I compared my camera a Canon SL11 to your Nikon Coolpix 830 dimensions on DPReview. It looks like a tight fit. If this is the only bag you are considering I would suggest a bigger camera bag. DPReview, the differences in our dimensions: http://www.dpreview.com/products/compare/side-by-side?products=nikon_l830&products=canon_eos100d At some point I am going to buy a bigger bag/hard case to accommodate more accessories I intend to buy.
It would be tight and only with a small lens at best. I would use the Case Logic Luminosity Zoom DSLR holster. The case in question is good for a camcorder or Canon Powershot SX510. I hope this helps. It is a quality bag for the right camera.