Conditions When Editing

[CatherineA]

I attended a talk recently given by Manfred on the best conditions under which to edit in order to achieve good colour rendition. It was valuable information and explained to me the many ways that my set-up is problematic. If I understood correctly, the most important feature is the monitor but I didn't think that I could justify purchasing a new one at this stage (but if I could, the BenQ 27" 4K looks lovely!) I was going to postpone making any changes to my set-up but the other night I saw a photo that I had put time and effort into and although I was pleased with it on my monitor (a newish iMac) it looked so different and disappointing when I saw it on a good monitor.

Here are some changes that I could make:

1) my room lighting. What artificial lighting do people use? Any overhead lights or table lights?

2) colours and brightness around me. Unfortunately, I love colours. My walls are red (a tasteful "Louisiana Hot Sauce" the paint chip calls it), my furniture is red, and I have a long window beside my working area. I could easily cover the areas around me when I edit with grey sheets...

3) colour calibration with i1 Display Pro. I know the iMac was a poor choice for photo editing but I can still calibrate it and get it to display to its maximum potential. I have free access to i1 Display Pro and I wonder if anyone has experience with it.

4) with respect to the monitor. I saw the chart that showed how much less the iMac monitor covers compared to a better monitors but I am not clear on how much is missing in practice. I know that there is no definitive answer to this but I still wonder whether, for example, it is with nearly every photo that I take that I will fail to see colours on the monitor that I had captured in the camera.

thanks for any thoughts!

[Manfred M]

I attended a talk recently given by Manfred on the best conditions under which to edit in order to achieve good colour rendition. It was valuable information and explained to me the many ways that my set-up is problematic. If I understood correctly, the most important feature is the monitor but I didn't think that I could justify purchasing a new one at this stage (but if I could, the BenQ 27" 4K looks lovely!) I was going to postpone making any changes to my set-up but the other night I saw a photo that I had put time and effort into and although I was pleased with it on my monitor (a newish iMac) it looked so different and disappointing when I saw it on a good monitor.

Catherine - remember my comments were suggesting what one should do when starting from scratch and going for an optimal setup. We all have things that are not 100% ideal.

Here are some changes that I could make:

1) my room lighting. What artificial lighting do people use? Any overhead lights or table lights?

The light source itself is quite unimportant, but there are two key considerations:

1. The light in the room when editing should be fairly dim so that the you get good contrast out of your computer screen. CAPA (Canadian Association for Photographic Art) recommends that we work in a room with light levels below 70 lux; and

2. The lights should be positioned in such a way to minimize reflections off your computer screen. One obviously does not want it getting it into your eyes either.

I use ceiling mounted fluorescent tubes and the light at my work area is 40 lux. These are located behind me and my screen is reasonably well protected from direct light.

2) colours and brightness around me. Unfortunately, I love colours. My walls are red (a tasteful "Louisiana Hot Sauce" the paint chip calls it), my furniture is red, and I have a long window beside my working area. I could easily cover the areas around me when I edit with grey sheets...

The issue is that we want to prevent the room colours from affecting our colour vision; i.e. colour adaptation issues. Most pro editing suits will have neutral coloured walls and ceilings as well as using neutral colours on work surfaces. The most important area is going to be in the direction you are looking at when working. I have a gray wall directly in front of me when I work.

If you can put a gray drop behind your screen, that will help a lot.

3) colour calibration with i1 Display Pro. I know the iMac was a poor choice for photo editing but I can still calibrate it and get it to display to its maximum potential. I have free access to i1 Display Pro and I wonder if anyone has experience with it.

Load up the software and run it, attach the i1 Pro Display to your computer and just follow the instructions. If you have any issues, ask me. Your should set the screen output to be between 80 and 120 candela per square meter and use the D65 illuminant for sRGB and Adobe RGB. DCI P3, I'm not sure about.

4) with respect to the monitor. I saw the chart that showed how much less the iMac monitor covers compared to a better monitors but I am not clear on how much is missing in practice. I know that there is no definitive answer to this but I still wonder whether, for example, it is with nearly every photo that I take that I will fail to see colours on the monitor that I had captured in the camera.

thanks for any thoughts!

A decent modern camera like your Sony can capture around 14 stops (dynamic range) when shot at base ISO and can capture the entire range of colours that we can see.

A good computer screen, like the one on your iMac located in a room that is not too bright will have a dynamic range of around 10 stops (assuming it has a 1000:1 contrast ratio). On top of that, sRGB can only reproduce ~ 35% of visible colours while even the best screens that are close to 100% Adobe RGB compliant are capable of reproducing 50% of the colours humans can see. Unfortunately, given current technology, that's as good as it gets.


