Problem of persistent blue/green cast

I am having recurrent problems with inaccurate blue/green casts in many of my photos. The problem seems to have mainly emerged since I upgraded to a Nikon Z8 and simultaneously upgraded my Mac operating system to Sonoma 14.5.  Often I do not notice the cast when I am initially engaged in raw processing in Lightroom. However, looking again at the photos, especially when exported into JPEG format, the cast becomes more apparent. I seem to have a constant need to make individual RPG adjustments, sometimes with unsatisfactory results (ie with other colours in the bird's plumage being adversely affected). Attached are two recent images illustrating the problem.

In discussion with moderators, I am aware of the need for using the colour profile that works best with the my Apple Thunderbolt display. However, I am at a loss as to which of the long list of profiles that the Sonoma 14.5 selection menu comes up with for the Thunderbolt display might be the best. I have variously tried the "Thunderbolt Colour Profile" and the Nikon Color Match RGB 4.0.03001 without seeming to improve the problem.

I would greatly appreciate if any fellow Nikon Z8-Lightroom Classic (plus Topaz plug-ins)-Apple Thunderbolt Display users could suggest a particular colour profile that is working for them, or have any other ideas on how to resolve my problem.

Aside from the choice of Colour Profile, there may also be possibilities for fine-tuning Lightroom to better match Nikon Z8 NEF file colour profile (I seem to recollect having seen something about that).

Further, moderators have suggested to me that there are ways of objectively checking the RGB balance by hovering a cursor over the relevant part of the image but I have not yet worked out how to do this on a Mac.

There is also possibly an eye-adjustment problem involved in the fact that when I spend initial time working on an image my eyes might be in some way adjusting to and compensating for a blue or green cast so that I do not really notice it, analogous to the phenomenon of after-images. This might explain why when I come back to the photo with fresh eyes the next day, I begin to notice the cast. If there is an eye-adjustment problem, that does suggest the solution of never being satisfied with initial raw processing, especially in lengthy sessions. At the same time, adjustment problems may be related to having the screen too bright. I would be interested in whether anyone else has noticed this phenomenon. 

Finally, there is the issue of exporting from Lightroom files to JPEG, and whether there is something I need to be doing there to ensure colour matching.

Hoping fellow Nikon-Lightroom-Apple Display users might be able to assist or point me in the direction of any advice on this particular problem.

Thanks,

Michael

Hi Michael, as mentioned in previous exchanges, the jpg must be saved in sRGB colour space (this should be a save option) and ideally the monitor should be calibrated. The colour profile you load will affect the appearance of the image and calibration will create a new profile with accurate colour. As you have spent many thousands on camera, lens and computer, you may wish to consider buying a hardware calibrator like a Spyder.

In terms of the best colour profile to load prior to being able to properly calibrate your monitor, I hope you are able to get some helpful advice. Also, the colour should not change from when you have finished processing your photos to when you re-check them later or view them on our website. If it is changing, perhaps there is an issue with your monitor - the caveat being that you must save in sRGB colour for the appearance not to change between completion of processing and review on our website (any other colour space is likely to cause colour shifts).

I know we have discussed some of this before but am posting for the benefit of others who may be reading this.

Hope this helps all the same.

Glenn

Michael

I'm not a mac user so I can't comment on the specifics relevant to Apple devices.  However, a monitor calibration device will avoid your issues with choosing a predefined Apple colour profile because it creates its own profile, which is set as the default when you boot the computer.  At least, this is how it works in Windows.  Every time I start the computer I get the calibrated profile.  I have two monitors and a separate profile can be applied to each.  I am not sure precisely what these devices decide constitutes 'accurate' colour but at least you get consistent colour which seems to be reasonably repeatable across different viewing devices.  Calibration devices can also help you set a good brightness level for the monitor for the particular environment in which you work.

