Sigma 90mm F2.8 DG DN Contemporary
The Sigma 90mm F2.8 DG DN is a compact new lens, made to give excellent image quality, but how does it perform?
The Sigma 90mm F2.8 DG DN Contemporary lens is one of the most compact 90mm lenses available for full-frame cameras. By designing it specifically for mirrorless cameras, Sigma has been able to optimise the size and weight, whilst still offering exceptional image quality.
This is the sixth lens in the I series range, with the most recent, the Sigma 24mm F2.0 DG DN, also being released at the same time. Sigma is part of the L-Mount Alliance, and this lens is available in L-mount and E-mount.
Features
Being part of Sigma’s range of more compact lenses, the 90mm F2.8 lens has a weight of just 295g, and a length of 64mm. This makes it a good match for compact L-mount mirrorless cameras such as the Sigma fp and Panasonic Lumix S5, and Sony’s E-mount cameras like the Sony Alpha 7 IV and Alpha 7C.
The lens is designed to give high optical performance, even when shooting at the maximum aperture of f/2.8. By correcting certain optical issues such as vignetting in software, Sigma has been able to minimise the size.
The lens is made up of 11 elements in 10 groups, with 5 SLD elements, and 1 aspherical lens element. Sigma says this construction is designed to reduce axial chromatic aberration that can’t be corrected in-camera.
There are 9 rounded diaphragm blades, which should give smooth round bokeh. The minimum focus distance is 50cm, and the filter thread size is 55mm.
The lens measures 64x59.7mm, and weighs 295g. This makes it suitably lightweight for smaller cameras as well as larger models. On the Sony Alpha 7 III, it feels like just the right size, being quite portable.
Despite the ‘Contemporary’ label indicating Sigma’s entry-level range, this lens is far from entry-level when it comes to build quality, except for perhaps the lack of full weather-sealing. In line with other I-series lenses, the 90mm boasts all-metal construction, with precision-cut aluminium, as well as a durable brass bayonet mount.
While the lens is not specifically weather-sealed, it benefits from an oil- and water-resistant coating on the front of the
lens. The mount is also dust-resistant and splashresistant, thanks to the rubber seal on the rear.
The lens features Sigma’s Super Multi-layer coating to suppress flare and ghosting, preventing reflections within the lens. It also uses a high-speed stepping motor, which gives quiet fast AF performance, suitable for both stills and video use.
There’s a solid metal ring for setting the aperture, which adds a nice level of manual control. The aperture ring offers a range from f/2.8 to f/22, with two clicks between the main aperture settings, as well as an A/Auto position. There is a stronger level of resistance between A and the aperture settings, to help you avoid accidentally switching between them. There is no option to make the lens clickless.
As the lens doesn’t feature optical stabilisation, if you would like to have image stabilisation you’ll need to ensure you pair the lens with a camera with an in-body system.
In the box you get the choice of a standard lens cap or a magnetic metal alternative. You’ll also find a round lens hood that is made out of metal. The L-mount version is compatible with the Sigma USB Dock UD-11.
Build and handling
Regarding the feel and handling of the lens, the manual focus ring feels good, with a great level of grip on offer here. In fact, the manual focus ring is larger on this 90mm lens than the recently reviewed 24mm lens, which is a little odd considering this lens is smaller. The focus ring features an electronic fly-by-wire design, with no end stops. This means that once you’ve reached the focus limit, you can continue turning it and nothing will happen.
The metal lens is designed to be ergonomic, and with a simpler design than the Sigma 24mm lens, there are less ‘jarring’ edges on this lens.
The aperture ring has neatly designed ribs for grip, with this raising up from a smooth surface at the edges of the labelling. The aperture ring features click stops, and there is no switch to de-click its operation.
On the subject of labels, the printing on the lens is of a very high quality, being etched and painted rather than simply painted or printed on. This means that even with extended use, the labelling should stay intact.
There’s an AF/MF switch on the side, letting you select between autofocus and manual focus without having to use a function button or menu setting on the camera body. But there are no other switches or function buttons on the lens.
As well as the standard plastic lens cap, you’ll also find a stylish magnetic lens cap provided in the box. This is a nice added bonus, but it doesn’t work if you have a filter attached to the lens.
Despite the good level of grip on the focus and aperture rings, the fixed section of the barrel in between the aperture ring and camera is particularly smooth. This can make attaching and removing the lens from the camera body particularly difficult, as it provides very little grip.
On the Sony Alpha 7 III used for this review, the mount felt quite tight, adding to the difficulty attaching the lens. With some practice this becomes easier, and the aperture ring can be used as a grip when turned fully in the direction needed.
The lens hood fits neatly onto the lens, and is also made of metal, which a nice surprise, because it adds to the quality feel of the package. The inner section of the hood is made of plastic, and the hood will fit the standard way, as expected, as well as reversed. But this does completely block both the focus ring and most of the aperture ring, so isn’t recommended while you’re shooting.
Weighing in at 295g as mentioned, the lens feels great on the camera. It’s not too light to suggest low quality, while bringing enough heft to feel like a solid lens. But it doesn’t feel too heavy when paired with a mid-size
full-frame camera such as the Sony Alpha 7 III.
Autofocus
The lens gives rapid autofocus with no lack of speed, even when shooting in low-light conditions. The only hesitation I noticed was in darker conditions, or when using the lens at the closest focus distance.
Switch to manual focus and there is a smooth action to the focus ring, with plenty of travel available for fine-tuning focus as needed. To focus more precisely you simply turn the focus ring more slowly.
Image quality
The Sigma 90mm F2.8 DG DN C provides an impressive level of sharpness, going beyond what our 24MP test camera can resolve. In fact, processing raw files, there were times when images were too sharp, with signs of moiré present. This isn’t a weakness of the lens, but rather a sign that it’s capable of resolving even more detail than this camera can capture. You can shoot with the aperture wide open and get impressively sharp results, particularly when shooting distant subjects.
You can focus on a subject as close as 50cm, but you will need to stop down quite a lot to get the best results, as close subjects do appear soft when shooting at f/2.8. There’s an improvement at f/4.0, but it wasn’t till f/7.1 that I saw impressive levels of sharpness. If macro photos at wide-open aperture are something you’re interested in, then this lens isn’t going to be the one for you.
In-camera chromatic aberration correction takes care of any purple fringing or chromatic aberration. But even with this feature switched off, it didn’t appear to be an issue, and is easily corrected in software, if necessary.
Vignetting is very noticeable when viewing uncorrected images, and is strong when shooting wide-open. However, as this lens is designed to be used with vignetting/shading correction switched on, it isn’t something to be concerned about. If you are shooting with vignetting correction switched off, then vignetting is gone completely by f/7.1.
In addition, if you leave distortion correction switched off, there is a high level of pincushion distortion visible. However, as this lens is designed to be used with lens distortion correction switched on at all times, this shouldn’t be an issue for most photographers.
Flare resistance is very impressive, with some flare visible only when shooting with a very bright light in the frame (such as the sun). If you’re looking to use a lens for creative flare, then you’re unlikely to find it here.