Bokeh questions...

[Stacey]

Steep in the learning curve here, I notice that different shots at similar focal lengths produce very different background results. At first I wondered if it was the lens. I have some gorgeous creamy bokeh in some shots from my cheapo Tamron 70-300 zoom, where the subject is in bright light or sunshine.

I just forked out my entire "secret stash" of "coffee money" for a 24-105L, and saw some strange stuff. I'm trying to figure out what the deal is, if it's just lighting, or???

First:



Bright daylight, sun coming in at about 130deg over my right shoulder, breezy but not dusty due to rain the previous night. LOTS of weeds, so busy in the near background. These are not "art" shots, just getting a feel for what I can do with the new lens.


Second:



Same busy bokeh, notice the "fairy orbs" in the photo. These have shown up in several shots, but only in that very bright daylight. Again, the angle of sunlight is coming over my right shoulder.

Last:



Same lens, shade, note the background is very smooth, so it doesn't appear to be a lens issue. Unless there are potential refraction issues that only happen in bright light. Any ideas on what I can do to improve the first two? Does using a lens hood change the appearance significantly? Or is this how it's supposed to look and I should get out my sharpie and write n00b on my forehead?

[guitarbug]

Its the depth of field controled through you're apeture settings and distance from subject. The larger the apeture and the closer you are the more background blur you get (Bokeh) I would like to know the way to pronounce bokeh?

[AndrewCCM]

Focal length and subject to background distance are also factors.

Chris - just like a group of flowers... Bouquet (with a long O, not as in Halloween Boo) lol

[Arlington Camera]

Here is a good source. http://www.bobatkins.com/photography...cal/bokeh.html

[Stacey]

I get some of that, but how much does light play in bokeh, the last pic was taken at the same focal length as the first two, and approximately same distance to subject, at f5.6, the two blue flowers were f4.0. So theoretically, shouldn't the bokeh be smoother on the blue flower backgrounds than on the rose?

So does the lighting have a significant impact on background blur of still subjects? Faster shutter speed? There's a piece I'm missing.

Arlington, that's a good reference, unfortunately I'd have to read it 20 times before I understood. I'm a little n00bie beginner. Baby steps please.

[iCe]

My guess, and it's only a guess, is that the amount of light on the subject and background (respectively) plays into it. Something like the way shutter speed, aperature, and flash "dance" together...

[Donner]

If i'm not mistaken, the difference you are seeing has a lot to do with the distance from the subject to whatever is BEHIND the flower. It looks like the blue flowers have something closer to them than the rose does. The amount of light hitting whatever is behind the flower also plays into the bokeh. It appears that whatever is behind your rose is getting less light, while whatever is behind the first photo appears to be catching the light more.

but those are just my two ideas.

[Stacey]

You're right about the set-up, Donner and iCe, and that makes good sense. Maybe the background on the first two are simply not far enough away to get that nice creamy blurrr... and the rose background was in shadow. It appears to be the same with other pics too: close, well-lit background just doesn't blur the way a shadowed distant one does. doh. hehe.

I'm still trying to figure out the little orbs. That's a strange one. I've only ever seen those with flash photography.

[Arlington Camera]

The idea is that the effect has multi variables F-stops, focal length, aperture shape. I prefer the look of number 2. Good luck

[guitarbug]

Originally Posted by AndrewCCM

Focal length and subject to background distance are also factors.

Chris - just like a group of flowers... Bouquet (with a long O, not as in Halloween Boo) lol

Thanks Androow!, lol...

[billbunton]

Remember that the word bokeh refers to the quality of the out of focus highlights. It's not the amount of depth of field (how much the background is blurred), it's a particular reference to the quality.

The 24-105/4 IS is not known for particularly nice bokeh. Not saying it's bad, but more just run of the mill.

As for the photos posted above, the difference doesn't seem to be the bokeh, but rather how out of focus the background is (the DOF and subject/background separation). It appears the third one has the most separation between the subject and background, by a fair amount. So even though it was shot at a smaller aperture (f/5.6 vs. f/4), with more separation the background is farther out of focus than the other two.

[iCe]

Originally Posted by billbunton

Remember that the word bokeh refers to the quality of the out of focus highlights. It's not the amount of depth of field (how much the background is blurred), it's a particular reference to the quality.

The 24-105/4 IS is not known for particularly nice bokeh. Not saying it's bad, but more just run of the mill.

As for the photos posted above, the difference doesn't seem to be the bokeh, but rather how out of focus the background is (the DOF and subject/background separation). It appears the third one has the most separation between the subject and background, by a fair amount. So even though it was shot at a smaller aperture (f/5.6 vs. f/4), with more separation the background is farther out of focus than the other two.

There you go making sense again. A good example of nice bokeh would be something shot with the 85mm f1.2 at f1.2 (generally speaking). The background is smooth and it takes on a pastel look. The 600 f4 shot wide open has nice bokeh too. I'm sure that here are many other lenses that have good bokeh but the two I listed above are the lenses that I've used and been happy with.

[johnastovall]

Very good article on what Bokeh is by Mike Johnston.

Excellent examples of what to look for...