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12-30-2009, 08:50 AM   #16
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QuoteOriginally posted by wallyb Quote
And this is why talking about this subject will lead nowhere... everyone has a different opinion on what makes a "3D effect"...
It's true.

Unfortunately, we are left with a majority factor. I'm reminded of a specific tour at an art museum with a group.
As we went through some of work, I couldn't help but take note of variations in opinions as some people express what they saw or got from the art work.

And what was most striking was that though I knew that artistic variations are a healthy part of diversity, I found myself struggling with the thought that others would either be missing the point or at a lesser state of appreciation that I myself felt for the art at the time of the viewing.

In case someone wanted to waist time reading a completely unrelated comment

12-30-2009, 09:00 AM   #17
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QuoteOriginally posted by asdf Quote
Here are my 2 cents: Zeiss lenses tend to be sharp and have good color contrast wide open. So there is a clear demarcation between what is in focus and what is not.

Also, since you didn't take two photos of the same composition with two different lenses at the same aperture setting, your post is nothing but the perpetuation of mythology.
Thanks for your valuable input.
12-30-2009, 09:09 AM   #18
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Every lens exhibits bokeh. The shape of the aperture determines the shape of the bokeh. Wide open, lens apertures are circular; lenses with many aperture blades retain the circular bokeh shape as the aperture is closed. Apertures with hard-edged shape such as pentagon, produce pentagon-shaped bokeh.

Every lens is capable of 3D plasticity when dof is shallow. Dof determines how much subject depth is in acceptable focus. A subject within the acceptable focus region, being in focus, is rendered in 3D focus-contrast with out-of-focus regions.

The question becomes for a given f/#, at what distance does dof cover the subject but leave the forground/background enough out-of-focus to produce 3D?

Bokeh is determined by lens-correction characteristics. Reflected light radiating from the subject strike the entire lens surface; the rays from the edge of the lens form a small circle of light around a center of light formed by light rays from more central parts of the lens surface. The evenness of the illumination within the small circle determines bokeh characteristics. An extreme example is doughnut- or ring-shaped bokeh from mirror lens where small circle has bright outer and center regions but dark in between. Lenses with less illumination variation within the small region produce harsh, busy bokeh. Lenses with even illumination within the small region produce buttery smooth bokeh. Lens correction also determines the diameter of the small region.
12-30-2009, 12:01 PM   #19
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QuoteOriginally posted by pingflood Quote
"3d effect" is hard to qualify, but I will say that in *my opinion* Zuiko glass on a large sensor tends to produce it with higher frequency than anything else I've used.
I'm following this discussion pretty well, but I have to ask...what's the "Sensor". And how does it effect me and my K2000 exactly?

12-30-2009, 12:26 PM   #20
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QuoteOriginally posted by Winnie Quote
I'm following this discussion pretty well, but I have to ask...what's the "Sensor". And how does it effect me and my K2000 exactly?
I think that was in reference to a Canon 5D FF sensor.
12-30-2009, 12:52 PM   #21
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QuoteOriginally posted by pingflood Quote
Thanks for your valuable input.
You are quite welcome.

BTW, talk of magic should probably remain in advertising pamphlets.
12-30-2009, 01:53 PM   #22
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QuoteOriginally posted by asdf Quote
You are quite welcome.

BTW, talk of magic should probably remain in advertising pamphlets.
Well, the "3d effect" is a pretty subjective thing, to the point where people don't agree on whether an image exhibits it or not. So, there's really no hard data to discuss; perhaps you'd prefer nobody bothered to reply. However, I've owned and shot with a significant amount of lenses over the past 15 years or so in formats from point and shoot sensor to 4x5, and what *many* agree on looks "3-d" has been the result of a particular subset of lenses more often than not. That leads me to believe that the optical characteristics of said lenses yield this *very subjective* look.

Nobody's trying to sell snake oil here, just sharing experiences.
12-30-2009, 09:00 PM   #23
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Of the lenses I have the 3-D effect is most evident using M42 Super-Takumar 85/1.9 and Pentacon 135/2.8 MC Auto. The Takumar is less sharp and less contrasty than the S-M-C version, with better-looking bokeh. The 85/1.9 Super Takumar is a "magical" lens, somewhat difficult to use well, but when used well results are "magical." Same with the Pentacon; it is more difficult to get good results, but those results can be "magical" compare to a sharper lens.

Color rendition is an important factor. Takumar color is better saturated than Zeiss, but Zeiss has more visible detail, texture, in colored regions, can lead to more 3-D effect. This is called micro-contrast. Takumars may have higher resolution than Zeiss, but with less microcontrast the higher resolution is not as effective at showing detail in similarly colored areas: texture contrast is lost, and the image is visibly less sharp.

Zeiss and Asahi followed different lens design philosphies. Asahi say "sharp lens" has color-correction, high resolution, and high contrast, while Zeiss say if high micro-contrast, color will be accurate with no extra effort, and image can be sharper than high-resolution lens.

