Image Quality
As I mentioned earlier, most add-on conversion lenses tend to do a number on image quality vs. the native bare lens. While there is some loss of definition to the files, I was very pleased to see that overall image quality of the FE 21mm f/2.8 combination was actually quite good.
Sharpness
Sharpness is the thing that suffers most with these conversion lenses, but overall, the FE 21mm conversion lens bucks this trend fairly well. While distortion correction does cause a notable reduction in corner sharpness, which I’ll talk more about in a bit, I was generally quite happy with the sharpness the FE 21mm produced. Starting from wide open, the lens starts with good central resolution, though rather poor edges and corners. However, upon stopping down to f/5.6 or smaller, the edges sharpen up considerably. While it’s not going to achieve critical edge-to-edge sharpness, as you might expect, the central 80% of the frame becomes very sharp, while the edges and corners do sharpen to a good level. While it’s not the sharpest ultra-wide lens in the world, it’s definitely good enough for most shooting, especially if you don’t shoot ultra-wide-angle a tremendous amount. Click on the image below and click the green arrow at the bottom of the screen to view the image at full size to get an idea of what you can expect.
Bokeh, Color and Contrast
I’m combining a few categories here, as in many cases there are close similarities to the FE 28mm f/2 that makes up over half the optical path when using the UWA converter. The UWA converter doesn’t appreciably alter the color, contrast or bokeh characteristics of the FE 28mm. The bokeh remains quite creamy when shot close up, and still fairly nice further away, though a bit more nervous. Color is natural and contrast is good without being overly punchy.
Distortion, Chromatic Aberration, Vignetting and Flare
If you’ve read my FE 28mm review, you’ll know that lens suffers from rather strong barrel distortion, and the UWA conversion lens simply adds to that distortion. In the major weakness of the FE 21mm, heavy barrel distortion will require digital correction for almost all shots. Simply consider it part of the workflow. Thankfully, JPEGs are automatically corrected and Lightroom has a profile as well that eliminates most of the distortion, though I found I often needed to add an additional few steps of correction beyond the profile.
While the FE 28mm performed quite well with regards to chromatic aberration, this is another area where the conversion lens adds a bit of fault. While lateral CA is still negligible, some purple fringing can be induced with the FE 21mm, especially at wide apertures. Vignetting, however, is actually slightly reduced with the 21mm converter attached.
Flare resistance, thankfully, continues to be excellent, with the FE 21mm turning in a performance with minimal ghosting and virtually no loss of contrast when shooting into bright light.
Great review as always. I just bought this addon lens and can’t wait to review it myself. I wonder if in the long run the 16-35 would be the better option, however.
Thanks for the review. It strikes me that the cost of the adapter is about as much as a few of the old MF glass options around this (21mm adapted) focal length- eg canon Fd 19 or 20 or Olympus 21 etc. For landscape use on an A7II from what you have seen, (keeping in mind that shooting stop would be at least an 8) How does the IQ compare? I have been using an fd 24mm it is very sharp copy and was very economical. (My Fd 28 is not!) It has been hard to justify getting something else modern so far as i keep testing at the local camera store and nothing has been sharper or that much superior to justify cost. I really liked the Sony 28, but what I need is wider! Enter the adapter. what’s your take? Cheers!
I wonder if there is a way to use this with another lens.
Can you post the back of the lens?
are there moving parts in it?
thank you
I know this is an apple vs orange comparison, but which one will come up on top in terms of optics, IQ, sharpness etc? FE28 + 21mm adapter or Fuji XF14mm?
The Fuji by a mile. Not that the 21 isn’t a good combo, but the Fuji is an exceptional lens. Sharp to the very corners, no distortion, etc.
Any thoughts on how it compares to the ~19-21mm legacy primes at a similar price point? I’m thinking of the Nikon 20mm f/2.8 AI and D, Canon FD 20mm f2/.8, Minolta Rokkor-X 20mm f/2.8, Voigtlaender 20mm f/3.5, Olympus 21mm f/3.5, and Pentax 20mm f/4, all of which are ~$200-350. Probably some others I’m forgetting as well.
I had been planning on getting the UWA converter, based on my good experience with the SEL16F28 + VCL-ECU1 on the NEX. The SEL16F28 wasn’t a great lens, but the VCL-ECU1 did a great job, was cheap ($100), and seemed to increase IQ rather than degrade it.
Then I realized that the Nikon 20mm f/2.8 that a friend was selling weighed the same as the UWA converter. If it can perform any better than the FE 21mm, it might make more sense for me.
Thanks for a great review, as usual.
thank you for your great review … i just ordert the combo to have a closer look.
best regards
jan