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04-27-2011, 08:41 PM   #31
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QuoteOriginally posted by jsherman999 Quote
It's very subjective, and like pixies themselves, sometimes goes away when you look too closely - or when you try to show someone else.
Do you think the Sigma 85/1.4 is kissed by pixies before it leaves the factory?

You certainly liked the OOF transitions in this shot. I'm not a fan of the colours and contrast of this image (neither of which are the lens' fault) but the rendering surely is very nice.

04-27-2011, 09:20 PM   #32
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QuoteOriginally posted by Class A Quote
It is not an automatic effect in that the scene has to have certain quality to allow it to be seen but if the scene has the potential, some lenses produce "magical" results and others don't.

the highlighted part is exactly the reason why I can't comment on either lenses when it comes to pixies. they have certain attributes where they would excel on certain scenes. it's too bad that we don't have much samples yet on the Sigma (Pentax mount) which would give us a clearer perspective of it's own pixie effect.
04-27-2011, 10:53 PM   #33
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QuoteOriginally posted by jsherman999 Quote
Exceptional bokeh.
QuoteQuote:
Tamron 70-200 f/2.8
LOL what? Tamron? Bokeh?
May be you meant "exceptionally nervous bokeh"?
04-28-2011, 07:10 AM   #34
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QuoteOriginally posted by Class A Quote
"Pentax snobbery" certainly exists but I don't think that "pixie dust" is a term that Pentax snobs invented. To me "pixie dust" describes a certain "je ne sais quoi" about a lens' rendering. It is the opposite of "clinical" and adds an ever so slight touch of dreaminess, lending the subject a 3D appeal, and letting it float above the background. It is not an automatic effect in that the scene has to have certain quality to allow it to be seen but if the scene has the potential, some lenses produce "magical" results and others don't.
An excellent description!

04-28-2011, 07:28 AM   #35
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QuoteOriginally posted by Class A Quote
Sure. However, the truly great lenses go beyond "smooth bokeh" and "tack sharp"; they have a certain rendering that is hard to describe but definitely adds something to a good image.
I know what you mean, so in that sense, there is a small amount of pixie dust in every lens, it is just a lot harder to find in some, because each lens is, under capable hands is able to produce images in this way
QuoteQuote:


"Pentax snobbery" certainly exists
no, really!
QuoteQuote:
but I don't think that "pixie dust" is a term that Pentax snobs invented. To me "pixie dust" describes a certain "je ne sais quoi" about a lens' rendering. It is the opposite of "clinical" and adds an ever so slight touch of dreaminess, lending the subject a 3D appeal, and letting it float above the background. It is not an automatic effect in that the scene has to have certain quality to allow it to be seen but if the scene has the potential, some lenses produce "magical" results and others don't.
If you consider this last point as a discussion point, I think the best way to describe it is related to, but not the same as the bokeh. More specifically it is in the transitional region between in focus and out of focus. I have noticed this on my screw mount 135's, where I compared an S-M-C tak F3.5 and a tele lentar preset F2.8. Although at each aperture, both lenses produce the same depth of field, the preset lens had an undescribably different level of separation between subject and background. I attribute this, perhaps wrongly, to the difference in lens design and placement of the iris towards the front in presets and towards the rear in auto aperture lenses.

I too have also a specific comment about the highlighted last phrase, I am not so sure this is any lens, or the photographer who knows how to exploit the scene.
04-28-2011, 11:49 AM   #36
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QuoteOriginally posted by Class A Quote
Do you think the Sigma 85/1.4 is kissed by pixies before it leaves the factory?

You certainly liked the OOF transitions in this shot. I'm not a fan of the colours and contrast of this image (neither of which are the lens' fault) but the rendering surely is very nice.
I suspect the famous Sigma reverse-engineers may have reverse-engineered the pixies, or found a way to forcefully conjure them for their own purposes, because that Sigma 85 looks suspiciously dusted.
04-28-2011, 12:11 PM   #37
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QuoteOriginally posted by Emacs Quote
LOL what? Tamron? Bokeh?
May be you meant "exceptionally nervous bokeh"?
No, I don't. The Tamron 70-200 2.8 has very pleasing bokeh.

These are very 'busy' backgrounds which are handled nicely, IMO:
.











.



A longer telephoto (zoom or not) with good bokeh can make for a fantastic portrait choice outdoors. Here are some easier backgrounds, Tamron dissolves them nicely:




.





Last edited by jsherman999; 04-28-2011 at 12:25 PM.
04-28-2011, 12:22 PM   #38
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Looks good to me. Dang, I already had "mad respect" for that lens, this just deepens it. I gotta learn to quit falling in love.

05-03-2011, 03:28 AM   #39
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out of those two I would pick the FA77 because if it's built in lens hood and compact size, however I prefer to use a SMCP-K 50mm f/1.2 for portraiture.
05-03-2011, 08:44 AM   #40
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QuoteOriginally posted by Lowell Goudge Quote
I know what you mean, so in that sense, there is a small amount of pixie dust in every lens, it is just a lot harder to find in some, because each lens is, under capable hands is able to produce images in this way no, really! If you consider this last point as a discussion point, I think the best way to describe it is related to, but not the same as the bokeh. More specifically it is in the transitional region between in focus and out of focus. I have noticed this on my screw mount 135's, where I compared an S-M-C tak F3.5 and a tele lentar preset F2.8. Although at each aperture, both lenses produce the same depth of field, the preset lens had an undescribably different level of separation between subject and background. I attribute this, perhaps wrongly, to the difference in lens design and placement of the iris towards the front in presets and towards the rear in auto aperture lenses.
I do not believe in pixies or in magical dust, but I do believe that different lenses render differently. Much of this discussion has centered on the transition from sharp to out of focus areas and on the quality of bokeh. These factors are important, but they do not tell the whole story. At least as important is what some call microcontrast, which really refers to the transmission by the lens of the most subtle variations in tone and color. This, more than anything else, is what creates a lifelike quality of three dimensionality: Solid objects appear solid and have an aura of space around them.

