Sigma 100-300 F4

http://www.ebay.co.uk/itm/Sigma-100-300mm-F4-APO-IF-EX-Pentax-Fit-STN-29027-/252...?
£399 inc. 3 months warrantee.

PS: it's the "APO", and not the "APO DG", version and so I think it is probably one of the early copies.

Confirmed: see the links in Post 5 of this US forum thread

OTOH, SRS have one of the later versions at £699 with a year's warrantee

So maybe the perceived drop in prices relates to the version that is for sale?

There were 2 versions of the APO DG , the first had the same pattern on the focus ring as the original APO and the second (below) has straight vertical lines. If you look at the one SRS has it has the same pattern on the focus grip as the one from Mifsuds and is not the same as the second one on the post you linked to at Pentaxforums.

If anyone was going to buy one then this is the version they want as there no supposed front/back focus issues.

Sorry, you are correct - and I am confused because I looked carefully at the images for both versions and thought I was correct about the SRS offering! .!!!!

BTW, today I have been doing some AF tests with my later version (which was fully serviced and checked by Sigma Imaging a couple of years ago) on my K3/K5/K30 in my garden at the longest focal length - and it back-focuses badly (needs about +8 to +10!) with all of them, DUH!

OTOH, the very old 70-200 APO is fine with the K-3 & K5 but back-focuses quite badly with the K30, and the 150-500 HSM (which was serviced by Sigma last year) needs little or no correction with the K5 & K30 - but needs -9 or so with the K-3. The 18-135 needs a lot of back-focus correction with all 3 bodies!

What DO you make of that?

Anyway, I think I will redo the tests on Tuesday if the weather is reasonably OK to confirm the above.

BTW2: the old 70-200 APO and the 100-300 appear to have the same internal chip that the body reads because I did the 100-300 test first, and when I then fitted the 70-200 the K3 read it and applied the same +9 correction - whereas when I readjusted the correction for the 70-200 I got a correction factor of +/-0.

BTW3: All the tests were done with the lenses wide open, although the lighting conditions varied because the cloud levels changed minute-by-minute.

Maybe one of the Mods could move this thread to the Lenses part of the forum?

Did a quick recal of my 100-300 with the K-3 and it still requires +10 adjustment - i'll have to live with it for the next couple of months but then the K3, which I think is the problem as the lens was fully serviced by Sigma 2 yrs ago, is going to Johnsons for check/adjustment at the end of the Summer

Seems strange that it's back focusing with all of them.

Although the one I bought the other day is in excellent condition I may send it into Sigma for a service, I know parts are near on impossible to find for the lens now so maybe a good going over will mean less problems in the future.

Can you remember how much they charged for the service?

Re first comment: I agree but other Sigmas appear to do the same, so that's why I think the body needs looking at as well. FWIW I think the charge was pretty similar 2 yrs ago.

Re 2nd comment: the basic lens has been available for other mounts for a lot longer than for the PK mount, so the situation may not be quite as bad as you think.

Re last question: see here, Tariff 7 = £131.99 (includes return RMSD IIRC).

Again, maybe one of the Mods could move this thread to the Lenses part of the forum?

Sigma are no longer servicing 100-300mm f/4 I called them last month and they have no parts available at all. This was in Nikon mount but I assume all other mounts are affected.

I wonder what SRS will do if their lens develops a fault in the next 12 months.

The 100-300 is still shown on the Tariff 7 list, so I'll send Sigma an email to see if the PKA mount version can still be serviced and to what extent.

Just heard back from Sigma (Daniel Cortez, the Service Manager) - he believes that the lens needs a new circuit board to fix the back focus issue and is checking with Japan to see if they are still available.

BTW: if you contact Sigma (see their UK website for contact details) they will need the S/N of your lens before they can check/confirm what they can do.

John

That's odd when I called them they where adamant they could get no parts for any 100-300mm f/4 otherwise I would have got mine repaired. Will be interested to here what they say.

Gary

Won't we all!

Heard from Mr Cortez today - he now has the new circuit board and is holding it for me until I can get the lens to him!

Cool I will be giving Mr Cortez a call