Way different image exposure using Adobe with Apple devices

[Peturbed5513]

Help, please

Hi, I'd be really exceptionally grateful for your assistance.

I nowadays have a very simple photographic workflow. I shoot images in raw, do the basic manipulation on Lightroom for IOS on a IPad Pro 11 inch M2, which you cannot screen calibrate. This is really for the sake of convenience when one os on the move. However, for some of the finer work and image manipulation, Lightroom on IOS is a bit unrefined, so I always save my images from Lightroom on the Cloud as highest res Tiff files, and import them into Photoshop on my MacBook Pro, which has a calibrated monitor.

The problem is that my images, while mostly color accurate open between 1 and 1,5 stops darker on Photoshop on the Mac. There are no color management settings on the IOS version of LR, and I just cannot get consistency across my devices. If I look at the same image on my phone, its somewhere in between the iPad Pro, and the MacBook - a tiny bit dark, not as dark as the MacBook, and the colours are a bit less contrast.

With all the software up to date on all three devices, I am absolutely at my wits end trying to get an image I can trust and I dont know which image to trust or which device to trust. I sort of expect the Apple ecosystem and Adobe ecosystem to be a bit more consistent, so it must be (my) user error.

I'd appreciate any input.

[TheDigitalDog]

Use a color reference image for testing. Adjust the IOS devices manually to get closer to the Mac (calibrated and profiled) display.

http://www.digitaldog.net/files/2014PrinterTestFileFlat.tif.zip

[Bob_Hallam]

A couple of questions: Why are you using an iPad/IOS workflow and a conventional Photoshop on the Mac.  What about the iPad/has made you decide it would work with a more tested PS on the Mac calibrated environment?

Then I would ask are you shooting ETTR? (Expose to the right) using your histogram on your camera to produce properly exposed images.  ETTR is a longstanding method to provide optimal exposure in a raw file workflow.  So that would be your number one cause of exposure problems.  Then when processing to pixels you have all of the data you need to achieve optimal image detail and contrast with the lowest amount of noise.  

When the time comes to convert Raw to pixels use the image histogram to make sure you are exposing properly, turn on the highlight clipping warning, and check the highlights and shadows to find out if the exposure you have chosen in pressing is accurate.  Aim for the numbers that produce a properly exposed image and there will be no doubt that the highlight and contrast range of the file is correct.  

As Andrew suggests use a test file, one that contains a highlight detail image as well as others that could show differences in each display calibration between your iOS devices and your Mac.  Using this method will assure you that you have processed your images accurately and should make it obvious where the Visual" problem in your workflow is,  I would suspect the iPad  but that will be easy to determine.  

[Peturbed5513]

Thanks so much for your kind response.

I'm using the iPad Pro primarily out of portable convenience and the time deadlines to get the basics done. I find that while I'm on the move the iPad Pro with the Apple Pencil to be convenient especially in travel situations and I had assumed that as it was in part designed for graphics and image work, it would be a useful and time saving workflow intervention. 

There are definitely no exposure issues with the raw files I am using, I have always followed the ETTR principle and I actually don't need to do that much image correction. The completed image looks perfect on Lightroom IOS but is 'visually' underexposed on the Mac. Unfortunately there is no way of calibrating the iPad screen other than adjusting the brightness levels. The issue may be with the iPad and maybe the answer lies with somehow getting a balanced file on screen on the Mac and the same image up on the iPad and adjusting the iPad brightness accordingly so the images look similar. It just seems rather crude to me. Because I use the Cloud heavily for my work and upload all my images onto the cloud and then do additional work on them when I have time on the Mac, I probably erroneously assumed that a correctly calibrated Mac would be reasonably similar to a factory calibrated iPad, given that Apple markets these products as being part of an ecosystem.

I'm going to follow Andrew's advice and yours and see if i can come up with a fix to elimate this frustration and I'm perfectly prepared to admit that it may well be user error on my part.

many thanks

[Conrad_C]

I might be telling you some things you already know, but anyway: On iOS devices most inconsistencies with desktop displays have to do with how the various Display & Brightness options are set in iOS Settings, and consistency with a desktop should be closer (through probably still not perfect) if these are locked down:

TrueTone: Disable, so that brightness and white point do not auto-adjust to react to changes in ambient light.

Night Shift: Disable, or at least set its hours outside the time of day when you normally edit, so that the white point does not shift to extreme warm.

