Some Sigma lenses could leave scratch on the Pentax K-1 camera body

Pentax-K-1-sensor
This just in from Sigma – some Sigma lenses could leave a small scratch on the Pentax K-1 camera body:

Use of Pentax mount SIGMA interchangeable lenses when attached to the Pentax K-1

We have found that some SIGMA interchangeable lenses for Pentax mount could leave a small scratch on part of the camera body when they are attached to the PENTAX K-1, released by RICOH IMAGING COMPANY, LTD. on April 28th, 2016. In this circumstance, please do not use the following lenses for Pentax mount on the PENTAX K-1.
We are planning to provide a repair service for this issue. We will make a further announcement on our website when specific details, such as the service period, are finalized.
In addition, please also refer to the usage notice related to this announcement below.

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.

Applicable products
Current Line-Up
30mm F1.4 DC HSM| Art
35mm F1.4 DG HSM| Art
APO 50-500mm F4.5-6.3 DG OS HSM

Discontinued Lenses
50mm F1.4 EX DG HSM
85mm F1.4 EX DG HSM
24-70mm F2.8 IF EX DG HSM
APO 70-200mm F2.8 EX DG OS HSM
APO 70-200mm F2.8 II EX DG MACRO HSM
APO 50-150mm F2.8 II EX DC HSM
APO 120-400mm F4.5-5.6 DG OS HSM
APO 150-500mm F5-6.3 DG OS HSM

Usage Notice for customers who are using Pentax mount SIGMA lenses on a PENTAX K-1
In some cases, depending on the lenses to be attached on the camera, the angle-of-view cannot be recognized automatically. Please select an angle-of-view that is appropriate for the lenses to be attached from “Crop” in the camera’s menu.

When DG lenses are attached, please select “FF”.
When DC lenses are attached, please select “APS-C”.

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  • Zos Xavius

    Oh I see you got this already. Thank you.

  • Art Coses

    This is good to know.

    Will likely purchase Sigma’s 24-70mm Art lens–when released–for the K-1, provided they offer a Pentax mount for it. Suspect the Sigma will (greatly) outperform the Pentax 24-70mm.

    • TinusVerdino

      Because? Will they make it F2.4?

      • Art Coses

        Sigma’s optics for their 20mm, 24-35mm, 35mm and 50mm Art series are phenomenal–both in resolution and bokeh. The Pentax (Tamron) 24-70mm has very good resolution, but has a rather disappointing onion bokeh.

        On a Nikon D810, the Tamron 24-70mm scores a DxOMark sharpness score of 22, compared to Sigma’s 24-35mm 26 sharpness score. Additionally, the MTF scoring of both lenses at ephotozine.com indicates that the Sigma lens holds its sharpness much better at wide apertures. For example, the Sigma 24-35mm performs better at 24mm at F2.0 than the Tamron 24-70mm does at 24mm at F2.8; the Sigma is dramatically sharper in the center and better at the edges.

        Provided that Sigma’s 24-70mm F2.8 Art lens has the same quality features as the other Art lenses, it will significantly outperform the Pentax 24-70mm, providing better overall IQ results on the K-1.

      • Art Coses

        Sigma’s optics for their 20mm, 24-35mm, 35mm and 50mm Art series are phenomenal–both in resolution and bokeh. The Pentax (Tamron) 24-70mm has very good resolution, but has a rather disappointing onion bokeh.

        On a Nikon D810, the Tamron 24-70mm scores a DxOMark sharpness score of 22, compared to Sigma’s 24-35mm 26 sharpness score. Overall, the Sigma has a DxOMark score of 36 compared to Tamron’s DxOMark score of 31. Additionally, the MTF scoring of both lenses at ephotozine.com indicates that the Sigma lens holds its sharpness much better at wide apertures. For example, the Sigma 24-35mm performs better at 24mm at F2.0 than the Tamron 24-70mm does at 24mm at F2.8; the Sigma is dramatically sharper in the center and better at the edges.

        Sigma also offers an optional USB Dock for fine-tuning their lenses. On Sigma zoom lenses, the focus can be fine-tuned for 16 distances, providing better performance across the entire zoom range. With the Pentax zoom, you can only make a single AF Fine adjustment within the K-1-and that single adjustment is applied to the entire zoom range.

        Provided that Sigma’s 24-70mm F2.8 Art lens has the same quality features as the other Art lenses, it will significantly outperform the Pentax 24-70mm, providing better overall IQ results on the K-1.

