Sharpness: I'm going to say the center of the frame is very good. It's nearly impossible to get really good measurements from lenses this wide, as you'd either need to be at closest focus distance or have really huge charts to get accurate numbers. My observations are mostly based upon examining real images, not testing. While subjects such as auroras are forgiving of soft images, Milky Way photos demand stars be sharp corner to corner. The 11mm TTArtisan does quite well. When used wide open at f/2.8 stars do exhibit astigmatism at the corners that elongates stars into radial streaks, though images are still tight and not bloated by spherical aberration. So for example, if I was looking for a high-quality fisheye for capturing 360-degree images, or had intentions to use it for interiors or the like, or maybe something for ultra-wide angle shooting for de-fishing… I might look elsewhere. But then, if I was shooting those types of photography, I think I would have already looked elsewhere for the camera too. An SLR would be infinitely easier to shoot for those types of work.

Chromatic Aberration: Longitudinal CA is low, lower than I would have expected. This is good news, because makes the lateral CA you'll clearly see at wide apertures easily correctable. With the sun close to the corner or just out of the frame the situation is worse though – as is the case with most lenses by the way. Wide open we have some patterns that look like internal reflections that go away on stopping down (see comparison above). Flare: Decent if the light source is somewhat centrally located. Put the light source towards a corner, though, and things get really complex, with everything from prisming to colored ghosting occurring.

As with the older full frame fisheyes, this lens can produce very distinctive shots you can't get otherwise. It's also a bit fun to shoot with a lens that produces such results. The 11mm I tested was for Canon’s mirrorless RF lens mount, but versions of the same lens are available for Nikon Z, Sony E, and Leica L and M mounts.

Note: I have seen some samples from others on the Web that show that there may be some sample variation. My sample seems well-centered and doesn't tend to smear corners but just blur them. I've seen examples from others where there must have been some de-centering or element variation. The focus ring has a hard yet nice resistance and turns about 100° from the minimum focus distance of 0.2 m to infinity. Also similar to the Voigtlander UWA primes and some of the wide Laowa primes ( 12mm 2.8 and 15mm 2.0) this lens shows some slight green color cast in the corners which can become visible with bright or evenly lit skies. Sharpness infinity (42mp Sony A7rII) Let’s clear the air: I’ve never before used a fisheye lens. In fact, so lost and daunted was I by the prospect of using one that time and time again I delayed publishing this review. Prior to it arriving I boned up on how to shoot a fisheye lens. Hints came from the general internet as well as from the comments section of Fauxtaku Lounge. I’m still not confident that the examples I shot really get the picture across, but I hope I’ve learned a thing or two and that this review will help someone. Thanks to everyone for the advice and help.Fisheye design renders an immensely wide angle of view to produce distinct visual appeal characterized by dramatic distortion and a creative depiction of space. The lens comes with an external 11mm metal viewfinder (very helpful if you don’t have live view, no frame lines in the viewfinder):

At the frame centers all three lenses were sharp wide open, and showed little flaring from a bright off-center Moon. There was no evidence of longitudinal chromatic aberration adding blue halos around bright stars. Overall, the TTArtisan presented images that looked very sharp, making this a fine lens for Milky Way images. Refocusing the TTArtisan when using a clip-in filter changed the aberrations at the corners, with more coma but less astigmatism. Credit: Alan Dyer Already in the sharpness section we saw solid but not outstanding corner sharpness and most of the time the performance there is closely related to the coma correction. Generally the correction is decent at f/2.8 and I think slightly better than the TTArtisan’s. Even stopped down to f/5.6 the corners don’t look perfectly clean though. Proper rangefinder focusing would make all of this simpler, at least on an M, whose EVF and live view are stuttery messes. Other mirrorless cameras fare better, but not better enough to ensure reliable focus speed and accuracy. Yes, zone focusing works fine. Yes, stopping down yields deep focus. But none of that is as accurate or fast as focusing through a discrete rangefinder. At 15.4 ounces (436g), the lens isn't light, but it's also not exactly what I'd call heavy, either. The smallish size and metal construction mean that it feels a bit "dense" in the hand. The excellent optical design of 11 elements in 7 groups has successfully improved the soft edge of fisheye lens.Even at longer distances loCA are hardly a problem, if you zoom in to 100% you can see a bit of color fringing but nothing that will ruin a shot. Alternatives Les principales différences sont expliqués ci dessous. : caractéristiques, angle de vue, piqué et bokeh In conclusion, I was impressed with the new TTArtisan 11mm, especially considering its price. For mirrorless shooters, it can open up some new photo opportunities at low cost, and without taking up much space in your camera bag. A fish-eye is also great for taking in the Milky Way from horizon to horizon and for circumpolar star trails. I’ve also used such lenses during total solar eclipses to capture the passage of the Moon’s shadow across the sky.