72DPI PSD Images showing a different size at 100% than when viewing the output jpg at 100%

[#1]

Hi all,

We're on MacOSX Big Sur and Running Photoshop 2021.

iMac Retina 5k, 27"

Here's a seemingly new problem I have found after installing and setting up this new machine.

When i work on a 72dpi image in Photoshop it appears to me at one size when viewed 100% to scale.

When myself or someone else opens it on web, preview, acrobat, etc the image appears to be about 150% bigger and distorted.  If i then grab that jpg and open it in Photoshop- it appears the way it originally did at 100% in Photoshop.

What little i've found so far has people muttering about the 5K monitor being the issue, but, i dont understand why the image would appear two different sizes at 100% on the same machine.

I have been using Photoshop for almost 20 years and never ran into an issue like this.  I am working at 100% scale in Photoshop, but, finding out my images are getting distorted once they leave PSD.

Any information/ workarounds/ etc on this?  Thanks so much.

Attached I have the same file opened in Photoshop and Preview- both are viewed at 100%. You can see the giant difference.

[#2]

Hi all,

We're on MacOSX Big Sur and Running Photoshop 2021.

iMac Retina 5k, 27"

Here's a seemingly new problem I have found after installing and setting up this new machine.

When i work on a 72dpi image in Photoshop it appears to me at one size when viewed 100% to scale.

When myself or someone else opens it on web, preview, acrobat, etc the image appears to be about 150% bigger and distorted.  If i then grab that jpg and open it in Photoshop- it appears the way it originally did at 100% in Photoshop.

What little i've found so far has people muttering about the 5K monitor being the issue, but, i dont understand why the image would appear two different sizes at 100% on the same machine.

I have been using Photoshop for almost 20 years and never ran into an issue like this.  I am working at 100% scale in Photoshop, but, finding out my images are getting distorted once they leave PSD.

Any information/ workarounds/ etc on this?  Thanks so much.

Attached I have the same file opened in Photoshop and Preview- both are viewed at 100%. You can see the giant difference.

[#3]

100 % zoom in Photoshop has nothing at all to do with a physical size. I just means 1 image pixel mapped on to 1 screen pixel.  So the size on screen depends on the monitor pixel density, nothing else.

Some browsers and viewers scale the image when using retina screens.

Incidentally the 72 PPI resolution you mention is for printing. It is irrelevant for screen viewing.

Dave

[#4]

I do understand all of this so forgive me if this is a naive question.

If I have a 1200pixel wide image that has clean, crisp type on it at any resolution (72, 150-300, etc.)

And then i save it as a jpg thats 1200px wide regardless of resolution.... why does it 'blur' the image when its in anything but Photoshop? I understand that Preview, or Acrobat, or Firefox, etc might be dong their own thing- what is the best way to work TOWARDS the outcome of the scaling?  I tried opening in Low Resolution mode.  I tried working in PSD at 200%. All suggestions i found online, but, with negative results.

My screenshot for instance in my post- how do I work so know the quality of the images will match the best?

[#5]

Just work at 100%. It will be scaled in those other apps, along with everything else. If you scale up in Photoshop, it will be four times the size elsewhere.

This has nothing to do with Photoshop. It's the other applications that scale and don't display accurately.

Set View > 200% in Photoshop if you want to see how it will look.

[#6]

Actually, there is a case where it is relevant:when type is set to size by physical units, like points. Type set in pixels does not have this issue.

[#7]

Good point 🙂

Dave

[#8]

As mentioned before, the DPI only applies when you print the image.  It does not affect viewing the image on a digital device.

The size difference between Photoshop and Preview is due to the UI Scale setting in Photoshop Preferences; however, this setting is set to Auto by default. and cannot be changed.

You can read more about it here in the Photoshop support FAQ for HiDPI and Retina Display support.

HiDPI and Retina Display support FAQ

https://helpx.adobe.com/photoshop/kb/hidpi-retina.html

One change to make in Photoshop, if you're not already doing it, is to set your rulers to Pixels rather than Inches for content being created for screen viewing.

You can also connect a non-Retina/HiDPI display, dragging the image that you're working with over to the non-Retina display or use Window > Arrange > "New Window for" so that you can view your document (and it's quality) on both Retinal and non-Retina at the same time.

As long as the image is viewed at 100% - where ever that might be, it should look good.

[#9]

"The size difference between Photoshop and Preview is due to the UI Scale setting in Photoshop Preferences; however, this setting is set to Auto by default. and cannot be changed."

This isn't about UI scaling. This is about image scaling in consumer-oriented image viewers  when they detect a high-density (retina) display. With this scaling, one image pixel is represented by four screen pixels. In Photoshop, one image pixel is represented by one screen pixel. That's what 100% means.

To mimic this image scaling in Photoshop, set View > 200%.

UI scaling is a different matter unrelated to what we're discussing here.

[#10]

Thanks guys- I know this topic is beating a dead horse- guess I wasnt searching the correct terms before i posted.

I appreciate you putting it into clear terms for me- we just got new machines last week and were engaged in an argument over image quality until we were able to jump on someone elses machine and see what they were talking about.

Is what it is, i guess.  I think the only way to fight the battle is to just keep it in my mind and do our best to get through.  Thanks again.

[#11]

As long as the image is viewed at 100% it should look fine.