When I click on the image below:
C-130T Fat Albert
I end up in the 'viewing tool', where, when I click '1:1 one hundred percent' I really get the '2:1 two hundred percent' view.
The reason I know the tool is going to behave the way I describe, is because that is how it behaves when I click on the image in another thread.
The reason I know it is 200% and not 100% is because I can see how the 100% image looks like in say, Lightroom or Flickr, and also, because I know the image is 4000 pix-wide and I know how wide my screen is.
It is not only my browser/machine behaving that way. Other computers display 200% when they are supposed to display 100% as well.
Is this some browser setting, or is it the DPR site issue?
Can you screenshot the problem? Also, are you on OSX or Windows and which browser? Using Chrome on Windows 10, the 100% is working fine for me.
Thanks for your reply. Here is the problem in screenshots:
100%, Flickr screenshot:
At max size, a 4000 pix-wide image takes ~4/5 of the width of the screen
100%, DPR 'viewing tool'
same image in DPR viewer, at '1:1 one hundred percent'
Flickr is obviously right at 100%.
DPR seems even larger than 2:1.
Can it be fixed?
Are you using a 5K iMac? What scaling do you have set for the UI? Your screen shot (including menus, windows etc is 2x bigger. Take a look at the canon ad on the right. That is designed and delivered to your browser at 300x250 pixels, yet in your screenshot it is approx 860 pixels wide (coincidentally a 'more than 200% increase').
I'm not super familiar with 5K iMacs, but i know that our retina iMacs had problems with scaling in adobe applications for a few months before Adobe added fixes to LR and PS.
I do want to get to the bottom of this for you but just responding with 'you're wrong, fix it' when yours is the only complaint is not making it easy.
Sorry if it comes across that way. Did not mean it that way at all.
I am not at all super familiar with 5k displays myslef. I am just a user

From what I recall I read somewhere the new high dpi displays all have the same issue. When displaying the content designed for the 'old' (~100dpi) displays, the result is impossible to accept - it is just too small (obviously). And hence the user iface is being 'doubled' in size - all that icons/menus/whatnots.
But there seems no reason to force 'double' the other stuff - like for example when a photo is displayed.
I am likely off on technical details, but I believe OSX 'pretends' to be the old-style display (when it is actualy running a Retina display), so that the 'normal' content displays as expected. Then there is something (whatever that is) that needs to be queried/checked to see what the 'real' screen resolution/size actualy is. And some sites, like flickr, do query/check that something, and display photos in the right resolution/dimensions.
I believe DPR falls into that same category (as flickr), and so it should try and make an effort to accomodate the bigger/higher dpi displays as well.
I believe it is an important issue, because there are going to be more and more high dpi displays in use. Moreover, I suspect all Apple laptops/iPads with Retina displays suffer from the same issue. It is just likely, that for the screen, which is few inches wide, nobody cares enough to complain, or perhaps even wants the true 100% to be displayed - those screens are too small for that.
Anyway. I am happy you want to get to the bottom of it. I suspect we'd need some "graphics geeks" to find out what it is that flickr does to figure out the screen it is drawing on.
Thanks for your attention to this matter.