The issue about using the cursor to check colour balance will depend on the software program.  However, usually this involves something like selecting an eye dropper tool and hovering it over an area of colour you want to check.  In my software, I then open the histogram, and underneath the histogram it has three numerical values, for R, G and B.  As I move the dropper over the image these values change depending on the pixel values under the dropper's point.  If you use Lightroom I am sure you can find some help file somewhere that explains this is more detail, if it is not obvious.  This tool can usually be used in conjunction with white balance;  you select an area of clean white or a neutral gray and click on it with the tool, to use the tone as the default tone for white balance.  I am not sure if using the eyedropper tool will help much with colour casts.  You'll be able to see the values of any area of colour but it won't necessarily give you useful information about whether those values are 'correct', whatever that means.  However, if you have a fairly neutral white area (that is not over exposed or clipped) you would expect the R, G and B values to be approximately similar if your white balance is correct, but the trouble is that in nature even apparently neutral tones can have casts depending on the light, time of day etc.

A simple way to check if your monitor is leading to unbalanced colour decisions is to process and image to your taste on your main device, and then view it on other devices to see if any strong colour casts are evident.  Of course, you are at the mercy of the displays on those devices, but if there is a strong cast such as blue or magenta you should still be able to see this even if the two monitors display the image slightly differently.  If you have a good quality modern tablet device handy such as an iPad, they are generally pretty good at showing decent colour in a well lit room. You could also attach a different monitor to the computer and compare the results.   Alternatively, shoot a large JPEG in the camera's standard profile and compare what it looks like on different devices, to see if there is any significant colour shift with your device.

The colour profile of your exported image, as Glenn notes, will be set in the export parameters.  For example, in my software I can choose sRGB, ProPhoto and Adobe RGB.  In my experience these generally default to sRGB, but if not you need to set this for general web use.   There are generally no other tweaks one can make to colour in the actual export process.

I doubt very much that your camera is at fault but if it would help I am happy to look at a raw file and see what results I get on my computer.

Regards
Simon

Dear Glenn and Simon,

Thank you for getting back so quickly about these problems and for all your very helpful advice.

I have now checked on what is happening when I save to a JPEG from Lightroom and realise I was not using the sRGB colour space you recommend, Glenn. I have changed to the only similar option on my Mac which is sRGB IEC61966-2.1, which I hope is the same or equivalent to what you recommend. I have already checked a few images with saving with that colour space,  and the colours do look identical to what I am seeing on my screen, so this may already be part of the solution.

Thanks Simon for all your additional advice, and particularly your offering to look at one of my raw files for an image that was creating the green colour cast problem. I will send you a separate email with the raw image of the Brown Falcon attached (the one that I originally attached in my first posting in this string plus a new JPEG I saved from it with minimal Lightroom adjustments and now using the sRGB colour space as recommended by Glenn. I will also send another couple of images in early morning sunlight that I took earlier this week in case my problems with colour cast are also affecting birds taken in such conditions (one of an Australian Hobby and one of a Little Grassbird).

With much appreciation to both of you for all the trouble you have been taking to help me with this.

Regards,

Michael

Michael

That is the same sRGB name that my program uses.  It is the technical name given to the sRGB standard adopted by the IEC, in the late 1990s I think.

Simon

Just expressing my great appreciation and thanks to Glenn, Simon, and Rob Solic for all the assistance you have given me in tackling this problem. While still  needing to try out some of the suggestions, especially with actual camera settings for particular conditions in the field, I think the recommendations relating to colour space settings for display, camera and most importantly downloading from Lightroom to jpeg files have already made a difference in avoiding some the colour cast problems.

Other Nikon Z8, Thunderbolt Display and Lightroom users encountering similar problems may want to also check their colour space settings as to whether they had different ones rather than the sRGB colour space recommended by Glenn, Simon and Rob. I did have different ones and now that I have changed all three to sRGB I am finding that the jpeg files are pretty identical in colours and cast to what I am seeing on my screen.

Thanks to Simon's reprocessing of one of my original raw files with the colour cast problem, I am now alerted to the importance of the white balance settings in the camera and various options for different conditions, and to the need for ensuring optimum exposure. My raw file revealed significant underexposure leading to a bluish cast, and I realise that either I was overcompensating with my manual exposure compensation dial at time of taking the photo, or in the excitement of the moment had not readjusted it from a previous manual setting. I am also going to try out Simon's suggest of the Matrix exposure setting.

Altogether I am much more aware now of the all the factors making for accurate colour rendition, both in taking the photo in the first place and in the processing. So many thanks again for all the time and detailed assistance you have given me in tackling this problem.

Regards,

Michael