Zeiss high micro-contrast lenses have produced many images many people said exhibit 3D.

Those focal lengths 85-135mm seem common for 3D lenses. At f/2.8 or faster, the dimension of the shallow depth of field permits easy separation of subjects from out-of-focus fore and background; background color contrasting with subject color increases 3D separation. Subject textural details increase 3D realism; focus precise.


Last edited by rhodopsin; 12-30-2009 at 09:39 PM. Reason: correction
12-30-2009, 09:10 PM   #24
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QuoteOriginally posted by wallyb Quote
And this is why talking about this subject will lead nowhere... everyone has a different opinion on what makes a "3D effect"...
I respectfully disagree. While this discussion may not lead to a quantifiable definition, it can point in a direction, and give readers of the thread something to think about the next time they go out shooting. In my book that's not nowhere, and discussions of this nature are infinitely more productive for me than brand wars or pixel peeping or product rumors....
12-30-2009, 10:30 PM   #25
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Thanks everybody for the interesting comments.
Regarding creating a 3d image using composition. I don't think this is the same as the 'oof' factor that some lens exhibit.

In my original post I mentioned Rice High's opinion regarding DA lenses not having tne oof factor. Do people agree with this. Looking at some of my 70mm photos I am not so sure he is correct in this.

Also it has been mentioned that much of the oof effect is down to the skill of the photographer. Again one or two of my 70mm (i like this lens) have some oof factor but then this probably has more to do with luck than skill.

I also mentioned earlier that I couldn't afford new lenses known to exhibit this quality and would try to find secondhand k or m lenses. How stupid I was to think this. These lenses are rarely parted with and if they are they are just as expensive as new lenses. I did see a super tak 85mm f1.9 which was within my budget. May get that.
12-31-2009, 07:08 AM   #26
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QuoteOriginally posted by johnmflores Quote
I respectfully disagree. While this discussion may not lead to a quantifiable definition, it can point in a direction, and give readers of the thread something to think about the next time they go out shooting. In my book that's not nowhere, and discussions of this nature are infinitely more productive for me than brand wars or pixel peeping or product rumors....
But it won't point in "a" direction at all. It will point in multiple directions. That's the point I'm trying to make. The best that can be accomplished in a subject like this is that the OP reads someone's statement that mostly agrees with what they already believe, and reinforces it, and has that opinion perpetuated whether it's scientifically accurate or not.
12-31-2009, 09:25 AM   #27
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QuoteOriginally posted by wallyb Quote
But it won't point in "a" direction at all. It will point in multiple directions. That's the point I'm trying to make. The best that can be accomplished in a subject like this is that the OP reads someone's statement that mostly agrees with what they already believe, and reinforces it, and has that opinion perpetuated whether it's scientifically accurate or not.
It's no more or less accurate than discussing whether a given out of focus blur (bokeh) is attractive or not. Since photography is an art form more than anything, it can be quite interesting to see what people think makes an image; what is attractive; and yes, what is "3D". There have been some 3D threads on FM that were interesting, and if you care to read them you'll see that a substantial number of images come from a not statistically insignificant set of lenses. It's something that people find interesting to discuss, and if you don't enjoy it, then there's no need for you to participate.
12-31-2009, 09:35 AM   #28
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QuoteOriginally posted by pingflood Quote
It's no more or less accurate than discussing whether a given out of focus blur (bokeh) is attractive or not. Since photography is an art form more than anything, it can be quite interesting to see what people think makes an image; what is attractive; and yes, what is "3D". There have been some 3D threads on FM that were interesting, and if you care to read them you'll see that a substantial number of images come from a not statistically insignificant set of lenses. It's something that people find interesting to discuss, and if you don't enjoy it, then there's no need for you to participate.
You're right, thank you for agreeing with me. A lot of times, people don't agree on what the "best" bokeh is. But usually it's not "best" (or if it's attractive or not, same difference), it's smoothest or most interesting that is compared. Those are at least a *bit* more quantifiable than "best" and "worst" or "what is the 3D effect". And don't play the "if you don't like it, get out" card, that's silly. My opinion that this discussion is invalid is just as valid as the actual discussion, and if you don't like it you can get out
01-01-2010, 08:33 AM   #29
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QuoteOriginally posted by wallyb Quote
You're right, thank you for agreeing with me. A lot of times, people don't agree on what the "best" bokeh is. But usually it's not "best" (or if it's attractive or not, same difference), it's smoothest or most interesting that is compared. Those are at least a *bit* more quantifiable than "best" and "worst" or "what is the 3D effect". And don't play the "if you don't like it, get out" card, that's silly. My opinion that this discussion is invalid is just as valid as the actual discussion, and if you don't like it you can get out
I am confused too about the difference between 3D effect & bokeh
Here is an image taken by my daughter Sigma 16-50mm/K100D Super



She did that with no flash indoor with very little DoF







I tried that lens in DC area which is pretty much very close in character with my Sigma 24-60mm

Daniel
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