Feather or Blur Mask's

[neumanns]

Quite some time ago I fell into the habit of using Gaussian blur on my mask's.
But CS4 has included a masking panel and includes a feather selection option.

I do not understand the differances or the advantages of one over the other.

I realize I can still stick to my old methods but I figured with the added convience of the feather feature incorperated on the mask panel in CS4 now would be a good time to understand the differances.

So if you would be so kind....Enlighten me.

P.S. I am new to your site and for now will mostly remain a lurker as it has become obvious to me there are some extreamly talented people here and I have so much to learn. But I will contribute where I can.

[TommyO]

I suppose we should wait and see what the new CS4 users say. Hopefully, feather has been revamped if used within the panel, as G. Blur is generally superior.

Prior to CS4, they also differ based upon the shape of the selection. On straight edges, there is no reason to use feather, as it has no effect. But, since most masks in photography have randomly shaped edges, the two can appear similar. But, they really are not. Try an experiment with a solid black and white image (no gray scale). Make two selections and use a feather to refine one edge, blur on the other. Zoom in and look at the difference. The effect stands out and should answer your question on which to use when. If the intent is to simply randomize the selection edge a bit, feather is fine. But, for better softening, blur remains superior.

[gmitchel]

You can use either for the same purpose: to soften hard edges along a mask. The benefit of using a Gaussian Blur instead of feathering a mask is that the Gaussian Blur tends to be easier to see as you try different settings.

It is not true that Feather has no effect along straight edges. You can prove it to yourself. Create a new file. Add a square marquee. Feather the selection 5 pixels. Watch the corners of the selection round, for example.

Cheers,

Mitch

[neumanns]

I have been running some test's. Feather does apply to straight edges. A feather of 5 pixals vs a Gausian blur of 2.5 (gausian measures radius, feather measures distance).

It's hard for me to explain the differances accuratly but it has been enlightening to say the least. I would say Gausian is a smoother transition but it works in both directions off the selection edge. So while I would consider it smoother it aslo mushes the edge more. Feather works outward only from the edge and leaves a crisper yet more abrupt transition.

Since feather is built into the mask panel on CS4 I'm gonna try and give it a fair try but somtimes old habits are hard to break. I wouldn't say one is better than the other at this point, but deffinatly diffrent.

I'm not sure but it seems to me the original reason I made the switch to gausian was in CS2 there was no way to preview Feather. But I could be mistaken on that count also.

Funny how we somtimes do things just because that's how we have always done it without understanding why. That's definatly the case for me on this one!

Keep the opinions, observations, & facts comming...I would like to get a better understanding and this is somthing we all do on a regular basis. After all masks selection's and getting them to blend is somthing pretty intergral to what we do in photoshop.

[gmitchel]

The big distinction is this:

Feathering is applied to a selection.

Gaussian blur is applied to a mask.

Masks and selections are different. We can use selections as well as brush tools, etc. to make masks. We can then refine those masks.

We can also take a mask, make it into a selection, refine the selection with something like Feather, and then save a new mask based on the refined selection.

When you have a selection, you can use Feather to soften the edges of the selection. It is hard to determine visually how much the edges will soften just by watching the marching ants for a selection. With quick mask, you can somewhat.

I usually find it easier to make a selection, save it as a mask, and then refine the mask with Gaussian Blur, Median, etc.

There are generally comparable transformations using selection commands like Feather, Grow, etc. or using pixel-based transformation applied to masks like Gaussian Blur.

Cheers,

Mitch