SAMYANG 20mm f1.8 ED AS UMC Wide Angle Lens Review.
20mm has been a favorite focal length of mine for a long time, wide enough to fit a lot in, wide enough to allow long exposures without star trails at night, but not too wide that details get lost in the distance. When I found out Samyang was releasing a 20mm f1.8 lens a few months ago I was itching to get a copy for review, last week Samyang Optics Australia sent me the first copy in the country.
The Samyang 20mm f1.8 ED AS UMC lens is a wide angle manual focus lens designed for DSLR Cameras with a full frame sensor. The lens is available in 10 different mounts like many Samyang lenses, Canon Eos, Canon M, Pentax K, Sony a, Sony E, Fujifilm X, Samsung NX, Four-Thirds, Micro Four-Thirds and Nikon Mounts.
It has a max aperture of f1.8 and a minimum of f22. This is fantastic for low light situations, f1.8 lets a lot of light in, it also helps you to isolate your subject and throw backgrounds out of focus. It has 7 circular aperture blades for nice out of focus areas and easily accepts filters via a front 77mm filter thread.
The lens is constructed of 13 glass elements in 12 groups. This includes two aspherical and three extra low dispersion lenses that help minimise aberration and deliver high resolution. Samyang’s Ultra Multi Coating helps to minimise flare and ghosting.
Initial thoughts after opening the box.
The Samyang 20mm f1.8 ED AS UMC is built quite solid much like the rest of Samyang’s line up. Typical Samyang build of aluminium alloy, plastic and metal lens mount that is quite good at the price point, I believe they are doing a great job here. I’ve pointed out in the past that I don’t like the feel of the plastic aperture ring, but it’s a personal preference and it’s never caused me a problem in use, or anyone else that I’ve heard of for that matter. The aperture ring in use clicks into position nicely.
Focus ring is smooth with a rubber grip and includes a distance scale. I like the feel of the smooth focus with some resistance, think old school film lens.
Included in the box is a cloth lens bag, the norm for all Samyang lenses and keeps your lens dust and scratch free, a detachable petal lens hood that looks great and does the job intended. Also included is front and rear lens caps, the front being a centre pinch type, nice!
Manual Aperture and Manual Focus.
The Samyang 20mm f1.8 lens in Canon EF mount is a fully manual lens, this means you adjust the aperture via the lens aperture ring and focus manually. Some of Samyang’s lenses are “chipped” to allow communication between lens and body, giving on body aperture control, exif data, metering and focus confirmation (although you still need to manual focus).
Fully manual lenses have their pros and cons.
– No auto focus
– No on body aperture control (although some mounts may allow this)
– Wide angle lenses like the 20mm f1.8 are popular for landscape and Astro photography where manual focus is generally used. A wide angle like this is quite easy to focus at large apertures due to their huge depth of field and in low light situations its often more accurate to focus manually.
– Manual Aperture. I like manual aperture for a few reasons. One is at night when shooting the stars it’s harder to accidentally change your aperture. Another reason I like manual aperture is for when shooting time-lapse, a manual mechanical aperture allows you to lock the aperture in position and avoid aperture variation that is caused when the aperture opens and closes to a slightly different position, this avoids flicker in the final footage due to tiny changes in exposure. This is a huge advantage when shooting time-lapse.
Samyang 20mm f1.8 lens.
The front 77mm filter thread allows you to easily use a filter or filter system. In this case just a circular polarising filter was used, helping me to gain a longer shutter speed for smooth water and nice saturated colours.
How does the Samyang 20mm f1.8 ED AS UMC perform?
So far I have been pretty happy! As you can see by the above image it’s a capable, sharp lens and performs well in its corners. Distortion is there as expected for a wide angle lens but it is easily correctable in post processing. I didn’t come across any purple fringing when shooting contrasty scenes, but the lens did flare a bit when pointed at the sun. When not pointed directly at the sun it performed well with no surprise flaring.
The minimum focus distance of 0.2m meant that I could get in close to my subject and easily throw the background out of focus when shooting wide open, out of focus areas looked quite good.
The distance scale seemed reliable especially on infinity although I like to use live view with manual lenses to get good focus.
Brick wall test. Slight distortion typical of wide angle lenses, no lens distortion correction added, performs well.
Brick wall test. Slight distortion correction in post processing straightened the lines up quite nicely.
At f1.8 and focussing close it was easy to throw the background out of focus. Out of focus areas look quite nice.
Wide open at f1.8 and at approx 20cm away the sign was quite sharp.
20mm F2.8, 15sec, iso3200, Canon 6d.
Shooting the stars.
The Samyang 20mm f1.8 ED AS UMC is going to get a lot of interest from wide-field Astro photographers, Aurora photographers and those shooting nightscapes. It’s fast aperture, wide angle and manual features makes it potentially a great lens for these subjects.
So how does it perform? Not bad! Although you need to be careful with focus to get the most out of this lens at f1.8.
Shooting wide open at f1.8 there is some coma in the very extreme corners, with careful focussing you can really minimise this or a slight cropp in post removes it all together, this is a common problem with fast wide angles and this lens handles coma well given its fast maximum aperture, by f2.8 the coma is completely gone and image quality is excellent.
I noticed very little fringing of stars, there is a bit of vignetting but thats pretty normal for a fast wide-angle at night. All in all the lens performed very well for such a fast wide angle.
Here’s some straight from camera examples, no post processing.
f1.8, 15sec, iso3200, Canon 6d
Top Left Corner – approx 1/4 of the whole frame. f1.8, 15sec, iso3200. Canon 6d
Extreme Top Left Corner with LMC in frame to give a sense of position in the frame. f1.8, 15sec, iso3200, Canon 6d
f2.8, 15sec, iso3200, Canon 6d
Top Left Corner – approx a 1/4 of the whole frame. f2.8, 15sec, iso3200, Canon 6d
Extreme Top Left Corner again with LMC to give a sense of position in the frame – f2.8, 15sec, iso3200, Canon 6d. Coma has cleaned up nicely.
The Samyang 20mm f1.8 ED AS UMC is a decent performer and does well givin it’s fast maximum aperture. It’s fast and sharp, the slight distortion can be easily correctable, it makes a good wide landscape lens that can be opened up to isolate close in subjects and blur away backgrounds.
At night, shooting the stars you can open it up and capture a lot of light with a bit of a trade off of some coma, or you can stop it down for truly excellent performance. The 20mm sits in between the super popular Samyang 14mm f2.8 and 24mm f1.4 lenses, two of the most popular astro photography lenses out there. 20mm is a nice focal length for astro and I dare say this will also become a popular choice given its price point of $750-$800 and it’s great performance.