[Winder]

I don't think having a mount plate that is a couple mm larger is analogous with "poorly crafted". Sigma makes a lot of lenses that are larger and heavier than the average lens, so for all we know it could have been a conscious design decision that use a mount plate that was slightly beefier, to put less stress on the small flanges for lenses such as the 50-500mm. And since there had always been plenty of allowance around the mount in the past, even on the vast majority of the old film cameras, then why not?

And despite all the talk of official "published" specs, nobody so far has been able to provide proof of such a thing, so at this point I have to assume that those people are talking out of their you-know-whats.

If you want to complain about a company cutting corners on the mount plate to save a few cents, then lets look at which company has made a large number of lenses with plastic mounts. I've never owned a Sigma lens with a plastic mount, not even the budget lenses I have come across.

People are just looking for something to bitch about. Most of the people who own and use Sigma glass don't care about the very small mark. The people who seem to care the most are the ones who don't own or use Sigma glass. Ironic. When the 3rd party suppliers abandon K-mount they complain. When the 3rd party suppliers make products for K-mount they complain.

Sigma uses a thicker, and possible stronger mount than Pentax and people want something to complain about.

[luftfluss]

People are just looking for something to bitch about.

Umbrage may be second only to p0rn for Internet usage.

[Edgar_in_Indy]

Sigma still produces poor quality controlled mediocre lenses, that does include the "Art" thingies, which are no better than the older ones (only now they make the less brainy customers pay for repair tools for faulty Sigma lenses such as the USB dock).

Now it has turned out a whole bunch of them have even more been poorly designed (poor design quality comes to poor production quality ), even though it really is only a small Sigma error this time.

Now they try to control damage they have caused, which is the absolute minimum they need to do if they want to stay in the game. Sigma lenses damaging customers main gear is not a good sign.

Good for them, but nothing to really rave about, unless you are die hard Sigma fanboy (and there are enough of them around).

These quality issues are the very reason their lenses have to be priced -40% below OEM equipment and why even then nobody would buy it without a 50% extra warranty period.

Your rant about Sigma's alleged lack of quality control is pretty rich, considering that Pentax is the company whose top-of-the-line, bread-and-butter zoom lenses are almost guaranteed to fail not too long after the warranty expires. And what's more, Pentax lets their loyal customers take the hit, pretending like the rampant reliability problems do not exist.

And the cherry on top is how when you do send your SDM lens to a Pentax affiliate to be repaired, it can take weeks or months to get it back, often with very poor communication.

I guess some people are just gluttons for punishment.

This is all in stark contrast to how Sigma operates and takes care of their customers.

[D1N0]

brand bashing

[cafazucar]

Fanboys will be fanboys. Defending one company by attacking another doesn't make you look reasoned, it makes you look childish.

It has always been the responsibility of 3rd party manufacturers to stay up to date with new releases and ensure their products continue to function properly. Which is why Sigma is taking on the repair costs, so as to not alienate their Pentax-using base. Did Pentax designers take 3rd party lens manufacturing tolerances into account when designing the K-1 mount? It doesn't seem likely.. Should they have? Well, you know, that's just like your opinion man.

[Edgar_in_Indy]

Fanboys will be fanboys. Defending one company by attacking another doesn't make you look reasoned, it makes you look childish.

Why are you calling names? I was pointing out the irony of his willful blindness when it comes to Pentax's own track record of quality and customer support. If anything I've said is un-reasoned, then feel free to point it out.

[cafazucar]

Why are you calling names? I was pointing out the irony of his willful blindness when it comes to Pentax's own track record of quality and customer support. If anything I've said is un-reasoned, then feel free to point it out.

Attacking one company does not do anything to help defend another company's mistakes, it's a logical fallacy (false equivalency) and devolves the thread into a flame war. Also it wasn't only directed at you, but from the beginning of this thread you've been down-talking the Pentax brand, products, customer service, all on a Pentax forum. Nothing wrong with stating your opinion, but Sigma already stepped up and took responsibility for this one. Yet somehow this is still Pentax's fault? I don't think he's the one who is willfully blind

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Last edited by cafazucar; 05-29-2016 at 06:50 PM.

[sculptor666]

there are a few possibilities, but the sigma lenses existed before the k-1, which leads me to believe:

pentax sends a pre-production body (or cad drawing or whatever) to sigma for testing, and sigma gives incorrect feedback somehow. could be as simple as "we have 1.0 mm clearance" instead of "we have .10 mm clearance" and the production is .3mm different the pre-production, and now you have scratches instead of a gap.

[D1N0]

Pentax does not support Sigma so they don't consult them, or take Sigma into account when designing a camera.

[Kunzite]

Do you not get that the difference never mattered until recently?
Why achieve any kind of precision, if it does not benefit anything, other than preventing an illogical argument to be made?

Do you not get that Sigma made lenses with a mount significantly larger than every Pentax K-mount, i.e. than the OEM products they were reverse engineering? They deliberately ignored a very obvious physical characteristic of the OEM products.
As for the "why", how could you even ask that? Because they risked their lenses not fitting future products, which is what happens with the K-1. Doh!

