Web Hosting Talk : Web Hosting Main Forums : Web Design and Content : Image Quality

[Xshare]

I would by no means call myself a photoshop pro, but as most people do, I know my way around the software. My question deals with image quality. Usually whenever I save as a JPEG, even at 100 quality, the quality doesn't seem very good. I don't know but other people's graphics usually seem just much better quality... wondering if anyone has any ideas why this might be happening?

[marengo]

I always play around settings. Some image looks good on 60% .
jpg, some - 80% (I have never used 100%) , some images are good in .gif. Also when you create your new document in Photoshop (ctrl + N) be sure resolution of your image is good. I use always ( even for web ) 300 dpi. Normally for web 72 dpi is ok, but I use 300 like for print. Which version do you use, btw?



Nat

[MG315]

^there's no point of using 300 dpi for web, you're just making the image larger. (pc) screens cant render higher than 72dpi ^

about the quality of jpegs, jpeg is a lossy file format - that means when you save it you actually lose some quality. the amount of quality lost depends on the image but it is always there. quality is lost so as to compress the image. an example of a lossless file format is tiff. you save a tiff and you wont lose any of the original quality. this is what many scanners default to because they don't want to lose quality before you even look at it.

of course this is only with raster images, once you get into vector there's no quality loss at ANY size or resolution.

[marengo]

^there's no point of using 300 dpi for web, you're just making the image larger. (pc) screens cant render higher than 72dpi ^

are you sure? right now I have tried with aqua button 72 dpi and 300 dpi - 80% .jpg - result is 600 kb for both pics.
But as for monitors I didn't know. I use 300 cause it's par default in my settings. Thanks for info.
Nat

[MG315]

(pc) monitors can only render up to 72 dpi. 300+ is used for printing. however, i've heard that macs can see up to 91 dpi but i'm not sure if that's true.

do this. open up photoshop or fireworks (i'm using fireworks right now since i dont feel like opening photoshop) and make a new image 100px x 100px @ 300dpi. then go to "Image size..." and uncheck "resample image". now change the dpi to 72. you should see the size of the image change from .333in to 1.389in. that's what i meant. it is still the same amount of pixels (there's 10,000 pixels in each image) its just how far they are spaced apart is different. if you print both images, the sizes and quality (although it might not be too noticable) will be different. but when viewing on screen, you don't see the 300dpi, only a 72 dpi rendition of it.