Results 1 to 14 of 14

Thread: Simulated Depth of Field

  1. #1

    Join Date
    Oct 2009
    Location
    Nelson New Zealand
    Posts
    68
    Real Name
    Barry Doig

    Simulated Depth of Field

    I attach a rodeo photo I recently took. I wanted to simulate the depth of field effect of a reasonable lens, putting the background out of focus but the foreground still in focus. My method was to select the guy and the bull, and use a gaussian blur to put the background out of focus but keep the guy & the bull in focus. I then used the eraser tool to bring the foreground sharp again, gradually reducing the opacity as I moved the tool across in broad strokes and moving up the picure. The end result should be a graduated depth of field effect. But it's not right. The background blur is too abrupt. Is there a way to use a gradient to give me that graduated depth of field that I'm looking for? I would be interested in some comments. I'm using Elements 6 Thanks, Barry

    time-get-off.jpg
    Attached Images Attached Images
    Last edited by Colin Southern; 9th March 2010 at 08:35 AM.

  2. #2

    Join Date
    Dec 2008
    Location
    New Zealand
    Posts
    17,662
    Real Name
    Have a guess :)

    Re: Simulated Depth of Field

    Hi Barry,

    For what it's worth, I've never had much luck doing this either; I'm wondering if part of the problem is that a gaussian blur doesn't emulate lens bokeh particularly well.

    Possibly easier to just install a ND filter on an existing lens, and shoot wider?

    Additionally, I am aware of the existence of plugins that supposedly simulate a tighter DoF during post-processing, although I've never used them. In Photoshop I'd probably select bull & rider - select the inverse - copy to seperate layer - apply gaussian blur (or perhaps some other filter/effect?) the use varying shades of gray on a layer mask to conceal / reveal appropriate amounts of each layer.

    The following Adobe help documents might be of interest also ...

    http://livedocs.adobe.com/en_US/Phot...DD602CA63.html


    http://www.adobe.com/designcenter/ph...plensblur.html

    Hope this helps,
    Last edited by Colin Southern; 9th March 2010 at 08:58 AM.

  3. #3

    Re: Simulated Depth of Field

    Why do you guys use guassian blur when there's lens blur right next to it?! Gaussian blur is completely different and cannot emulate shallow depth of field. Lens blur is much better at this and produce more natural look!

  4. #4
    arith's Avatar
    Join Date
    Sep 2009
    Location
    Burton on Trent, UK
    Posts
    4,788
    Real Name
    Steve

    Re: Simulated Depth of Field

    I've only ever thought of doing this but now can see the problems with it. Firstly the outside edges of the lens would have less resolution but also some of the foreground. A radial gradient on a selection mask on its own will not be good enough but the mask would also need to be touched up with a linear gradient. I suspect it is possible but don't know how to do it, blending selection masks is not something I've done.

  5. #5

    Join Date
    Oct 2009
    Location
    Maryland, USA
    Posts
    1,015
    Real Name
    Rick

    Re: Simulated Depth of Field

    Quote Originally Posted by Pawel View Post
    Why do you guys use guassian blur when there's lens blur right next to it?! Gaussian blur is completely different and cannot emulate shallow depth of field. Lens blur is much better at this and produce more natural look!
    Elements (at least PSE6 and PSE8) doesn't have lens blur in the filter menu, at least in the versions I have (US, both direct from Adobe). Maybe there are plug-ins available.

    Cheers,
    Rick

  6. #6
    arith's Avatar
    Join Date
    Sep 2009
    Location
    Burton on Trent, UK
    Posts
    4,788
    Real Name
    Steve

    Re: Simulated Depth of Field

    Just to give an idea what I mean and to discover how hard it is to do. This is an image sharp throughout and using Gimp I created a duplicate layer ( maybe there is a way to create just another layer but this is the way I did it) and filled it with black. Using a black to white gradient I then placed a radial gradient bang in the middle. Created another layer this time on multiply and applied a white black white linear gradient, messing around with opacity to sort of get what I want merged the top onto the middle and then copied it to the clipboard. Delete the layer and bring up the selection mask and paste into it. Then use gaussian blur on the selection.

    It is hard and a lot of work, here quickly done I've discovered it isn't really something I would like to perfect.
    Simulated Depth of Field

  7. #7
    arith's Avatar
    Join Date
    Sep 2009
    Location
    Burton on Trent, UK
    Posts
    4,788
    Real Name
    Steve

    Re: Simulated Depth of Field

    Well I didn't think that out but here is another try but this time making the top layer addition, I could possibly have chosen a better picture but all mine with a single subject are already dof I think.

