[Robanstan_AU]

After reading all the reviews and specs I thought I was going to get a nice lens, this APO 70-200mm F2.8 II EX DG Macro HSM, and it was for my new K7... however, maybe I still have a lot to learn about setting up this outfit, but to me, with not a great deal of experience to call upon, I think I have a serious problem. First of all, I do not know if this is how an image should look from this lens, you can see it here, http://www.shootingnature.com/K7test.jpg , and after trying dozens of different settings, I can not seem to get a sharper picture. I have my suspicions about this lens, because my 15yr. old Sigma 75-300 f4.5 seems twice as sharp?? - I have been shooting with the default settings. Q1. Have you seen this before and could it be 'tweeked' out? 2. If not, would this be a manufacturing problem? Q3. Can anyone send me a nice sharp image showing how this should look?? - Ahhhh! - glory without pain is no glory at all!! - I will be sooo happy to resolve this problem one day!

[LeDave]

1/500s, f/4.5, ISO 100, AF-S

Hmm interesting, it doesn't look too good. Where you shaking a lot?

[Ash]

Also don't mean to assume user error, but have you tried capturing images using a tripod and the 2 sec shutter delay to see if the lens has trouble rendering a sharp image?

Have all images been soft? Any possibility of front or back focusing?
The lens shouldn't normally give you a headache just trying to get a decent result. But do consider the plethora of possibilities causing the problem.

[davidreilly3207]

Definitely looks like motion blur. What speed, what f-stop, etc. would help. try shooting at least 1/250 or faster.

[Denis]

After reading all the reviews and specs I thought I was going to get a nice lens, this APO 70-200mm F2.8 II EX DG Macro HSM, and it was for my new K7... however, maybe I still have a lot to learn about setting up this outfit, but to me, with not a great deal of experience to call upon, I think I have a serious problem. First of all, I do not know if this is how an image should look from this lens, you can see it here, http://www.shootingnature.com/K7test.jpg , and after trying dozens of different settings, I can not seem to get a sharper picture. I have my suspicions about this lens, because my 15yr. old Sigma 75-300 f4.5 seems twice as sharp?? - I have been shooting with the default settings. Q1. Have you seen this before and could it be 'tweeked' out? 2. If not, would this be a manufacturing problem? Q3. Can anyone send me a nice sharp image showing how this should look?? - Ahhhh! - glory without pain is no glory at all!! - I will be sooo happy to resolve this problem one day!

I have this lens. It is much sharper. Your image is blurry from motion and off focus. Be careful in focus selection such as center focus only versus auto. HSM focus will be different from one to the other. To test sharpness, use a tripod. I use mine on a K10D with excellent results.

[rawr]

Although that lens is apparently not the sharpest lens in the world, I am seeing motion blur more than anything else.

Use a sturdy tripod, DON'T put any filters on the lens, use MLU as suggested.

Also stop the lens down to f5.6 or f8 if you want the maximum resolution out of this lens. This is confirmed by both these tests of similar versions that lens:

Sigma AF 70-200mm f/2.8 EX APO HSM DG - Review / Lab Test Report - Analysis

Sigma Lens: Zooms - Sigma 70-200mm f/2.8 EX DG HSM APO (Tested) - SLRgear.com!

Then post an 'after' shot to see if all that made a difference...

[LeDave]

Also have to make sure that you press the shutter button halfway down for at least a second before fully pressing it down because it takes awhile for the SR to kick-in, you should hear a beep.

[jeffrey r]

So as not to start a new Sigma 70-200mm HSM thread, if I could ask a quick question, I'd appreciate confirmation from any owners of this lens out there. I just picked up a used copy of the Sigma 70-200mm HSM lens, and it simply will not AF on my K200D. I've moved the AF/MF switch on the lens back and forth a ton of times, I've twisted the focus ring, re-mounted it several times, tried it with my K100D Super, and it will not AF. I know there have been reports of the HSM on these lenses failing, so I suspect this could be the case, and I'll have no problem returning this to the Seller if need be. But I got a great deal, so I'd love to find out there is some trick I am missing. I fear this is not the case though, and that I just got a dud. Any thoughts out there? Thanks.

[kenyee]

Robanstan: looks like a decentering issue to me. I'm looking at the image zoomed out and the right side of those cans looks fuzzy but in the same focal plane, they're pretty sharp on the left hand side. The leftmost can on the cart w/ the red berries on top looks fairly sharp. I'd swap it for another one if you can.
When doing testing, also test on a tripod. I had a hard time holding it still because of the weight. I have since switched to the 60-250 and don't have the shake problem for some reason...it's only 500g lighter.

jeffrey: this lens doesn't have screw drive support. It won't work on your K100D. Not sure about the K200D but it should on that I think (check to see if it supports SDM lenses)...

[jeffrey r]

Thanks kenyee, but both my K200D and K100D Super support SDM lenses. Again, I think I just got a dud, but I figure it is worth a shot to see if there is something I am missing.

[Robanstan_AU]

Hey........ a big thanks for everyone who has replied, I am working thru the info now.... Just one thing, I used a tripod, I shot with the "Mirror Up', and I used a a remote to avoid any shake. ..and yes, I wait for the 'beep', Hmmm. - I was hoping this might have been caused by the software. Maybe I need to test the lens on another Pentax, but none near here for a 100k or more.

[Robanstan_AU]

...... thanks RAWR I think you hit the nail on the head.

I totally forgot I had a UV filter on the lens, ...let that be a lesson to all you amateurs!! , - and after taking a heap more shots I am sure the image is now 50% sharper. I am confident that my camera is 'still' by using tripod, remote & Mirror up, so here is a sample image to compare.and another. I think with a little tweaking & Photoshop, I should find satisfaction. The images are split, showing the use of a filter on the left. Ignore other stuff like exposure, I didn't sinc that too well. I would still like to see a nice sharp shot from someone else using a 70-200 f2.8 sigma. Comments on the images most welcome.

[LeDave]

What kind of UV filter were you using?

[rawr]

That's a good result.

For some examples of good shots taken with that lens, see here:
Full-size sample photos from Sigma 70-200mm F/2.8

The filter business doesn't surprise me. Most filters have horrible effects on IQ, and are also un-necessary.

But if you still want to use a UV filter, get something like a Hoya HMC UV-0 filter.

Lenstip put lots of UV filters through various lab tests. Results are here:
UV filters test - Introduction - Lenstip.com

[Robanstan_AU]

I bought a set of 75mm filters on eBay, being the Massa brand, and ok, I am embarrassed to say they only cost a few bucks so once again, you get what you pay for I suppose. Thanks for the links RAWR, that was great to see the results for this lens and a whole lot more. - Hi ho, hi ho, it's of shooting I will go!! -