You might wish to read this article. It covers the issues with the DCI P3 colour space used by Apple in its latest iMac offerings quite well.

http://www.colourspace.xyz/the-new-a...-colour-gamut/

[Shadowman]

I use ColorMunki calibration and it is set for ambient light adjustment, the difference is minute (visually) but I suspect it equals about half stop of light, the instrument uses cd/m2 to measure the ambient light and the value set by the user for the software.

[Manfred M]

"the instrument uses cd/m2 to measure the ambient light" puzzles me; I thought ambient light (incident onto your monitor) is measured in lux, as in lumens/sq.m?

The i1 (and Colormunki, which has similar functionality) can be set to monitor ambient light and adjust the display brightness accordingly.

After the calibration / profiling action the user pulls the built-in diffuser over the sensor. leave it plugged into a USB port and place it in someplace where ambient light will hit it. In theory it will check the ambient light level and make the appropriate adjustments.

[ST1]

The i1 (and Colormunki, which has similar functionality) can be set to monitor ambient light and adjust the display brightness accordingly.

As does the Spyder device that I have. The ambient light monitoring can be disabled in the device software.


Sent from somewhere in Gods County using Tapatalk

[CatherineA]

Thank you for your reply Manfred.

with respect to the light source:
I don't have a lux meter but googling different lux measurements has given me a rough idea of the type of light. I'm not sure how you have light behind you but it isn't going to the screen. Maybe you have the light going to the screen that has your editing software rather than your image?

with respect to the monitor:
An additional 15 per cent of visible colours is a significant difference! Oh well.

When an image is printed are the colours reduced to what is shown on a monitor or is the full range that is captured by the camera reproduced - or at least reproduced to the limits of the printer?

[CatherineA]

I use ColorMunki calibration and it is set for ambient light adjustment, the difference is minute (visually) but I suspect it equals about half stop of light, the instrument uses cd/m2 to measure the ambient light and the value set by the user for the software.

I see, thank you! I hadn't realized that.

[Manfred M]

Thank you for your reply Manfred.

with respect to the light source:
I don't have a lux meter but googling different lux measurements has given me a rough idea of the type of light. I'm not sure how you have light behind you but it isn't going to the screen. Maybe you have the light going to the screen that has your editing software rather than your image?

So long as the light is fairly far away and does not hit the screen directly, the impact is reasonably minor. My screen has a hood on three sides to reduce stray ambient light from hitting it.

with respect to the monitor:
An additional 15 per cent of visible colours is a significant difference! Oh well.

The DCI P3 colour space is a wide gamut colour space that is approximately the same size as the Adobe RGB colour space. The issue, from a photographic standpoint, is that this is not a colour space that is commonly used by photographers. It loses greens and adds reds and yellows. As a photographer, I would prefer to have the colours that can be reproduced by a printer and the areas that this colour space takes us is where ink jet printers tend to have problems.

That being said, the only time that this will actually be an issue is when the colours in question are out of gamut.

When an image is printed are the colours reduced to what is shown on a monitor or is the full range that is captured by the camera reproduced - or at least reproduced to the limits of the printer?

The colours shown on the screen are what is in the image, so long as the colours are within the colour gamut of the device. If they are not, then the relative colorimetric rendering intent is applied, bringing those colours that are out of gamut to the edge of the hull of the colour space that can be reproduced.

When the image is printed, the output will be based on the colour space that was assigned to the image data and the gamut of the printer ink set and paper selected. If a wide gamut colour space like ProPhoto is used, colours that are outside the gamut of the screen being used will be reproduced, so long as they are in-gamut for the ink set / paper.

[CatherineA]

I did the calibration with the i1 Display Pro and it gave an orange colour cast. It looked decidely worse so I have gone back to the default colour settings of the iMac. X-Rite has a page titled "Poor Results With iDisplay on Mac" and I might try again following these longer instructions. They are probably easy enough steps for someone better with a computer.

[Manfred M]

I did the calibration with the i1 Display Pro and it gave an orange colour cast. It looked decidely worse so I have gone back to the default colour settings of the iMac. X-Rite has a page titled "Poor Results With iDisplay on Mac" and I might try again following these longer instructions. They are probably easy enough steps for someone better with computer.

Something is obviously not working correctly, otherwise you would not be seeing results like you are getting.

