[rdj92807]

Sandy, I have been testing my 20-40 against a lot of my good lenses. Mine may be a bit decentered wide open, favoring the left side. But I noticed it's not that great at 20/2.8. Mine is basically an f4 lens, like my FA 20-35 for example. It outperformed my FA 20-35 at the edges in general. But in the center, my Pentax 16-50, 17-70, and Sigma 18-250 macro (a $400 super zoom) were just as good. And it's larger than I thought. So it's has a very limited range, not wide enough (should have started at 16 or 18), not that small (similar to Sigma 18-250 w/o hood), and of course very expensive. Focusing is OK, not that fast. It's great in the 30-40mm range for sure.

I'm not sure if I will keep the lens. Clearly the much heavier, larger Sigma 18-35 is the better lens optically.

[TedH42]

Sandy, I have been testing my 20-40 against a lot of my good lenses. Mine may be a bit decentered wide open, favoring the left side. But I noticed it's not that great at 20/2.8. Mine is basically an f4 lens, like my FA 20-35 for example. It outperformed my FA 20-35 at the edges in general. But in the center, my Pentax 16-50, 17-70, and Sigma 18-250 macro (a $400 super zoom) were just as good.

How does it compare to the FA 20-35 in the center? For me personally, that's its competition. From what I am reading and seeing, it seems to have a more uniform-across-the-field IQ, with IQ in the center apparently traded off for better IQ in the edges.

[lytrytyr]

From what I am reading and seeing, it seems to have a more uniform-across-the-field IQ, with IQ in the center apparently traded off for better IQ in the edges.

That seems consistent with the general DA Limited philosophy,
seen particularly in the pancakes (but not so much in the DA 15).

[lytrytyr]

And it's larger than I thought.

It was always expected to be about the same size as the FA 20-35.
DA zooms don't come much smaller.

not wide enough (should have started at 16 or 18), not that small

Wider would have meant larger.

Clearly the much heavier, larger Sigma 18-35 is the better lens optically.

If you're against the light, that may not be as clear.

[Grokh]

Clearly the much heavier, larger Sigma 18-35 is the better lens optically.

The typical Sigma's color rendition and saturation are unfortunately far away from the Pentax DA* and Lim. You can look on the next thread "20-40 for testing, I have post three pictures from the similar point of view: Sigma 10-20, DA* 16-50 and Lim 20-40. The difference is great, IMHO.
But, of course, some people may prefer sharpness against bokeh or color. I am also like the very sharp lenses but I am use Sigma only because Pentax does not have the lenses with "my" focal ranges.
(This is not for the starting the holy war Pentax against Sigma or sharpness against color and bokeh.)

[rdj92807]

Grokh, your comments about Sigma color are no longer true, with their new lenses. They have really improved their coatings.
Testing my Sig 18-250 at 20mm and 40mm, you can really not see any major color difference between it and the 20-40 ltd.
Older Sigma lenses had a yellow cast and lesser color vs Pentax, for sure. I bet the Sigma 18=35 colors will be just as good as Pentax at this point.

Ted, re the FA 20-35, here are my test results:

Overall, somewhat better contrast than FA 20-35

At 20mm 4.0 the 20-40 sharpness center/corner was close but FA 20-35 was better; my 20-40 copy is decentered and weak on the right. Same at 5.6. At 8.0, 20-40 finally slightly better at edges.

At 24mm, 20-40 beats my FA 20-35 at edges at 4.0 and 5.6; are equal at 8.0

At 35mm, 20-40 beats my FA 20-35 with much better edges at 4.0, slightly better at 5.6 and 8.0

Again, no question this lens can perform very well 24 to 40. My issue is at 20mm, which given that is 30mm in 35mm format and not that wide, will be used extensively by most people. I would prefer strength at 20, and less at 40 if a compromise was needed. My FA 20/2.8 was WAY better than the 20-40 at 2.8 and 4.0, for example. In fairness, the 20-40 is way better than my Pentax 16-50 at 20 and 2.8 at the far edges (not center), so every lens has it's issues. The Pentax 16-50, for edges, is just not great at 2.8 but really improves by 4.0.

So I'm really struggling with my feelings on the 20-40. I am leaning toward the Sigma 18-35 when it comes out. Yes, it's bigger and heavier but SO much sharper and faster, by all reports. Many lenses can match the 20-40 at 20, and it's range is just so limited for the slower speed.

[Grokh]

Grokh, your comments about Sigma color are no longer true, with their new lenses. They have really improved their coatings

My Sigma 10-20 is two years old, the color difference is too big. My new Sigma 50-500 has been bought this year, it is much better than my previous Bigma, but the color rendition still not the same as by DA* 60-250. But of course, current Sigma is not the same as three-four years ago.

[TedH42]

Ted, re the FA 20-35, here are my test results:

Overall, somewhat better contrast than FA 20-35

At 20mm 4.0 the 20-40 sharpness center/corner was close but FA 20-35 was better; my 20-40 copy is decentered and weak on the right. Same at 5.6. At 8.0, 20-40 finally slightly better at edges.

At 24mm, 20-40 beats my FA 20-35 at edges at 4.0 and 5.6; are equal at 8.0

At 35mm, 20-40 beats my FA 20-35 with much better edges at 4.0, slightly better at 5.6 and 8.0

Thanks for your comparison of your FA 20-35 and DA 20-40. For me, the jury is still out. I really like my FA 20-35, and the DA 20-40 has to step up to knock it out. Not yet sure if it does for me. Still looking at the evidence.

[Cannikin]

And twice the size of any limited prime

If it were twice the size of the FA 31 LImited, it would be quite the monstrosity.

[krebsy75]

This glass gets points for WR and classic industrial design. Not sure how points equates to dollars. That's up to you.

[Andr3w]

And twice the size of any limited prime I myself expected it to be a lot smaller, I suppose the weather sealing might add to its size. It's not bad at all but IMO, it feels a bit like an oddball compared to the other Limiteds. Makes a great close-up lens, though!



This time we're probably just going to jump right in to the in-depth review. It'll definitely be posted before the end of the year

Can't wait. PF may be the first out with an in-depth review.