01-28-2020, 03:35 PM
(This post was last modified: 01-28-2020, 03:43 PM by Brightcolours.)
LOL. The MTF graphs were copy/pasted from Tamron? It would be logical as this is a Tamron lens. But they are in a Pentax format, not a Tamron format. And the Pentax format MTF curve at the tele end drops off a bit more than the Tamron published one, so what you are trying to say about it being copy/pasted is unclear to me.
So you claim that Pentax "probably" made changes to the design because Pentax wants to point out 1 more "special" glass type than Tamron does, but at the same time you don't want to claim that that will make the lens perform in any way differently?
You claim that "PLM" makes a Pentax combination focus faster/more accurately than with other lenses? Or what is it you claim? So.... This lens has no PLM. And so Pentax cameras will be as ho-hum with it as with other lenses, and slower than for instance a Canon camera with the current Tamron lens. So yeah, that may well be a reason they decided to add the focus limiter. Another reason can be that because it uses the same lens body and has the VC removed, they just added the focus limiter to give the 2nd button a function.
Pentax just calls fluorine coating SP for marketing reasons, not because it is anything different. There are coating related patents "assigned to" ALL lens makers.
That review shows the CA issue the Pentax has, and the Tamron lens does not have. So yeah, that review. Does better CA performance make the Tamron a worse lens?
And I can't think of much that makes a lens worse or better than other lenses than how it actually renders images. The Tamron renders quite a bit nicer, and according to you does that make the Tamron a worse lens? Both lenses are plenty sharp, only one is close to 200mm at MFD. I guess that must make that lens worse?
So you claim that Pentax "probably" made changes to the design because Pentax wants to point out 1 more "special" glass type than Tamron does, but at the same time you don't want to claim that that will make the lens perform in any way differently?
You claim that "PLM" makes a Pentax combination focus faster/more accurately than with other lenses? Or what is it you claim? So.... This lens has no PLM. And so Pentax cameras will be as ho-hum with it as with other lenses, and slower than for instance a Canon camera with the current Tamron lens. So yeah, that may well be a reason they decided to add the focus limiter. Another reason can be that because it uses the same lens body and has the VC removed, they just added the focus limiter to give the 2nd button a function.
Pentax just calls fluorine coating SP for marketing reasons, not because it is anything different. There are coating related patents "assigned to" ALL lens makers.
That review shows the CA issue the Pentax has, and the Tamron lens does not have. So yeah, that review. Does better CA performance make the Tamron a worse lens?
And I can't think of much that makes a lens worse or better than other lenses than how it actually renders images. The Tamron renders quite a bit nicer, and according to you does that make the Tamron a worse lens? Both lenses are plenty sharp, only one is close to 200mm at MFD. I guess that must make that lens worse?