Mindy,

You are right in that UF doesn't have the same kinds of color controls that Photoshop has. I was actually thinking of that quite specifically when I said there were things PS could do that UF can't, and things UF can do that PS can't. And that's because the two programs are completely different.

With PS, what you're looking at is just a collection of pixel data. PS lets you select color ranges, boost contrast, adjust levels, etc. by working directly with that pixel data. The same thing goes for all of those filters; PS has the pixel data handy and it just manipulates it in whatever fashion you describe.

UF never treats your image as a collection of pixel data. It always treats your image as something generated mathematically. When you adjust the gradient in UF, you're tweaking the numbers that go into producing the image, and UF then recomputes the image. If you have a gradient with two separate blue ranges, you can tweak each independently in UF; in PS, this would be extremely difficult, as selecting "blue" pixels over the entire image would get areas covered by both ranges. On the other hand, editing color in a localized area in UF is done differently than in PS; for PS, you just select the area and edit away, but in UF, you have to create and use a mask for the area (not always easy).

If UF were to support all of PS's color control options, it would require a very confusing interface. The whole philosophy of working with UF is that you look at the final result, but UF retains separately all the pieces that went into assembling it. So all of those lovely color tweaks would have to appear in a list somewhere, for you to create, edit, and manage. There's never a concept of "just do this one action", because UF has to be able to re-create every action you do to reproduce an image. It is a difference in approach. You have more control over some things than you would in PS, but it's not a direct translation between the two programs.

Using PS's filters is problematic unless you're working directly at print size. A Gaussian blur with a radius of 10 pixels on a 1600x1200 has to be scaled to 50 pixels on an 8000x6000, as you know. But some effects flat-out won't scale properly. (It's possible to use effects like this in UF, too; I'm careful not to.)

I just this evening finished a new piece my wife really likes (it's in her favorite colors) and I've been sweating over certain effects for two days. In PS they would have been fairly straightforward, except for that pesky print-size issue. In UF they required me to write a custom formula for this image, which I hate to do generally, but now that it's done I know I can render at whatever size I want.

There is no one-size-fits-all. It's funny this discussion should pop up, since someone recently asked on the Apophysis list why anyone would want to put a flame into UF when Apo can edit the flame so much more directly. It's the same sort of thing: if your creative process flows down a particular path, using a particular set of tools, to have that option closed off is not acceptable. I would never encourage you to ditch PS, because your workflow doesn't support it. That's just not the way you create your art. The good news is, there are options. You may find in some circumstances you want to use layering in UF and export a PSD to PS for further tweaking. Or you may just want to treat PS alone as your canvas, and work from there. There's no "right" way, there's just "your" way. Sometimes there's more than one way to do the same thing, in which case one way might be more efficient than the other, but there's usually more to worry about than just efficiency.

Sorry for the rambling nature of this reply. I had to run out halfway through and cook dinner, so it might not be totally coherent. ;-)

--Damien