[jimr-pdx]

I was happy with my copy to 100mm or so, but now I'm happier with a used 17-70 Sigma. That near-silent whoosh to focus sure is nice though!

[hawk1500]

they could've gotten a bad copy of the lens too...I've seen revisions in their reviews before.

[Pål Jensen]

Glad to see you're still around - everybody's favorite Pentax curmudgeon! Hope you're healthy, happy and well!

Got a 645 D yet?

Cheers,
Cameron

I may be healthy, happy and well, but I'm not rich
No 645D for me.....

[GeneV]

This was the part that bothered me:
Apparently, the poor border and corner resolution at shorter FLs, and the nearly non-existent border and corner resolution the longer FLs is a design feature.
I hope this isn't a trend. It used to be that the single biggest benefit to using a Pentax camera was that you could attach Pentax lenses to it. If this is their new "factory spec" for resolution they have serious problems ahead.

My question when I read that was, what does that mean "the tested lens is within factory specifications?" Does it mean that Pentax tested the lens and got similar results or just that the local Pentax people didn't notice anything physically wrong with the lens?

[Cannikin]

My biggest complaint about this lens is the high level of CA on the sides. As for the resolution, well...

Here's two 100% crops taken from the extreme bottom right corner of some test shots I did. First one at 100mm, second at 135mm. Both at f/8. Certainly not great, but is it really as bad as they're implying? Decide for yourself.

100mm, f/8:


135mm, f/8:

[Parallax]

My question when I read that was, what does that mean "the tested lens is within factory specifications?" Does it mean that Pentax tested the lens and got similar results or just that the local Pentax people didn't notice anything physically wrong with the lens?

Good question. I don't whether minimum resolution requirements are specified or not.

[Cannikin]

Another 100% crop, this time at 100mm, f/5.6, far left border (ignore the tree branch, it's out of focus), which according to Photozone should be absolutely abysmal:



Again, not fantastic, but with a bit of sharpening (not applied here), I find it rather acceptable.

---

Last edited by Cannikin; 04-16-2011 at 03:23 PM.

[GeneV]

Good question. I don't whether minimum resolution requirements are specified or not.

But perhaps it was the right size, weight, focal length, aperture.....

[rawr]

Here's two 100% crops taken from the extreme bottom right corner of some test shots I did.

Interesting. It would be good to see an overview of your test shot image (ie a small version of the whole picture) just to get an idea of where those crops are coming from.

DXO also have that lens on their list for addition to DXO Optics Pro as a lens module in May 2011, so that may provide some comfort to users of this lens who also use DXO. I wonder if DXO's testing of this lens showed the same issues.

[Cannikin]

Interesting. It would be good to see an overview of your test shot image (ie a small version of the whole picture) just to get an idea of where those crops are coming from.

Sure thing. Red box marks where the crops came from.

100mm f/5.6:


100mm, f/8:


135mm, f/8:

[Cambo]

I may be healthy, happy and well, but I'm not rich
No 645D for me.....

got to try one briefly in a store...MAGNIFICENT machine! Big, BIG BIG...WAY bigger than the film 645. Beautifully damped mirror mechanism, the shutter sounded wonderful, gorgeous thing all in all...$5,000.00 for a 25mm lens...YIKES! Don't know if you saw this, but there a review with GIGANTIC tiffs available;

Pentax 645D review

Cheers,
Cameron

[Cambo]

Sure thing. Red box marks where the crops came from.

100mm f/5.6:


100mm, f/8:


135mm, f/8:

one little correction patch in photoshop or aperture will fix that up.

Photozone's off my Christmas card list...

Cheers,
Cameron

[GeneV]

Like the ones others posted months ago, Cannikin's shots are not consistent with a lousy lens. I have to wonder what was going on.

[Cannikin]

Took the same shots as above and applied 30 seconds worth of post-processing in Lightroom (CA correction, a bit of sharpening):

100mm, f/5.6 (again, ignore the tree branch, it's out of the plane of focus):


100mm, f/8:


135mm, f/8:


Time to head to the dump with my lens?

[Katsura]

Who cares about numbers (to a certain degree)? All these bloody lab tests are meaning less unless you only shoot test charts for a living.

Go out and take REAL photos people, like some have done here with the 18-135:
PHOTOHITO: PENTAX(??????)???? smc PENTAX-DA 18-135mmF3.5-5.6ED AL[IF] DC WR ?????????? (???????)