I got two images rejected with this message "The execution of isolation contains stray areas that are either too feathered or rough". to select i used polygonal tool and then Modify --> contract by 2 pixels and Modify --> Smooth by 2 pixels.  I remember someone mentioned blur,
but I do not see that in Modify menu. What I am missing ?

Probably blur tool in the tools pallete. What about doing isolations with a pen?

I would like to know how to properly use polygonal tool also.

Polygonal selection are bascally... useless. With the pen tool you can easily make polygonal selections if you want an a LOT more. The pen tool is not easy to master, but it is definitively the one you should concentrate on 

The rejection of your photo is probably due to the use of the polygonal selection tool. Even if you smooth the selection you will not get a clean selection with this tool.

let me reformulate my question: after selection is done (Pen tool, or whatever tool selection tool) is it enough just to  Modify --> contract by 2 pixels and Modify --> Smooth by 2 pixels ? What about Blur or Feather options ?

let me reformulate my question: after selection is done (Pen tool, or whatever tool selection tool) is it enough just to  Modify --> contract by 2 pixels and Modify --> Smooth by 2 pixels ? What about Blur or Feather options ?

It really depends on your subject.

If the shape of the subject is not too complex, you should be able to get a perfect isolation with the pen tool only and this is the best way to proceed IMHO. When transforming the path to a selection, you can specify a small feather radius (e.g. 0.3)  and check the anti alias box.

Contract is useful if your selection does not fit perfectly the shape of the subject, but with the pen tool you can modify the path at wish before making the selection.

Smooth is useful... when the selection is done with the inapropriate tool such as the polygonal selection tool.

Blur applied in Quick Mask mode is similar to Feather and is useful to make the edge of the isolation fade into the background color. If you want a true isolation (no shadow), it sould be avoided or used very carefully (small radius). But it's still better to use the pen tool and set a small feather radius when transforming the work path into a selection.

If the shape of the subject is very complex... you should forget with isolation: you will spend a lot of time with limited success whatever the technique.

Isolation is all about clean selection and selection techniques are probably the most complex subject in Photoshop. There are zillions of different techniques and each of them is more or less suitable depending on the original photo.

But learning and mastering the pen tool is the way to go 

But I forgot something... do you shoot your subjects over a white background?

Because all what I said is true (really ?) when trying to isolate a subject which was not shot against a white background.

I personnaly have many isolated objects in my portfolio, but they are all shot against a white background and in this case the solution is somehow different.

yes, i shoot over white background. Eager to know you solution ...

My own personal solution is simple: I do not try to get "true" isolations, but I prefer to keep the object shadows while ensuring that the border of the image is pure white.

There are many discussions concerning true isolations vs isolation with shadow. Which one is better?

I think there are pros and cons to both options, but I can tell you that my isolations do sell very well and are most of the time accepted with the shadow and with the keyword "isolated on white background" everywhere, including at iStock.



In this case, you don't need to create a precise selection of your object: all you need is to use various techniques to make the border of the image pure white without affecting your subject too much.

The best solution is then to try to get this result directly when shooting the photo by using a good lighting setup. In PS ou then just have to finish the work and I often use a simple selection with a huge feather radius (20-250).

A lot easier to do than a true isolation and I think that sales would not be better with a true isolation (which would be impossible to obtain with the example above anyway).

Now, you decide

Hi I am new to Stock Photography last year but leaning fast, I have learned quite a few tips about isolation, and have settled on a particular work flow.

I have posted a step by step overview on the process to pick up them stray area's, I use it all the time now and have halted the fall in my acceptance rate, as I have received a lot of help, I now hope this will help others, sort of payback.

http://www.adeptris.co.uk/HowtoIsolation/tabid/67/Default.aspx

There are some more examples in my gallery and on Istock (Adeptris)

David