Perhaps I overthought it but added this possibility to display the image on large monitors too when the slide image doesn't have enough resolution. Is this a bad idea?
It's the combination of choices that's bad. The default image bounds are 1000x800, which is much too small. The slide images are too small for the most common monitor resolution, which is 1920x1080. Then, to compound the error,
Tiger shows the image larger than its native size.
I can always spot a
Tiger album. The images are slightly out of focus. But it's the most widely-used skin, so I can only conclude that users
like to have their images shown slightly out of focus. In my skins, the slide images are never shown larger than their native size. Never. Ever. Not under any circumstances.
A site visitor might start doing things like browser zooming, but there's nothing I can do about that, short of driving over to his house and beating him about the head and shoulders.
Browser enlargement is better than it used to be, but there's no magic. The "extra" pixels just aren't there, and have to be approximated. I don't know of a serious photographer on the planet who wants that.
When it comes to the HiDPI images, I think users expect their image bounds to be respected. Choosing HiDPI images should not result in the images being shown twice as large. That defeats the purpose of them.