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03-24-2017, 08:55 AM   #16
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Y would be my choice for being a little bit sharper and also higher contrast. If I have to guess, maybe it's the Pentax?

X and Y are close enough that unless I really favoured 70mm over 50mm I'd probably go with the Pentax based on it's tiny size. Both are probably better than I am, and unlikely to disappoint so I volunteer to take the loser off your hands

03-24-2017, 09:13 AM   #17
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I find that sigma lenses (the older models) tend to look like they have had extra clarity added via PP.
Thus I am voting Sigma = Y
What I find interesting is that people look at the pictures, trying to discern which picture they find most appealing. Then take that as a reference as to what lens must be Pentax.
03-24-2017, 09:15 AM   #18
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Thanks for the comparison. Y is obviously the Sigma and illustrates well why I have a strong desire to own one.


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03-24-2017, 09:25 AM   #19
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QuoteOriginally posted by BigMackCam Quote
I like the Y lens best, but a large part of that is the contrast. Both look good
Yep, I agree

03-24-2017, 09:28 AM   #20
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I prefer Y, and to hazard a guess I'd say it's either the Sigma or the Pentax
03-24-2017, 09:31 AM   #21
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I like Y due, as others have noticed, to the contrast. Both are admirably crisp, so it's probably more a matter of focal length and lens size to choose between them. I'm thinking Y may be the Pentax, but that's just a guess...
03-24-2017, 09:43 AM   #22
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QuoteOriginally posted by quh86 Quote
What I find interesting is that people look at the pictures, trying to discern which picture they find most appealing. Then take that as a reference as to what lens must be Pentax.
My guess was not based on much, I am probably 'cheering' for the lens I'd actually held in my hands for a few minutes and not the one I've never seen in person before. I wouldn't in any way be surprised if the sigma is Y, I really have no reasonable basis for comparison. Most tests like this just support my belief that no one makes a poor dedicated macro lens, and focal length + handling + price are safe things to concentrate on.

03-24-2017, 09:56 AM   #23
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Prefer Y samples. My guess would be Y=Pentax based on more consistent exposure over aperture range and less blue/purple hue than the X sample which I think i characteristic of Sigma.
03-24-2017, 09:57 AM   #24
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QuoteOriginally posted by stevebrot Quote
Y is obviously the Sigma
Pretty confident, Steve
03-24-2017, 10:21 AM   #25
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QuoteOriginally posted by BigMackCam Quote
Pretty confident, Steve
Yep...based on the DOF differences, I am. For some reason, the OP gave us crops of the slant portion of the target rather than the flat portion. Assuming that both lenses were properly positioned and in focus, Y has less DOF at f/2.8 than X. If both lenses were not properly positioned and in focus there is no sense commenting further.*


Steve

* Ideally, comparison shots should be done at the same magnification. These were not.

Last edited by stevebrot; 03-24-2017 at 10:28 AM.
03-24-2017, 10:27 AM   #26
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QuoteOriginally posted by KevinR Quote
less blue/purple hue than the X sample which I think i characteristic of Sigma.
That is interesting. I have never shot with the 70/2.8 EX DG, but own the same generation 50/2.8 EX DG. My lens has a distinctly warm rendering, which by conventional wisdom of the time was expected for Sigma.


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03-24-2017, 11:05 AM   #27
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QuoteOriginally posted by Stavri Quote
I would disregard that in my analysis...
Why? Am I wrong?
03-24-2017, 01:46 PM   #28
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QuoteOriginally posted by FozzFoster Quote
Why? Am I wrong?
I didn't say that............then again...
03-24-2017, 02:57 PM   #29
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The sigma has a t stop of 3.2 vs 3.0 for the pentax. At f2.8 the y lens looks much darker so between that and the fov i go with y as sigma. I love this lens on apsc. Don't own the pentax but dont use my 50's anyway preferring my 40xs. On full frame that would probably change.
03-24-2017, 05:20 PM - 1 Like   #30
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Reveal...

Thanks to all the members for their contribution....

Lens Y = Pentax D-FA 50mm f2.8 macro
Lens X = Sigma Ex Dg 70mm F2.8 macro

I put the 50mm f2.8 macro on the marketplace when I got the Sigma, now I'm having second thoughts parting with it...(jewel of a lens)
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Last edited by Stavri; 03-24-2017 at 05:36 PM.
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