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05-27-2016, 09:02 AM   #16
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QuoteOriginally posted by Kunzite Quote
Of course. Ricoh wouldn't redesign part of their camera for a non-conforming 3rd-party product...
I guess it's not worth pointing out to you that the Sigma lenses conform to every other Pentax DSLR ever made.

05-27-2016, 09:07 AM   #17
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What scratch are we talking about ? Can anyone post a photo of it ?
05-27-2016, 09:18 AM   #18
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QuoteOriginally posted by Edgar_in_Indy Quote
I guess it's not worth pointing out to you that the Sigma lenses conform to every other Pentax DSLR ever made.
No, actually, they don't - and they never have.

As you well know.
05-27-2016, 10:21 AM   #19
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One possible reason for the prompt and open response from Sigma to this problem is the possibility of metal filings getting in to the camera/lens. Metal filings can short out the electronics, and scratch the surface of the lens or sensor. It's better to repair the product now than Possibly have to replace the product later. and maybe have to deal with a class-action lawsuit because of it. I'm glad the Sigma Corporation knows the importance of damage control, when it comes to their product. Other companies try to hide the problem and hope for the best. And they hope that the public doesn't put two and two together and file a class-action lawsuit against the company.

Sigma seems to be a responsible And Honorable company. and I for one appreciate that.

Thank You Sigma.

05-27-2016, 11:48 AM   #20
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QuoteOriginally posted by monochrome Quote
No, actually, they don't - and they never have.

As you well know.
I'm sure you realize we are talking about the clearance issue that only effects the K-1. If there have been past Pentax DSLR's that had the same issue, then that's news to me.

But regardless, other than my 50-150mm needing a firmware update to focus in live-view, I've never had a problem with any of my Sigma lenses not working properly with my Pentax DSLR's.

Last edited by Edgar_in_Indy; 05-27-2016 at 11:54 AM.
05-27-2016, 12:05 PM   #21
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QuoteOriginally posted by Edgar_in_Indy Quote
I'm sure you realize we are talking about the clearance issue that only effects the K-1. If there have been past Pentax DSLR's that had the same issue, then that's news to me.
I suggest you review dcshooter's detailed posts regarding the published K-mount Standard minimum clearance around the mount itself, which has been 58.5mm for over 40 years.

To summarize: The K-1 mount clearance is just slightly less than 62.5mm. The offending lenses have a poorly machined plate (a big washer) behind the actual male bayonet, which makes the Sigma lens match the K-mount register distance. The plate, which is what actually grazes the K-1 body, is between 62.25 and 62.5mm in diameter; some are said to actually be elliptical. Some lenses don't actually touch the body - others do. Sigma will replace that plate with one of a smaller diameter.

The affected lenses have never been K-mount compliant.

Pentax actually allowed for the plate, but Sigma's manufacturing tolerance for this part is sloppy - as can be shown by members' photos whose lenses do not actually scratch the housing.

Sigma isn't doing anything heroic nor commendable. They're correcting a product fault. Pentax has been silent because they've done nothing about which to speak.

Last edited by monochrome; 05-27-2016 at 12:19 PM.
05-27-2016, 12:40 PM   #22
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QuoteOriginally posted by monochrome Quote
I suggest you review dcshooter's detailed posts regarding the published K-mount Standard minimum clearance around the mount itself, which has been 58.5mm for over 40 years.
I didn't see the post you're talking about. But it doesn't matter, because my comment was not that all Sigma lenses conformed to a publication of the K-mount from 40 years ago. Pentax cameras have changed a lot since then. My comment was that the lenses conformed (eg had no clearance issues) with all other Pentax DSLRs ever made.

I also wasn't aware that it was just a problem with the lens plate. I figured it had something to do with the overhang of the lens body itself. If it's just the plate, then that should be a simple and inexpensive fix.
05-27-2016, 02:01 PM   #23
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QuoteOriginally posted by Edgar_in_Indy Quote
I guess it's not worth pointing out to you that the Sigma lenses conform to every other Pentax DSLR ever made.
Yet Pentax isn't obligated to design their DSLR to function with 3rd party, unlicensed lenses. It isn't a Pentax issue, it is a Sigma issue if they want to continue selling K mount lenses and have them function (without issue) on subsequent bodies from the time they released them.

