For the past three years
I've been publishing my comics in both standard (100 dpi) and "Retina" (200dpi) resolution, and decided to just check to see how much of an impact it has in general.
Even with my small viewer base, about 1 in 4 viewers are on a high-DPI display.
Also, for me there's a clear difference between standard and high-DPI comics in terms of how sharp they look - and notably, I started doing this because my comics looked muddy and fuzzy compared to the rest of the page and I got tired of that. If you're on a high-DPI screen (such as a modern MacBook or a system with a 4K display) try opening these two pages in separate tabs and flip between them:
Pretty clear difference, right? (At least there is to me.)
Anyway: if you want to set up high-DPI comics on your site, that depends a lot on the CMS you're using. My CMS is an ungodly assemblage of Movable Type and some custom PHP and so it probably isn't that helpful for others to know how I set it up in mine, but if someone who is so inclined to modify any of the common comic CMSes to support it, here's what I do:
1. I save the image at its native resolution (2880x1440 in my comics' case)
2. I have a script convert it to the two resolutions (100dpi = 960x480 at 90% quality, 200dpi = 1920x960 at 60% quality), with filenames like comicfilename.jpg and comicfilename.HIDPI.jpg
3. When I post a comic, I post it as comicfilename.jpg, and some of the custom junk in my CMS detects that comicfilename.HIDPI.jpg exists and converts the IMG tag to:
|<img src="comicfilename.jpg" srcset="comicfilename.jpg 1x, comicfilename.HIDPI.jpg 2x" width=960 height=480> |
Probably the way that one would do this in, say, WordPress is to have whatever plugin you use for displaying comics set out two output resolutions, one double the other, and rewrite the IMG tag accordingly. I know very little about WordPress, ComicPress, Easel, etc. so I'm just hoping this will be useful information for others who are more involved with that software.
If you're HTML-savvy but haven't seen the srcset attribute before, read up about it over on the W3C HTML standard. And stop making your comics look cruddy on high-density displays!
i am a busy bee