One can still buy this lens new, like a number of other Tamron lenses in K-mount.

So, no, you did not provide evidence for your claim that without rebadging we wouldn't be able to use Tamron lenses on our Pentax DSLRs.

Just in case you are talking about new Tamron designs like the 24-70/2.8, I doubt you can provide evidence that Tamron wouldn't have offered it (and similar ones) for K-mount after the introduction of the K-1.

I never claimed "that without rebadging we wouldn't be able to use Tamron lenses on our Pentax DSLRs", I would never make such silly claims. So naturally, I won't ever attempt to "produce evidence" to support it.
What I said instead is that Tamron last introduced a K-mount lens in 2008 - that's 8 years ago; there's no indication they would have introduced the 15-30 and the 24-70 in K-mount if it wasn't for the Pentax deal. So your claim that the Pentax deal makes things worse is dubious, unless you could prove that without it we'd have those lenses cheaper.
Yes, the burden of proof is yours.

---------- Post added 29-05-16 at 11:52 PM ----------

Your rant about Sigma's alleged lack of quality control is pretty rich, considering that Pentax is the company whose top-of-the-line, bread-and-butter zoom lenses are almost guaranteed to fail not too long after the warranty expires. And what's more, Pentax lets their loyal customers take the hit, pretending like the rampant reliability problems do not exist.

Pentax' top of the line zoom lenses are the D FA 70-200mm f/2.8 and D FA 150-450mm (as well as the Tamron rebadged 15-30mm f/2.8 and 24-70 f/2.8). I'm not aware of any of them being "almost guaranteed to fail".

[UncleVanya]

For those defending Sigma and saying Pentax deliberately or ignorantly messed up the clearance - ask yourself this. If the spec is xyz, but they allowed for much greater than that - an amount that happens to be about the exact amount plus a bit of the Sigma clearance - and the only lenses scratching the mount are those that seem to have a poorly machined eliptical rather than round part - how exactly was Pentax able to predict this?

It seems simple enough. Some reasonably sloppy machine work was done to make some mount spacers. These did not cause issues with past cameras and so Sigma let them slide because they did not detract from the usefulness or put off buyers. They never anticipated this change from Pentax and despite the fact that Pentax appears to have attempted to make allowances it seems like Pentax did not know about the eccentricity of the parts.

It doesn't take malice or failure - it just happens. Sigma did nothing wrong by accepting the eccentric parts since they caused no issues prior to this. Pentax wasn't trying to harm Sigma users and force them to Pentax products either. Kudos to Sigma for stepping up and offering a solution - there is nothing practical that Pentax could do in this situation other than perhaps make the repairs available to Sigma and perhaps cut them a break on price.

In any case - I have no idea why people take umbridge on this topic. Problem exists, sigma offers a fix, the end.

[Not a Number]

Oh course. Sigma calls the shots. Ricoh has to dance to Sigma's tune. Sigma decides the flange register should be 1mm shorter or move the locking pin socket 3mm. Ricoh has to come up with a solution and redesign all their bodies and lenses to accommodate Sigma's new standard.

[Edgar_in_Indy]

For those defending Sigma and saying Pentax deliberately or ignorantly messed up the clearance - ask yourself this

That was actually the theory floated by Monochrome, who is most definitely not a fan of Sigma. My theory is that it just happened, without any specific intent on either side.

It seems simple enough. Some reasonably sloppy machine work was done to make some mount spacers.

Why assume that "sloppiness" was the cause? Sigma seems to actually make really nice lenses, so that does not seem like a fair assumption.

If you look at the list of effected lenses, they are all the larger/longer/heavier lenses, with the sole exception of for the 30mm. So I think it seems more likely that the mount plate was simply beefed up a bit to help distribute the weight/leverage of the larger and heavier lenses.

[Edgar_in_Indy]

Oh course. Sigma calls the shots. Ricoh has to dance to Sigma's tune. Sigma decides the flange register should be 1mm shorter or move the locking pin socket 3mm. Ricoh has to come up with a solution and redesign all their bodies and lenses to accommodate Sigma's new standard.

Yeah, except that's not what happened. Which past Pentax cameras do the Sigma lenses not work on?

And besides that, it's not even a matter of the lens not working. It's a tiny, tiny scratch that many people probably would not have even noticed, had Sigma not decided to fix the "problem".

[UncleVanya]

That was actually the theory floated by Monochrome, who is most definitely not a fan of Sigma. My theory is that it just happened, without any specific intent on either side.



Why assume that "sloppiness" was the cause? Sigma seems to actually make really nice lenses, so that does not seem like a fair assumption.

If you look at the list of effected lenses, they are all the larger/longer/heavier lenses, with the sole exception of for the 30mm. So I think it seems more likely that the mount plate was simply beefed up a bit to help distribute the weight/leverage of the larger and heavier lenses.

The coincidence seems unlikely.

The rings in question are eccentric not round and it affects only a portion of the impacted models of lenses. That seems to clearly indicate this isn't intentional.

I think you are just looking for shadows where none exist.