First of all, many thanks for the precious information and great images !
I am also considering an A7 or A7r in addition to my medium format gear.
I used to have a D3x next to the Alpa for its versatility and quality. It was a great addition: a pleasure to use, very clean files, very good dynamic range, better colors than my former Canon 5D2. I sold it due to its size and possibly I asked too much in terms of colors when comparing with MF. I miss it now and dream a Sony could bring the same quality in a much smaller package.
I will shoot mainly handheld, with a 50mm or longer lenses, no wide.
If the quality of the A7 is similar to the D3x’s, in terms of color and definition, I can probably forget the A7R.
I wouldn’t go for the A7R for the extra pixels but quite certainly for better colors (depth, transition, accuracy) and better pixel-lever detail (I like clean pixels without artificial sharpening, I care less about the number of pixels).
I understand that there is no major gap in character between both cameras, but I am ready for extra efforts to get the 7R if the nuances result in more pleasure with the files (again, apart from pixel count, but colors, transition, accuracy, textures, natural looking).
I will consider the cost difference and extra efforts of usage in a next phase, for now I am more looking for your pure qualitative feedback.
Thank you for your help !
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EDIT : please don't reply ... in the meanwhile I went for an A7R and a 55/1,8 FE
Statistically when screening the images in different forums, I was more often impressed by the A7R. Lots of factors on top of the camera, for sure.