Tiff VS JPEG Full Sized - When, Where, How and Why

Whenever I send a LR3 edited raw file into CS5 to do addiitonal editing and I just check save, it converts the file into a Tiff file which are usually over 200mbs each.
My question is, when is it necessary to use a Tiff file over a full sized JPEG?
Is it possible to have CS5 automatically convert it to a full sized JPEG instead of a Tiff file?
Is there anything else significant that I should know about the 2?

There are a couple of reasons I can think of. First, when you need to retain all of the color data, tiff is better. Jpeg reduces the color data per channel from 12/14 to 8 so you are loosing 16,128 of the potential 16384 gradations per color channel.

Also, if you are planing to edit you picture over a period of time going through save/load cycles, tiff is a better format. Tiff files are lossless. Each time you save/open the file it comes back exactly as it was before. With jpeg, it goes through a compression cycle with each save. when you open the file again, it will be different then the orriginal. With enough save/open cycles, you can start getting weird artifacts from the compression.

You can use "Save As", but you first have to convert to 8 bit mode and flatten all layers.

If the image is for the web, then a jpg is fine. If you intend to make big prints, then I save a tiff, though usually only in 8-bit. I can always go back to the raw file later if I need to.

ChasP505 wrote in post #11894162
You can use "Save As", but you first have to convert to 8 bit mode and flatten all layers.

Why "flatten all layers"? Keeping the layers is what using a tif or psd is all about?

PhotosGuy wrote in post #11898408
Why "flatten all layers"? Keeping the layers is what using a tif or psd is all about?

If you save as a JPG.

PhotosGuy wrote in post #11898408
If the image is for the web, then a jpg is fine. If you intend to make big prints, then I save a tiff, though usually only in 8-bit. I can always go back to the raw file later if I need to.
Why "flatten all layers"? Keeping the layers is what using a tif or psd is all about?

ChasP505 wrote in post #11898968
If you save as a JPG.

I usually dont flatten the image. That could be the problem.

I am a little confused now. Whenever I save a tiff files, the layers are usually not retained. I only get to keep my layers when I save it as a PSD. This is something else I have to figure out.

bimmeracer3 wrote in post #11900021
I usually dont flatten the image. That could be the problem.

I am a little confused now. Whenever I save a tiff files, the layers are usually not retained. I only get to keep my layers when I save it as a PSD. This is something else I have to figure out.

From raw editor comes out a tiff then you use the tiff in PS and do your layers or whatever you do. Then save that as a psd to retain the layers and what you just worked on. If you need a tiff or a jpeg out of the psd then you will flatten it then will have to be 8 bit to choose save as a jpeg but of course don't use save when you're all done and mess up your psd file. Hope that made some sense, typed real fast

macroshooter1970 wrote in post #11900074
From raw editor comes out a tiff then you use the tiff in PS and do your layers or whatever you do. Then save that as a psd to retain the layers and what you just worked on. If you need a tiff or a jpeg out of the psd then you will flatten it then will have to be 8 bit to choose save as a jpeg but of course don't use save when you're all done and mess up your psd file. Hope that made some sense, typed real fast

Thanks
Thats what I thought. This threw me off a little.

PhotosGuy wrote in post #11898408
Keeping the layers is what using a tif or psd is all about?

You're welcome, glad to help out.

macroshooter1970 wrote in post #11900074
From raw editor comes out a tiff then you use the tiff in PS and do your layers or whatever you do. Then save that as a psd to retain the layers and what you just worked on. If you need a tiff or a jpeg out of the psd then you will flatten it then will have to be 8 bit to choose save as a jpeg but of course don't use save when you're all done and mess up your psd file.

What!? Why would you convert a TIF to a PSD? (Or a PSD to a TIF?) They both have full support of layers and can be 8 or 16 bit. And TIF is a more universal file format than Adobe's PSD. It's only the JPG which must be flattened and saved as 8 bit.

bimmeracer3 wrote in post #11900021
I usually dont flatten the image. That could be the problem.

I am a little confused now. Whenever I save a tiff files, the layers are usually not retained. I only get to keep my layers when I save it as a PSD. This is something else I have to figure out.

When you say "Whenever I save a tiff files, the layers are usually not retained" what software are you using to open/view the tiff? If you save the tiff in Photoshop before flattening, the layers should be intact if you open them in Photoshop. Of course, Lightroom won't "see" the layers. In fact, once I go from Lightroom to Photoshop and Save the results, I typically don't mess with the tiff anymore, and can't give info about what happens if you try to do some adjustment on a layered tiff in LR -- I think I'd stick with Photoshop for that once I have a tiff, at least one with layers.