[nostatic]

My 50-135* makes terrible espresso, so I think I might have a bad copy as well.

[m42geo]

Ok ok ok!!

I was exoecing too much. I have never bought a lens at such high price so I was really expecting something perfect.

Again anyone have bad copy lenses can show me example??

[attack11]

i make awesome espresso, but that won't help you.

um, any lens wide open under tungsten will suffer from CA when it's a zoom. even a prime will probably have some fringing.

if you're going to judge a pro spec lens based on a hair brush on a messy desk you're being unrealistic. take it outside or use it with better light, you'll see a very clear difference. btw, viewing the images at 100% is akin to a 20x30" print.

[Marc Sabatella]

First, you probably won't find many people with bad copies of the 50-135. The 16-50 is another matter. I think if you search this forum or dpreview, you'll find examples. The most common problem to my recollectin was "decentering" - where an image might be sharp in the center and on one side, but the other side would be noticeably softer. Your shots here couldn't possibly uncover a problem like that, because there isn't anything in focus on the sides. You would need to construct a test in which there is something in focus along each side of the frame. Ideally, the scene would be perfectly symmetrical, so if there is something in focus on side of the frame, the same exact spot should be in focus on the other side. That's why you see poeple posting test shots of a sheet of newspaper or a brick wall. Although the actual "plane" of focus may be slightly curved, so it would be better to construct a test in which the sides of the frame includes objects at a range of different distances (also symmetric) so you are guaranteed that soemthing will actually be in focus. In a brick wall, it would be normal for the sides not to be in perfect focus when the center is.

[jslifoaw]

I think the OP is expecting that the 50-135 would be magically exponenetially better than the Sigma based on price, but I've mentioned that the Sigma is already good, and that the Pentax is more expensive for other reasons too.

i.e. the Pentax is infinitely better at F2.8 since the Sigma cannot open up to F2.8. At F4 the Pentax is easily as good and a bit better since the Sigma has more LoCA. They're equal after that, but the price premium of the Pentax is to have the 50-135 range with F2.8.

[bwield]

A DA* 50-135mm at 135 and Wide open at 2.8

Just look at all the purple fringing!!!!!!!

[m42geo]

A DA* 50-135mm at 135 and Wide open at 2.8

Just look at all the purple fringing!!!!!!!

Hi

why do you have both F and M 50mm F1.7?? aren;t they the same thing?

[asdf]

Hi

why do you have both F and M 50mm F1.7?? aren;t they the same thing?

They have the same optical formula, but it seems that some of us are collectors.

[Andi Lo]

Hi

why do you have both F and M 50mm F1.7?? aren;t they the same thing?

The M is way nicer to focus with. This matters quite a bit if you have a manual focus body. Using a lens and camera body that feels nice inspires confidence and (may) result in better pics

For many of us photography is just a hobby for fun, and lens with good handling (like my SMC tak 50) delivers fun

[rperez]

K7 cost too much, in the UK it is going to sell at £1200 which is far too expensive.

Also pentax are incraseing the price for lenses as well. I don;t know if pentax will still have the market.

I bought my K110d 2 years ago was because of it only priced at £250 with the kit lens.

But if I am to buy a DSLR now I would go for nikon.

best of luck with that. Be sure to sell your 50-135* to someone who will make good use of it.

Nikon never raises their prices...

I'll make good use of it, let me know when you make the switch