Best backup camera for sports/general/travel usage? D600? D5200? Something else?

I have thought about the d5200 as a second camera. I tried a d3200, but found it very difficult to avoid accidentally moving the focus point - there is no lock like the d7000 and d800e and such have. This may seem trivial, but when you have to think fast it really makes a difference.

Just looking at the pix of the d5200, I do not see a lock. Perhaps someone with a d5100 could tell us.

The smaller viewfinder also makes a difference.

You might also consider the d7000 as a backup, even a used one.

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www.pbase.com/bertramm pbase & dpreview supporter