DOF/bokeh

[Metalhead]

I work for Kodak (shooting a Nikon D70s :-P) at my local Six Flags. Most of the people they hired don't have a background or real interest in photography, so I try to make my shots of the guests look as good as I can by choosing nice locations and getting a good depth of field. When I have kids all by themselves, I like put them in front of a plant or something that's really far back with a low depth of field to soften up the background and get a much sharper and more personal looking shot.

I like to do my own research and learn my doing so I pick up my D200 when I get home and screw around with focal length and aperture and I'm pretty good at getting optimal DOF on my camera and the one I use at work, but I'd like to hear from some other photographers, too.

What do you guys do to get good bokeh (soft, out-of-focus background) with a low depth of feild? Is there something other than the focal length, aperture, and focus distance I should be taking into account?

[srwatters]

The quality of the lens has a lot to do with how 'creamy' the out of focus areas look, but you have the basics with aperture and distance to the subject and BG. The greater the working distance, the deeper the DOF at a given aperture and focal length. Get closer to the subject and your DOF will decrease (given the same aperture and focal length).

In the Nikkor portrait lens family, the 85mm f/1.4 is considered by many to be the bokeh king. I also like the 70-200 and 80-200 f/2.8 models. YMMV.

[Wes]

Originally Posted by srwatters

In the Nikkor portrait lens family, the 85mm f/1.4 is considered by many to be the bokeh king. I also like the 70-200 and 80-200 f/2.8 models. YMMV.

Not much that I can add to what Scott said. Just curious - does the 85mm f/1.4 really have that much better bokeh than the 70-200 f/2.8 or even the 28-70 f/2.8? I thought they both used the same number of blades (9) in the diaphragm and that this is one of the main contributors to the bokeh that they produce.

[srwatters]

There is a little more than just the number of blades. Their shape and the size of the aperture contribute to the roundness of the opening. Also consider the distance from the blades to the focal plane and the number of elements in the lens. Control of aberrations in the design has an effect with respect to flare and other nasties that show up in OOF areas also.

28-70mm f/2.8 @ f/2.8


70-200mm f/2.8 @ f/3.5


85mm f/1.4 @ f/1.8


You be the judge, but in my opinion the bokeh on the 85mm f/1.4 reigns supreme for creaminess

[ndsimm]

good info Scott, thanks for sharing. Would the Portrait setting on the D200 help or would it make a difference with these lenses?

[srwatters]

Originally Posted by ndsimm

good info Scott, thanks for sharing. Would the Portrait setting on the D200 help or would it make a difference with these lenses?

The only thing that might effect the bokeh would be the sharpening setting. It doesn't change anything for me since I shoot RAW most of the time. For the most part, bokeh is only a factor of the things mentioned in the first post.

[engstrom]

Originally Posted by Metalhead

What do you guys do to get good bokeh (soft, out-of-focus background) with a low depth of feild? Is there something other than the focal length, aperture, and focus distance I should be taking into account?

As has been stated the lens used determines the bokeh. The depth of field is a roughly linear relationship to aperture - open up by one stop and your DOF decreases by a factor of 1.4. Open up two stops and your DOF decreases by a factor of 2. But, the depth of field is a square relationship to focal length and focus distance. If you cut your focus distance in half you will only have 1/4 of the original DOF. So, if you want as thin a DOF as possible get as close as possible to the subject.

[MRCPix]

how does the boken on the 85 1.4 compare to the 85 1.8?

[Metalhead]

thanks for all the info, everyone, especially you, Scott--the pictures helped, and I agree, the 85mm f/1.4 is the king of bokeh from all the lenses I've ever seen or used.

[darktiger]

Cant wait until after my China trip, that is when I get my 70-200 2.8 IS. Man that bokeh looks awesome with the 70-200...

[Metalhead]

I might invest in a better lens for bokeh one of these days, but I'm satisfied with what I can get right now.

Here are some sample shots that I took yesterday; all are shot with a Nikon D200 and a Nikkor 18-200mm VR lens. (sorry for the DA watermarks, but it's easier for me to post on deviantart than a separate online portfolio until I get a better internet connection)

[Wes]

Quick question, Scott..... First of all, I like the images that you posted. However, is it a fair representation of the bokiness of each lens? One image was shot at f/1.8, one at f/2.8, and one at f/3.5. How is it possible to compare the bokeh of a lens shot at 1.8 with one at 3.5? Or, does it matter at all? Just curious?

[hhscr]

The bokeh is a result of the lens design and quality. The aperature has a direct effect on the DOF, and not so much on bokeh result.

So the images that Scott posted is a fair representaion of the bokeh ability of each lens regadless of aperature.

[johnastovall]

Bokeh is more complicated than just a creamy background. Here is just a small discussion of the issues involved.

My current favorite Bokeh from a lens is any thing but creamy but more along the lines of an impressionist painter's brush strokes.

We have tried in the west to make what is more a matter of aesthetics an issue of technology.

[picasso]

Originally Posted by Wes

Not much that I can add to what Scott said. Just curious - does the 85mm f/1.4 really have that much better bokeh than the 70-200 f/2.8 or even the 28-70 f/2.8? I thought they both used the same number of blades (9) in the diaphragm and that this is one of the main contributors to the bokeh that they produce.

IMO the 85 1.8 is just as good with bokeh as the 1.4 and unless you need the exrta light you can save the money by getting the 1.8. I LOVE it. I was talked out of the 1.4 by the owner of the camera store I bought mine from and I have to say he is correct.

Although Scott, your 1.4 does a great job. I am on my laptop right now and don't have any to post as examples of my 1.8. I will try and post some when I get to the machine I do my PP on.

Paul