Forum: Photoshop


Subject: distance blur

mickey2 opened this issue on Jan 12, 2002 ยท 13 posts


mickey2 posted Sat, 12 January 2002 at 8:59 AM

Hi gang , I have often heard the term distance blur,(hobbit mentioned it as one of the methods that he uses )but I have never seen it mentioned in a Photoshop manual. Does anyone know this term or how to get to this function. ( and yes I have asked Andy but got no reply) I know with all the masterminds out there I should have no problem becoming well versed with help or links to help on this funtion. thanks all


svdf posted Sat, 12 January 2002 at 9:05 AM

i'm not a mastermind, and i'm not shure, but isnt this just that you blur (with the blur tool...) everything on the background? there are plug-ins (i don't know which, but i see them sometimes...) that could blur, and you only have to say what you don't want to blur... maybe one of these plug-ins is called distance blur??? i hope i've helped you a little bit... (not mutch maybe, but hey... i'm not a mastermind ;) )


mickey2 posted Sat, 12 January 2002 at 9:16 AM

Thanks for the reply, and I consider a Mastermind not as a person with a masterful mind, but a person that can master his or her mind!! (smile)


paden posted Sat, 12 January 2002 at 11:03 AM

You can mask the background from the parts you would like to be sharp then blur it without affecting the foreground. You can use the mask to build a gradient alpha channel and blur usign the alpha. Bryce will do this for you if you render as a distance mask. then use that mask either for an alpha channel or as an easy way to isolate the background from the image for masking. I know this isn't explained very well, sorry. I would just play around with one or several different masks and blurs for each one.


Impudicus Rex posted Sat, 12 January 2002 at 12:09 PM

It's a built in filter for Photoshop. It's actually called "Motion Blur". One sets the direction and distance to create the kind of blur/dstreaking seen in this image. (cropped from a much larger one) There's also "Gaussain", "Radial", and "Smart", as well as the standard "Blur"

Jim Burton posted Sat, 12 January 2002 at 6:33 PM

To make distance blur (which is actually due to the limitations of a camera's depth-of-field, when you think of it, eyes don't really have this problem, except really close for us with bifocals) work you need something to seperate the distant parts from the close ones, either manually or using a 3D program like Bryce wich can render an image in grayscale to distances, (or maybe it does it as an alpha channel, I forget). Once you have the information you can do some kind of variable selection (like select, load selection if it was in a alpha channel from Bryce) to have the distant parts fully selected, the close ones less selected, and put a Gaussian blur on the picture - the result would be distant parts would be blured more. Anyway, the hard part is getting the variable selection, there is no way for a plug-in to do that automatically..


Impudicus Rex posted Sat, 12 January 2002 at 6:54 PM

Ah I see! you're talking about depth of field. My mistake.


Jim Burton posted Sat, 12 January 2002 at 9:52 PM

I gather he was, but I could have been wrong and you right! ;-)


Varian posted Sat, 12 January 2002 at 11:25 PM

Attached Link: http://www.andromeda.com/info/varifocus.html

There is a good plug-in that can help create the distance blur/depth of field effect. Called VariFocus, follow the link for info. :)

dreamer101 posted Sun, 13 January 2002 at 3:51 PM

DreamSuite Series 1 has a nice focus plug-in (or stand alone) Auto FX Software


mickey2 posted Sun, 13 January 2002 at 6:53 PM

Thanks for the info folks, I was referring to depth of field, and as a result of reading your comments my mind has focused on somethings to experiment with, and hey isn't that really how all the good stuff is born anyway. (smile) see ya, if I come up with anything cool I'll share , see ya.


lundqvist posted Mon, 14 January 2002 at 4:24 AM Online Now!

Another thing that's been poiunted out to me before: if you are working with an image output by a rendering engine and have (or can get) the z-buffer in an alpha channel, you can use this as the basis for a mask when applying Gaussian Blur.


Hoofdcommissaris posted Thu, 24 January 2002 at 8:50 AM

A lot of times I masked out figures, because I wanted to blur the background. And then used a gradient to get a non-linear depth of field. If you starting doing this, inspired by this thread, I have two nice tips, learned it the hard way: First, if you end up with at least two layers and want to blur the background, some kind of halo will surround the masked figure (because it is also there). Before you blur, crop the masked item in the background layer with the clone tool. The effect will be much better. Second, If you use an alpha chanel or a gradient, do not try to blur your background in one pass, do it a lot of times, with a small value. Areas that are selected for 50% (because of a corresponding grayscale value) look 'ghosted' i.e. half of it is sharp, half of it blurred. With more passes this effect becomes less.