[deejjjaaaa]

UPDATE: lens was delivered to Sigma service center yesterday... called them today to ask to really do the testing before sending them back... went through 5-6 people on the phone before being able to talk w/ somebody who can speak the way I can understand... explained my problem - as usual their defense strategy was - it is all in the (camera) body, we (Sigma) test all lenses before sending them back, blah - blah - blah.... whatever, let us not argue - do me a favor, ask the people to test it for me please - I understand that you are testing - can you test it twice please, old fashioned way - no lab equipment please - just human eyes @ 100% zoom on your monitor, thank you.... 30 minutes... we'll see.

[little laker]

Have you tested it on another camera deejjjaaaa?
It is possible that they're right about it being your body in this case. The 17 - 70 is one of their best lenses, and I don't recall ever seeing another complaint about it

On the other hand I know first hand that Sigma isn't perfect. I know a store that tests every Sigma product before they ship it off, and they do get he odd out of focus lens, and the odd spec of dust in a new body.
They even just got in a new 50mm f1.4, that appeared to be off just a little, although Bill thought it might be his test body. I wish I was around at the time to test it on mine.

[gkopeliadis]

Have you tested it on another camera deejjjaaaa?
It is possible that they're right about it being your body in this case...

The body? Doing this only with that specific type of lens? Naaaaa

[deejjjaaaa]

Have you tested it on another camera deejjjaaaa?
It is possible that they're right about it being your body in this case. The 17 - 70 is one of their best lenses, and I don't recall ever seeing another complaint about it

On the other hand I know first hand that Sigma isn't perfect. I know a store that tests every Sigma product before they ship it off, and they do get he odd out of focus lens, and the odd spec of dust in a new body.
They even just got in a new 50mm f1.4, that appeared to be off just a little, although Bill thought it might be his test body. I wish I was around at the time to test it on mine.

I have 2 (TWO each time - read below) Pentax cameras and I was able to test 4 Sigma lenses

1) K10D + *istDL : 1st copy of Sigma 17-70/2.8-4.5 + Sigma 24-135/2.8-4.5

and then

2) K20D + *istDL (the same one) : 2nd copy of Sigma 17-70/2.8-4.5 + Sigma 24-135/2.8-4.5 (the same) + Sigma 24-60/2.8

ONLY Sigma 17-70/2.8-45 was producing soft sides... the 1st one on the left side and the 2nd one on the right side... and soft I mean even @ f8.0 from 17 to 70... if somebody wants to claim that I do not have 90 degrees angle @ target... I have made not couple but hundreds of pictures w/ those combos (camera - lens) to make sure that I do not
have tilted sensors in cameras...

[furby]

I don't know if it's what they usually do, but I just got my 17-70 back from them and it actually came with a CD with some test shots. One was from 17mm at 2.8 and the other at 70mm at 4.5. Now my lens is perfect. If you didn't get one then I suggest asking them to send one back with it just to be sure.

[deejjjaaaa]

I don't know if it's what they usually do, but I just got my 17-70 back from them and it actually came with a CD with some test shots. One was from 17mm at 2.8 and the other at 70mm at 4.5. Now my lens is perfect. If you didn't get one then I suggest asking them to send one back with it just to be sure.

in my case they did not send me a CD w/ the first return... but the last person I was talking to today - mentioned that they can... thank you for the tip, I should pay attention to that.

[res3567]

Hi,

Just want to share my experience dealing with Sigma 17-70/2.8-4.5 DC macro (or "macro") lens and Sigma service center in Ronkonkoma, NY.

The lens was purchased new from Jack's Camera / Delaware Camera (Sigma dealer) on ebay (to use M$ live.com 25% cashback /RIP/, etc).

I have read some topics here and there about Sigma plus I own Sigma 24-135/2.8-4.5 so I was expecting to get an item ready for a service
on arrival. And so was the case. The left side was soft, no - SOFT, no - SOFT compared to the right side (brick walls/newspapers) from 17mm to 70mm, and from f2.8 to f8.0... while the center sharpness was good starting even from 17 @ 2.8. The testing was done using Pentax *istDL
and Pentax K10D.

And to Ronkonkoma, NY it was sent the next day or so after arrival.

Here is the how fast was the service :
mailed (USPS) on 07/25/2008 - received by Sigma on 07/28/2008 - received back from Sigma on 08/05/2008.

Did they fix it ? I do not know yet - I am sitting right now at work and my camera(s) are at home. Hopefully will be able to update you in a day or so.

PS: may be we can use this topic to share experiences dealing w/ Sigma service for various lenses ? what do you think ?

I own a Sigma 28-105 f2.8-4.0. I bought it years ago for my ZX50. I now own a K10D. Without going into the frustating details, the A position essentually does not work. I have a autofocus lens that has no autoexposure capibility whatsoever. I am getting tired of pressing the green button for an auto lens. I also own legacy glass in which I have no problem doing the total manual thing because these are manual lenses. I am interested in your experience. Please let me know how it went (well I hope!).

