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Sigma : FE mount too small for ART quality lenses

ptomsu

Workshop Member
Sensor size in m43 is actually 1/4 of FF (~225 square mm for m43 vs over ~860 for FF) and as m43 lenses have much smaller sensor area to cover designing and manufacturing quality lenses is much easier, but this is much more of the factor of sensor size than anything else.
Of course you are right with sensor size of m43 compared to FF - sorry for my fault.

But on the other hand you exactly get what is one of the biggest advantages of sensor size - smaller sensors allow for much more relaxed lens/camera designs while still keeping IQ high. Plus given the advances in sensor design today under practical circumstances the differences to FF have shrunk considerably! Sure there are less MP possible and DR is not as good, but end of the day for practical photography the possibility to design easily better lenses/cameras outweigh the relatively small improvements of IQ, DR and better high ISO.
 

iiiNelson

Well-known member
...but end of the day for practical photography the possibility to design easily better lenses/cameras outweigh the relatively small improvements of IQ, DR and better high ISO.
For the web I would agree 100% but when you want to print larger sizes without having to resort to dialing back the PPI then a picture taken with a larger sensor and equally/better lens will almost always be more impactful when the person holding the camera does their job.

Yes a camera is just a tool but better tools usually lead to better end results.
 

Godfrey

Well-known member
Eh? Sounds like spin to me. I doubt I'll ever buy any Sigma ART lenses anyway, for either Sony or any other mount.

My A7 is a means to a specific end: a digital body for my Leica R lens kit. I have all the lenses I want there, so it's a companion body to the Leica R8 and Leicaflex SL at best. For me, it's a good sensor and a decent viewfinder, able to work with my lenses well, and otherwise a clunky little thing.

Frankly, I'll take the Leica R lens imaging qualities over any Sigma ART lenses. ;-)

G
 

ZoranC

New member
It doesn't surprise me to hear this. When I first heard of FF behind NEX E-mount I looked at it and felt no space for it has been left, that it was designed for APS-C and FF ended up an afterhought, an "Oppppsss, demand for FF caught us by surprise and we were not designing for it, let's see can we manage to fit it in anyway by the skin of our teeth" kind of moment.
 

philber

Member
I think there are a variety of reasons why Sigma aren't yet releasing lenses for the A7. One is that, for premium lenses, Sony-Zeiss and Zeiss themselves have a huge advantage, and that would be hard for Sigma to overcome, except maybe in the short term. Then, porting a design to the A7 may not be that straightforward: short register, not-very-wide mount, 2mm sensor cover glass are all issues that need taking care of. Lastly, while ART lenses are excellent, they aren't exactly light and compact, unless you compare them to OTUS. Thus, Sigma ART lenses would be a bit counterintuitive on the light and compact A7. But, if Sony are successful with that camera line, as they seem to be for now, Sigma will have no choice anyhow and will follow suit.
 

pegelli

Well-known member
I'm afraid the CEO of a rival company comes even further down the 'ladder of knowledge' especially one of a firm that has just locked itself into a strategy totally dependent on the continued health of the enthusiast segment of the falling DSLR full frame market, with two early releases of its headlining ART range characterised by boat anchor weight levels, huge complexity and Otus level physical dimensions.
I think this sums it up nicely, for me it's a clear mixture of spreading poppycock and FUD because Sigma doesn't want to develop FE ART lenses. They probably think it isn't good business for them, however it would be much better to just admit that then raising a smoke screen like this. There's enough proof out there from other brands that show how pityfull this Sigma statement really is.
 

Steve P.

New member
But, if Sony are successful with that camera line, as they seem to be for now, Sigma will have no choice anyhow and will follow suit.
They may well do, but perhaps not with the quality of their Art series. Sigma are to be applauded for their Art lenses which represent a step-change in the quality and reputation of their brand, which for years had been known for wide ranging sample variation from excellent to poor in many of it's lines, leaving many with the feeling they were entering a 'lucky dip' and hoping they wouldn't have to return too many samples before they found one that was acceptable. I'm pleased that Sigma are leaving those days behind but I'm not yet sure they've done enough to make me trust their judgment over that of Zeiss in the matter of manufacturing top quality lenses for Sony FE mount cameras. The man from Sigma's comments have the whiff of someone trying to get his excuses in early!
 
