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09-23-2010, 01:27 PM   #46
m8o
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A bit OT, but say, how did I miss this?!

Sigma 85mm f/1.4 EX DG HSM Lens For Pentax Digital SLR 320109 -

B&H says "arrives in November".

09-23-2010, 01:57 PM   #47
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QuoteOriginally posted by m8o Quote
I'll give you that. But outside a controlled environment, I think it's worth saying that's also ignoring that few if any 300/2.8 lenses perform near optimally when wide open. Don't get me wrong. These Sigmas do quite well there. Hey, I use it at or near wide open plenty; I've taken hundreds that way (at or near wide open) and still have many more of photos I need to go thru and PP that make excellent use of isolation provided by a wide aperture. But that still doesn't change the fact that I'd have a sharper photo w/far less lateral CA had I stopped it down; dare I say the latter being something long Sigmas appear to be afflicted with.

Take this shot at f/2.8 for example of what I cite; there's a lot of red/pink blue/green in the branches in the OOF area, a.k.a. lateral CA. This being my early days of ownership of the lens before I knew its limitations, I specifically used a wide aperture so as to blur the other branches in the photo. But that only served to amplify the lateral CA that I often see with a gray background:
That is likely because of the subject to camera distance, plus the fact that you were in a backlit situation.
I get tons of pics like this and there isn't much you can do about it. The laws of physics apply.


[I realized it may sound like I'm diss'ing the Sigma 300/2.8, so let me add...]

Versus... this photo of mine also taken at f/2.8. The scene, specifically the nature of the back-ground, certainly lends itself better to using f/2.8:
I gather this one was taken a bit closer, right? And, the light seemed to be in your favour.
Nonetheless, this last pic shows how well one can isolate the subject, using a wide aperture, such as you did.

I frequently use my DA*300/4 wide open but that doesn't even come close to what you can get, for OOF effects, with an f2.8 lens.
My Tamron 70-200/2.8 does what it's supposed to at the widest aperture but I don't have the reach ... too bad!

Thanks for the post.

JP
09-23-2010, 01:59 PM   #48
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Someone has a great long >300mm Pentax lens (f2.8) for sale?

JP
09-23-2010, 02:56 PM   #49
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QuoteOriginally posted by m8o Quote
A bit OT, but say, how did I miss this?!

Sigma 85mm f/1.4 EX DG HSM Lens For Pentax Digital SLR 320109 -

B&H says "arrives in November".
There were a couple of threads on it a while back.

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