how to get bokeh?

tomd wrote in post #9129192
4g63: any photos to post here of bokeh?

That's like asking for photos of sharpness.

xarqi wrote in post #9126645
Works for me.

well, if you think that's good bokeh, all power to you!

personally, i think the quality of the blur there is quite distracting and ugly

sol95 wrote in post #9131563
well, if you think that's good bokeh, all power to you!

Thanks!

Little_W , I really like your photo , nicely done !

4g63 wrote in post #9126391
hi guys, newb question here. i've already tried the search engine but couldn't find any. i just recently bought an XSI and i am trying to learn the basics of photography. my question is, is it possible to get good bokeh with the 18-55mm IS lens that came with it? i use it for urban type photos and i'm trying to learn manual on everything. i just want to get a blurred background on my photos. any advice on the best settings? i'm in Iraq by the way, so light is pretty harsh during daytime. thanks in advance.

zoom your lens to 55mm @ f5.6. go as close as you can to your subject while keeping framing in mind, try to increase distance between your subject and your background. by decreasing the distance between the camera and the subject and increasing the distance between your subject and background, the greater the bokeh. try it out and post your examples.

sol95 wrote in post #9126486
in the strictest sense, bokeh isn't just simply the blur, it's the QUALITY of the blur. As such, the 18-55 IS kit lens won't give you "good bokeh". It's possible to get it to blur the background, but the quality of that blur won't be as creamy smooth as you would get from higher end lenses.

^^^^^

The 18-55 will simply have whatever bokeh in the out of focus areas that was endowed by its design, good or bad or indifferent. If you want GOOD bokeh, you have to have the right lens for that.

If you want great bokeh, get a EF 135mm 1:2 L Prime. You will have the best bokeh around.

4g63 wrote in post #9126438
thanks guys, i'll give it a try. oh by the way, the lowest F stop i can get on my lens is 3.5 so i hope that's enough to get the blurred background.

You don't need to run out and buy a new lens. Try to experiment with what you have now. Your lens is only 3.5 at the wide end. You'll have better success zooming out to 55mm and using 5.6

Try to frame the subject so that you are in close and have objects in the background placed quite far from your subject. Here is a quick example I just shot for you that shows what 55mm and f/5.6 on a crop camera can look like.

Best Thoughts To You

Here's wishing you a safe tour and a happy return from a retired Navy Combat Cameraman of a few wars ago!

Bokeh is a Japanese term pertaining to the quality of the out of focus areas of the image and is controlled by the diaphragm of the lens. As an example, the 50mm f/1.8 IS lens (Nifty-Fifty) uses a five bladed diaphragm while the 50mm f/1.4 uses an eight bladed diaphragm. The five bladed diaphragm does not make a smooth circle while the eight blades of the f/1.4 diaphragm makes a smoother circle. The smoother or less jagged the aperture, the smoother and more creamy your bokeh will be.

Now depth of field, although related to Bokeh, is a different animal. Depth of field is the area between the nearest point of acceptable focus and the farthest point of acceptable focus. Depth of field is determined by the following parameters:

1. focal length

2. f/stop at which you are shooting (as opposed to the maximum f/stop of your lens)

3. distance focused on

4. the format size you are using

Play with this depth of field calculator by entering different parameters and you can get a feeling for depth of field.

http://www.dofmaster.c​om/dofjs.html

You need to remember, however, that your lens has a variable aperture and that the aperture becomes smaller as you increase the focal length by zooming. So at your maximum focal length; your widest f/stop will be f/5.6.

If you want a mid-range zoom that will provide a more narrow depth of field (which is what I think you are aiming for) you would be better off with a lens such as the 17-50mm f/2.8 Tamron or even a prime 50mm f/1.8 Mk-I Nifty-Fifty.

If you are shooting with your 18-55mm lens using fifty millimeters and shooting wide open focused at 10 feet, your depth of field would be a total of 2.62 feet or 1.14 feet in front and 1.48 feet behind the distance focused on.

