Image appears brighter in Photoshop that other programs

Thanks for all the information. This was a good learning opportunity.

Thanks for the responses. I use a mac for processing and I checked that I am using sRGB for my programs.  My images are monochrome (actually narrow band 656.82nm, 393.4nm).  When they are initially stacked to reduce noise (another program) they are saved as .tiff 16bit files.  Since there isnt color data it will be saved as a grayscale image. When I check the profile in photoshop the default is set to Dot Gain 20%.  If I change it to Gamma 2.2 then the images are pretty much identical.  I assume it is assigning a Dot Gain 20% because the data is imported as a Grayscale and not RGB?   

As D Fosse suggetsed, many programs have no colour management capabity, what use are they then, you might ask! As long as the monitor display profile is good Photoshop will show you the true meaning of the image values on screen.

However:

Display profile issues 

At least once a week on this forum we read about this, or very similar issues of appearance differing between applications.

Unfortunately, with Microsoft hardware: Windows updates, Graphics Card updates and Display manufacturers have a frustratingly growing reputation for installing useless (corrupted) monitor display profiles.

I CAN happen with Macs but with far less likelyhood, it seems.

The issue can affect different applications in different ways, some not at all, some very badly.

The poor monitor display profile issue is hidden by some applications, specifically those that do not use colour management, such as Microsoft Windows "Photos".

Photoshop is correct, it’s the industry standard for viewing images, in my experience it's revealing an issue with the Monitor Display profile rather that causing it. Whatever you do, don't ignore it. As the issue isn’t caused by Photoshop, don’t change your Photoshop ‘color settings’ to try fix it. 

If you want to rule out pretty much the only issue we ever see with Photoshop, you can reset preferences, I never read of a preferences issue causing this problem though:

To reset the preferences in Photoshop: 

https://helpx.adobe.com/photoshop/using/preferences.html

Note: Make sure that you back up all your custom presets, brushes & actions before restoring Photoshop's preferences. Migrate presets, actions, and settings

To find out if this is the issue, I recommend you to try setting the monitor profile for your own monitor display under “Device” in your Windows ‘color management’ control panel to sRGB. You can ADD sRGB if its not already listed. 

And be sure to check “Use my settings for this device”.

(OR, if you have a wide gamut monitor display (check the spec online) it’s better to try Adobe RGB instead).

Quit and relaunch Photoshop after the control panel change, to ensure the new settings are applied.

If this change fixes the issue, it is recommended that you should now calibrate and profile the monitor properly using a calibration sensor like i1display pro, which will create and install it's own custom monitor profile. The software should install it’s profile correctly so there should be no need to manual set the control panel once you are doing this right. 

Depending on the characteristics of your monitor display and your requirements, using sRGB or Adobe RGB here may be good enough - but custom calibration is a superior approach.

I hope this helps

if so, please "like" my reply and if you're OK now, please mark it as "correct", so that others who have similar issues can see the solution

thanks

neil barstow, colourmanagement.net :: adobe forum volunteer

[please do not use the reply button on a message in the thread, only use the one at the top of the page, to maintain chronological order]

Photoshop is color managed and uses your monitor profile to correct for your display. If you use a calibrator to make an accurate profile, Photoshop will represent the file 100% correctly on screen. But the monitor manufacturer's profiles (often distributed through Windows Update) may not be up to that standard.

Most other applications aren't color managed at all. They don't use the monitor profile, and how the file appears on screen is entirely up to how your monitor behaves.

Avoid grayscale! Proper grayscale support is mostly absent anywhere outside Photoshop. Again, Photoshop treats it correctly, but most other applications don't know what to do with it and the results rather random. It will display, but unpredictably.

So you have two unknowns here. If you want accuracy you can trust Photoshop, but you must have a good monitor profile. Applications without color management will always be untrustworthy.