[Shashinki]

I tried out the 50-150mm HSM today and it looks good.

Smooth, fast and silent AF on the K20D. OK IQ as far as i can see on the camera's screen.

However: Current Sigma teleconverters will not give AF with this lens. Sigma needs to upgrade them methinks.

[k100d]

i would imagine it would focus a lot faster than the DA 50-135 and it does have true ring-type AF
the lens is looking good from all reviews. if i was on another brand, it'd be a close race between the Sigma and the Tokina

[nupentaxian]

wow so many choices: da*50-135, tamron 70-200, sigma 50-150, and upcoming sigma 70-200...which one to get?...

[soccerjoe5]

i wonder how much faster it'll AF compared to the 50-135 DA*?

i wish pentax would come up with a much faster AF USM/HSM/AF-S type for lenses

[k100d]

lighter, less length
da*50-135 - weathersealing and slow af
sigma 50-150 - fast af no weather sealing

heavier, more length
tamron 70-200 - better iq than sigma slow af
sigma 70-200 - worse iq than tamron faster af

[maxwell1295]

Hmmmmm.....just when I was all set to grab a 50-135. Looks like the price here in the US is about the same for both lenses. If the AF is really silent and faster, I may have to look into the Sigma.

[Denis]

lighter, less length
da*50-135 - weathersealing and slow af
sigma 50-150 - fast af no weather sealing

heavier, more length
tamron 70-200 - better iq than sigma slow af
sigma 70-200 - worse iq than tamron faster af

Data is based on what, review using Pentax, Nikon or Canon bodies.
Making my mind on simple and quick reviews of a production model is not enough.
I have seen IQ reports of all kinds. Best IQ and AF tests will be from use in the real world settings. On decent quality lenses, AF speed and IQ seem to vary from tester to tester. It is too early to form a solid opinion.

[k100d]

Data is based on what, review using Pentax, Nikon or Canon bodies.
Making my mind on simple and quick reviews of a production model is not enough.
I have seen IQ reports of all kinds. Best IQ and AF tests will be from use in the real world settings. On decent quality lenses, AF speed and IQ seem to vary from tester to tester. It is too early to form a solid opinion.

the comments on AF speed are based upon
i. the DA* 50-135 is one sloooow lens, the SDM motor only makes it quiet
SDM speed (or lack thereof): Pentax SLR Talk Forum: Digital Photography Review
ii. Sigma ring-type af motor has always been pretty quick
iii. Tamron will rely on the body af motor which is known to be not fast enough

in terms of the actual iq b/n 70-200 i went from what dpreview tested yes they were tested on different bodies. however there seems to be quite a concensus that the Sigma's IQ has deteriorated ever since they've added a macro focusing mode

[soccerjoe5]

i had a 50-150 for my D80 and it was pretty fast in AF. but not as fast as AF-S nikkors.

i wonder how the 50-135 does, it's supposedly faster than the 16-50 which i find pretty slow.

[Denis]

the comments on AF speed are based upon
i. the DA* 50-135 is one sloooow lens, the SDM motor only makes it quiet
SDM speed (or lack thereof): Pentax SLR Talk Forum: Digital Photography Review
ii. Sigma ring-type af motor has always been pretty quick
iii. Tamron will rely on the body af motor which is known to be not fast enough

in terms of the actual iq b/n 70-200 i went from what dpreview tested yes they were tested on different bodies. however there seems to be quite a concensus that the Sigma's IQ has deteriorated ever since they've added a macro focusing mode

OK, what are we talking about, 1 second versus 1.2 or 3 or 5. I'll bet it is less than 1 second. That kind of need is very specific and rarely an issue in the hands of normal everyday users, not pros. As for IQ, I'll bet if I took the same image with 3 different brands but similar type, all 70-200 as mentionned, perfectly focus, it would be difficult to identify the Sigma. For the price on all these lenses, IQ is quite acceptable otherwise one has to pay 3 times more at least to achieve great IQ.

[k100d]

OK, what are we talking about, 1 second versus 1.2 or 3 or 5. I'll bet it is less than 1 second. That kind of need is very specific and rarely an issue in the hands of normal everyday users, not pros. As for IQ, I'll bet if I took the same image with 3 different brands but similar type, all 70-200 as mentionned, perfectly focus, it would be difficult to identify the Sigma. For the price on all these lenses, IQ is quite acceptable otherwise one has to pay 3 times more at least to achieve great IQ.

af speed, it won't be ridiculously slow. but everybody can appreciate faster AF speed if it's a reasonable cost and different users have different needs.

regards to IQ if it's good enough for you that's great. i probably can't tell the difference, but i'm gonna always gonna look for the lens with the best reviews and user comments rather than just "good enough"

[rfortson]

I've never really noticed the 50-135 being slow. In fact, it's my "go to" lens when shooting action. What body are you using? I found that my AF-C performance improved when I went from the K10D to the K20D.

Here are a couple of shots I got with the K20D and the DA*50-135. The rodeo shot is obviously fast action, but it was really dim. This shot was at ISO2000 at f/2.8. I did miss some shots here, but I also got shots like this.



This second shot was when I really noticed the improved AF-C performance. I took ~100 shots of this race and maybe 2-3 were focused incorrectly (on the wrong target - more my error than the camera's). Obviously bright lights and sharp contrast, but still the lens/camera kept focus coming and going.

[Denis]

af speed, it won't be ridiculously slow. but everybody can appreciate faster AF speed if it's a reasonable cost and different users have different needs.
regards to IQ if it's good enough for you that's great. i probably can't tell the difference, but i'm gonna always gonna look for the lens with the best reviews and user comments rather than just "good enough"

I would rather look for best AF results, in focus, than speed but that is my preference.

That is my point, reviews and most important user's comments. As of now some of these lenses are just out. I know the Sigma might be with the old glass but may not. Until some are used and comments made, I reserve my judgement. When the DA 16-50 was first reviewed, many raved about it. It turned out slightly diffenrent when many users reviewed their results. Like many other companies, Sigma might be listening and correction might be done to production to improve IQ. As for good enough, I have seen some cheap kit lenses produce some amazing images. Overall most lenses are quite good. It is the person behind the camera that bring out their quality.

We have the same aim, best overall quality for the money. I do agree with some of your comments but I simply have different approaches and preferences in finding the right one.

Thanks for keeping this civil many would not. I do like a constructive discussion inspite of not being able to agree on all.

[Shashinki]

It really isn't that much better than the 50-135mm AF-wise. A bit perhaps (:edit: OK, maybe more than a bit but that 50-135 isn't the fastest lens out there), but I feel the bottleneck is more the camera's AF system than the lens itself now.

Getting the 70-200mm in stock come October, we will have to see how it performs.

As for the price vs. the 50-135mm, you might be lucky if you're norwegian in that case 'cause having a fellow Pentaxian working for the Sigma importer might give you some advantages

[itchyshutterfinger]

Thanks for posting Shasinki. I was wondering why you chose the 50-150 over the pentax 50-135. I'm looking to get a portrait lens soon, and it will be one of these two. Were you able to handle the 50-135? What other differences have you noted?

Thanks

Also, on Sigma's page for the 50-150, it states that there are two teleconverters that this lens will work with, Sigma 1.4x EX DG and 2x EX DG APO Tele-Converters.
Sigma - Lenses