reducing DOF with Photoshop

Does someone know a thread about this ? I would like to isolate a subject just as the shallow DOF of a luminous lens would do. I guess it should involve creating a mask to isole the subject. Setting some some blur around it in an layer apart.

Then creating a larger mask with same amount of blur to add to the first one and so on to end up with a total blur for things beeing well apart of the central subject. Is there a specific documented workflow to handle this ?

Many thanks in advance,

Jacques

I add a layer > gaussain blur 30 or more, mask the layer then use a soft black brush and adjust opacity and size to slowly bring back the detail I want. If I over do it I can change to the white brush and paint back the blur

yes but can't remember the thread. What I do is:

• isolate your subject on a second layer (erasing background)
• turn off sencond layer and go back to first layer
• "erode" the borders of the subject with clone tool, by cloning something that is near the border. do this for all the border
• apply gaussian blur on the first layer, and optionally film grain
• turn on the second layer and flatten layers

Does this enable you to progressively increase the blur effect to cope with the illusion of details beeing progressively out of focus and some totally out of focus but with a nice transition?

In theory, PS Cs and CS2 have a lens blur filter (Filter> blur> lens blur, I think) which you use in conjuction with a channel mask. I have never been able to get this filter to work in a believable way but you might have better luck.

I have many links to tutorials on using this filter and lens blur in general saved on my computer which I could post if you'd like. I'm not on my computer right now so I don't have access to them. I believe that the NAPP website has a video tutorial on lens blur.
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Kate

I am away from my photoshop pc right now. There is no emergency - I will wait for your links to tutorials if you don't mind Kate, hopping to have more luck than you. Should it be the case, I'll let you know of course. Otherwise I will rely on Tom and Nippur proposals .

The whole idea is not to have one layout sharp and the other blurred but to have one layout sharp and many different other layouts unsharp with a gradient of blur going from the main subject towards the borders of the image (to really mimic the shallow DOF of a 200 mm F2.8 for exemple).
Many thanks to all of you.

the gradual DOF is only achieved by the lens blur filter and can't be simulated with two layers and gradient mix (you get a sort of flou effect). So try the lens blur filter providing it a mask for the gradient blur.

As regards my technique of cloning the borders, it addresses another issue: if just blur a background a glowing "halo" appears around the subject. The higher the blur radius the higher the halo. By cloning the borders you avoid such halo.

Uncle Frank’s DOF tut using quick mask/gradient

http://forums.dpreview.com/forums/read.asp?forum=1007&message=7163492

CS:

http://www.russellbrown.com/tips_tech.html
Hocus, Pocus, Focus video on lens blur

Lens blur tutorial - Martin Evening

http://www.peimag.com/pdf/pei04/pei0304_04/eveningpei0304_04.pdf

Deke:
http://www.creativepro.com/story/feature/21878.html
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Kent

http://www.pbase.com/kentc
For prior discussions on most questions:
http://porg.4t.com/KentC.html
or d/l 'archives' at:
http://www.atncentral.com

Read the threads in this message.....

http://forums.dpreview.com/forums/read.asp?forum=1006&message=13216195
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• Pulsar

vanhorick said:

I am away from my photoshop pc right now. There is no emergency - I
will wait for your links to tutorials if you don't mind Kate,
hopping to have more luck than you. Should it be the case, I'll let
you know of course. Otherwise I will rely on Tom and Nippur
proposals .
The whole idea is not to have one layout sharp and the other
blurred but to have one layout sharp and many different other
layouts unsharp with a gradient of blur going from the main subject
towards the borders of the image (to really mimic the shallow DOF
of a 200 mm F2.8 for exemple).
Many thanks to all of you.

Click to expand...

These are the links I have saved. Some of them, I'm sure, are among the ones Kent provided.

This one tries to explain the CS lens blur filter

http://www.thelightsright.com/DigitalDarkroom/Tutorials/TakingControlOverDepthOfField.pdf

This one deals with the concept of depth of field
http://www.cambridgeincolour.com/tutorials/depth-of-field.htm

This one appeared on the dpr forum, posted by Uncle Frank
http://forums.dpreview.com/forums/read.asp?forum=1007&message=7163492

This is a further clarification of the above post:
http://forums.dpreview.com/forums/read.asp?forum=1007&message=7171858

Towards the bottom of the page one of these (excellent) tutorials is on Lens Blur:
http://www.photoshopsupport.com/resources/total-training.html#video-clips

This one is pretty good
http://www.escrappers.com/lensblur.html

Scroll to Hocus Pocus Focus. Probably the most extensive explanation and you should probably start here. The example of the boy hiding in the columns shows up on various tutorials as an excellent example of how well the filter works. I am bothered by the fact that the ground and part of the column immediately to the left of the boy blurs instead of being as sharp as the boy who is on the same plane. This is typical of the unrealistic results that I get when using this filter. But since Adobe considers this example a jewel in the crown, one is left to wonder if you aren’t better off doing it yourself with masks using your eye and your judgment and forget about this rather arbitrary filter.
http://www.russellbrown.com/tips_tech.html

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Kate

Thanks a lot for this information to all of you. Pitty enough I will not have much time to try that this evening but I will do that tomottow and let you know. Many thanks again,

Jacques