        • TinusVerdino

          You cannot compare a limited zoom lens 24-35 to a 24-70. The Tamron outperforms the current Sigma 24-70 by a margin. It even scores better than the Nikon. (http://www.dxomark.com/Reviews/Tamron-SP-24-70mm-f-2.8-Di-VC-USD-Nikon-review-An-affordable-fast-standard-zoom-that-comes-out-on-top/Tamron-SP-24-70mm-f-2.8-Di-VC-USD-versus-competition )So Sigma will also have to greatly outperform Nikon and Canon. Bokeh highlights isn’t the same as Bokeh by the way. So you can stop crying onion! I am getting the distinct Idea we are dealing with a Sigma fan boy here the way you are cherry picking. When you just have to compare pears.

          • Art Coses

            “You cannot compare a limited zoom lens 24-35 to a 24-70.”

            Well of course you can, as this is precisely the function of MTF charts and DxOMark’s sharpness scores, viz., lens comparisons–whether zoom against zoom or zoom against prime, etc. In fact, many say they prefer primes over zooms–a comparison which essentially pits two quite different lens types against each other.

            Additionally, Sigma’s 24-70mm hasn’t be produced, so how could it actually be compared? This is why I ended with a clearly-worded proviso:

            “Provided that Sigma’s 24-70mm F2.8 Art lens has the same quality features as the other Art lenses…”

            “The Tamron outperforms the current Sigma 24-70 by a margin.”

            This is irrelevant, as it’s not predictive of Sigma’s pending 24-70mm Art lens, which was the primary focus of my posts.

            “So Sigma will also have to greatly outperform Nikon and Canon.”

            You do realize that the Sigma scores are done sans using their USB Dock for focus fine-tuning, don’t you?

            “I am getting the distinct Idea we are dealing with a Sigma fan boy here…”

            Why the blatant ad hominem?

            “When you just have to compare pears.”

            Did you mean by this incomplete sentence that lenses must have the same focal lengths for them to be compared? I hope you’re not serious, as this assertion would effectively fully invalidate all of DxOMark’s work. The reductio ad absurdum quickly dispenses with this assertion.

          • TinusVerdino

            So it is irrelevant to compare the Tamron 24-70 with the existing Sigma 24-70, but you can compare it with an imaginary sigma 24-70 and than the imaginary one wins because some other sigma zoom is sharper and then you are not a fan boy? You are trying to write the rules so you will always be right. Be that way, but nobody will take you seriously.

          • Art Coses

            You’ve thoroughly and entirely missed the very simple point, which was clearly expressed in the proviso:

            “Provided that Sigma’s 24-70mm F2.8 Art lens has the same quality features as the other Art lenses, it will significantly outperform the Pentax 24-70mm, providing better overall IQ results on the K-1.”

            It’s a hypothetical construct, which has embedded in its antecedent, a reference to “the same quality features as the other Art lenses” as a sufficient condition for the pending Sigma 24-70mm Art to “significantly outperform the Pentax 24-70mm.” How was this hypothetical proposition missed?

            My postings have always–without exception–been anticipatory, as in my very first posting where I said, “Suspect the Sigma will (greatly) outperform the Pentax 24-70mm.” Note the term “suspect.”

            My focus was all and only on the quality of Sigma’s Art series as having warranted predictive value for the quality of its pending 24-70mm Art, thus the irrelevancy of comparing Sigma’s current 24-70mm, which has no such predictive value.

            I clearly expressed not knowing whether “the imaginary one wins” by using “suspect” and including the proviso. It’s absolutely puzzling why these terms and expressions were–or could have been–missed, when they were in plain view all along.

          • TinusVerdino

            Well your suspicions are based on the false premise it is as easy to make a sharp prime lens as it is a sharp zoom lens and the zoom range doesn’t affect sharpness (in fact it isn’t very hard, just make a bigger lens, but it’ll weigh 3kg :p).

          • Art Coses

            I have no idea how–or why–you conjured such a premise, as it certainly wan’t extracted from any of my postings. None of my arguments–and none were enthymematic–contain such a premise.

          • TinusVerdino

            You are basing your suspicions that the imaginary 24-70 art will greatly outperform this Pentax/Tamron lens on the 35mm art, 50mm art (primes) and a very short zoom 24 to 35. I am telling you you cannot simply extrapolate that to a lens that covers a greater zoom range and has to zoom from ultra wide to short tele distances. You have no Idea of what you are writing and you seem to think a usb dock can improves sharpness. It can’t. it improves focus accuracy (since sigma has to guess the protocols and they are often wrong resulting in front or back focus). Lens sharpness testing isn’t done using auto focus but critical manual focus through live view or sample shots.

