View source for Thread:Clockpuncher/@comment-30928085-20181102104458/@comment-26810597-20181103053643

Okay, so here's what I noticed: 

The previews of each image on their respective file pages ([[:File:Elite-Dangerous-Asteroid-Probe.png|PNG]], [[:File:Elite-Dangerous-Mining-Probe.jpg|JPG]]) do have noticeable differences. These differences are less noticeable, but still present, when those images are used as thumbnails or in a gallery on an article.

However, the full resolution originals of the images on Wikia ([https://vignette.wikia.nocookie.net/elite-dangerous/images/2/2c/Elite-Dangerous-Asteroid-Probe.png/revision/latest?cb=20181017012747 PNG], [https://vignette.wikia.nocookie.net/elite-dangerous/images/3/33/Elite-Dangerous-Mining-Probe.jpg/revision/latest?cb=20181103013346 JPG]) do not have those differences, even when you play around with zoom.

I can only guess at what's going on, but I think that Wikia uses some sort of automatic compression when PNG images aren't displayed at their full resolution. I don't think it's bad enough that we need to stop using PNG (it does have the advantage of being lossless, unlike JPG), but it is something to be on the lookout for.