In LR4, when I edit in PS CS5 it automatically saves an edit copy. That did not happen in LR3. Am I missing a preference so that doesn't happen?
Until you update to an equivalent version of Camera Raw (think ACR 7 in CS6) you won't have the choice. The default behavior is to allow ACR to open raw images in Photoshop as long as the LR version and ACR version are in sync.
When it's not, then you need to have LR render the files and that behavior requires LR save a TIFF prior to opening in Photoshop. This is non-negocatable…you can't change it other than by matching up the ACR/LR versions.
BTW, you can download and use the CS6 beta to render into Photoshop CS6 without having to save the TIFF beforehand.
Thanks, Jeff. For what it's worth, it's not opening or saving as a Tiff, but as a .psd. Are you saying that if I was opening my raw images in CS6, then it would open as a .dng as it used to?
TIFF, PSD doesn't matter...if you opened a raw image in CS6 (ACR 7.x) then yes, you would have the ability to so a Save As or not, and not have that TIFF or PSD automatically created...if you open in any version below ACR's version then yes, a TIFF or PSD must be created before even opening the image. LR4.x equals ACR 7.x, if you open in less that ACR7.x then yes, the TIFF/PSD will be created/saved before it's opening into Photoshop. There's nothing you can do about that.
You should install Adobe CameraRaw 6.7 RC from Adobe Labs: http://labs.adobe.com/technologies/cameraraw6-7/
It provides compatibility with Lightroom 4.x.
I would not recommend installing CS6 for this purpose because it's beta release, and ACR 7 in it lacks support for many newer cameras like Canon 5D Mark III, while ACR 6.7RC supports them.
I guess final CameraRaw 6.7 will be released during the next couple of weeks and then it will be available thru the update mechanism in your CS5.