Info regarding Sigma lenses on a K1


Algernon

Link Posted 13/05/2016 - 14:35
If Pentax want to do a straight swap..... My Sigma 150-500mm for their lens I'll gladly buy a K-1 Problem solved


--
Half Man... Half Pentax ... Half Cucumber

Pentax K-1 + K-5 and some other stuff

Algi

bforbes

Link Posted 13/05/2016 - 14:36
Just been looking at the differences in construction between my Pentax and Sigma lenses. The older Sigma's (24-70 f2.8 none HSM, 10-20 f4/5.6) have the metal part of the mount a smaller diameter (60.66mm and 62.78mm), and partially recessed into the plastic body of the lens.
My newer Sigma's (8-16 f4.5/5.6HSM, 17-50 f2.8 HSM) are 63.64mm metal mounts protruding from the plastic body.

In comparison the Pentax DFA 50 and DFA 150-450 have the metal part of the mount completely recessed into the body. It's worth noting the outside diameter of the 150-450 mount is larger the any of the Sigmas at 64.2mm

So I'm wondering if the scratch is happening when the lens is being aligned and the metal edge of the mount catches the body, otherwise I'm thinking it would also happen when mounting the 150- 450
Barrie
Too Old To Die Young

http://www.pentaxphotogallery.com/artists/barrieforbes

Kim C

Link Posted 13/05/2016 - 15:19
Algernon wrote:
If you had say 3 lenses that were effected would you buy a K-1?
They aren't Sigma's lenses..... they are YOUR lenses.

If you can only buy mail order would you buy and hope the lenses fit?

Would you be happy scratching your spanking new body?

Best possible case for Pentax would be that Sigma owners would say.... "I'll hold off until I see what Pentax do..... Maybe they will bring out a K-2...... Maybe they will sell off old stocks of the K-1 at 50% discount to Sigma owners"

--

Well if they were PK fit lenses, what other FF digital body will they work on
And Sigma will alter them so they do work.

Kim C

Link Posted 13/05/2016 - 15:23
bforbes wrote:
Are any Pentax made legacy lenses the wrong size to fit the K-1?

I believe the problem is only with some Sigma lenses where they have made the rear boddy slightly too large. Maybe if Sigma worked with Ricoh and paid royalties rather than reverse engineering it would help.

I don't have every Pentax lens but none of the Pentax, Zeiss or Voightlader glass causes a problem.

RobL

Link Posted 13/05/2016 - 17:45
I am sure the issue is with Sigma's mount construction. Here is a side by side comparison with Sigma on left:


To emphasise the difference in mount diameter here's one with a Pentax cap which completely covers a Pentax lens mount, but leaves a Sigma mount exposed by a wide margin:


The outer part of the Sigma mount with the four screws is raised by a very small amount, and as the screws are countersunk marginally below the surface of this ridge you can just feel the edges of the holes. I reckon these are the cause of the problem.
Last Edited by RobL on 13/05/2016 - 17:46

RobL

Link Posted 13/05/2016 - 17:55
PS. So here is a simple test to check whether a lens mount is ok - take a standard Pentax rear lens cap and see if it covers the mount; if not, then be careful.

Blythman

Link Posted 13/05/2016 - 18:45
smudge wrote:
Yes. I have the non HSM version of the 24-70. It is a comfortable fit - no rubbing - and performs very well on the K1

Thanks from me too Smudge. Good to know I've got a walkaround zoom, just in case the temptation gets too much.
Alan


PPG
Flickr

Mike-P

Link Posted 13/05/2016 - 20:06
bforbes wrote:
Has any one tried the non HSM version of the Sigma 24 70 f2.8 on the K-1?

No but after looking at my Sigma lenses I'm betting the older non HSM version will be fine. My 85mm f1.4 and 70-200mm OS have the problem (larger) mount, as did my 50-500mm OS but my 100-300mm f4 and 12-24mm have the much smaller diameter mount.
No equipment list here but thanks for taking an interest. My Flickr
Last Edited by Mike-P on 13/05/2016 - 20:06

Blythman

Link Posted 27/05/2016 - 16:44
Barrie, have you tried your old Sigma 24-70 on your K1? Happy with it?
Alan


PPG
Flickr

bforbes

Link Posted 27/05/2016 - 16:48
Blythman wrote:
Barrie, have you tried your old Sigma 24-70 on your K1? Happy with it?

