I am currently using A7S + FE 55mm which is very nice, but wish to go wider. Other than the FE 35mm and the upcoming Loxia 35mm, anyone has good results with the m-mount lenses with adapter? 28mm would be ideal, but can't wait until 2015 for the 28mm f2. Can't seem to find much info about m-mount lenses with the A7S. I am considering 28mm Elmarit, Voigtlander Ultron, Zeiss Biogon. Thank you!
What are you looking for or what is the subject matter?
Generally speaking, if you want all round dependability, stick to the FE35 or an adapted SLR 28mm/35mm.
The f1.8-f2.8 ones are not outrageously big anyway.
RF 28mm's may be cool small, but mixed bag in terms of off center results on A7 system (the sensor stack is rather thick and that causes issues with RF lenses )
However, if you only shoot shallow DOF stuff, then you may be able to live with the not too ideal edge issues of wide RF lenses.
So depends on your needs.
The ones I know that works w/o big issues CV35/1.2 and CV21/1.8.
My SLR 24, 28, 31, 35mm all work fine on A7.
If you don't need the fast aperture.
I would think just get the new FE16-35 and be done with it.
16-35mm, 55mm probably covers 85%-95% of most general needs.