All of the FA Limiteds excel in this aspect of lens performance, which I regard as more valuable than pure sharpness. (And realistically, both of the lenses under discussion have ample sharpness.) I have no idea how the Sigma 85/1.4 stacks up in terms of producing lifelike, three dimensional images. It may be fine, but the FA77 Limited sets the bar very high.

Rob

Last edited by robgo2; 05-03-2011 at 08:51 AM.
05-03-2011, 08:53 AM   #41
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QuoteOriginally posted by robgo2 Quote
I do not believe in pixies or in magical dust, but I do believe that different lenses render differently. Much of this discussion has centered on the transition from sharp to out of focus areas and on the quality of bokeh. These factors are important, but they do not tell the whole story. At least as important is what some call microcontrast, which really refers to the transmission by the lens of the most subtle variations in tone and color. This, more than anything else, is what creates a lifelike quality of three dimensionality: Solid objects appear solid and have an aura of space around them.

All of the FA Limiteds excel in this aspect of lens performance, which I regard as more valuable than pure sharpness and resolution. (And realistically, both of the lenses under discussion have ample sharpness.) I have no idea how the Sigma 85/1.4 stacks up in terms of producing lifelike, three dimensional images. It may be fine, but the FA77 Limited sets the bar very high.

Rob

Well said and I agree whole-heartedly! This is why I have decided that having the 77 means not needing the 85. I know there may be things that the 85 does better, but the 77 is so good at what I use it for, that buying a similar lens is madness. After all, one of the big perks of being a Pentaxian is that we get to use lenses like the 77...and the 31... and the 43...and...(insert your favorites here).
05-03-2011, 08:53 AM   #42
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QuoteOriginally posted by robgo2 Quote
I do not believe in pixies or in magical dust, but I do believe that different lenses render differently. Much of this discussion has centered on the transition from sharp to out of focus areas and on the quality of bokeh. These factors are important, but they do not tell the whole story. At least as important is what some call microcontrast, which really refers to the transmission by the lens of the most subtle variations in tone and color. This, more than anything else, is what creates a lifelike quality of three dimensionality: Solid objects appear solid and have an aura of space around them.

All of the FA Limiteds excel in this aspect of lens performance, which I regard as more valuable than pure sharpness. (And realistically, both of the lenses under discussion have ample sharpness.) I have no idea how the Sigma 85/1.4 stacks up in terms of producing lifelike, three dimensional images. It may be fine, but the FA77 Limited sets the bar very high.

Rob

I am not so sure about "micro contrast" as all lenses are passive filters, where contrast is generally the result of good control of internal reflections from stray (out of field of view) light. Hoods improve contrast, no doubt, as do coatings which do not "glow" with stray light, etc..but you can adjust contrast within the resolution of the sensor to render colors, so I can't believe that fine increments of contrast are lens dependant. to that extent. However I could be wrong.

I do agree with the observation of 3 dimensional aspect of some photos, but again, I am not sure if this is lens, or technique.
05-03-2011, 09:40 AM   #43
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QuoteOriginally posted by Lowell Goudge Quote
I am not so sure about "micro contrast" as all lenses are passive filters, where contrast is generally the result of good control of internal reflections from stray (out of field of view) light. Hoods improve contrast, no doubt, as do coatings which do not "glow" with stray light, etc..but you can adjust contrast within the resolution of the sensor to render colors, so I can't believe that fine increments of contrast are lens dependant. to that extent. However I could be wrong.

I do agree with the observation of 3 dimensional aspect of some photos, but again, I am not sure if this is lens, or technique.
I think that microcontrast is a good term to describe the ability of a lens to render subtle transitions in tone and color. I am not an expert in optics, and I do not know if there is a proper technical term for this phenomenon; nor can I explain what technical factors are responsible for producing it. But there is no doubt that some lenses render tonal transitions better than others and that this is one of the great strengths of the FA Limited series.

Rob
05-03-2011, 11:34 AM   #44
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I'm one of those that wanted the FA77 some years ago and for some reason I just lost my interest on it. I would think one of the main reason is my preference of still having an 85mm and sensor size has nothing to do with it. the built of the 77mm has always been a great asset of the lens. for someone who is on the budget, a $650 77mm would be a great deal and a must buy. I could afford the 77mm right now but can't seem to pull the trigger especially there is now another lens option and other purchase options as well. seems like this is a great year, as long as we have the budget to spend on things and that there are no delays on new items being available in the market.
05-03-2011, 09:55 PM   #45
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QuoteOriginally posted by Lowell Goudge Quote
I am not so sure about "micro contrast" as all lenses are passive filters, where contrast is generally the result of good control of internal reflections from stray (out of field of view) light.
A lens designer can choose to go for high contrast or high resolution. Both is not possible (-> Heisenberg uncertainty principle). The point spread function of a lens either has a small kernel but is spread out (high resolution) or a bigger kernel with less spread overall (high contrast).

The look (e.g., the so-called "Leica look") of a lens is partially obtained by the above engineering decision. Leica traditionally opts for contrast whereas Zeiss typically goes for resolution. Such lens characteristics can be measured and manifests themselves in different MTF scores. A high resolution lens will perform better in MTF-10 comparisons, a high contrast lens will perform better in MTF-50 comparisons.
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