.tiff or .psd, normal or 16bit?

[Kraftsims]

question regarding normal save format for Aperture.

I've been using Aperture for a while, pleased with it. It does all things I want, such as opens in CS4 with one click, auto save back into Aperture, etc. Lots of plugins, basically everything I find I hear about in LR.

Having now learned all things are essentially equal, I'm trying to understand a finer point about saving a file in .tiff vs .tiff 16bit, or .psd or .psd 16bit.

I've let it save in the past in .tiff and haven't previously thought about any other format.

What should I consider regarding these different formats as CS4 saves back into Aperture?

Advantage to using 16bit or disadvantage?

Any advantage to .psd or .tiff?

Thanks

[Kraftsims]

also, should I save in 300dpi or consider a different density?

[crazyfoo]

i use lightroom, not aperture, but that should not make a difference for this post.....

i am not sure what would really be different between the psd and tiff, but 16 bit would allow you to have more information in your picture than 8 bit would (8 bit is what you get if you don't choose 16 bit). for example, if you had a picture of a sky that was sort of washed out, you'd most likely be able to bring out more detail if you had a 16 bit file, where an 8 bit file is more likely to be what you see is what you get. if your edits are already made to the picture in aperture and you won't need the extra information again in photoshop, or when importing back to aperture, then you could use 8 bit to save some size.

i am also curious about any benefit of using a psd file, maybe just the ability to save layers and everything (although i think a tiff can do that to!!).