Interested in a wide angle for the A6000 and trying to compare between the Sigma 19mm and Sony 16mm. I have read good and bad about the Sony 16mm. Why does the Sony require the attachment? Does the attachment create any other issues or loss?
The 16mm does not require an attachment. You can get an attachment to make the 16mm wider (12mm I believe) or a fisheye attachment, but nothing is required to use the lens in its native 16mm focal length.
The 19mm is very, very sharp, sharper than the 16mm, but you give up width. It is also a larger lens, the 16mm is a pancake.
The Sony 16mm isn't great, but it's very small, very light, wide and cheap. I like it for astrophotography because it's not that too bad as far as coma. It's too wide for me for general use. It works well with the matched UWA adapter as well, with no decrease in quality.
The Sigma is better in a lot of ways, but it's less wide, bigger and heavier.
Frankly, the Sony is just not very good. Its low price, low weight and small package save it from being downright embarassing. It would defintely limit how much you would get from your excellent camera. The Sigma, while not the best lens in the world (its 30mm sibling is better), is a very good lens, and substantially betters the Sony on all counts. There used to be a deal on the 19mm and 30mm twins, and it was ridiculously good VFM
