The Sigma 40mm 1.4 Art DG is one of the heaviest non-super-tele prime lenses and on first sight it also looks more like a serious tele lens than a medium wideangle. But is it also as good optically as it is heavy? Let us have a closer look!
Most of the sample images in this review can be found in full resolution here.
- Sample Images
- Specifications / Version History
- Flare resistance
- Chromatic aberration
- Focus shift
- Sample Images
- Further Reading
Disclosure: this lens was kindly provided by a reader for the comparison to the 35mm 1.2 Art and 35mm 1.4 Art. I only had limited time with the Sigma 40mm 1.4 Art, so this review may not be as thorough as usual.
Specifications / Version History
The Sigma 40mm 1.4 Art reviewed here has the following specifications:
- Diameter: 88 mm
- Length: 157 mm
- Weight: 1265g (without hood and caps)
- Filter Diameter: 82 mm
- Number of Aperture Blades: 9 (rounded)
- Elements/Groups: 16/12
- Close Focusing Distance: 0.40 m
- Maximum Magnification: 1:6.5
- Mount: Sony-E
You may also have a look at the official page.
Unlike other native AF lenses for E-mount the former DSLR lenses by Sigma feature a physical distance scale and a direct coupling of focus ring and internal mechanics.
To me this is good news, as coupled with the nice resistance of the focus ring this gives a nice manual focus experience, only the rather short focus throw of 90° spoils the game slightly.
The lens further features an AF/MF switch but no other button and no aperture ring.
The Sigma 40mm 1.4 Art is a really big and heavy lens, even bigger and heavier than the 35mm 1.2 Art:
A bayonet type lens hood is also part of the package which offers improved build quality like the ones we know from the GM series with a release button and a mix of polycarbonate and rubber (which is really good at attracting dust).
The outside is made from the same high quality polycarbonate we already know from the other Sigma Global Vision lenses.
I cannot tell you much about the long term reliablity (yet) or about the internal parts.
Sigma claims the lens is dust- and splash proof and like all of Sigma’s full frame E-mount lenses there is a rubber gasket to be found at the bayonet.
In the limited time I spent with this lens I was not able to evaluate the auto focus performance.
Wide open there is noticeable light falloff of roughly 2.2 EV, stopped down to f/2.0 this improves to 1.7 EV, stopped down to f/2.8 it is 1.1 EV and further improves to 0.8 EV at f/8.0. You can either correct this in Lightroom or directly in camera.
These figures are slightly better compared to other recent big f/1.4 lenses which usually show around 3.0 EV vignetting at maximum aperture.
It is recommended to have a look at this article first to get an idea how this brightness graph works.
I did not detect any color cast issues with this lens.
Very fast lenses often show optical vignetting. Without going too much into technical details optical vignetting leads to the truncation of light circles towards the borders of the frame.
In the center of the frame almost every lens will render a perfect circle, but only lenses with very low optical vignetting will keep this shape in the corners.
So in the following comparison we move from the center (left) to the extreme corner (right) and see how the shape of the light circle changes.
This Sigma 40mm 1.4 Art shows an average amount of optical vignetting in the corners for a lens in this class.
And there is something else: onion ring structures are noticeably less pronounced compared to the Sigma 35mm 1.4 Art.
The Sigma 40mm 1.4 Art has amazing across frame sharpness. Already at f/1.4 it is usable across the whole frame with almost no field curvature. Stopping down to f/2.0 boosts contrast slightly and f/2.8 looks really amazing.
The exposure of the f/1.4 to f/2.0 corner crops has been lifted in post to reveal more details.
For portraiture it isn’t so important how flat the field is, it is more interesting to see what the sharpness is like when focused at different parts of the frame to take field curvature out of the equation.
This is what I did here, I refocused for every shot to get the best possible result at different locations in the frame (center, inner midframe and outer midframe).
Focus distance was roughly 1.2 m and the circle of the dollar bill is more or less the size of a human eye.
100% crops, A7rII
Also at portrait distance the Sigma 40mm 1.4 Art shows amazing sharpness across frame. You can see moiré everywhere, even far away from the center.
close (0.40 m, 1:6.5)
100% crops from center, A7rII, because of focus shift (see corresponding section) I refocused for every shot
Close focus performance is an area where the smaller fast lenses like the Voigtlander 40mm 1.2 E or 50mm 1.2 E struggle, as they don’t feature a floating elements design.
The Sigma 40mm 1.4 Art does feature a floating elements design and the performance at the minimum focus distance can be described as decent at f/1.4, good at f/2.0, and excellent at f/2.8. Across frame performance is really good, there is only minimal field curvature visible.
The Sigma 40mm 1.4 Art has a very high element count (16) and lenses with a high number of elements rarely fare well in this category.
On top you can see the worst result I could produce with ghosts and rainbow artifacts all over the frame.
When you place the sun close to the corner you can catch a good amount of veling flare:
Performance looks slightly worse compared to the Sigma 35mm 1.2 Art and noticeably worse compared to some smaller 35mm lenses like the Voigtlander VM 35mm 1.7, but it would take more time to fully evaluate this topic.
The Sigma 40mm 1.4 Art shows an amazing performance here, there is barely any coma visible at f/1.4.This is the best performance I have seen in an f/1.4 lens yet.