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tn1krr

New member
I think there are a variety of reasons why Sigma aren't yet releasing lenses for the A7. One is that, for premium lenses, Sony-Zeiss and Zeiss themselves have a huge advantage, and that would be hard for Sigma to overcome, except maybe in the short term. Then, porting a design to the A7 may not be that straightforward: short register, not-very-wide mount, 2mm sensor cover glass are all issues that need taking care of. Lastly, while ART lenses are excellent, they aren't exactly light and compact, unless you compare them to OTUS. Thus, Sigma ART lenses would be a bit counterintuitive on the light and compact A7. But, if Sony are successful with that camera line, as they seem to be for now, Sigma will have no choice anyhow and will follow suit.
Light and compact is not the only design goal for FE lenses. Sony has pretty big/huge 35/1.4 coming next spring. But other than that, I agree with you and can add even a few more things: current Art lenses have wrong kind of focus motors; they are pure PDAF lenses with focus motors quite far from optimal for CDAF & sensor-AF in general. Lens motors of Pure-PDAF lenses are optimized to go fast to certain focus point and not that good at making small corrections needed by CDAF which is based on iteration. Canon has some of the fastest PDAF focus motors (USM) there is, but their dual-pixel sensor AF works best with lowly STM lenses due to their step motors. This is the reason for Sony FE 70-200 having totally different AF and optical construction from the A Mount version.

So there would be a lot of work to be done to get a well working FF mirrorless lens out and they would have to be targeting single mount and competing with very high quality offering from Sony/Zeiss. If Sigma were to "port" current 35/50 ART lenses to E mount I'd say competitive picture is not to their liking; both focal length already have minimum of 2 very high quality offerings available and not that that many FF E mount bodies out there when compared to Canikon bodies. Business math just does not add up for them
 

Guy Mancuso

Administrator, Instructor
All sounds like a little BS to me. The issue is really all about money and investing in a mount that can only be used by one system , that's new, not totally established yet and does not have the market share of Nikon G, Canon EF or Sony A mounts which they make one lens for and reverse engineer the mount. For that kind of market share they would design and build for but for a single mount like Fuji, Sony FE mount. There not going to drop money in the R&D. I wish they just be honest about it and flat out admit it. I have the Sigma 35mm Art lens in the A mount and it is one of the highest rated 35mm lenses to date so yea it would be nice to make it in a FE mount and if Zeiss and Sony can make FE mounts than certainly Sigma can its not a technology barrier on there end it's purely money and market share. Not withstanding they would directly be competing with Zeiss and that's not a fun competition for them since the Zeiss glass is outstanding today. Btw with the La4 adapter it works very nicely. Big lens no question but really any 1.4 lens will be pretty big if you are designing for the least amount of aberrations.
 

Jack

Sr. Administrator
Staff member
Canon had to change their FD mount to the EF mount specifically to produce the 50/1.0 and 85/1.2 -- the FD mount was too restrictive to go faster than 50/1.4 and even do 85/1.4 well; and at the time, Nikon had the 50/1.2 and 85/1.4 and was literally killing Canon off. (Due to limited film speeds of the day and the hunger for faster glass.) Canon made the swap and in the process pissed off a ton of their existing customer base at the time since the new mount was not compatible with existing FD glass. But we all know how that story ultimately ends :)

Fact is, Sony may have shot themselves in the foot as respects FAST glass, or maybe not -- how does a Canon-mount 50 Sigma ART work on an A7 with one of the nicer Canon to FE adapters? I don't follow the Sony close enough to know if it's been discussed with images shown. Seems to me the results here would close the argument one way or the other...
 

tn1krr

New member
Canon had to change their FD mount to the EF mount specifically to produce the 50/1.0 and 85/1.2 -- the FD mount was too restrictive to go faster than 50/1.4 and even do 85/1.4 well; and at the time, Nikon had the 50/1.2 and 85/1.4 and was literally killing Canon off. (Due to limited film speeds of the day and the hunger for faster glass.) Canon made the swap and in the process pissed off a ton of their existing customer base at the time since the new mount was not compatible with existing FD glass. But we all know how that story ultimately ends :)

