I'm a big fan of wide angles, and the wider the better, especially when you're in the middle of a glorious mountain landscape. I've been using the Nikkor AF-S 12-14mm f/4G for years, which is an excellent performer, especially since when Adobe Lightroom provides lens correction in its workflow; but sometimes those 12mm are just not enough. So, in the past year I've started thinking of buying a fish-eye (a rectilinear fish-eye, since I'm not interested in taking funny images, just very wide ones). The problem is the price: the Nikkor AF 10.5mm f/2.8, or some other brands such as the Sigma 8mm f/3.5, cost about 700 €. Which is much less than the 1.000 € I paid for the Nikkor 12-14mm, but while the latter is a lens which I use a lot, the fish-eye would be specialized for a limited number of shots in one year - thus not justifying a big expense. I'm not against minor manufacturers, but my knowledge is that they are not good for "extreme" lenses such as very wide or very long ones.
But, a few weeks ago, my best friend Emmanuele Sordini told me about
the Samyang 8mm f/3.5, made by a Korean manufacturer. It's a fish-eye for DX camera formats, compatible with
Nikon, Canon and other major brand mounts. Emmanuele is an astro-photographer and photographing the night sky is a
good test case for lens defects such as coma and poor sharpness at the corners, some of the typical problems of
wide angles and fish-eyes - he told me that the lens behaves very well. Then I found some very good reviews [1,
and given that the price was about 230 €, I bought it.
A first day of trial shooting was performed at the massif of Estérel, in Côte d'Azur, together with my brand new Nikon D7000. In this first day, I just explored composition and behaviour in direct light, leaving sharpness and colour fringing tests for a further session. All the shots shown here have been taken hand-held.
First, the lens doesn't come with an autofocusing motor, which is part of the reason that it is relatively cheap. Manual focusing is really not a problem with landscape photography, where you have time to fine tune the shot; furthermore, modern cameras can assist you with the electronic rangefinder. But above all, such a wide lens basically provides an very deep depth of field and it's difficult to get it bad.
Second, the lens aperture needs to be configured by means of the aperture ring, rather than with the camera body commands. This is not a big deal, even considering that you will probably shot mostly at f/8 or f/11, which are the sweet spots for maximum sharpness, and mostly keep the aperture at a fixed value. But as a Nikon owner, I enjoy the fact that cameras supporting older Nikkor AI lenses, such as the D200, the D7000, are capable to automatically stop down at shoot time (that is, the lens stays at maximum aperture normally, so the image in the viewfinder is bright, and the camera body stops down to the required aperture just before the shot). Owners of other camera brands will have to manually stop down before shooting and then restore the maximum aperture after.
By default, the camera body will show the aperture in the LCD panel as Δf/0 ... Δf/n, indicating the aperture
difference from the maximum value; but entering the lens characteristics in the proper configuration of the
camera, you will be able to read the actual aperture (f/3.5 ... f/22). Also metering works fine - even though a
180 degree field of view will usually grab such a wide dynamic range that you'll often need manual compensation
and checking the histogram.
The first thing that impressed me at the first try is ... how many things get into the frame! I mean, you know that the lens has a diagonal coverage of 180 degrees, but you'll understand what this means only when you start shooting. You really need to be in the middle of your subject, or everything will be just small. Also, if you have foreground objects, very slight position variations - even less than one step - will cause significant composition changes.
Shooting in the direct light of the sun gives no apparent problems of flares and ghosts, with the exception of a few specific positions (usually the sun in one of the corners). It seems that these situations can be controlled very well. In typical shots where you partially mask the sun, e.g. behind some branches, you have a nice star-like effect.
I must say that it's one of the very first tests that I did just after taking the lens out of its box, so the
front element was perfectly clean. I suppose that every particle of dust can be a problem shooting in the sun, so
I'll make sure I have some cleaning tools always available. By the way, the curved front element makes it
impossible to put a protection filter, so you must be careful to avoid scratches and other damages. I'm resorting
to keep the front cap always on and to remove it just before shooting.
While this lens is a rectilinear fish-eye, that is it produces an image that fills the entire frame, as all fish-eye lenses it renders a heavy geometrical distortion: everything is curvy, with the exception of the central horizontal and vertical axis. Fortunately, the Samsung 8mm is designed with a particular projection formula (called stereographic projection) which is different than the one used by other lenses and reduces the geometrical distortion - but it's still there. This means, for instance, that the horizon line must be always placed at the middle of the frame - I've found that it's possible to do that very precisely activating the composition guidelines in the viewfinder. Unfortunately, this will force you to a "horizon-in-the-middle" composition. But you can move it somewhere else by properly cropping.
In many cases, shooting at naturalistic landscapes makes the geometrical distortion less relevant and you're fine.
Of course, if you have perfectly straight objects, such as poles or buildings (think of architectural
photography), the distortion is evident. There are pieces of software capable to remove the distortion, thus
rendering straight lines as straight lines ("de-fishing" the lens), but I've not tried them yet (unfortunately, it
seems that Adobe Lightroom 3.3 doesn't provide anything integrated in the workflow).
For the first day, I'm pretty fine with this lens.