Using another 50mm lens focused on 10 feet which can open up to f/2.8; you cut your depth of field down to: a total of 1.29 feet or half that which you get at f/5.6.

Now for your other problem: the harsh light of Iraq. It will depend greatly on what types of subjects and in what types of venues you are shooting. Fill flash will really assist in cutting down the dynamic range of your image by filling in the shadows. However, if you are shooting in combat related situations, the use of fill flash would be ridiculous and would put yourself in mortal danger.

Apropos of nothing, see if you can get a pair of OPTECH Rain Sleeves. I use these great plastic protectors to guard my cameras against not only precipitation but, against blowing sand and grit when I am shooting in the desert Southwest. They are dirt cheap and light enough to be mailed by first class mail.

Again, here's wishing you the best and I hope you will have a happy return to CONUS soon.

msowsun wrote in post #9133574
You don't need to run out and buy a new lens. Try to experiment with what you have now. Your lens is only 3.5 at the wide end. You'll have better success zooming out to 55mm and using 5.6

Try to frame the subject so that you are in close and have objects in the background placed quite far from your subject. Here is a quick example I just shot for you that shows what 55mm and f/5.6 on a crop camera can look like.

Mike is right about the longer FL having benefit to increased background blur, even with 18-55mm smaller max aperture at the longer FL. While DOF calculators will show 55mm f/5.6 has 0.5" more DOF, the background out of focus items are more out of focus. With the difference of 55 vs 18mm, the difference in blur is not a huge one, though...

I suggest trying various macro lenses. They're great for getting bokeh, from my point of view. I prefer Tamron lenses for that:

To the OP - I think you should first try to understand the concept of depth of field (DOF) and how it works with focal length, lens aperture and distance, as well as how the field of view (FOV) of a lens would affect what or what would not show up on the out-of-focus (OOF) background.

By distance, I meant the distance from the camera to subject, as well as distance from the subject to foreground or background objects that you want to blur. Try varying the distance with the below DOF calculator and you'll see how things would change.

Once you've understood the concept, you'll know how to get bokeh that you like a lot easier (and bokeh is subjective).

There are many places online and in books that describe the above. Here are just a few:

http://www.mediachance​.com/dvdlab/dof/index.​htm
http://www.cambridgein​colour.com/tutorials/d​epth-of-field.htm
http://www.dofmaster.c​om/dofjs.html (also posted above by RPCrowe)

'Bokeh' is not the 'amount of background blur' but the quality of the out-of-focus circles of confusion. And it is not merely about the shape, which is defined by the count of the apeture blades.

It is also the distribution of the density within that circle. For a perfect point, a uniformly dense disc of light is reasonable bokeh, a donut like denser outer area is poor bokeh. 'Mediocre bokeh' is a relatively uniform disc. 'Good bokeh' = a denser center in the circle, surrounded by lower density edge area which gets less dense the farther goes from the center of the circle.

Wilt wrote in post #9136059
'Bokeh' is not the 'amount of background blur' but the quality of the out-of-focus circles of confusion.

A circle of confusion is something completely different. I think you are talking about OOF specular highlights in the shape of diaphragms.

Furthermore, bokeh is not only about the shape, form or rendering of these diaphragm shapes, but also of the rendition of the OOF background, and the OOF foreground for that matter.

The shape of those highlights is caused by the shape of the aperture, which is influenced by the number and shape of the aperture blades (f.e., rounded, or pentagonal as with the 50 F/1.8 II when stopped down), the shape of the lens barrel and any obstructions in or surrounding the lens barrel (think 85L, with the cut-outs), and the position in the image as related to the AoV and lens barrel diameter (cat's eye shapes).

This conforms to what many people consider to be true for the rendition of the diaphragm shaped specular highlights. As mentioned, this is only part of "bokeh", even though it is often easiest to estimate how bokeh looks based on these specular reflections.

Finally, bokeh is a very personal thing. What one person finds good bokeh, another doesn't.

Kind regards, Wim