Photo format question

Newbie question: when designing an ID document (let's say ID CS4, since that's what I'm using), is there any difference in placing a Photshop image (.ps) versus a .TIF file? I've done both. And is there any harm in using high-res .JPG's? I have a friend who works in Quark and he always changes every photo to .TIF before placing. Thanks.
Photo format question
Your friend needs to change the format because his version of Quark doesn't support native psd files (or he has an old habit). I stopped updating Q at 6.5 and I'm not sure if .psd support was ever added.



In any case, there's nothing wrong with tiff files, but it's an extra step if you already have .psd's. High quality jpeg files are usually OK for print (but images prepared for the web usually are not), but you need to remember that resaving jpegs always does damage to the image due to lossy compression, so most print professionals convert to another format if they need to edit a jpeg, and usually don't save in that format to start out.



Peter
Photo format question
Peter: thanks. I am a newbie at this. So if someone gives me a high-res .JPG to place in my document and I need to re-size it or edit it, I should open it in PhotoShop and then IMMEDIATELY save it as a .psd (or .tiff or some other non-lossy format) before tinkering with it? Thanks....

%26gt; I should open it in PhotoShop and then IMMEDIATELY save it as a .psd (or .tiff or some other non-lossy format) before tinkering with it?



Pretty much. Actually you can tinker with it all you want, then Save As

to some other format, just as long as you don't Save.



--

Kenneth Benson

Pegasus Type, Inc.

www.pegtype.com

Resizing is a different issue altogether from format.



It's safe to scale the image in ID regardless of the format. If you look in the info panel with the image selected you'll see two resolution numbers listed, actual and effective. Actual is just the resolution at the dimensions the image was saved and is essentially irrelevant. Effective resolution is what you have at the dimensions you are currently using, and that's the number that counts. If that number is in the range that is acceptable for the type of output you are using, there is no need to resize the image in Photoshop at all.



If you MUST resize the image, then yes, convert to something besides jpeg if that's what it is to start. And keep in mind that up-sampling won't improve image quality in general, and downsampling more than 20% or so can cause you to lose fine details (but so will scaling down).



Peter