[Class A]

I'm not a huge fan of the DA* 55 but I don't hold its slow AF against it. The long throw should help with AF precision, let alone manual focusing. The gear in the Sigma is great but 90° is not much.

[robgo2]

I am sorry to report that my fourth and final copy of the DA* 55/1.4 was probably the worst of the lot. Back focus was so severe that even with +10 AF adjustment, I could not get close to correct focus. It was also extremely erratic. I never knew whether a shot would be sharp or blurred. So back it goes. Thank goodness that the better retailers have free return shipping for defective items.

I would think that the problem is with my K-7, were it not for the fact that all of my other lenses focus perfectly on it. I have decided to give the Sigma 50/1.4 a try. I don't see that I have much to lose.

Rob

[RonHendriks1966]

Thank goodness that the better retailers have free return shipping for defective items.

And what is happening with al those lenses? Are they shipping them back and forward till someone keeps it or so? If so then after some time they will only have defected lenses in their store.

It's a shame it didn't work out for you.

[robgo2]

And what is happening with al those lenses? Are they shipping them back and forward till someone keeps it or so? If so then after some time they will only have defected lenses in their store.

It's a shame it didn't work out for you.

That's a very good question. I would hope that the more respectable retailers, such as Amazon and B&H, would return all defective items to the manufacturers, but I have no definite knowledge of this. Do you think that by ordering directly from Pentax, one would be more likely to get a good copy? The trouble is that Pentax does not discount anything that they sell, at least not until an item is going out of production, and they need to clear inventory.

Rob

[creampuff]

That's a very good question. I would hope that the more respectable retailers, such as Amazon and B&H, would return all defective items to the manufacturers, but I have no definite knowledge of this...
Rob

I don't believe this to be the case at all. If they can sell it, they'll ship it out to someone else who wants to buy. I guess that comes with a generous return policy and the need to move inventory.
Four lenses that are off? I'm inclined to believe your camera body probably needs checking.

[robgo2]

I don't believe this to be the case at all. If they can sell it, they'll ship it out to someone else who wants to buy. I guess that comes with a generous return policy and the need to move inventory.
Four lenses that are off? I'm inclined to believe your camera body probably needs checking.

Perhaps, but I have very recently checked all of my other lenses by the same system (LensAlign,) and all focus properly, including the DA* 16-50, which is also SDM. We will see how the Sigma performs. If it, too, is way off, I may send my camera in for adjustment. I might add that I wrote to Pentax Customer Service last week about my problems and asked whether they thought the camera might need some attention. Response: NOTHING. I suppose that I should not be surprised, as Pentax is not known for attending to customers.

Rob

[DogLover]

I think there almost has to be an issue with your body or the combination of your body and this particular lens. Four bad copies? I really have a hard time believing that. My DA55* requires no focus adjustment at all on my K7. Slightly slow AF is the only chink in the armor for this lens, it's one of my favorites.

[robgo2]

I think there almost has to be an issue with your body or the combination of your body and this particular lens. Four bad copies? I really have a hard time believing that. My DA55* requires no focus adjustment at all on my K7. Slightly slow AF is the only chink in the armor for this lens, it's one of my favorites.

Yes, it could be an issue related to my K-7 and the DA* 55/1.4, but how would I know this other than by keeping a lens beyond its return date and sending it with the camera to Pentax for service? I am reluctant to do this with a brand new lens that they may not be able to fix. My past experience with Pentax's repair service was not one that instilled confidence.

The Sigma should arrive tomorrow. We will see if it has similar problems.

Rob

[sewebster]

Yes, it could be an issue related to my K-7 and the DA* 55/1.4, but how would I know this other than by keeping a lens beyond its return date and sending it with the camera to Pentax for service? I am reluctant to do this with a brand new lens that they may not be able to fix. My past experience with Pentax's repair service was not one that instilled confidence.

The Sigma should arrive tomorrow. We will see if it has similar problems.

Rob

Yes, it is an annoying situation. Since the lens would still be under warranty, you couldn't really end up with a "broken" lens, but I suppose it's possible that they could tell you your k7 is defective, and if it is out of warranty, then that could cost money to fix. Of course this is kinda crazy if your k7 otherwise works fine. You could also sell the lens, but you'd take a loss of course.

Anyway, hope the sigma works better!

[robgo2]

Yes, it is an annoying situation. Since the lens would still be under warranty, you couldn't really end up with a "broken" lens, but I suppose it's possible that they could tell you your k7 is defective, and if it is out of warranty, then that could cost money to fix. Of course this is kinda crazy if your k7 otherwise works fine. You could also sell the lens, but you'd take a loss of course.

