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Seems as if two Sigma FE lenses are coming (finally)


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#1 Klaus

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Posted 30 May 2017 - 11:23 PM

http://www.sonyalpha...nounced-summer/

 

It is about time for Sony to receive some serious heat regarding their pricing.


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#2 Ayoh

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Posted 31 May 2017 - 04:42 AM

Agreed. Although I think it will be a 35mm 1.8 rather than the rumoured 1.4 as this is an obvious gap in the line up. Also I don't see how a FF 35mm 1.4 from Sigma can be half the size of the Sony without serious performance compromises

 

Sigma should also make a 24-120mm as this is highly sought after.

 

And I hope they dont make another 50mm..



#3 JoJu

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Posted 31 May 2017 - 06:10 AM

Why should Sigma go for slower glass than the already existing 35/1.4 Art? Mind you, "being compact" is not the biggest strength of Sigma's lenses  ;) more "delivering outstanding performance".



#4 toni-a

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Posted 31 May 2017 - 07:06 AM

Sigma had autofocus problems in Canon and Nikon world let's see if it still persists in mirrorless world.
Wonder why Sigma isn't strongly present in MFT world

#5 Klaus

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Posted 31 May 2017 - 07:41 AM

If you are referring to front/backfocus - these do not exist in mirrorless land EXCEPT for RSAs ( and even then it's depending on the system).
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#6 Ayoh

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Posted 31 May 2017 - 08:10 AM

Well they can also sell a 35/1.8 to other APS-C and m43 systems and still have a compact lens that makes sense for those systems. A 35/1.4 for FF would be unnecessarily large and expensive for APS-C/m43 and would make no economic sense. Sigma doesn't really make lenses for only one mount - they typically achieve low cost with large volumes over many systems. Thats why a 35/1.4 doesnt make that much sense, but i could be wrong.

 

Also despite all the internet mania about copy variation, my copy of the Sony Zeiss 35mm/1.4 is very good (bought from overseas with no exchanges) - instant silent AF, sharp, smooth bokeh, nice build. If you wait for sales it can also be had for ~$1500 AUD so Im not sure how a Sigma would offer much of a benefit over this option

 

 

Why should Sigma go for slower glass than the already existing 35/1.4 Art? Mind you, "being compact" is not the biggest strength of Sigma's lenses  ;) more "delivering outstanding performance".



#7 thxbb12

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Posted 31 May 2017 - 10:03 AM

If you are referring to front/backfocus - these do not exist in mirrorless land EXCEPT for RSAs ( and even then it's depending on the system).

 

What is RSAs?


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#8 Rover

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Posted 31 May 2017 - 11:16 AM

Residual spherical aberrations, the cause of focus shift.

 

P. S. Maybe Sigma can release a smaaaaaaaaaawwww 35/2 and thus plug the perceived gap in the FE lineup. :) After all, this is one of the most widely expressed complaints about the status of the lens family......



#9 Brightcolours

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Posted 31 May 2017 - 11:44 AM

I very much doubt that RSA will be the issue causing missed focus images with mirrorless cameras.

 

Anyway, some mirrorless cameras miss focus consistently when the lens focusses coming from one end, not the other end of the focus range. This points to inaccurate back steps after the contrast AF saw that best contrast has been passed.

 

Other cameras (like Sony MILCs) seem to totally miss focus without a real clue as to why sometimes.

 

And some focus just fine.



#10 Klaus

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Posted 31 May 2017 - 03:57 PM

Brightcolors ... you speak in mysteries.  In conventional scenes I have never used a mirrorless camera that wasn't able to lock on.

It's a different topic for sports and available light but then I've used DSLRs that fail to do so here as well.


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#11 thxbb12

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Posted 31 May 2017 - 05:31 PM

I very much doubt that RSA will be the issue causing missed focus images with mirrorless cameras.

Anyway, some mirrorless cameras miss focus consistently when the lens focusses coming from one end, not the other end of the focus range. This points to inaccurate back steps after the contrast AF saw that best contrast has been passed.

Other cameras (like Sony MILCs) seem to totally miss focus without a real clue as to why sometimes.

And some focus just fine.


I extensively use Fuji, Panasonic and Olympus and there is absolutely no AF inaccuracy whatsoever. Maybe Canon is prone to what you're describing I don't know... but that sounds quite doubtful.
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#12 youpii

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Posted 31 May 2017 - 07:37 PM

I'd be more interested in a F/2 series with AF: 28/2, 35/2, 50/2, 100/2 as a travel kit.

Maybe also with a compact 50/4 Macro (1:2 ratio).


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#13 Brightcolours

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Posted 31 May 2017 - 08:37 PM

Brightcolors ... you speak in mysteries.  In conventional scenes I have never used a mirrorless camera that wasn't able to lock on.

It's a different topic for sports and available light but then I've used DSLRs that fail to do so here as well.

Sure, they "lock on". And when you check the result you see that images are not spot on focussing from one side, the other side is spot on. Not all brands, models, lenses, but some combinations.  Just something that happens, with some models and some lenses. I remember that the Panasonic GH4 was one of the models that showed this issue, very clearly with the Olynpus 45mm f1.8. starting focus from behind the subject gave sharp(er) results that starting focus from in front of the subject, very consistently. 

 

hxbb12, I have not read about a Canon mirrorless model having that issue, but that does not mean that it can not/does not occur. It just means that I have not come across someone testing it and finding out that/if it does. The modern M versions have mixed contrast detect and phase difference AF, so they can see if something is in focus. If I had an appropriate bigger aperture lens (like  EF 50mm f1.8 STM) I could do a test with my EOS M, but I don't. The 22mm f2 has a smaller aperture, so a bigger DOF and so it is less easy to judge how spot on focus is.

 

And the Sony missing focus totally-issue, it surfaces often on internet. Even on here:

http://forum.photozo...ures-are-major/

I have read a number of times now about it, also from A7 series users. Including images that showed the extreme missfocus.

 

thxbb12, I have not read about a Canon mirrorless model having that issue, but that does not mean that it can not/does not occur. It just means that I have not come across someone testing it and finding out that/if it does.



#14 JoJu

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Posted 31 May 2017 - 09:51 PM

One explanation for the phenomenon you found (I didn't, but that doesn't mean it's impossible) could be a lens axis not rectangular to the sensor or the sensor itself not parallel to the lens mount. Or simply a picture taken at open aperture, but not properly aligned to the plane. Field curvature would hit both sides the same.

 

You know there were also issues with Nikon's AF module which was misaligned to the sensor?

 

Okay, now I rethought your defintion of "side" (for me right or left, but not back or front - these I see more as depth or distance)

 

So there's a possibility of some play in the focus by wire (Olympus 45/1.8? Is that fbw?). But this I also saw when I was adjusting AF with FoCal. And I think to remember that when I was doing manual focus with matte screen in the film days, the "in-focus-jump" happened more visible the way from infintiy to distance than the other way round. I guess, the contrast detection struggles the same direction






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