[f/2] Everything I hope they would be and more. fits nicely on the 28mm.

[f/22] I've used my 21mm Ultra-Wide Conversion Lens for a week now and just finished using it for Autumn landscapes this weekend with great results. I'm seeing that there is little to no IQ degradation in using it, and also find that it is much easier to remove this lens from the end of my 28mm FE f/2 than doing complete lens changes. Actually, when I want to switch I simply remove it, keep it in my hand as I take my shot when I want the longer 28mm focal length, then return it to the front of the 28mm for safe keeping as I walk about. This provides a flexibility very near that of a zoom, but really what I'd call a multi-focal length lens combo. The maximum aperture does drop to f/2.8 from f/2 when adding this conversion lens, but I haven't found that an issue, as I still consider that wide, and allows for good low light capabilities. In Lightroom, my RAW images can be adjusted to control distortion by clicking on the lens profile check box, or shoot JPEG and have it controlled automatically. The add-on conversion lens is recognized in the body and through the RAW converter as a 21mm lens and the adjustments to profile work seamlessly. For the cost, this is a highly recommended piece of kit for your Sony full frame and the 28mm FE prime. BTW, check out the quality and sharpness rating for the FE 28mm on DxOMark. It is in the top 5!

[0.8 lb] I bought this lens to use with my Sony Alpha a9. I needed something wide, prime, sharp, and light/compact for travels + run & gun shooting. I shoot fashion, beauty, and artistic portraits and this lens has been AWESOME for that. What I love about this lens is that it's fairly tiny, keeps the weight down. I pack this with my Sony FE Carl Zeiss Sonnar T* 55mm F1.8 ZA & Sony FE 85mm F1.8 lenses. Not exactly a replacement for the true 35mm, but if you're looking for something with a wider aperture than the Sony FE Carl Zeiss Sonnar T* 35mm F2.8 ZA lens, this would it. It's very sharp even at f/2, and you can close it down to 2.8 to make it even sharper. The focus is quick and accurate as well, even in low-light from my experiences. The only challenge may be strong backlighting (like shooting the model in front of white sheers or with sun gleaming in the back around sunrise/sunset). The only thing I would note for your awareness about this is that it is has some distortion to it, so I recommend shooting in RAW when using this (though ideally you should always be shooting in RAW), so that you can use profile correction in Lightroom to fix it. It'll look great after you do that! For the price, quality, and performance, this is a must-have in your kit. =

[75°] Fast aperture, fast autofocus and sharp images for 200 grams or so. It looks bigger on the pictures, but performs really well. I use it for video on my Sony A7S II and I call this the Low Light Combo Monster :) F2 is really good for shooting at night and I haven't had issues with autofocus speed even with the A7S II's CDAF. I was used to Nikon DX format so it was a little wider than I expected but in a good way (so much so that I'm planning to use it for vlogging). Anyway, awesome lens for video from my experience.

[f/2] I love it. Keep in on my 28mm all the time.. A little scary that I cant put a filter on it but I keep the cap with me at all times.

[f/2] Works great. Decent wide open but gets better as you stop it down. I mainly used it on my a7sii for wide shots on a gimbal. The fact that i have essentially a 21mm auto focus lens made it worth it.

[Autofocus] Works like a charm

[0.13x] I purchased this lens to use on my a7s and gimbal, however I found that it gives an interesting look for photography as well. I've used it in a couple weddings so far and this lens is very sharp and has good auto focus. For video, this is a great focal length for a stabilizer. It is not so wide that you have to stand a foot away from what you are recording and it is not so narrow that you have issues with movement speed. I was considering the 35/2.8, however that extra stop of light is nice for receptions. The lens does have some distortion, however it is to be expected on a wide lens. It doesn't bother me at all and just use it to create more interesting photos.

[Full-Frame] My prefect lens for my a7sii and crane after 2 years it's my never fail baby

[Full-Frame] I love the detail on this lens and taking some long exposure with an 8x ND filter the pictures came out great. My zeiss 35mm 1.4 is great but its huge. It's not great walking around with it. I found the color sharp and loads of detail using a full size sensor. Also for food shots, you can get a lot of the scene into the image and then just crop if needed. I think the 28mm is a fun focal length for everyday shooting. I will carry my zeiss 55 for anything more up close. Overall I couldnt be happier.