Anyway, hope the sigma works better!

I once owned a DA 17-70. I liked the lens, except for the fact that it was noticeably soft at the long end when focused near infinity. I sent the lens and my K10D to Pentax Repair twice along with out-of-focus sample images. On both occasions, I was told that the lens was performing within factory specifications. In other words, they would not take responsibility for a defective lens. I sold it and bought a DA* 16-50, which works great.

That is why I am reluctant to trust my fate to Pentax's Repair service, especially with such an expensive lens. Now, if the Sigma exhibits the same misfocusing behavior, then I will have to suspect that I have a problem with my K-7, but, as I said, all of my other lenses seem to focus perfectly. Also, I believe that there are two postings in the Pentax Forums' Lens Review section for the DA*55/1.4 in which the users said that they required +9AF adjustment. This suggests that the lens is, indeed, prone to fairly severe backfocusing, so my experience may not be as outrageous as it sounds.

Here is a dilemma: if the Sigma also misfocuses, where would I send the lens and camera for service? Pentax would almost certainly have no interest in fixing a Sigma lens, and Sigma might not know how or be willing to adjust a Pentax camera. This is making my brain hurt.

I will report on the Sigma tests in a day or two.

Rob

[DogLover]

I once owned a DA 17-70. I liked the lens, except for the fact that it was noticeably soft at the long end when focused near infinity. I sent the lens and my K10D to Pentax Repair twice along with out-of-focus sample images. On both occasions, I was told that the lens was performing within factory specifications. In other words, they would not take responsibility for a defective lens. I sold it and bought a DA* 16-50, which works great.

That is why I am reluctant to trust my fate to Pentax's Repair service, especially with such an expensive lens. Now, if the Sigma exhibits the same misfocusing behavior, then I will have to suspect that I have a problem with my K-7, but, as I said, all of my other lenses seem to focus perfectly. Also, I believe that there are two postings in the Pentax Forums' Lens Review section for the DA*55/1.4 in which the users said that they required +9AF adjustment. This suggests that the lens is, indeed, prone to fairly severe backfocusing, so my experience may not be as outrageous as it sounds.

Here is a dilemma: if the Sigma also misfocuses, where would I send the lens and camera for service? Pentax would almost certainly have no interest in fixing a Sigma lens, and Sigma might not know how or be willing to adjust a Pentax camera. This is making my brain hurt.

I will report on the Sigma tests in a day or two.

Rob

I would be pretty surprised if you had the same kind of problem with the Sigma, not because it's of better quality, but just because I think the problem is with the combination of the DA*55 and your body. It's definitely weird and given your past experience I can certainly understand your reluctance to send in the combo to Pentax. I know the Sigma is a fine lens but it is a shame that you will not know first-hand how good the DA*55 is. Good luck.

[robgo2]

I would be pretty surprised if you had the same kind of problem with the Sigma, not because it's of better quality, but just because I think the problem is with the combination of the DA*55 and your body. It's definitely weird and given your past experience I can certainly understand your reluctance to send in the combo to Pentax. I know the Sigma is a fine lens but it is a shame that you will not know first-hand how good the DA*55 is. Good luck.

I'm not so sure that my problem is an isolated one. In their test report, Dpreview made note of how much difficulty they had finding a copy of the DA*55/1.4 that focused properly. I guess that you have to be lucky to get one that does.

Rob

[Class A]

Here is a dilemma: if the Sigma also misfocuses, where would I send the lens and camera for service?

I'd ask Sigma what to do, i.e., whether they need your camera to calibrate the lens or not. I've heard good user reports from Sigma service centres, so I'd give it a try.

Good luck with the lens, hope it won't disappoint!

I've seen some very nice shots from the Sigma. Not such a fan of the DA* 55/1.4.

N.B., by looking for 55/1.4 shots, I found this mini thread in which other DA* 55/1.4 users report about focus problems.

[DogLover]

Not such a fan of the DA* 55/1.4.

You definitely have a contrarian point of view on this. Not saying it's perfect by any means, but the vast majority of users really like this lens.

[creampuff]

With Sigma's QC, you really got to test thoroughly. I got friends using Canon, Nikon and Pentax who had to send their Sigma 50mm f/1.4 for re-calibration for focus issues with my local Sigma service center. This is a known issue and using the camera's AF fine adjustment is not the solution. Having said that, once calibrated, it is a stellar lens, just like the DA* 55mm f/1.4.


K-5 Sigma 50mm f/1.4 wide open