05-27-2016, 02:45 PM   #24
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I just can't get my head around what the K-1 shell design has to do with any of the APSc bodies that went before. I get that Sigma lens owners might be disappointed, but I don't get that they're disappointed with Pentax.
05-27-2016, 03:12 PM   #25
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QuoteOriginally posted by mee Quote
Yet Pentax isn't obligated to design their DSLR to function with 3rd party
That depends what view ricoh exec have on developing their business. There are other products that must work according to a standard in order to interoperate with complementary third party products. For example, WIFI must comply to WIFI specification so that the camera WIFI can effectively work with other device using the same standard, and every manufactured has to test their appliance with the most common third party products supposed to inter-operate, that's the case for mobiles phones, NFC and many other things. This sigma lens issue means that Ricoh did not test the K1 with Sigma lenses, ignoring that some users already have sigma lenses and that sigma lenses are part of the ecosystem (tamron, zeiss etc). The K1 also has issues of interoperability with third party flashes. The sigma lens issue is a minor issue IMO. Flash interoperability and lens interoperabilty just tells me that Ricoh did not care much about it, maybe they had no time , no interest, no idea to test it, or all, however for business it is not a good idea to ignore interoperability issues. That being said, in the canon community, Sigma has a bad reputation, I've heard of sigma hsm damaging canon AF camera drivers... Several canon guys had trouble, and advised me not to buy a sigma lens because of potential issues, so it's not always up to Pentax to cope with Sigma but the interest of Sigma is also to make sure their lenses can work correctly with camera bodies .
05-27-2016, 03:16 PM   #26
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QuoteOriginally posted by monochrome Quote
I just can't get my head around what the K-1 shell design has to do with any of the APSc bodies that went before.
Especially if the K-1 shell design is within the published dimension specifications for K-mount lenses.
05-27-2016, 03:46 PM   #27
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QuoteOriginally posted by biz-engineer Quote
That depends what view ricoh exec have on developing their business. There are other products that must work according to a standard in order to interoperate with complementary third party products. For example, WIFI must comply to WIFI specification so that the camera WIFI can effectively work with other device using the same standard, and every manufactured has to test their appliance with the most common third party products supposed to inter-operate, that's the case for mobiles phones, NFC and many other things.
Wrong analogy; in this case, it's Sigma who did the "nonstandard WIFI". Yet your post is suggesting that it's the OEM who didn't work "according to a standard"... I wasn't aware that Sigma can alter the K-mount specifications on their own (and why stop with the physical dimensions, why shouldn't they decide the communication protocol, too... perhaps making Pentax products incompatible!).
05-27-2016, 04:13 PM   #28
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@biz-engineer We do not know that Pentax did not take the Sigma design into account. A shim plate on some examples of the lenses touches the body. Some users have posted photos showing that their example of one of the enumerated lenses has a plate that does not touch the body. Others show the same plate does touch the body. One user described the plate as elliptical.

The K-mount minimum surrounding space specification is exceeded by 4mm on the K-1 - IOW, Pentax could have allowed for the Sigma lens design. The plate itself is coincidentally 4mm larger in diameter than the K-mount minimum standard, and the excess space allowance is 4mm more than the minimum K-mount standard, so there really shouldn't be a problem if Sigma had good QC. The problem is, Sigma poorly machined the offending plate.

NOTHING Pentax did designing the K-1 shell is impeachable.
05-27-2016, 04:33 PM   #29
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If Sigma is not licensed by Ricoh for the K-mount Ricoh has no obligation to check Sigma's implementation for compliance.

If a third party uses a non-standard implementation of WiFi the responsibility is up to the 3rd party to make sure their implementation works with standard implementations.

What does it matter? Sigma has taken responsibility and is offering a solution.
05-27-2016, 04:41 PM - 1 Like   #30
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QuoteOriginally posted by Edgar_in_Indy Quote
I figured it had something to do with the overhang of the lens body itself
It does. In recent DSLR's Pentax has been visibly and clearly reducing the body clearance above the mount. It's easily visible from model to model. The latest reduction in clear space above the mount is also poor design on behalf of the K-1 body designers, IMHO. It's seems just practical to keep the area around the mount reasonably flat and clear, like previous and older Pentaxes did (and other brand DSLR's do), not have the body arch up immediately from the lip of the mount plate.

So I think Sigma and Pentax share responsibility for this problem. Both contributed to it.

It could have easily NOT been a problem if Sigma and Pentax had talked to each other during the evolution of the K-1, as partners in the Pentax eco-system. Or if Ricoh had simply run a broad beta test program during the evolution of the K-1, so that the K-1 body design would have been exposed to the Sigma lenses that real-world users would likely mount on the K-1, allowing the K-1 designers to nip any physical design problems in the bud.

My Sigma lenses have no problem with the K-1, even though they are on the 'problem lens' list, so I don't have a personal axe to grind here with either Sigma or Pentax. Just observing this fracas with a little disappointment that experienced Japanese designers and engineers in both camps could make such simple but annoying blunders. I hope Ricoh or Sigma don't ever work together on aircraft design.

Last edited by rawr; 05-27-2016 at 04:46 PM.
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