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-   -   70-200mm Sigma or Tamron (https://forums.steves-digicams.com/pentax-lenses-87/70-200mm-sigma-tamron-209746/)

TCav Jan 24, 2014 8:00 AM

Unfortunately, the Sigma 70-200/2.8 OS HSM is one of LensRentals' least reliable lenses. Remember that, as rentals, their lenses undergo more use, abuse and rough handling during shipment, than most lenses, so this may not apply to your situation.

Since you've got 45 days, use that time to put that lens through its paces.

Photo 5 Jan 25, 2014 11:59 AM

Not sure which version exactly I have coming. I ened up not ordering from bhphotovideo and used the same shop that sold me by K-5, K-5ii and K-3. They were able to offer me $50 off the lens over bh and $25 off a UV filter. They told me that their national supplier of Sigma lenses would send it to the shop and they'd mail it to me. It is due on the 28th according to the tracking numbers. If it arrives Tuesday I will be able to test it Wednesday. If it arrives Wednesday I wouldn't be able to fully test it until Saturday. I will do my best to post a few samples hereafter testing and conversion from raw to jpg (I always shoot RAW).

They also told me I have 45 days to test it and get it back to them if its not what I need or doesn't work out being sharp etc. So once it arrives I will be shooting a load of images with it over the course of my days off of work over a 3 week period.........

Photo 5 Jan 28, 2014 10:36 PM

1 Attachment(s)
Here is a sample from my new 70-200. At first I had focusing issues as all it wanted to focus on was the falling snow and everything was out of focus. I played with it for two hours and finally got it to make some good images. I only saved about 54% of the total images as the rest were trash/out of focus etc. The more played with it the higher % were keepers. I need to test it more when it stops snowing to make sure their is not a serious focusing issue with it.

I had to very heavily compress this image to get it small enough to post. Original image was 6.5MB. Take with 70-200/K-3 (taken in raw and converted to jpg) and unedited before the heavy compression and resized in PhotoShop Elements. Photo from Decatur GA (outside of Atlanta) where is snowed today.

Photo 5 Feb 4, 2014 10:36 AM

Update: I took approx 1300 photos at the airport yesterday. Had few times where focus got screwed up and the lens had to completely reset the focus and zoomed in and out for few seconds to lock back into focus. Of the photos I took 10% had focus issues of one sort or another - not motion or hand held blur but AF/focus issues. I have deleted all the bad photos at this point and working on the good ones in lightroom now. As for the AF and Focus issues I played around with center point, selected point and all points in AF and it didn't seem to matter. Also if the first image in a burst was in Focus I could fire off 5fps for 30 frames and every one was in focus with the plane landing or taking off. Also the focusing issues are the images are not in focus plain and simple it doesn't appear to be a front or rear focusing issue just that the lens for what ever reason did not auto focus as it should have. Will be investigating more and shooting more tomorrow.

Will try to post a couple of good sots tonight

Old Boat Guy Feb 4, 2014 8:14 PM

Which OS did you use? When trying an OS version on my Sony the lens was not happy when I used the in-body OS over the in lens system.

Dual OS systems regardless of which one is used (never both at once) has never been a good idea with my camera.

jelow1966 Feb 5, 2014 9:33 AM

Quote:

Originally Posted by Photo 5 (Post 1367516)
Update: I took approx 1300 photos at the airport yesterday. Had few times where focus got screwed up and the lens had to completely reset the focus and zoomed in and out for few seconds to lock back into focus. Of the photos I took 10% had focus issues of one sort or another - not motion or hand held blur but AF/focus issues. I have deleted all the bad photos at this point and working on the good ones in lightroom now. As for the AF and Focus issues I played around with center point, selected point and all points in AF and it didn't seem to matter. Also if the first image in a burst was in Focus I could fire off 5fps for 30 frames and every one was in focus with the plane landing or taking off. Also the focusing issues are the images are not in focus plain and simple it doesn't appear to be a front or rear focusing issue just that the lens for what ever reason did not auto focus as it should have. Will be investigating more and shooting more tomorrow.

Will try to post a couple of good sots tonight

I have had the same 2 issues with my Sigma 135-400 but had always put the focusing issues down to using it on an older body. Obviously not the problem in your case. I quit using it because I was losing too many shots waiting for the thing to rack thru the entire focus range again when it was a millimeter from locked on to start with.

John

TCav Feb 5, 2014 11:52 AM

Quote:

Originally Posted by Photo 5 (Post 1367516)
... Had few times where focus got screwed up and the lens had to completely reset the focus and zoomed in and out for few seconds to lock back into focus. ...

Quote:

Originally Posted by jelow1966 (Post 1367592)
... I quit using it because I was losing too many shots waiting for the thing to rack thru the entire focus range again when it was a millimeter from locked on to start with.

It's a little disappointing that the lens needs to "reboot" occasionally.

Old Boat Guy Feb 5, 2014 5:15 PM

Quote:

Originally Posted by TCav (Post 1367604)
It's a little disappointing that the lens needs to "reboot" occasionally.

I would not have said "reboot" but you are correct.


Remember when I bought this same lens? You gave me the lens guide to never buy an OS lens with a OS body

TCav Feb 6, 2014 10:47 AM

Quote:

Originally Posted by Old Boat Guy (Post 1367625)
Remember when I bought this same lens? You gave me the lens guide to never buy an OS lens with a OS body

The newer stabilized Sigma 70-200/2.8 is a lot sharper than the older unstabilized Tamron 70-200/2.8, especially when paired with 16MP and 24MP sensors. It's unfortunate that Sigma's stabilization gets in the way, but the image quality is superior.

Photo 5 Feb 6, 2014 12:15 PM

I have a non OS model (which is the current offering that will mount to a Pentax) and OS turned on in the body. It is very interesting after more testig that my 18-250mm focuses faster and gets more useable shots. But with that said the shots with the 70-200 are just a tad sharper over all (before any editing is done). I will be testing again next week and if it not better it will go back, maybe try a Tamron or maybe get another Sigma as swap out not sure right at the moment. Also it doesn't seem to matter what focal range of f/s I am using. Seems to be totally random as it did it for both flying-faster moving items and slower moving items. However on still items (park planes) it was not an issue.

I do like TCav wording of reboot. a 2.5 to 3.5 second reboot and I am good to focus the lens again.


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