Quick Picasa question

LHC · Oct 11, 2007, 04:14 PM

I'm doing photography for the yearbook club at school, and using my own camera, but the pictures need to be at least 300 dpi, and I'm really not sure what DPI my camera takes pictures as. I've got a Canon Powershot S2IS, and the image resolution is 2592 x 1944 pixels.

When I import the pictures into photoshop, the resolution is automatically 72 on the imported pictures. Does this mean the camera takes the picture at 72 DPI? I installed Picasa for an indepth analysis and I got this..

Now, where it says JPEG quality 95 (422), is 422 the DPI? If it is, then it would be perfect

I know that you can change the resolution from 72 to 300 in photoshop, but the yearbook advisor said that the pictures will come out very grainy that way

Thanks

RoyBatty · Oct 11, 2007, 04:41 PM

I'm a little confused about this DPI thing too, so I can only give you some directions:

Dots per inch - Wikipedia, the free encyclopedia
All About Digital Photos - The Myth of DPI

I think that the second link perfectly fits your situation (especially the "The Horrible DPI Mistake" part

).

edit: I'd say that to make the advisor happy you just have to set the DPI to 300 without resampling the picture...

LHC · Oct 11, 2007, 05:01 PM

Thanks!

I actually found that site earlier and I read it and didn't quite understand it.. focusing more clearly now, I understand it well

And I found that I was right..

See, when changing the DPI, the advisor said not to because it would appear grainy. But when I did it in Photoshop, I did make sure "Resample Image" was deselected. Therefore, when printed, the image will NOT appear grainy or blocky, because the image isn't being enlarged by 4 times, correct?

All About Digital Photos - Changing the DPI of a Digital Photo

edit: just saw your edit, and I see it answers me question

Thanks a lot

RoyBatty · Oct 11, 2007, 06:16 PM

Yes, that's correct. Simply change the DPI value.

Mousey · Oct 12, 2007, 03:59 AM

72 DPI is Photoshop's default resolution i think, the only thing i've noticed it affecting is text sizes, I Doubt the camera takes photos at 72 DPI.
I'd probably advise asking the shop where you bought the camera if you can't find out anywhere else.
DPI Requirements though? That's ridiculous imo

LHC · Oct 12, 2007, 05:39 AM

Quote:

Originally Posted by Mousey

72 DPI is Photoshop's default resolution i think, the only thing i've noticed it affecting is text sizes, I Doubt the camera takes photos at 72 DPI.
I'd probably advise asking the shop where you bought the camera if you can't find out anywhere else.
DPI Requirements though? That's ridiculous imo

Yea, the requirement is ridiculous

But on the one site, it says

Quote:

Note that the internal DPI (which we now know is not relevant to digital image quality) of most digital camera photos is 72.

So... whatever, I'll just change the DPI