Blur and Masking

[jsachs]

Another way to heavily blur flower backgrounds is to create a mask for the flowers and save it. Then make a copy of the original image and crudely clone out the flowers by copying background over them. This doesn't have to be very accurate since you will be blurring this image heavily. Next blur the image with the flowers cloned out and finally composite the flowers back into the blurred background image using the saved mask.

[couman]

Another way to heavily blur flower backgrounds is to create a mask for the flowers and save it. Then make a copy of the original image and crudely clone out the flowers by copying background over them. This doesn't have to be very accurate since you will be blurring this image heavily. Next blur the image with the flowers cloned out and finally composite the flowers back into the blurred background image using the saved mask.

+1

Or, simply choose a focal length, aperture, and working distance to yield the desired result:)

[Dieter Mayr]

Or, simply choose a focal length, aperture, and working distance to yield the desired result:)

Bob, easy to say for us that are willing and have the strength to carry a heavy equipment ;) , but with todays mini and micro sensors it seems to be not so easy to achieve.

Back to serious:

To create a realistic looking bokeh can be quiet challenging. The bigger the distance the heavier the blur, so if you have for example a person standing on a flat place, the blur in the distance of the person should be zero, and increasing the more the distance to the person is.
Well, on a flat place this can be easily done with a gradient, but more complex landscape forms requiere a much more complex mask to look realistic.
for the image of the painter i would create a gradient from the bottom of the image to the trees and have a uniform area then for the back trees, with exeption of the branches in the foreground which should get less, if any blur. The latern and the fire extinguisher have to be uniform too, of course.
For the picture of the tennis court (?) a uniform blur would be fine i guess, the background is far away enough for this, maybe a light gradinet over all as it can be seen a light differnce of blur between the lowest and the highest rows of the seats

[tonygamble]

Dieter,

My point is that I don't think 'bokeh' is about blur. To me it is more about the way the lens distorts, for want of a better word, lighlights.

I googled 'bokeh' and these are three of the images it came up with







My experience of doing a 'blur' creates separation, but loses the punch of the image. I am sure there is a way of keeping that punch with PWP - but don't have the experience to know which of the tools to try.

Tony

[Dieter Mayr]

Tony, I got your point now.

I don't think there is a way to create "beautiful bokeh" like in your last images automatically from a picture made with a lens that produces "ugly bokeh".
If there are no beautiful unsharp disks produced by the lens, the only way I can think of now is to paint them by hand, as unsharp circles or elipses in the appropriate color.
Is a lot of hand work, of course, but i dont think there is a other way.
(Buying lenses that make a nice bokeh would be a other way, but can be a expensive one ...)

[tonygamble]

Dieter,

'Ugly bokeh'. My problem comes from using lenses that produce none - the DOF is too generous!

If what we are seeing is disks that appear because the background contains a brighter area do you think we could build a mask that created little disks controlled by the histogram?

When I started in photography I read how some photographers preferred certain lenses because of the number of blades in the lens aperture. I could live without that if I could make a pin prick of light in the background smear into a disk of light. Or I think that is what I am seeing. Yes/no?

More than anything I want to retain the contrast - and blurring seems usually to reduce it.

Tony

[Dieter Mayr]

Tony,

Im not a expert in optics, but to my knowledge theory goes like this:
The more round the aperture (usually it is more round with more blades) and the mory symetric (the same lenses before and after the aperture) a lens is the nicer the bokeh.
With modern lenses, especially zooms, but also wide angle lenses and true tele lenses the factor of being symetric is not true, also factors like floating elements or aspheric lenses have influence on the bokeh. So i imagine its quiet hard to construct a sharp + fast + ok in price + lightwight + small with maybe a gigantic zoom range lens that has a pleasant bokeh, too.

The disks usually come from relatively bright spots in the background, the are simply unsharp (or blurred, if you prefer) and appear as Disk instead of a point (smaller disk, to be correct).
This happens of course to all pionts in the backgound, but from bigger uniform objects the are overlapped and not so pronounced as disks, and from dark points they are just ... dark.

It would need some thinking and experimenting if it could be possible to create a mask that makes disks automatically, but i have my doubts by now.

[BSmall]

Tony,

I've tried a number of techniques and tools over the years that are supposed to produce artificial bokeh. None of them have been usable. I think Dieter is correct when he said "Buying lenses that make a nice bokeh would be a other way, but can be a expensive one ..."; except I would say it's the only way. I am a four-thirds shooter myself and I have found lenses that produce very nice bokeh. Specifically the Panasonic/Lecia 25mm ƒ1.4 and the Olympus Zuiko 50mm ƒ2.0. There are now equivalent lenses available for micro four-thirds:

Olympus M. Zuiko Digital ED 45mm ƒ/1.8
http://theonlinephotographer.typepad.co ... -45mm.html

Leica 25mm Summilux ƒ1.4
http://theonlinephotographer.typepad.co ... eview.html

[tonygamble]

Good point about thinking lenses rather than software.

I bought the 45mm a few weeks ago as a portrait lens but first used to photograph a musical. Two shots follow:-




What I might do is to buy the 25mm 1.4 and sell my 20mm 1.7. And then it use it more as a walk around lens. I have not thought of it before at the 4/3 section of the GETDpi forum mainly shows it being used as a landscape lens and few of the shots show much bokeh - but the TOP article shows how good the bokeh really can be.

Tony
PS. I'll still try to find the PWP solution though!!

[den]

TonyG...

Certainly no where close to the real thing, but you might try experimenting with multiple Median 5x5 Blur passes plus added RGB Gaussian Noise on the image's background after extracting the main subject with a mask... ...at least there is not the fogging nor main subject edge halo that a Gaussian Blur produces...

Original image, 1:1 image area... ...slight existing len's bokeh:

IMG_0597_1-1crop.jpg (43.02 KiB) Viewed 6975 times

10 passes of Median 5x5 Blur plus 10% RGB Gaussian Noise on the background with the main subject masked:

IMG_0597_1-1crop_10x100Median5x5Blur+10RGBGaussianNoise_masked.jpg (46.1 KiB) Viewed 6972 times

...perhaps an added 'tone/contrast' curve could be used to further achieve a background preference... ...and Dieter's suggestion regarding a gradient for an increasing blur with distance is an important consideration.