Distortion is very low, Lightroom also has a profile included to correct it.
Best have a look at the comparison to the Sigma 35mm 1.2 Art and Sigma 35mm 1.4 Art with many samples to see which lens you prefer.
In the end the 40mm Art’s bokeh is not as smooth as that of the Sigma 35mm 1.2 Art, but it does come pretty close and is certainly smoother than that of many other Sigma Art lenses, like e.g. the Sigma 35mm 1.4 Art.
Sunstar rendering has never been a high priority for Sigma. Sunstars look best at f/11 to f/16, but still the rays have varying length and distance to each other. Not something that worries me in a lens designed mainly for taking portraits or astrophotography though.
If you want to know more about sunstar rendering of different lenses have a look at this article.
There are only minor lateral CA which are easily corrected in camera or in post with the help of the built in profiles.
Near the minimum focus distance the Sigma 40mm 1.4 Art barely shows any loCA, a really good performance.
Longitudinal chromatic aberrations come in different forms. Unfortunately there are only few (if any at all) sources that give a clear differentiation. We will have a look at purple fringing (it shows up close to the plane in focus) and the “bokeh-CA” or “bokeh fringing” which you will see in the out of focus areas.
The Sigma Art 40mm 1.4 shows an amazing performance here, it is probably the best corrected f/1.4 lens I have seen so far.
100% crops, A7rII
At the minimum focus distance the lens shows a slight focus shift. At other distances I did not notice it and usually people will use this lens with working aperture – where this is absolutely meaningless – anyway.
Sigma 35mm 1.2 Art:
Get the Sigma 35mm 1.2 Art, if you want the smoothest bokeh, GM handling or the first 35mm f/1.2 lens with AF.
Get the Sigma 40mm 1.4 Art, if you are allergic to longitudinal CA or want the best lens in this focal length range for milky way panorama stitching. Or you prefer the 40mm focal length, obviously.
buy from amazon.com | B&H | ebay.com | ebay.de for $1499/1529€ (affiliate links)
Sigma 35mm 1.4 Art:
If you are looking for a native 35mm lens with AF but feel the f/1.2 version or the 40mm 1.4 reviewed here are too big, heavy and/or expensive this remains my recommendation.
buy from B&H | amazon.com | amazon.de | ebay.com | ebay.de for $770 (affiliate links)
You can also have a look at my comparison of Sigma 35mm 1.2 Art, 35mm 1.4 Art and 40mm 1.4 Art to see how these lenses compare.
Sony FE 35mm 1.4 ZA:
Unfortunately this is nothing like Sony’s newer GM primes and furthermore plagued by severe sample variation. If you have a good sample it gets the job done, but I cannot recommend going down the rabbit hole of finding one of those golden copies.
buy from B&H | amazon.com | amazon.de | ebay.com | ebay.de for 1499$ (affiliate links)
Samyang 35mm 1.4 AF:
This Samyang is the cheaper version of the Sony FE 35mm 1.4 ZA in many ways: similar size, similarly high CA, similar questions regarding sample variation. No button or aperture ring and according to some reports the manual focus experience is really bad with this lens.
This is your cheapest option when looking for a native 35mm f/1.4 lens with AF, personally I would pay slightly more to get the Sigma 35mm 1.4 Art.
buy from B&H | amazon.com | amazon.de for ~550$ (affiliate links)
Zeiss Batis 40mm 2.0 CF:
This is the only other 40mm lens with AF available for Sony E-mount. I don’t really like this lens, as I like to decide myself when to stop down.
buy from B&H | amazon.com | amazon.de | ebay.com | ebay.de for 1169$ (affiliate links)
Voigtlander 40mm 1.2 Nokton E:
What are the differences compared to the Sigma reviewed here? No AF, lower corner sharpness, slightly less smooth bokeh rendering, more vignetting, more pronounced onion ring bokeh, better flare resistance, only 420g heavy and much smaller size.
Furthermore this Voigtländer is optimized for portrait distance and is a worse performer at minimum focus distance and infinity at wider apertures.
Many people like this lens though and it is certainly more fun to carry around.
buy from B&H | amazon.com | ebay.com | ebay.de for ~1099$ (affiliate links)
The Sigma 40mm 1.4 Art may very well be one of the – if not the – best corrected f/1.4 lens(es) you can buy. Despite being an f/1.4 lens it is an almost apochromatically corrected design and coma as well as astigmatism are pretty much non existent. Even vignetting is lower than that of the competition at maximum aperture.
When it comes to the bokeh rendering the Sigma 35mm 1.2 Art is slightly smoother by comparison, but the 40mm 1.4 is noticeably smoother than the older Sigma 35mm 1.4 Art, you can have a look at my comparison and see for yourself which one you prefer.
The only real downsides are flare resistance and even more noticeably size and weight. For some this will surely be a reason to stay away from this lens, while for others this won’t be an issue at all.
As an E-mount user I prefer the 35mm 1.2 Art, but this 40mm lens features better correction of longitudinal CA and even better coma correction.
It also seems to be the best lens for milky way panoramas in this focal length range, featuring almost perfect coma correction and less vignetting than the competition.
Most of the sample images in this review can be found in full resolution here.