How effective are .psds?

[emoryarts]

Just out of curiosity, do any designers use .psds (converting to .jpeg/.gif/.png respectively) or is everything pretty much handled in .ai and other similar programs?

[resurepus]

I don't understand the question
if you use Photoshop you store you originals in .psd and if Illustrator in .ai that's it

[emoryarts]

Sorry for being unclear.

What I'm trying to get at, and understand, is how effective it is to design in Photoshop. Perhaps it is best to assume that one isn't as efficient in Illustrator and relies on Photoshop most of the time. When it comes down to logo designing, I understand that Illustrator provides the best work, but how does Photoshop still vary? Does it even compare? Is it still essential to use?

[rinaldidesigns]

One is vector(illustrator) the other bitmap/pixel based(pshop)

A logo should be vector, this way quality isn't an issue when printed, scaled etc.
On a rare occasion(like one out of 20 clients) ask for a psd file...Illustrator allows you to export as a layed pshop file.

[thenameisjolo]

You can do vector work in Photoshop using shape layers, and those can be exported to Illustrator as objects I think...