However, while some lenses behave badly when refocused with clip-in filters, the TTArtisan still showed good star images across the frame, trading the astigmatism at the corners for mild coma and some image softness. With no automatic lens profile available, correcting vignetting required dialing in manual corrections, here +60 Vignette and 0 Midpoint in Adobe Camera Raw. Credit: Alan Dyer The thing that most obviously lets the TTArtisan 11mm f/2.8 fisheye lens down – or at least my particular copy – is the decentered optics. Shooting at f/2.8 it is a little disappointing to see some softness toward the right hand side fo the frame. This isn’t the first time I have seen or heard of this when talking about the new “Artisan/s” brands of lens coming out of China either. Would this put me off buying this lens? I’m not sure. I really do think it would depend on my goals. Stopped down to f/4 all the lenses improved at the corners, though the TTArtisan still showed some astigmatism. The Rokinon 12mm does provide a slightly wider field of view than the 11mm TTArtisan, despite its 1mm longer focal length. Open full-size image in new tab. Same image at f/5.6 with 200% zoomed-in crop boxes showing star performance. Not much improvement to stars over f/4. Open full-size image in new tab. Commentary

As you can see from the below the TTArtisan 11mm is covering less than the Samyang 12mm, so it is more a 13mm than a 11mm

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 TTArtisan 11mm f/2.8 Fisheye is a manual focus lens that delivers 180° across the diagonal of the frame, what is sometimes called a "full frame fisheye." Full frame in that instance means that the fisheye produces image data all the way into the corners of the frame, and not a circular image as traditional fisheyes do.

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. TTArtisans ( different from 7artisans) currently has three lenses for Leica M-mount and a new 50mm f/0.95 lens coming soon. Summary: Available only for mirrorless cameras, the TTArtisan 11mm fish-eye works well for several types of astrophotos, and is affordable enough to include in the kit bag. 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.Architecture was my next idea to shoot with the TTArtisan 11mm f/2.8 fisheye. I wanted to get a really bloody tall building entirely in frame from an unusually close distance. There’s a tall spire right near my work, so I made a beeline for it. In the end, I found that even as close as maybe 15-20m from the bottom I could get it all in, so I decided to frame in some tree to help draw the eye. I think it worked too. What’s interesting about this shot to me is that at f/5.6 you can see the effect of the softening down one side of the frame is no longer an issue. My second outing with TTArtisan 11mm f/2.8 fisheye lens would prove to be a lot more entertaining. I decided I wanted to push the envelope of conventional fisheye photography (if there is such a thing) and take some portraits whilst out on a photowalk. The results speak for themselves.

When you adapt it to a medium forma (55mm sensor), this lens is a beautiful portrait fisheye. The built-in lens hood is removed. Focusing and aperture rings are smooth but a little bit too tight for my taste (some like it that way), I have the feeling they will loosen in the future My final shot of the outing was shooting up into this tree. I’d been shooting with the add-on Visoflex viewfinder and whilst up until this point I had found its articulation useful, I’d not found it essential. For this particular shot, the fact that the Visoflex articulates 90 degrees upward was very useful indeed. I held the camera in front of me pointing directly upward and yet was able to shoot with my eye to the viewfinder with comfort. 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.

Shooting experiences

What confused me while I was browsing through the various discussions and articles is that while the manufacturer is stating that the lens is 11mm, which should be pretty ultra wide on a full-frame lens, that in reality it is more like 15.6mm, which suggests that it actually was meant for a DX/APS-C "crop factor" lens. If I were buying a lens that was supposed to be 11mm on full frame I would want it to be just that rather than 15.6mm. Then again I suppose when one gets into the wide angle realm it really doesn't make that much difference; I really don't know, as wide angle/ultrawide angle/fisheye has not been something I've explored much through the years. When shot wide open at f/2.8 the old Canon 15mm was rife with coma at the corners. The Rokinon 12mm had less off-axis coma than the Canon but it was mixed with some astigmatism and softness. The TTArtisan had worse astigmatism than the Rokinon but crisper star images overall. Stopping down the lenses to f/4 improves the lenses’ performance but some astigmatism remains in the TTArtisan. Credit: Alan Dyer The fast f/2.8 aperture of the TTArtisan 11mm makes it easier to use shutter speeds short enough to freeze the motion of an active aurora, or to shoot 4K videos of auroras, as many mirrorless cameras are now capable of doing. A fish-eye lens is great for capturing overhead passages of the Space Station and other bright satellites. Credit: Alan Dyer