[macTak]

Sigma has announced another prime in the Art series, a 50mm f1.4 lens (covering FF). It has an entirely new optical construction (13 elements, 8 groups; including a moulded aspherical element and 3 SLD elements), internal focusing (floating as well), 9 bladed diaphragm. As is Sigma's trend, it is also rather big: 100mm X 85mm, 77mm filter thread. Considering how good the 35/1.4 Art turned out to be and the specs here (and that Sigma's prior 50/1.4 was no slouch), I expect it will also have outstanding optical quality (and a relatively high price). Sadly, Pentax is not one of the mounts announced for release (at least yet)....




Optical Diagrahm:


I cannot resist commenting on the optical design--it's pretty strange, and I've never seen a lens with a similar design. The first quadruple-Gauss lens!? Let's start with the rear half of the lens, which would itself be a relatively expected design for a fast 50--a Biotar/Xenon type, though one with a particularly enhanced rear group (two elements in the rear has been done on some fast 50mm, but here one of those elements is turned into a doublet and the other is aspherical). This rear half is much the same as the entire prior Sigma 50mm f1.4 DG EX lens (including that enhanced rear group with doublet + aspherical), except that lens split the front doublet (Ultron-type). But then there is also the whole front part of the lens design, and guess what, it clearly looks like another double-Gauss feature (stripped of any extra elements besides the opposed Gaussian elements themselves). In this case the front group remains split, and the rear group, instead of being the usual doublet (or split), has been made into a triplet! Like I said, pretty crazy. You can see, though, that this design has a lot of correction going on, so I expect performace to be very high indeed.

Link:
50mm F1.4 DG HSM | Art - Standard Prime Lenses - SigmaPhoto.com

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Last edited by macTak; 01-08-2014 at 03:00 AM.

[Mistral75]

It's a retrofocus formula, the second one for a standard lens after the Zeiss Otus Distagon T* 55mm f/1.4.

[Digitalis]

Sigma taking On Zeiss?...now that is a battle of the titans.

[macTak]

It's a retrofocus formula, the second one for a standard lens after the Zeiss Otus Distagon T* 55mm f/1.4.

The Sigma has a very different design to the Zeiss and is certainly not a standard retrofocus formula (by which I mean a retro-telephoto design: neagative elements in the front, telephoto design for the rear, as the Zeiss is). The front part of the Sigma (first five elements) seems very clearly to be on the model of opposed gaussian lenses (note the shape elements 3-5 take; they should have a positive effect) and rest is a dead ringer for a fast 50-55mm prime design. If you have any parallels to the Sigma design (using a double-gauss setup within the front of the lens to correct), please do share. But you are right that like Zeiss, with this lens Sigma has abandoned the standard double-gauss design that almost every other fast fifty has used so as to achieve levels of optical correction that presumably aren't possible with just a double-gauss design.

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Last edited by macTak; 01-07-2014 at 06:51 AM.

[ElJamoquio]

"Art" doesn't get WR, correct?

Bummer...

[causey]

"Art" doesn't get WR, correct?

Bummer...

Nor does it come in a variety of colors...

[macTak]

Nor does it come in a variety of colors...

But at least for us it gets SR

[Apapukas]

The lens isn't labeled as WR but it probably will have the same build quality and features as the 35mm.

That means it will be IF and have a very good, tight build. So, I believe it will be able to take a little rain, dust, cold with no problem.

I don't understand people complaining about plastic. Glock pistols, G-36 rifles are made mostly of plastic because of weight and durability compared to metal.

[devorama]

I am hoping that they will announce a Pentax version later, as they did with the Sigma 18-35mm. But then we've yet to see that get released.

[indy]

The lens isn't labeled as WR but it probably will have the same build quality and features as the 35mm.

That means it will be IF and have a very good, tight build. So, I believe it will be able to take a little rain, dust, cold with no problem.

I don't understand people complaining about plastic. Glock pistols, G-36 rifles are made mostly of plastic because of weight and durability compared to metal.

....and thermal stability and resistance to condensation etc... The current sigma 50 1.4 is my most used and favorite lens. If this follows the immage quality of Sigma's most recent offerings it will decimate the new Nikon and may match the Otus.

[Na Horuk]

What a best! Is Pentax the last manufacturer that makes small SLR lenses? (I mean mostly the limiteds)

[JinDesu]

My Sigma 50 F1.4 is one of my best lenses.. very sharp by F2 and reasonable at F1.4. HSM being quicker and quieter than the SDM in my DA*55, it's a fantastic lens - and if they can make it sharper and better bokeh (better aberration correction), that would make it outdo anyone except the Otus.

[Apapukas]

....and thermal stability and resistance to condensation etc... The current sigma 50 1.4 is my most used and favorite lens. If this follows the immage quality of Sigma's most recent offerings it will decimate the new Nikon and may match the Otus.

Agree.

I've had 50 in my sights for some time, but then after losing the FA31, I decided to fill the gap this Christmas with the new Sigma 35mm. Impressive lens.

If Sigma will keep the bar high with the new 50, it will be world class lens for sure But I will wait for the new 85mm, 50 is too close to 35.

[seventysixersfan]

You can get their old 50 f/1.4 version, refurbished, from the Sigma Outlet, $349.00 with free shipping.

50mm F1.4 EX DG HSM Refurbished | Sigma

[indy]

I wonder when/if this will be released for Pentax. As interested as I am, I would much rather see the new 12-24 released first. Were there not similar rumors about it also making an appearance in Pentax mount?