I've had it on, it fits no problem, but I've got no images with it yet.
Barrie
Too Old To Die Young

http://www.pentaxphotogallery.com/artists/barrieforbes

Blythman

Link Posted 27/05/2016 - 17:00
bforbes wrote:
Blythman wrote:
Barrie, have you tried your old Sigma 24-70 on your K1? Happy with it?

I've had it on, it fits no problem, but I've got no images with it yet.

Do it ... lol
Alan


PPG
Flickr

Mike-P

Link Posted 02/06/2016 - 18:47
UPDATE- Use of Pentax mount SIGMA interchangeable lenses when attached to the "Pentax K-1"

Thank you for purchasing and using our products.

We would like to inform you of our policy on the repair service that we announced on May 11th,regarding the use of Pentax mount SIGMA interchangeable lenses when attached to the “Pentax K-1”.

For customers using our interchangeable lenses with aforementioned camera body,
we apologize for the inconvenience. Please find the following details for the phenomenon and products;

【Phenomenon】
When some SIGMA interchangeable lenses for Pentax mount are attached to the PENTAX K-1,
the upper part of the mount can be scratched.
※This phenomenon is due to the interference with the shape of the upper part of the mount on the PENTAX K-1
camera body and it does not occur to any cameras other than PENTAX K-1.

【Products】
・Current Line-Up
SIGMA 30mm F1.4 DC HSM| Art
SIGMA 35mm F1.4 DG HSM| Art
SIGMA APO 50-500mm F4.5-6.3 DG OS HSM

・Discontinued Lenses
SIGMA 50mm F1.4 EX DG HSM
SIGMA 85mm F1.4 EX DG HSM
SIGMA 24-70mm F2.8 IF EX DG HSM
SIGMA APO 70-200mm F2.8 EX DG OS HSM
SIGMA APO 70-200mm F2.8 II EX DG MACRO HSM
SIGMA APO 50-150mm F2.8 II EX DC HSM
SIGMA APO 120-400mm F4.5-5.6 DG OS HSM*
SIGMA APO 150-500mm F5-6.3 DG OS HSM*
* it is applicable to the models without OS function, too.

For details of this repair service, please contact your nearest authorized subsidiary/distributor of Sigma.

【In case of scratch on the PENTAX K-1 camera body】
In case your PENTAX K-1 camera body has got a scratch from attaching aforementioned lenses,
we are planning to repair the damaged part of camera body, too.

The detail of repair will be announced later, and we would probably ask customers to send the camera body and lens to us.

* Once we receive the camera body, we would ask RICOH IMAGING or its authorized repair stores to repair it.

We will inform the lead time for repair, and return the body and lens as quick as possible.

We appreciate your continued support for our company and products.
No equipment list here but thanks for taking an interest. My Flickr

RobL

Link Posted 09/06/2016 - 16:38
Took mine into the local LCE today, be interesting to see what Sigma do with it as I will be very cautious about using it again. Luckily the mark on my camera body is barely noticeable so i won't be letting Sigma treat that as well.

Mike-P

Link Posted 09/06/2016 - 16:45
Did they ask you for proof of purchase?

Both my 70-200mm OS and 85mm 1.4 were purchased used and previously Sigma have always wanted original proof of purchase before doing any work.
No equipment list here but thanks for taking an interest. My Flickr
Last Edited by Mike-P on 09/06/2016 - 16:46

RobL

Link Posted 09/06/2016 - 19:48
Mike-P wrote:
Did they ask you for proof of purchase?

Both my 70-200mm OS and 85mm 1.4 were purchased used and previously Sigma have always wanted original proof of purchase before doing any work.

No, but I suppose this isn't a warranty issue.
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