Sigma 105mm f/1.4 DG HSM ART Lens review

In this review, we are going to look at the new Sigma 105mm f/1.4 ART lens, nickname Bokeh master! This lens is available in Nikon F, Canon EF, Sony E and also Sigma mount. And I’m testing the Nikon F mount version in this review

Body and Design

The Sigma 105mm f/1.4 DG HSM ART is the latest additional to Sigma’s highly successful ART lens series. The build quality of the lens is excellent. I love the signature Sigma ART lens design which looks modern, classy and it feels very well made and super solid.

Following the tradition, this is a huge and heavy lens. I always think my Sigma 50mm f/1.4 ART is quite a big lens but put them side by side, all of a sudden my Sigma 50mm ART looks almost like a micro four thirds lens!

There are 17 lens elements in 12 groups, (3 FLD glass elements, 2 SLD glass elements, 1 aspherical lens element) including a humongous front element! The result is a heavy weight lens at 1645g. This is even heavier than some of the 70-200 f/2.8 lens in the market!

Tell me if you think that is not a huge front element

Disclaimer: I only used my Nikon F and F2 Titan for the product photos.
In the last three weeks, I have been carrying the lens with me almost everyday and shot thousands of photos. As I’m a wedding photographer, I’m quite used to carry big and heavy camera gear. But to tell you the truth, there were a few days I end up just left the camera at home because I knew I need to do a bit of walking and I really don’t want to carry such a heavy camera with me.

The Sigma 105mm f/1.4 ART lens comes with a removable and rotatable tripod socket. It’s quite a beefy tripod socket and it is also Arca Swiss compatible. However I found the tripod socket does get in the way when I handhold the camera no matter how I rotate it so I removed the tripod socket very soon after I started working on this review.

The focus ring at the front of the lens is large and smooth. If I am being picky, I would say the ring maybe a little bit too tight for best manual focus experience when compared to some of the best manual focus lenses.

There is only a AF/MF switch on the body. The lens has no optical image stabiliser and hence no I.S. mode switches and there is no focus limiter switch as well.

Autofocus

The autofocus performance is great. Autofocus speed is fast but I won’t call it lightning fast. The autofocus is virtually silent as well which makes it suitable for video work. For a third party large aperture lens like this, people are usually more concerned about the autofocus accuracy than other aspect of the autofocus performance. I’m happy to say that the autofocus accuracy is pretty decent. While I do have some photos that I shot at f/1.4 that is slightly out of focus, the percentage isn’t that different from when I was testing the Nikon AFS 105 f/1.4E. I believe this is mostly due to the ultra shallow depth of field so any tiny movement of my subject or myself would easily results in out of focus photo. When I put the camera on a tripod and shoot a focus test chart with my D800, the results are consistently accurate.

With camera (Nikon D800) on tripod shooting test chart, the result is always spot on even when the target has strong backlight with no AF adjustment.
Even when I was shooting moving objects at f/1.4 using continuous autofocus, my keep rate is still very high. That was a bit of surprise, a pleasant surprise of course.

(All these four photos were shot at f/1.4 using continuous autofocus)

During the review, I shot an indoor night event and I mounted the Sigma 105 onto my Nikon Df (because it has better high ISO performance than my D800) and I noticed two issues.

My fingers became sore very quickly because the Df doesn’t have a big and deep grip to support the heavy Sigma lens. The camera feels very unbalanced and quite uncomfortable to hold. I expect you would have the same issue with the first and second generation Sony A7 mirrorless cameras as well.
There were more than usual percentage of shots that were mis-focused. I suspect this is mainly due to the fact that the Nikon Df doesn’t have a very good autofocus system. I had similar experience when shooting with Nikon lenses in dark venue with rapidly changing and strong colour lights so I wasn’t entirely surprised I was having a bit of issue with the Sigma 105mm lens. So while I believe the issue is mostly due to the camera rather than the lens, I thought I should mention it in this review anyway.

Nikon Df | Sigma 105mm f/1.4 ART | ISO100 f/1.4 1/125s

Nikon Df | Sigma 105mm f/1.4 ART | ISO1250 f/1.4 1/100s

Nikon Df | Sigma 105mm f/1.4 ART | ISO110 f/1.4 1/100s

Filter Size

The lens has a huge front element and has a monster size 105mm front filter thread. If you are planning to use filter, the 105mm filter is going to be very expensive and you don’t want to put a cheap low quality filter in front of this lens as well.

