a57 to the nex 6 ?

It was very hard for me to leave my 5N, but there were some things than I simply missed. External mic was one. Serious flash work was another. In the NEX and generally mirrorless world features like these are simply not there or you pay a very high price to get them. For example in order to have external mic in nex 6 you'll have to get the xlr kit. Of course there is always the zoom-like external recorders and syncing audio afterwards scenario. NEX 6 features a hotshoe so you're not stuck with the proprietry connected flash like in the 5 series, which i had to struggle with. In body stabilization? Can't beat that one for sure. Always have to pay those expensive lenses to have stabilization whereas with the slt cameras you get that even with the cheap legacy ones.

I never stopped thinking about that tiny amazing quality camera, one of the reasons being exactly what you mention, i took it with me almost everywhere easily without second thought, though A57's size and weight sometimes discourages me. Best solution, budget allowing of course, is to own them both. Mine doesn't

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Zenit 12 / Sigma SA-300 / Sigma SA-5 / Olympus C770UZ / Canon PowerShot A720 IS / Sony NEX-5 / Sony NEX-5N / Sony A-57