Aliasing/moire in the photoshop workspace. What's the deal?

Question

Take a look at any open file in photoshop. Now zoom to 16%, 33%, or any other odd-numbered zoom level. Notice the aliasing and moire? It has always annoyed me - to the point where I only work in 25%, 50%, 100%, etc zoom levels. I avoid 16, 33, etc altogether.
But there's got to be a way to correct this. I have CS3 at home, and I use CS5 at work. is there a setting or option to turn on anti-aliasing, or mipmapping, or I don't know, something?
Andy

Answer 1

There is some aliasing.  I wouldn't say it's so excessive that I would think to avoid certain "stops" though...
Can you do one or more screen grabs and post them here to see if you're seeing something most folks are not, or whether you're just more sensitive to it than most?
Photoshop appears to use a resampling algorithm that's optimized for speed to create one of a number of pre-downsized cache images, and from there it resamples the image further to give you the exact zoom level you want.
 I have recently programmed a similar process in my own software.  Following what OpenGL expects, in my case I downsize a set of "mip maps" by half and half again until I get to the smallest size (1 pixel).  The advantage to using half sizes (4 pixels into 1) is that the code can be quite simple and fast yet still yield a very clean, smooth resample.
Enabling OpenGL in Photoshop does help smooth out the image between the "stops", but I think there's just no getting around the fact that there is still code left over in Photoshop from times gone by. Don't forget they still fully support non-OpenGL operation.
The remaining resampling - to odd sizes between "stops" - is done quite handily in the GPU using floating point and the massively parallel processing GPUs provide. This is why in Photoshop they can provide things like the smooth zoom transitions.  Not that many years ago not too many things moved on the screen in real time!
-Noel