Colour

The lens produce beautiful colours straight out of camera. All the photos in this review are raw converted to JPG with minimal changes (mostly correct the exposure and white balance). The contrast, micro contrast and colour are all just very nice. Look at the photo below, my daughter’s red jersey really pops even though the photo was shot on a cloudy day with really flat (boring) light.

Nikon Df | Sigma 105mm f/1.4 ART | ISO100 f/1.4 1/640s

Nikon Df | Sigma 105mm f/1.4 ART | ISO100 f/1.4 1/2500s

Sharpness

The Sigma 105 f/1.4 ART is a very sharp lens. Even at maximum aperture f/1.4, the image sharpness is already excellent.

Center sharpness is already very good at f/1.4. Stop down to f/2 the sharpness becomes excellent. Stop down further doesn’t actually improve sharpness much as sharpness at f/2 is already very good.

100% center crops (click on the photo to see it at 100% size)
Corner sharpness is also very good. While the corner appears to be slightly softer than the center at f/1.4, it becomes very sharp from f/2.8 onwards.

100% corner crops (click on the photo to see it at 100% size)

Bokeh

Bokeh is really smooth and round at maximum aperture. If you examine the photos at 100% you don’t see any onion bokeh either. There is a little bit of cats eye bokeh at f/1.4. Not very serious and this is pretty typical for any large aperture lens. At f/2, there is virtually no more cats eye effect.

When stop down around f/4-5.6, the bokeh starting to become less rounded and slightly polygon shape. But even at f/5.6, the bokeh still look ok. You wouldn’t shoot at f/5.6 anyway if you want some bokehlicious photos.

The transition from foreground to background is also beautiful. Well deserve it’s nickname “Bokeh Master”.

Vignetting

At f/1.4, vignetting is noticeable on the white wall test shot. Having said that, it is still much better than most f/1.4 lens at maximum aperture probably thanks to the huge front element (105mm front filter thread). Stop down to f/2 then the vignetting would reduce quite a bit. From f/2.8 onwards you won’t notice any vignetting when shooting real world photos.

I noticed one minor thing is that the supplied lens hood actually would create a TINY bit of extra vignetting. But I would still highly recommend you to use the lens hood as the benefit of using the lens hood (physical protection, lens flare reduction) far exceed the tiny bit of vignetting it would create in your photo.

Lens Flare

Lens flare is exteremely well controlled. I barely see any lens flare from all my real world photos, even the one with the sun or a strong light source shinning towards the camera.

Check out the two photos below. The sun is at the top right corner (within frame) and the left side is shadow area. This is probably one of the best way to reveal any lens flare issues but surprisingly. Both photos (one at f/1.4 and one at f/8) show very minimal lens flare

Nikon Df | Sigma 105mm f/1.4 ART | ISO100 f/1.4 1/8000s

Nikon Df | Sigma 105mm f/1.4 ART | ISO100 f/8 1/1000s
Chromatic aberration

Another big tick is the chromatic aberration. There is very small amount of Chromatic aberration even when I’m shooting some very high contrast scene at maximum or near maximum aperture. Check out the photo below that was shot at f/2 with the sun directly behind the tree branches/edge of the building.

Nikon Df | Sigma 105mm f/1.4 ART | ISO100 f/2 1/8000s
Distortion

Look at the photo below and you’ll agree the Sigma 105mm ART lens has virtually no distortion. This is exactly what I expected from a good quality short telephoto prime lens.

Conclusions

Sigma has done it again with the new 105mm f/1.4 ART lens. The image quality is almost perfect as there is nothing I can even nitpick. It’s sharp, bokeh is very nice, very minimal lens flare, chromatic aberration, distortion and colour is also beautiful. I’m a big fan of the Sigma ART lens design and construction. Autofocus appears to be very good even though I did have some issues when shooting under challenging condition with my Df. (but not with my D800).

While the price of the Sigma 105mm f/1.4 ART would not really break your bank (compare to other lenses with similar specs) , it’s monster size body and weight could easily break your arm and back if you want to carry it around whole day. But this is how Sigma choose to make their ART series lens, make no compromise when it comes to size and weight.

If you have never got a big heavy lens before, I would warn you that if you bought this lens, you may end up not using this lens much because of the weight and size.

But if you want the best picture quality? The huge size and weight is a small price you have to pay.

Bokeh Master? Given it’s humongous size and superb image quality, I would call it Bokeh Beast.

Sample Photos