          • Art Coses

            The Sigma Art series, with the exception of its 24-105mm Art, has exceptional optical qualities which have earned each member of that set top ratings compared to similar and different lenses. Based upon this:

            1. It’s either the case that the Art series quality has predictive value for pending Art lenses or it does not.

            2. If it does not, then Sigma would not invest in producing a 24-70mm Art.

            3. However, Sigma is producing a 24-70mm Art.

            4. Therefore, the Art series quality has predictive value for pending Art lenses. (2, 3, modus tollens and 1, 2, disjunctive syllogism)

            There’s no question that predictions need to be confirmed, but the prediction is, in fact, reasonable, thus my suspected quality of the Sigma 24-70mm Art lens is justified.

            “… you seem to think a usb dock can improves sharpness. It can’t. it improves focus accuracy…”

            Again, I hope that you’re not serious here, since focus accuracy correlates 1:1 with sharpness, i.e., focus accuracy is both a necessary and sufficient condition for sharpness. However, it is the case that optimal focus accuracy doesn’t strictly imply that one lens is sharper than another–all other things being equal.

          • TinusVerdino

            “with the exception of its 24-105mm Art”
            there you go. A longer zoom :p it is easy to predict sharpness will be between the 24-35 and the 24-105. So it will be about on par with Nikon an Tamron and not greatly outperform them.

            Out of focus is not the same as unsharp, you can make the sharpest lens unsharp by not focussing correctly. Sharpness is defined by when the lens is focussing correctly. Something Sigma has al lot of problems with (phase detect and contrast detect) because of backwards engineering. So much it can’t even be corrected by in camera focus correction. The dock is a work around.

          • Art Coses

            The Sigma 24-105mm Art is a single outlier in the Art series, having been produced in 2013–even though it wears the “Art” moniker. The other Art lenses I mentioned were released in 2015, with updated optic protocols.

            “Out of focus is not the same as unsharp…”

            You’re equivocating on the term “unsharp.”

            “Sharpness is defined by when the lens is focussing [sic] correctly.”

            This is incorrect. A lens’s sharpness is a function of resolution (information gathering capacity) and contrast (adjacent tone discernibility)–both of which are directly impacted by focusing.

            “Something Sigma has al lot of problems with (phase detect and contrast detect) because of backwards engineering. So much it can’t even be corrected by in camera focus correction. The dock is a work around.”

            Well, then, the makes things look even better for Sigma. If what you say is true, then the current set of sharpness scores for Sigma lenses at DxOMark–which are better than most other lenses–likely fall dramatically short of the scores that would have been produced from USB-dock optimized Sigma lens. Especially for the K-1, I have no issue with using the USB-dock to get the very best out of Sigma lenses.

          • TinusVerdino

            As I said before, sharpness tests are done manually. They are not AF accuracy tests.

          • Art Coses

            Ah, yes you did. Then I stand rightly corrected on this issue.

    • sickheadache

      Here you go…You mean Tamron’s 24-70 with Pentax’s Name on it.

      • Art Coses

        Just about–sans Pentax’s proprietary optical coatings. The re-branding may also come with better QA/QC, but I’ve not heard that officially announced.

      • Randy Stiefer

        I think Pentax add some weather sealing as well.

        • sickheadache

          Pentax 1% Tamron 99%….Yep it is a Pentax.

  • TinusVerdino

    Sigma makes the outer dimensions their mounts too wide. That’s causing this.
    http://static.bhphoto.com/images/multiple_images/images500x500/1394655534000_IMG_377992.jpg
    Look at how far the contacts are from the edge.

  • Zos Xavius

    It’s not a big deal really.

    • TinusVerdino

      still wondering for which lens they made the upper groove

    • Lightleak_101

      Mine is scratched far far worse. Huge scratch..

      • Zos Xavius

        Bummer. 🙁

  • Lightleak_101

    Too late already scratched S#!7!!! Thanks Pentax!

  • Wesley

    Interesting to me is the 85mm 1.4 being listed as Discontinued. Maybe it happened and I missed it, but I wasn’t aware that had occurred. An Art version can’t be far away.

    • silmasan

      70-200/2.8 S too.

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