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The problem with that is that it doesn't simulate the bokeh effect that is present in a genuine OOF area. The other problem is that is doesn't simulate cariations on depth based on distance from the film plane in 3d space. There are photoshop plug ins that CAN do this, but they are very very expensive. Photoshop CS has the lens blur option, which looks slightly better than guassian blur, but is not completely convincing.
Posted 98 months ago.
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Personally I don't think the gaussian blur produces as nice effect as the lens blur filter does.
Another advantage of using the lens blur filter is that you can use a layer mask as a 'guide' for the blur. That means using gradient fills in the mask you can create some realistic and subtle effects.
When my only camera was a point and shoot I used this technique quite a lot on images like this:
mute.rigent.com/index.php?ladat=2005-02-05
and the top one here:
mute.rigent.com/index.php?ladat=2004-12-20
And to more obvious effect here:
mute.rigent.com/index.php?ladat=2004-11-11
and here:
mute.rigent.com/index.php?ladat=2005-03-08
(the second link includes a description of the technique in the comments.)
Using the layer mask you can create a map of the visual planes in the image and connect them using gradients of various tonal ranges.
Also, I'm not sure what technique people use for 'cutting out' the various planes in an image for this but I favour using the lasso. You can make a rough outline and then using the tool in combination with the alt and shift keys 'sculpt' the selection to your subject.
Posted 98 months ago.
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Ah thanks for that mute-photoblog, I have been wondering how to apply a gradient effect, thus far I have cut layers out of the image and added more blur to each layer then added them together, to give a relativistic focus effect:
The effect is subtle here, I didn't push it too far so that the joins would be invisible.
My cut out technique is to use the mask brush first and then tidy up using a much finer brush. I also use the magic wand.
@Lunatic Fringe, Agreed bokeh aren't possible with this technique, perhaps combining this with the whole image arithmetic technique GustavoG published may work?
Posted 98 months ago.
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i'm a big fan of doing this, but adding a bit of noise to make it look less 'digital'
Posted 98 months ago.
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Picasa does this effect, too. You pick the area of the photo you want to remain in focus, and it progressively blurs the rest.
--Pat
Posted 98 months ago.
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urbandiscount [deleted] says:
it just occurred to me that replicating DOF effects in photoshop is the pushing and pulling from the era of film. ;)
Posted 98 months ago.
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The effect in picasa isn't really depth of field though, it's more like the effect you get with a lensbaby where the focus is applied regardless of visual planes.
The lens blur filter in PS CS has a nice noise generator to make your blur fit in.
Posted 98 months ago.
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*grumble, grumble*
Unless the amount of blur is a function of the distance from the "film", then it's just selective blurring. A uniform blur will be somewhere between merely distracting to painfully obvious. I think that's really puja's problem. mute-photoblog has it right.
Unless you can reconstruct the depth dimension in some way, you've lost valuable information, and faking a short focus-field depth will be really hard.
Posted 98 months ago.
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the lens blur filter in PS CS can apply a more realistic lens blur using an alpha channel/selection as a mask, so you can basically paint in your different planes in different tones of white or black [you can do either] and then use that DOF "map" as the lens blur map. Works really well...and you can pick different lenses for different shapes in your blurred highlights.
i've been using CS since it came out...[and PS for almost a decade] and I didn't notice lens blur until about 3 weeks ago. old habits.
Posted 98 months ago.
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One way of reconstructing some amount of depth dimension is to use a gradient mask that slowly blends the slightly OOF plane to the completely out of focus plane. Takes a lot of work, but you can get some nice results.
It's true that these techniques are not exactly like true DOF but in response to Chad's comment, I'd like to note that for me, having Every Single Thing In The Background In Clear Focus is far more painfully distracting, which makes it worth it to attempt to approximate DOF.
Posted 98 months ago.
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fd
says:
I played with this a little but while trying to achieve a different effect. Using multiple gradient masks you can blur different parts of the image in different amounts. Like shimonkey said, you can approximate DOF effects with this if you're careful. It is easier with scenes that are easily divided into multiple planes.
 
Posted 98 months ago.
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Definitely, if you're careful with the 'map' you create for the lens blur then you can get a good approximation.
This is one of the photos I used the lens blur filter on and the layer mask image that I used as a guide for the lens blur filter. (black for in focus, white for out of.)
Posted 98 months ago.
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Thanks for the illustraition of your technique Mute. I have been using layer masks for a while now but for either 'hard' element selections or large gradients but I had never thought to use a combination as shown here. Now I just need to find a good use for it before I forget.
Posted 98 months ago.
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I find it useful to create the 'solid' elements first you can create a selection from them, reverse it and then apply the gradient to the selection without the gradient interferring with the solids.
If you alt click a layer mask you can see it's literal representation, as above. Most people probably know that but I was clueless until I did it by accident!
Posted 98 months ago.
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shimonkey and Mute*, I've been recently using that trick of combining hard masks and gradients to get DOF style shots from my digital point-and-shoot.
The there's a "hard" mask around the subject, and a gradiated horizontal mask going from his position to the trees at the background. The "sharp" version of the pic goes through these masks, on top of a blurred (and slightly darkened) version of the same image. The main thing I found was to be reasonably subtle with the background blur- if it's too much, it wouldn't match up to well with the foreground.
BTW Mute, I know what you mean about the Lens blur versus the Gaussian blur. (I've only just found about that recently, th3ph17 as well!)
Posted 98 months ago.
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Selective blurring seems to make the picture look like its a macro shot too like Mute's tram picture, which is very cool !!
Posted 98 months ago.
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I have to agree with alephnaught that a very subtle graded effect is required (which is what I employed here ) or it does get to look very odd. Unless that is the effect you are looking for....
Posted 98 months ago.
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f8125, never thought about the "macro" look, but now you mention it, I see what you mean. It must be that because people normally associate depth of field with objects that are close up in comparision with the background, they apply that perception to DOF shots where the objects in focus are much further away.
Posted 98 months ago.
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OK, I've experimented with fake DOF again, on this series of shots, this time using lens blur. :)
Posted 98 months ago.
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jwk [deleted] says:
I really like the look of the faked DOF shots. I don't think anyone would mistake the DOF as "real", though -- something just seems a little "off" about it. Having said that, there is my quick-and-dirty attempt:
Posted 94 months ago.
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Mute, if you don't mind my asking?...
Is the layer mask image you used a generated one from the original, or is it a hand-tailored map (drawn by hand)?
I use this often in one of my 3D programs - but it creates such greyscale images. I don't know how to achieve this in PSCS2.
Posted 86 months ago.
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If I'm understanding your question correctly: methinks the grayscale image of the mask he posted was obtained by simply getting a screenshot after alt-clicking the layer mask (as he mentioned in his next comment).
Posted 86 months ago.
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Oh, I'm sorry... I see - thank you!
:)
Posted 86 months ago.
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Here's my most recent attempt at DOF using a hard mask and gradient controlled gaussian blur. The mask was a bit messy, but if not examined too close, it works for me.
Posted 86 months ago.
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This one I did a bit too quickly..
But I liked the result.
I separated a second layer with the main subject and then blurred the whole background.
Originally posted 86 months ago.
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Mikelo edited this topic 86 months ago.
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