[Polar01]

Catherine I would suggest that you download the i1 Display drivers for the Mac, I could be wrong and am likely wrong, I believe that Macs' make it hard to add a profile to the correct folder in the library. I am not a Mac user thus find the instructions a bit weird trying to help a friend with his monitor using a Mac.

Cheers: Al

[CatherineA]

"Something is obviously not working correctly, otherwise you would not be seeing results like you are getting."

That's true but my browser is up to date and I followed the instructions correctly. This must happen fairly often though for the company to have a page that addresses poor results on Macs. The two sentences are:

Customers can sometimes experience poor results, unexpected results, color casts, or bad results with an i1Display Pro monitor profile on a MacIf a display profile produces poor results (color cast, low contrast, high contrast, low luminance, etc...), try reprofiling after making sure to check the following:

-------

Then follows a list of steps that I need to steel myself to face.

[Polar01]

Catherine you stated that your browser is up to date, that has nothing to do with your display screen. Your browser is an application program that allows you to access the internet and surf around and that. What I meant was to go to the X-rite site and download and install the newest drivers for your i1 calibration device for the iMac. You likely have done this just wanted to be sure, and that will check off that an older driver for an older iMac is not being used.

Cheers: Allan

[CatherineA]

Thank you very much for trying to help me with this, Allan!

Sorry for the confusion about my browser comment. I wrote that because it had been suggested to me elsewhere that that could be the problem so I just wanted to deal with that suggestion.

I did go to the X-rite site and used their newest drivers, the ones that are specifically for Macs. The X-rite directions do include these steps:

Navigate to Contents > MacOS > Profiles and then copy and paste the “XRite_LinearProfile.icc” profile to the Mac HD\Library\ColorSync\Profiles folder. Close Finder.
Open “Displays” in System Preferences and select the “Color” tab. Click on the profile named “DisplayProfile_Linear.icc” to reset your display’s RGB channels to a linear fashion. The onscreen color should change and will likely look bad.

-----

So I think you are on to something. I will just have to really pay attention when I launch into these steps. If I mess up I want to be at least be able to get back to where I started. (I could wait until my son comes home for Christmas but that would be so wimpy.)

[xpatUSA]

I did go to the X-rite site and used their newest drivers, the ones that are specifically for Macs. The X-rite directions do include these steps:

Navigate to Contents > MacOS > Profiles and then copy and paste the “XRite_LinearProfile.icc” profile to the Mac HD\Library\ColorSync\Profiles folder. Close Finder.
Open “Displays” in System Preferences and select the “Color” tab. Click on the profile named “DisplayProfile_Linear.icc” to reset your display’s RGB channels to a linear fashion. The onscreen color should change and will likely look bad.

-----

So I think you are on to something. I will just have to really pay attention when I launch into these steps. If I mess up I want to be at least be able to get back to where I started. (I could wait until my son comes home for Christmas but that would be so wimpy.)

Catherine, I've been following your thread with great interest; even posted a couple of times but then thought better of it and deleted them.

What bothers me generally is the posting of gamuts for comparison in the CIE 1931 chromaticity diagram which is perceptually non-linear (the green is "stretched"). The result is that the Adobe RGB (1998) gamut looks much bigger than sRGB and your iMac's P3 gamut looks much smaller than the Adobe RGB (1998).

However Apple, who pretty much invented Color Management, knows better and presents their stuff in an equally-perceptual space known as CIELAB.

For your iMac, please read more here by Mac-savant Conrad Chavez:

https://blog.conradchavez.com/2015/1...ina-late-2015/

You might have to read it all the way through more than once.

Then look closely at his diagram for a more perceptual relationship (i.e. what you see) between the gamuts being discussed in this thread!



HTH ...

[billtils]

... HTH ...

Ted, thanks for posting this and the link- it most certainly helped me!

[Manfred M]

Ted - no one is arguing that the P3 colour space is not wider than sRGB. The main argument is that P3 is not particularly useful to for photographers as it does not cover the the colours and colour spaces of interest to them (as per the article in #2). The question asked is still valid, why a screen that emulates the output of a Xenon bulb lit digital feature film projector when this is such a small target audience (the majority of the content growth for the video industry is in home entertainment via streaming services like Netflix that are taking re-rendering feature films into the sRGB colour space). Where is the 4K HD industry heading? Right now I would suggest the Rec 2020 colour space. The 8K is still in its infancy and I have no idea where that will settle out; best guess is the Rec 2100 colour space.

