing I have changed is that I chose Custom WB according to patch shown by cursor. I shot the target outside in sunlight using Daylight WB. You can use Auto-WB for general subjects but it is better to choose a preset WB or make in-camera Custom WB if your image has one or two dominant colors. 

(Note: What you see above is a sRGB image. That´s the only practical option to show in the internet. If you download it and measure patches, they have sRGB values and differ from what I show as measured from converted RAW file below.)

The image above shows the lightest and darkest patch measured (Custom WB, other LR settings at default). The lightest patch is very close to my aim, 96%. The image looks mostly fine but you may need to make some adjustments to darker tones if your subject had low or extremely high contrast.

In general photography subjects many times have brighter spots or areas than my critical value. They are mostly light fixtures and specular reflections where tonal definition is not needed. They may and must go purely white otherwise the image will look flat. I´m interested in where I want tones to end.   

Basically this was it. I am done with telling how I expose with E-M5 when images are opened in Lightroom 4.1. But I go on and write some more background information which might be useful to some people.

Quick-checking Color Channels

If you need to be more precise about colors everything is not done yet. Namely, some highly saturated colors may have a blocked channel as seen in Lightroom RGB preview. In this target all the other patches have definition but yellow patch shows red channel as over saturated and blue patch shows the same channel as zero with LR default settings.

Note: If shooting casual images to be seen just on monitor, I could expose even more to the right. There is some headroom left. By setting Custom Menu D > Histogram Settings > Highlight: 255 I would expose lighter by 1/3 of a stop. And even from there you could expose still a full stop more before the lightest patch would become hopelessly over saturated and blocked. I have tried it but the risk of saturating color channels beyond repair becomes too big AND the time needed to tweak the image colors grows too long. That´s why I have chosen my approach with Lightroom 4.1 as shown here. You may find Histogram Setting 255 worth trying. 

Here I have corrected those two patches to have definition in every channel by slightly lowering yellow and blue saturation in HSL panel.

Note: Actually I can use Spyder Checkr to calibrate my camera to show the colors in target correctly, but that would be a subject for another blog.

RGB Profiles and Soft Proofing

This image shows the same situation seen as Adobe RGB Soft Proof in Lightroom 4.1. Soft Proofing is a new feature in Lightroom 4. It gives you a tool to check that your image has sound values for a needed use. If your image will be printed in a magazine (or offset printing), the general workflow is to prepare and send it in AdobeRGB color space before color separation (conversion into the right flavor of CMYK). With my exposure the lightest patch goes just where the tonal definition end generally in offset printing, at RGB values of 245. Depending on paper the darkest tonal definition would fall between RGB values 16 to 30, with 16 meaning high quality glossy magazine cover and RGB 30 meaning a cheap matte cataloque paper. Instead of Histogram it says now Soft Proofing and the histogram has been changed to show values according to Adobe RGB profile. Below histogram you can see now RGB values, these here are for the lightest patch. I have copied the corresponding RGB values on each four color pick window. Gamut warning is on, as shown by the little square in the upper right hand corner of histogram. Blue patch has still some traces of warning color showing that it is just barely inside Adobe RGB gamut. RGB numbers all show definition in every RGB channel (maybe just barely but still) and they would print out nicely enough with CMYK colors. There´s more to this (Intent etc.), but what´s important, you can see how easily this method of exposing with E-M5 gives you technically very good images. 

Here we are soft proofing the same RAW file with sRGB profile (LR at default settings, same custom WB). The lightest patch has the same values (244) as with AdobeRGB profile but the darkest patch is darker. The main difference, however, is the smaller color gamut of sRGB. Five patches are covered by red gamut warning color. 

Here I have tweaked those five patches into inside sRGB gamut by using saturation sliders in HSL panel. Again: Exposure is fine but RAW image makes a lot more colors possible than can be had inside sRGB color space. This kind of mapping is also what happens if you shoot JPEG and choose sRGB as color space in your camera. Your camera maps colors inside sRGB color space. The method may be different from what I have shown here by simple means but the idea is the same.

Note: For casual images shown on your monitor there is no need to force all colors inside sRGB (or AdobeRGB, if your monitor is capable of it). You are free to have over saturated colors if you like them, but for many professional purposes colors need to be inside gamut. Also all cameras do not behave right and map colors inside chosen color space for JPEG images. Bleak inside gamut colors are not pretty enough, it is commercially better to leave colors saturated, strong and beautiful.

The last example comes back to my reasons to do things my way. My favorite printing paper for my pigment ink printers is Canson Infinity Platine Fibre Rag. Here we have again the same target shot with Lightroom at default values (same custom WB). All the colors are beautifully inside Platine Fibre Rag gamut with this profile for Epson 9900 printer. What coud be better? Perfect exposure for the lightest tones and even strong colors have full definition out of the box. I only need to tweak dark tones as needed. Most of the time I do a lot more with my images but that´s not out of necessity. 

-p- 

Update on June 22, 2012 at 15:35 by Pekka Potka

Two examples of lots of gain with no pain

This morning, while walking the dog, I shot a couple of comparisons to show the difference in details and noise between images that are exposed "normally" with E-M5 and "my" images. "My" meaning of course using settings and blinkies as said earlier in this blog.

Example one:

Same view shot first at camera´s (E-M5) autoexposure and secondly so that red blinkies just lit the trailer´s bright side. Both shots opened here into Lightroom 4.1 with Lightroom´s default settings. Readings under histogram are from trailer´s white side.