Fact is, Sony may have shot themselves in the foot as respects FAST glass, or maybe not -- how does a Canon-mount 50 Sigma ART work on an A7 with one of the nicer Canon to FE adapters? I don't follow the Sony close enough to know if it's been discussed with images shown. Seems to me the results here would close the argument one way or the other...
The are pile of users that are super happy about how F/1.4 Zeiss Otuses, both 55 and 85 work in A7 series. They are in fact saying it is the very best body for those uber-lenses due to way better MF tools than in the DSLRs

Dierk Topp Otus 85mm review: “The Sony A7R is the best camera for the OTUS today!” | sonyalpharumors

3D Kraft has nice real world tests on fast/high quality glass on A7R

Otus 85/1.4
Otus 1.4/85 - ZEISS's new Flagship sailing from Imaginary to the Real World

Sigma 50/1.4 + others

Most adorable 50s - UPDATED: Sigma Art 50/1.4 DG HSM Review

Even 0.95 lenses seem to be ok, although the real T-value is propably around 1.2 due to digital sensor inefficiency

The 0.95 Shootout - Mitakon / Zhongyi Speedmaster 50/0.95 vs. SLR Magic HyperPrime CINE 50mm T0.95
 

Guy Mancuso

Administrator, Instructor
Jack I have the Sigma Art in Sonys bigger mount the A model and use Sonys Lae4 adapter much better AF than a Canon mount and a Metabones adapter. So if you do go this route with the bigger DSLR lenses you can just simply buy A mount Sigmas, Tamron or Tokina and use the LAe4 adapter. Now my canon 17tse I use the metabones adapter. I'm manual focus lens anyway so AF does not exist but for other EF lenses I hear its slow focus. Which for some may not mean much. But bottom line if you want faster AF outside the FE mount itself than A mount lenses work very nicely. I actually have 3 A mount lenses the Sigma 35, Sony 85 1.4 and 135 1.8. The only downside of the Lae4 adapter is the AF is in a center 9 point cluster. Which still means focus and recompose. The FE mounts will use all the AF points available per bodies. The A6000 for instance it's almost the whole frame , maybe 75 percent or something like that but to get that you need the FE mount lenses.

Now Zeiss is making a FE mount 35mm 1.4 mount lens. So fast can be done just a matter of commitment to it and that's where Sigma is at this time not interested in making FE. You know as well as I they don't want to commit the R&D for a single mount only one cam series can use. They build for 3 DSLR mounts where the major market is at.
 

Slingers

Active member
What must be "difficult" to create for the E mount is small and fast lenses. The word small is what I'm sure has been missed. Large and fast lenses shouldn't be difficult as they can add a little bit distance to the exit pupil and make it like an M mount or SLR lens
 

jfirneno

Member
...current Art lenses have wrong kind of focus motors; they are pure PDAF lenses with focus motors quite far from optimal for CDAF & sensor-AF in general. Lens motors of Pure-PDAF lenses are optimized to go fast to certain focus point and not that good at making small corrections needed by CDAF which is based on iteration. Canon has some of the fastest PDAF focus motors (USM) there is, but their dual-pixel sensor AF works best with lowly STM lenses due to their step motors. This is the reason for Sony FE 70-200 having totally different AF and optical construction from the A Mount version.

So there would be a lot of work to be done to get a well working FF mirrorless lens out and they would have to be targeting single mount and competing with very high quality offering from Sony/Zeiss. If Sigma were to "port" current 35/50 ART lenses to E mount I'd say competitive picture is not to their liking; both focal length already have minimum of 2 very high quality offerings available and not that that many FF E mount bodies out there when compared to Canikon bodies. Business math just does not add up for them
This reasoning makes sense to me. To change the motors on an existing lens from PDAF-compatible to CDAF-compatible must be quite complicated and expensive.
Regards,
John
 

Annna T

Active member
I'm not sure that this is backtracking : the date of the Imaging Ressource interview seems to be anterior to that of the Spanish interview; the first was clearly hold in September at Photokina, but only published now, while the Spanish DSLR interview seems to have taken place later in Barcelona and was published at the very end of October.

Plus in the IR interview, the questions are more developed than the answers of Sigma which are very reserved. Sigma just acknowledged that they are getting a lot of requests for E-mount lenses, that there is a lull in the FE line of lenses and thus may be an opportunity for them.
 
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