You are right; Apple has been leading edge, but their track record has been questionable too. In fact, innovations outside of the iPhone have been quite meager and the users of the Apple desktop and laptop computers have been very much ignored for the past number of years. The content creation side has suffered when Apple abandoned the well regarded Aperture software and they lost the pro film / video market that they owned when they came out with Final Cut Pro X; Avid picked up that part of the business. The Mac Pro has not been refreshed in about four years and the design was not well thought out for that market niche.

From what I have seen, Apple is not supporting the photographic side of content creation and that is of primary interest to users here. Here the industry (for historical reasons) is closely linked to working in three colour spaces; sRGB, Adobe RGB and ProPhoto RGB.

I'm currently making my way through Jeff Schewe's book "The Digital Print" (again), and while it is getting on a bit (published in 2014), he does paint a slightly different view of Apple and colour management. It is definitely a solid read from one of the foremost experts on the subject. It is one that I highly recommend to anyone interested in this aspect of photography. A few telling quotes from Jeff's book...

"My workflow is more or less Mac based, but I do run Windows for testing and to be sure I know how to run on the other platform. Naturally, I have some pretty strong opinions on how well and how poorly color management works on the Mac. In general, color management on Mac and Windows is almost the same except Apple has a tendency of breaking color management with OS updates, whereas Microsoft tends to avoid breaking the important aspects of color management."

"Unfortunately, Apple has complicated color management (unnecessarily)."

"Photoshop and Lightroom use the Adobe Color Engine (ACE) color-matching module. Actually, Thomas Knoll (who wrote Photoshop and Camera Raw) was the principal engineer for ACE and made a few additions that are not part of the ICC specification. Instead of performing the color transforms in 8-bit or 16-bit precision, Thomas uses 20-bits of precision in color conversions for better accuracy. Additionally, although the ICC specifies a method of mapping the source profile’s white point to the destination profile’s white point, ACE also includes a mapping for the source profile’s black point to the destination profile’s black point.

Apple has its own CMM called Apple CMM as part of ColorSync, and Microsoft uses a different CMM called Image Color Management (ICM), which was originally written by Heidelberg. Which is the best CMM? Well, I tend to defer to Thomas Knoll on color science and management issues, so I’m predisposed to use his CMM."

[xpatUSA]

Ted - no one is arguing that the P3 colour space is not wider than sRGB. The main argument is that P3 is not particularly useful to for photographers as it does not cover the the colours and colour spaces of interest to them (as per the article in #2).

Manfred, my post was quite specifically about the perceived but distorted amount of difference between the gamuts when shown in xyY space, especially in the greens. This amount of difference is more properly shown in the perceptually uniform spaces such as CIELUV or CIELAB. From Chavez' diagram I posted, it is obvious what the differences are, being undistorted by xyY's stretched greens.

Roll on Rec. 2020 - a truly wide-gamut ... not unlike Adobe's Wide Gamut or even CIE's RGB ...

[CatherineA]

Thank you Ted! I've read it a few times now and am following it to the best of my ability.

It refers to the over-saturation of colours in "untagged objects" I don't know what they are: would they include my photos when looked at in Lightroom? What about the photos that I see posted in CiC? I will keep looking for a definition of that term that I can understand.

The author also says:
If color management is set up properly on your system, it will compensate for whatever color space your display uses and you should see consistent color.

So I will try calibrating with i1 Pro again but this time following the company's longer set of instructions for when your Mac gets poor results after the first attempt.

[xpatUSA]

Thank you Ted! I've read it a few times now and am following it to the best of my ability.

It refers to the over-saturation of colours in "untagged objects" I don't know what they are: would they include my photos when looked at in Lightroom? What about the photos that I see posted in CiC? I will keep looking for a definition of that term that I can understand.

Indeed. Why call something a "review image" when something obscure like "untagged object" can be used?

The very heart of color management of image files is their color profiles and every image file should have one. "untagged" means no profile which, in turn, means no color management.

For sRGB, the most common profile is for displays such as monitor screens, created by Hewlett-Packard long ago and now an IEC standard, for what that's worth. What's supposed to happen is that when you view an image on your screen, the app or the screen driver will note the color profile, will use it's multipliers to make a conversion to the XYZ 'profile connection space' and then transform the image to whatever profile your monitor used.

Over-simplified but that's how it works. Printing is a bit different and more complicated. That'll probably do for now.

Utilities called EXIF Viewers can usually show you whether your images have embedded profiles or not. If not, your stuff will assume sRGB - even if you shot and edited in Adobe RGB ...