Next I clicked Auto Tone for both images. As you can see, Lightroom gives almost exactly one stop difference between needed adjustments. Again readings from the same spot from white area. I could have gone further here with tweaking both images but doing so has no real relevance here. Like you also can see white area is not really white but has details like over painted markings. These highlight details would be quite similar after any reasonable tweaks in both images. Looking at other things in these images, you notice that I have applied an overly strong but equal combination of sharpening and no noise reduction for both images. This to illustrate how ETTR image is clearly superior in blue sky and in yellow and green surfaces. It has a lot more headroom for tweaking. These are 100% crops.

Crops from upper right hand corner show how darker but still medium blue sky behaves. Same overly strong sharpening to better show the differencies. ETTR image keeps wisps of cloud much better intact.

Example two:

Again the other picture shot with camera´s autoexposure but this time the other on was exposed to the right up to the last setting where red blinkies did not light up the lightes part of sky. Both images here opened into Lightroom 4.1 with Lightroom´s default settings. This example is to show the behaviour of darker tones.

And again, I just clicked Auto Tone to normalize images. These details from the back of chair are 2:1 screen captures from Lightroom. All noise reduction (color and luminance) is again off (at 0) and strong sharpening applied. As you can see ETTR image shows much more detail and less especially color noise. What you would get is even more detail with similar noise reduction in every image. The more you tweak the greater the gain from ETTR would be. Also note how much more details with smoother tones the background (easiest seen on the right) shows.

-p-  

E-M5 vs. E-P3: RAW Image Quality

This is a "rewrite" of my previous blog concerning JPEG image quality of these two cameras. It can be found here.

Below I have combined test charts shot with E-M5 and E-P3 at various ISO settings. Settings while shooting:

• Lens Zuiko D. 50mm f/2 Macro @ F4
• Equal aperture and shutter speed settings in both bodies at corresponding ISOs. (These cameras have equal sensitivities)

RAW files were opened in Lightroom 4.1 (Release Candidate 2), normalized and cropped equally. E-M5 crops are 100%. E-P3 crops were enlarged to the same size during Lightroom Export. All images are slightly sharpened and noise reduction applied in Lightroom. I kept the values for these the same for every file.

I chose to enlarge E-P3 files because I am interested in seeing quality in same size prints. This is closest to that situation on screen. Just remember: To see any real difference in sharpness at ISO 200 to 400 you need to print larger than A3. 

In JPEG comparison E-M5 was markedly better in every regard. At higher ISOs E-M5 gained about two stop improvement. I wrote then: This result comes from new sensor with more resolution and better pixel per pixel quality and thinner low pass filter. Now I know better, a lot of it comes also from improved JPEG algorithms. 

With RAW images differencies are not as big in a test target like this. This test target shows now mostly differencies in resolution and noise. E-M5 has a 14% advantage in linear resolution and thinner low pass filter. This is best shown in rhombus structure. Starting from ISO 800 up, E-M5 shows gradually more and more its better sensor. Further tweaking of the relation between sharpening and noise reduction would have benefitted E-M5 more than E-P3. With more demanding subjects E-M5 gives even more headroom for adjustments. I would say that for me the total gain is almost 2 stops in the way I tweak my images in Lightroom. With E-P3 I never went over ISO 1600. Now the limit will be slightly under ISO 6400.

Image below E-M5, M.Zuiko 12mm f/2 (Same image is shown shot as JPEG in previous blog).

• ISO 200, @F6.3
• Adjusted in Lightroom 4.1 (RC2)
• Crops 100% from brightest and darkest area without any modifications

Image below E-M5, Zuiko D. 12-60mm f/2.8-4

• ISO 200, @F5.6, underexposed on purpose.
• First image: opened into Lightroom 4.1 (RC2) at default settings, no adjustments
• Second image: adjusted by +5 stops in Lightroom, full Highlight correction (-100); two simple adjustments just to show the pushability
• Third image is a 100% crop. This radical opening of shadows brings out luminosity noise, as expected. But that´s all. No smearing to mention (grass is always difficult, stone had this mottled surface), relatively sharp details.

-p-

Olympus E-M5: Dynamic Range - RAW

I posted in February a blog on E-M5 dynamic range. At that time it was about jpeg images. Now we have two popular and well known converters supporting E-M5, which enabled me to take another look with raw files. These converters are Lightroom 4.1 (Release Candidate 2) and CaptureOne 6.4.

This graph shows the same E-M5 and E-P3 dynamic ranges (orange and red) for jpeg images as shown in my previous blog. They are actually measured from raw files converted into jpegs in Olympus Viewer 2. This software emulates in camera jpeg process, which means I can tweak the jpegs to show optimal jpeg quality.

Blue and green lines  show what can be achived from E-M5 and E-P3 raw files. I opened raw files into Lightroom and CaptureOne and measured dynamic ranges at various ISOs. Both software showed almost the same numbers for E-M5. With E-P3 there was slight variation at some ISOs but there was no trend in favor of either software. What you can see here is the average performance of these software. The biggest and maybe most important difference was for E-M5 at ISO 200. With Lightroom I was able to read a 12.6 EV dynamic range and with CaptureOne it was 12.0EV.  At ISO 400 they both gave the same 12EV.

When you look at this graph, please do not take exact numbers too seriously. Look at trends E-M5 versus E-P3 and raw versus jpeg. While saying that I think it is no mistake to have E-P3 dynamic range at 10EV, which is the same as DxO Mark result for the same camera. Also two well respected software giving practically same numbers (sans ISO 200) for E-M5 should be no mistake either.

I have now shot a few thousand images with E-M5. Those images show the same trend in real life situations compared to E-P3 as this graph.

-p-