“When I’m saving a JPEG, what does ‘quality level’ mean?”
Yeah, why is it when you, say, setup your digital camera or save a JPEG in Photoshop or wherever, it asks you what quality level you want. And probably like me, you choose the highest. But then I did some intense research and compared the compression levels. Here’s what I got:
Here’s a pic from my digital camera:
This pic was saved at level 12 (the highest) in Photoshop… lets zoom in and see:
Alright, you get the point — more compression / lower level, the worse the image gets. But what’s not so obvious is the diff between 12 quality level and 10. Try it yourself, you can’t tell the difference with the naked eye. If you want to save some space on your memory card or harddrive then you don’t necessarily need to save it at the highest level.
So, then why do they — whoever sets the levels — offer this? Here’s what I think. I get a few old school photographer clients and they always worry about the file size. “How much to scan a photo so it’s 100MB?”, “Why is it only 3MB, that’s a small file size isn’t it?”… and more like that. Finally what I understood was, the more digital info you have the more bytes you have to play around with when you’re editing. Except if you’re serious about editing your photos, then use a TIFF or RAW file. They are uncompressed. They are 16 bit, unlike JPEGs at 8. And they can be as big as 300MB in file size. If you’re gonna go all the way, may as well use TIFFs or RAW files. JPEGs were made for low file size without compromising quality. The difference between 12 and 10 has nothing to do with quality… quality is the same. All that level 12 quality is doing is keeping more info you don’t need just to bloat the file. It’s not giving you any more detail.
Of course, I’m not telling you to keep the level at 10 or at 3MB. I’m just letting you know that a 3MB JPEG file is just fine. It’s your choice if you want a 12MB.
K.
