Sweet spot for image (map) file size?

[lsujonno]

Hey guys,

Ran my first game as a DM and my first game on FG this weekend. First I just wanted to say what an incredible piece of software this is. You are enabling buddies separated by thousands of miles to get together like we're back in college. Thanks!

My question is, is there a recommended "do not exceed" file size to use for maps? This wasn't something I was paying attention to, but I had a map size over 7Mb this weekend, and when we loaded it we had huge lag in our voice program (Skype; I know we'll use something else next time) and FG. I was just wondering if you guys had any rules of thumb to not exceed say a 2Mb file size when sharing maps.

[Mask_of_winter]

Under 1mb.

For battle maps I try to size them under 1000 X 1000 pixels and less than 500kb. Always have maps in jpeg instead of png as well.

[damned]

Smaller is always better. I too aim for under 500kb but will use a 1MB map if really needed/helpful.
Save as JPG down as low as 40% quality and you might be surprised at how good it can still look - and at how much smaller it is.
Use a grid size of 50px is pretty common amongst GMs here.

[lsujonno]

Great intel guys, thanks!

[Xorn]

For dimensions I usually aim for no more than 50 pixels per square on the grid, since it's rare that were zoomed in close enough to actually have squares bigger than 50 pixels on your screen space. Though Roll20 has 70 px/sq as their standard assumption. I save them as JPGs, with 60% quality default, and I'll drop as low as 10% if required. The standards for web JPGs are Very High Quality (90), High (60), Medium (30), Low (10). 90 is usually the default for most JPG save options, but I have rarely been able to tell the difference between 60 and 90, so that's a free decrease. 30% will see minor artifacting on complex images, but still looking nice--I use it for really large maps. 10% will have artifacting for sure, but still, looks pretty amazing considering how small the file is--but I only use this for colossal maps, like the entire Keep on the Borderlands master map, stuff like that.

Example: Caves of Chaos entire map, 50px/sq, 6900x4500, 24MB PNG https://puu.sh/k6E2C/cdaae19f33.jpg (just a screengrab zoomed out)
A straight save to a 90% JPG is 10 MB and this is the quality: https://puu.sh/k6EgS/7dcdc4f99a.jpg
This is crushed to a 10% JPG and is 900 KB! https://puu.sh/k6EMT/cec035ac74.jpg

Does it look as good as the original? No, but it's under a MB, and still more than adequate for VTT use! Now just look forward to the groans when they see how big the mask is!

https://puu.sh/k6F4O/3dcfef3c40.jpg The 10% map, if anyone wants it. :)

[lsujonno]

Thanks Xorn!

And while I'm at it, thanks for your useful youtube tutorials!