[deejjjaaaa]

I own a Sigma 28-105 f2.8-4.0. I bought it years ago for my ZX50. I now own a K10D. Without going into the frustating details, the A position essentually does not work. I have a autofocus lens that has no autoexposure capibility whatsoever. I am getting tired of pressing the green button for an auto lens. I also own legacy glass in which I have no problem doing the total manual thing because these are manual lenses. I am interested in your experience. Please let me know how it went (well I hope!).

Did you try to deal w/ Sigma service center to get it serviced (not under warranty which is over I guess) - please share your experience here... if not then they provide a free estimate and I think it will cost you < $10 to try (mail it to them) - you do not need a big insurance or even tracking number for it, so the cost might be like $5 (USPS) ?... or I think you can get an eq. lens (eq to Sigma 28-105 f2.8-4.0) very cheap... my Sigma 24-135/2.8-4.5 was less than $100 from Cameta through their ebay auctions ~2 years ago...

[deejjjaaaa]

just received my 3rd copy of the lens back (2nd from the Sigma service center in Ronkomkoma - the first one was the original purchase).

timing : mailed w/ USPS on 09/05/2008 - delivered to the service center on 09/09/2008 - received back on 09/16/2008.

the work done : as usual the lens was just replaced w/ another copy and serial number reattached to that new copy.

will 3rd time be a charm ? will see tonight... wish me luck people

[deejjjaaaa]

well, it looks better comparing w/ 2 previous copies...

here is the most challenging setting for it : its widest focus distance (17mm) & wide open (2.8) - distortions and vignetting were not corrected in my examples below.

17mm @ f2.8, 1/60, ISO100, daylight, AF central point, handheld, SR off.

per photozone.de - its sharpness (17mm @ 2.8) should be (center - border - extreme border) : 1944 - 1739 - 1038

Sigma AF 17-70mm f/2.8-4.5 DC (Pentax K) - Review / Test Report

looks like my main issue (non uniform corners) was fixed - all 4 corners are sufficiently similar... are they ?

@ 25% (simple resizing in photoshop)



@ 50% (simple resizing in photoshop) - click-click for a full size



@ 100% (1:1, no resizing) - click-click for a full size




PS: I did not have time to check for a BF/FF yet - so it still might be not 100% in focus... again my main concern was to get left & right side (or top & bottom) to be similar, that is not
to have any tilt of any glass, whatever inside the lens itself.

[kenyee]

You have to check multiple focal lengths and focusing distances.
I returned one that was realllly bad at a few focal lengths. I thought the current one was good, but found out during a vacation that at 19mm and certain focal lengths, it has another decentering defect and it's also somewhat soft at 70mm :-P

[deejjjaaaa]

You have to check multiple focal lengths and focusing distances.
I returned one that was realllly bad at a few focal lengths. I thought the current one was good, but found out during a vacation that at 19mm and certain focal lengths, it has another decentering defect and it's also somewhat soft at 70mm :-P

once the weekend come... I need to find first that I am OK w/ focus first... it seems that daylight requires AF +2 adjustment for K20D

[jamesm007]

Looks very good for f2.8. I have found this lens performs very good at 17mm and f2.8 when perfectly in focus and has very little corner softness, or at least nothing I would call soft, not until the deep corners as your pic shows the softness does not come till very deep into the corner. Now at 70mm and f4.5 it should be OK, but not super crisp, go to f5.6 and it gets good, go to f8 and it should be very good. Sigma just keeps trying and trying and they are quick, may have some QC problems but...

[deejjjaaaa]

Looks very good for f2.8. I have found this lens performs very good at 17mm and f2.8 when perfectly in focus and has very little corner softness, or at least nothing I would call soft, not until the deep corners as your pic shows the softness does not come till very deep into the corner. Now at 70mm and f4.5 it should be OK, but not super crisp, go to f5.6 and it gets good, go to f8 and it should be very good. Sigma just keeps trying and trying and they are quick, may have some QC problems but...

70mm @ f4.5, 1/8s, ISO100, tungsten, AF central point, tripod, SR auto off by remote... you can see a bit of softness in very corners... (I need a better target w/ more symbols)... note that pin holding the paper was not exactly @ 90 degrees to the wall - do not pay attention to it.

@ 25% (simple resizing in photoshop)





@ 50% (simple resizing in photoshop) - click-click for a full size





@ 100% (1:1, no resizing) - click-click for a full size

[jamesm007]

Its kinda hard to tell as you say with just the small amount of detail on the page, but as far as the lens being aligned I believe things are looking very good for you. Now its time to take just a short time and check for BF/FF and make adjustments with your K20. Then start enjoying the lens, its a good one, sharp, great contrast and nice color.