I'd like to dabble in video since I now have a little more horsepower at home now on the Mac. The D300 is sufficient for still images but doesn't do video. My iPhone is an option but I'd love to utilize my prime lenses for better video. Anyway, just curious what DSLR ppl here might recommend as a backup for my existing camera that would double as something i could use for video on occasion.
Something like the D3300 SLR is under 500$ ... good option?
I've had 6 different Nikon DSLR's and I can say with utmost certainty that if I had to pick one for video it would be the Sony a6000.
Seriously, unless you're shooting only on a tripod or with a steadycam rig, if you want to shoot video then get something for video. I know that's not the a6000, but at least you can get an adapter and use your Nikon lenses on it. :)
Go rent or borrow one for a weekend to see if DSLR video is for you. I have had it on the last four Nikon DSLRs that I've owned, used it rarely, but have been happy with the results.
Yakatme's em5II is a good camera for video as it has the 5 axis image stabilisation.
Another one to look at would be the Panasonic GH4, GX8 or G7.
You can get a speed booster to use your prime nikon lenses with m43's cameras (makes a lens one stop faster e.g. f4 becomes f2.8 and wide also - sort of like a teleconverter in reverse)
Your 35, 50 and 90 would work well on the speed booster.
The D300 is big and old. You want to carry around two bodies and old technology? Sell it with the Nikon 35 1.8 and upgrade to a Sony A7-II with a native FE lens for autofocus. The Sony has 5 axis image stablization and in the process you get a 35mm sized sensor. The Olympus already mentioned along with Speed Booster adapter will cost you about the same as for the Sony body. One system simplicity.