I thought long and hard about the aquisition of the Sony A7s. I've been looking at images and reading reviews for some time now. It's not something you can purchase every day unless you have money to spare that is. Some might ask why I was thinking about the the A7s when I already have the A7r and it boils down to this; my Voigtländer wide-angle lenses. I just miss using them.
I've been using them on the Nex-5N, m4/3 and my Fuji systems but it's just not the same. The m4/3 system has a 2x crop factor, the Fuji and the Nex have a 1.5x crop factor so the lenses don't really behave the way they were designed. I was very impressed with the specs of the A7r and and purchased that camera to replace my Sony A900 which delivers excellent images at base ISO, but it is big and heavy especially when using the f2.8 zooms on it.
I also had great hopes for the Nex-7 with it's excellent sensor and great ergonomics but those wide angle rangefinder lenses just didn't want to play. That purple colour cast was everywhere. So, two of my favourite cameras, the Nex-7 and the Alpha A7r both rule out the use of lenses at 35mm or wider. Some might say just purchase SLR lenses and avoid the rangefinder lenses. Well yes, I could do that but I believe the rangefinder lenses are some of the best lenses ever made and I want to use those. Hence the predicament about the A7s. With the reviews and posts at soundimageplus and stevehuffphoto and the fact that I could either keep using my rangefinder lenses with cropped sensors or sell them. I really didn't want to sell them so I aquired the A7s recently. No purple cast, full frame sensor and a low light shooting that we could only have dreamed of a couple of years ago.
Some complain it's only 12MP but you'd be surprised what you can do with those 12MP files. Plenty for me and I'm sure 12MP is enough for most people. The image above shows the A7s mounting the 15 f4.5, the 21 f4 and the 35 f2.5 lenses. Just compare these to the SLR lenses. They are positively minute. I'll let you know how I get along but I have a feeling this is all the camera I need for some years to come.