Sigma IQ Expectations...

Thanks for your time & advice, Mike.

I'll ring Chris at SRS tomorrow & see what the procedure is.





Thanks also for the pointer to AF Contrast focus in live view, with the ability to zoom-in to check focus. This sounds very handy for macro!

Thanks again, all.

Roger.

This was one of my first shots to test what was then a recently acquired 150-500 last September (equally boring subject!):




K-5 with Sigma 150-500
1/800 @ f8
ISO 400

I usually take a similar shot with my new lenses to compare them. It seems quite a bit sharper than the one you have, but I've stopped it down a little and it was a brighter day so may not prove anything.

My suggestion is to find a similar flat subject on a brighter day and try again before dismissing it.

John

It is difficult to tell what's going on from full size images which have been resized for web (which itself adds blur). An unedited 100% crop would be helpful to see, maybe compared with another lens at the same settings.

Hi Roger
You havent seen all the worrying I did before I realised that good lighting a good subject and high contrast help this lens perform. First impressions are that your lens is not performing as it should but it may not be a focus issue--
Do a test on a fence that is running away from you at a slight angle. Set the camera to f8 or smaller aperture if possible, focus on a part of the fence some distance away (Mark it with chalk so you will see the bit you focused on later) Take several shots at different speeds etc.
Then review the shots in camera and on PC. The sharpest area should be the part you focused on.
Remember
1) The camera MUST NOT be set to Manual Focus
2) The Sigma lens OS must be set on if hand held, especially at full length
3) The camera OS must not be set
4) Ensure you avoid over exposing images, slight under exposure can be rectified and gives you the chance to up the shutter speed
5) If possible take only RAW photos
6) The Sigma seems best around f8 and shutters above 1/200sec if possible
7) My K7 doesnt seem good especially in poor light above 1250 ISO

Hope this helps best wishes
David

Hi Roger, certainly looks like a problem. Maybe focus needs adjusting for this lens?

Roger

I use my Sigma 150 500 every single day. Its a great lens when you get to know it.

I would echo what everyone says above - especially the F8 tip.

QC

Further thanks to all for the pointers to solving my problem(?) with this lens.

I'll try further tests this week when I get time/light to make it worthwhile!

I'm getting a little cheesed-off inasmuch as, given: tripods, monopods, mirror-up/remote release, stopping-down, high shutter speed, "good" light, high contrast subjects, (K7!) high ISO, etc., etc., etc.......

In the real world this lens/my K7 does not yield acceptable image quality!

Mind you, it was only 600 quid, so, what the hell.....!!!!!!!!!!!!!!!!!
(Are we down hearted...?
Too *%%^$""£! right, we're down hearted!)


R.

Sorry if I seem to be dismissing your problem, I am certainly not and was only relaying my personal experience. From what you say this lens/camera combination dont seem to be performing correctly. If you have only just got the lens you should be able to exchange it, avoid repairs as Sigma seem to have a very long turn around time.
It sounds to me that it has a problem, has someone got the same lens for you to try nearby, Lincolnshire is probably too far, but you could try mine if your passing by.
Finaly £600 is certainly not cheap if it doesnt do what it should do so best of luck and hope you get it sorted soon.
Best regards David

Thanks, David.

Sorry to have led off a bit & I certainly didn't mean to appear to be biting the hands that have fed me such help & advice here!

Having slept on it, A PLAN!

Go out into the real world, not "testing", in some decent light & take some pics at f8 & at iso 800. See how I get on.

Meet up with someone I know here who has a 150-500 & a K5 & try my Sigma on his camera & his on mine. Note any differences.Move on, if necessary to SRS.

Calm!

Thanks again, all,

Roger.

Best of luck, I hope its not faulty but if it is lets hope SRS are sympathetic and exchange it ASAP.
Regards David

roger before you return it do try a higher shutter speed ,also try it on my camrea as well before you send it back.brian

And finally...in our kitchen this morning:
Enough light = Sigma 150-500 fine!

ISO800, K7 Sigma @ 500mm, AF200T Flash, autofocus, PSE9....


[IMG]http://i1021.photobucket.com/albums/af340/rogerhlane/150-500flashtest004ADJ.jpg[/IMG]

All's well that ends well!

Roll on SUMMER & GOOD LIGHT!

Roger.

Is that a crop?

No, Mike, full size.
Sharpened a bit in PSE9.
On the original, you can see the half-tone printing dots on the "Iceland" label!

Roger.

For ISO 800 with a K7 and the Bigma that looks pretty good, you didnt say what shutter and aperture you were using. Have you done anything to the set up to acheive this or do you think it is poor light thats the root of the problem?
I know if I try in poor light with speeds less than 1/200 and large apertures I will be dissapointed. The problem is the K7 doesnt seem to like ISO much above 1000 either.
As you say the sun must come out soon and when it does I'm sure you will be delighted.
Regards David