Brightness: With TrueTone disabled, set the Brightness to be consistent with the desktop. Most people can only do this by eye, but if you happen to have calibration hardware connected to your computer, and its software can report current luminance at the sensor when it is not in the middle of calibrating the desktop display, it might help you adjust iPad brightness to match the desktop display.

For example, if I open SpectraView software and choose Tools > Colorimeter Window, a window opens that reports the color of whatever the sensor is over. I can then place the sensor on the iPad showing a white background (I’m using an empty document in Photoshop for iPad), and the SpectraView Colorimeter window tells me the color specs it sees. The picture below shows that my active desktop hardware calibration preset (in the background SpectraView II window) is 120 cd/m2, and the SpectraView Colorimeter window (in front) is reporting 121.68 cd/m2 for the iPad it’s sitting on. So the iPad is slightly brighter, and I should try to nudge that down a little to match the desktop. But the iPad brightness slider is not easy to adjust precisely, so I might decide that’s close enough.

(If I am doing something incorrectly here, I’m counting on thedigitaldog to set me straight. 🙂 )

By the way, 120 cd/m2 turns out to be about half brightness on my iPad. That reinforces the observation I’ve had that setting my iOS devices to half brightness often works out “close enough” for matching the target luminance for the currently active calibration for my desktop display.

Also note that the SpectraView Colorimeter window is reporting the non-adjustable white point of the iPad as 6789K, which sure does not match my 6500K desktop calibration.

Again, doing these things still does not guarantee a perfect match. For example, they still might not match if the non-adjustable native contrast range and color gamut of the iPad display are enough different than the desktop display, or because my iPad Pro display is HDR-capable and my desktop display is not (so they might use different tonal response curves), and so on.

But when I at least turn off all iOS display auto-adjustment features and match the brightness, it does not seem too different than my calibrated desktop display. The name of the game is locking down and then matching as many iPad display variables as possible to the desktop.

[Peturbed5513]

This is EXTREMELY helpful information and I am going to try to do exactly as you suggest and see if I can as least get an approximate match. I really appreciate the time and trouble you have gone to in providing me with such useful feedback. I have been using the iPad on full brightness and I think this is where the problem lies. And leaving truTone on...a basic user error. Many thanks again!!

[NB, colourmanagement]

@Peturbed5513 heres a test to do

please go here and download the Adobe RGB testimage: https://www.colourmanagement.net/index.php/downloads_listing/

open in Photoshop 

next open this image on the phone or iPad in safari or your browser of choice: 

https://tinyurl.com/mobiletestimage-jpg

If they look different, maybe one device is inaccurate, IF your main screen is correctly calibrated and it’s a recent phone or iPad I'd expect a pretty good match

I hope this helps
neil barstow, colourmanagement net - adobe forum volunteer - co-author: 'getting colour right'
google me "neil barstow colourmanagement" for lots of free articles on colour management

[Peturbed5513]

Thank you very much Neil

I did the exercise very carefully, and tried it with both my own calibrated monitor profile as well as the built in Apple profiles. Obviously, I cannot calibrate the iPad Pro and all I can do with that is turn off the Truetone settings and adjust the brightness.

I'm not sure if this is a good or bad thing, but the built-in Adobe RGB 1998 profile seems to be the closest match on the reference image with the file opened on my iPad Pro. Better than my own calibration.

I'm not sure if that finding is a good or bad thing? Any comments on that finding would be appreciated. 

[NB, colourmanagement]

@Peturbed5513 "I'm not sure if this is a good or bad thing, but the built-in Adobe RGB 1998 profile seems to be the closest match on the reference image with the file opened on my iPad Pro". 

That’s a little confusing.

When I need to know that a calibration result is satisfactory (i.e. the sensor is OK & the cal. target settings are correct for my environment) I use this:-

Have you ever wondered how to KNOW whether your screen [or printer] is ACCURATE and not just 'pleasing'?
If so please check this out: http://www.colourmanagement.net/products/icc-profile-verification-kit

I hope this helps
neil barstow, colourmanagement net - adobe forum volunteer - co-author: 'getting colour right'
google me "neil barstow colourmanagement" for lots of free articles on colour management

[Peturbed5513]

..oh and its a 2022 IPad Pro 11 inch M2 so its as recent as one can get...