    Simulated Depth of Field

  8. #8
    arith's Avatar
    Join Date
    Sep 2009
    Location
    Burton on Trent, UK
    Posts
    4,788
    Real Name
    Steve

    Re: Simulated Depth of Field

    Is this one close, I think it is close.
    Simulated Depth of Field

  9. #9

    Join Date
    Oct 2009
    Location
    Nelson New Zealand
    Posts
    68
    Real Name
    Barry Doig

    Re: Simulated Depth of Field

    Thank you to those who replied to my query about simulated depth of field. I agree John that gaussian blur doesn't emulate lens bokeh very well. I am using Elements 6 which doesn't have the Lens Blur filter even if it does work. I downloaded a gradient blur plug-in which has proved useless. Steve your trees image is close to what I want and I'd like to know how you did it. Meanwhile I tried using a black to white gradient adjustment layer. Having first selected the foreground area I wanted - the horse and rider- I deselected it and applied the gradient to a levels adjustment layer and gave it a gaussian blur. I then reselected the hors & rider used the eraser tool to wipe away the blur and reveal the sharp Background underneath. The result is not too bad and I think an advance on my previous image.

    time-get-off-v2.jpg
    Attached Images Attached Images
    Last edited by Dave Humphries; 16th March 2010 at 10:07 PM.

  10. #10
    RobO's Avatar
    Join Date
    Dec 2009
    Location
    Lincolnshire, UK
    Posts
    56

    Re: Simulated Depth of Field

    Quote Originally Posted by barrydoig View Post
    I attach a rodeo photo I recently took. I wanted to simulate the depth of field effect of a reasonable lens, putting the background out of focus but the foreground still in focus. My method was to select the guy and the bull, and use a gaussian blur to put the background out of focus but keep the guy & the bull in focus. I then used the eraser tool to bring the foreground sharp again, gradually reducing the opacity as I moved the tool across in broad strokes and moving up the picure. The end result should be a graduated depth of field effect. But it's not right. The background blur is too abrupt. Is there a way to use a gradient to give me that graduated depth of field that I'm looking for? I would be interested in some comments. I'm using Elements 6 Thanks, Barry

    time-get-off.jpg
    I have found this http://www.ononesoftware.com/detail.php?prodLine_id=8 to be amazing software and works hand in hand with Photoshop. Focal Point is the package within the suite which you will require. The only down side I have found is that when they upgrade the software it's a "major" download - just short of 2Gb ! [I only have slow BB ] - As you will see - you can try before you buy and they occasionally have special offers too.
    RobO

  11. #11
    Moderator Dave Humphries's Avatar
    Join Date
    May 2008
    Location
    Windsor, Berks, UK
    Posts
    16,059
    Real Name
    Dave Humphries :)

    Re: Simulated Depth of Field

    Quote Originally Posted by barrydoig View Post
    ~ The result is not too bad and I think an advance on my previous image.
    Hi Barry,

    Yes, it is an improvement, I think if you study it and have another couple of attempts at it, you'll be getting quite good at it.

    I think I am just saying practice makes perfect.
    For me, this attempt has lost a bit too much focus and contrast in the background.

    Better though,

  12. #12
    arith's Avatar
    Join Date
    Sep 2009
    Location
    Burton on Trent, UK
    Posts
    4,788
    Real Name
    Steve

    Re: Simulated Depth of Field

    I think it is quite good.

    Before I read this I didn't think a computer could simulate dof, but often thought about it because what could be nicer to a landscape photographer to just choose the hyperfocal distance then choose out of focus in the computer.

    It takes three layers to simulate dof above the background. A linear gradient layer, a radial gradient layer, and one that picks out those objects in the foreground but not in the centre of the image.

    These are merged as additive layers (opacity dependent on what is required), and because I don't know how to do it and it is easier I just copy these and paste into a selection mask. Then straightforward ordinary Gaussian blur is applied.

    Cheers.
    Last edited by arith; 17th March 2010 at 12:25 AM.

  13. #13

    Join Date
    Oct 2009
    Location
    Nelson New Zealand
    Posts
    68
    Real Name
    Barry Doig

    Re: Simulated Depth of Field

    Quote Originally Posted by RobO View Post
    I have found this http://www.ononesoftware.com/detail.php?prodLine_id=8 to be amazing software and works hand in hand with Photoshop. Focal Point is the package within the suite which you will require. The only down side I have found is that when they upgrade the software it's a "major" download - just short of 2Gb ! [I only have slow BB ] - As you will see - you can try before you buy and they occasionally have special offers too.
    RobO

  14. #14
    arith's Avatar
    Join Date
    Sep 2009
    Location
    Burton on Trent, UK
    Posts
    4,788
    Real Name
    Steve

    Re: Simulated Depth of Field

    Looks great but I haven't got photoshop CS3 or 4, and I have only 2GB of ram of which 1GB is used. Then 2GB download would take me two hours to download. But it looks the business. cheers

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •