web resolution issue

[dmonks]

Hi all,

will these two produce the same results on a website/flash?

a 150 dpi image, displayed at 200% of its original size
a 72 dpi version of the same image, its image size doubles the first one, displayed at 100%

I tried it in flash 8, when I turned "allow smoothing" on, cant see any visible difference, but I want to make sure if it is really the case, thanks!

[Drazan]

It really all depends on compression. Turning the smoothing on produces a less compressed file, thus bigger. For the most part I only use smoothing if it's for non-web movies.

If you can't see the difference on your particular image then leave off the smoothing option.

[DrummerHead]

Worrying about dpi for screen images? What am I missing here?

Go with the 72 dpi image.

Seriously, is there something I don't know? As far as I know, if you work for screen, you just stay with 72 dpi; or don't even care, as no matter what the dpi will be, it'll show as 72 dpi. Except you place that image on illustrator or indesign, for whatever reason.

[jlknauff]

you just stay with 72 dpi; or don't even care, as no matter what the dpi will be, it'll show as 72 dpi.Yes, sort of. It will show up as 72 dpi but the dimensions will adjust proportionally based on the pixle count, so it will display larger.

[urstwile]

Go with the 72 dpi image. The only time I ever use higher resolution than that for screen resolution is for Powerpoint presentations that will be going up on a really large screen.

Use 72 dpi, and then adjust your pixel width and height from there to fit into whatever you've decided is the average monitor size of the end viewer. Don't forget to factor in browser interface area, etc.

[Alan G]

Actually, 72 dpi is a mythical resolution that's a hangover from days long gone, when the Mac's screen resolution was 72 to the inch. I doubt there's a monitor in existence today that's 72 dpi. Most are 96 or better. (Set up a 3-inch square in a 72 dpi Photoshop file, turn on the rulers, click Actual Size in the zoom tool, and then measure it. Compare the screen ruler measurement to the actual measurement. You'll get the idea.)
The only parameter that matters for screen design is the pixel dimension relative to the screen size you're designing for. Actual dpi depends entirely on the user's screen setting. This was one of the big conceptual hurdles I had to overcome when I branched out from a purely print design/photography background into web design. It's still not intuitive (old dog, new tricks...).

[urstwile]

Very good points, Alan.

The only reason I'll ever go beyond 72 for screen is like I said for Powerpoint, where I'm not sure what size the final output device will be, a printer or a large screen.