The Sony HC48 does not have a mic-in jack nor does it have the proprietary Sony "active interface shoe" - but this may not be important to you. It has a single 1/6" imaging CCD; 4 lux low light; and a 25x optical zoom.
The Canon ZR800 has an external mic-in and you are not locked into a proprietary mic format - anything with a 1/8 inch connector will do. The 1/6" CCD imager is the same size; it rates itself to 2 lux low light and a 35x optical zoom.
The Canon ZR850 looks the same as the ZR800 but they appear to have traded the mic jack (on the 800) for a remote control (on the 850). So... with the remote, I point the camera, run into the shot (hopefully), point the remote at the camera and hope it is recording There is likely a tally lamp on the front. Without the remote, I point the camera, press record on the camera and run into the shot.
Since you probably shouldn't be any more than a few feet away from the subject you want to be filmed with, personally, I'd go with the mic jack. If you were so far away that you needed to zoom to get the image right, chances are good that 1) you might fall out of the frame anyway and/or 2) you would not be able to hear what was going on (so you want an external mic)... but that's just my opinion.
That said, the ZR800 does not have an accessory shoe for an external mic. Do a search on "camera bracket" and you will find bars and brackets that have a screw mount to the tripod hole in the bottom of the camera - and a hole in that which the tripod can screw into... and it will give you a cold accessory shoe to mount an external mic - if you choose to go this direction. There is another Elura 100 post around here that has links to see what those brackets look like and their price range... and examples of external mics and a universal shock mount...
So... of the 3 cameras you allowed us to choose form, I guess I'd pick the Canon ZR800... Marginally better lowlight; mic-in jack and better optical zoom.
Guys!! Help me out!!
I'm between these three Camcorders after a 2 month debate! Actually I was hoping to find a Canon Elura 100 but is sold out everywhere and is time for a upgrade anyway! The big diference between the ZR850 & the ZR800 is the MIC port on the ZR800.
I love the features of the Sony DCR-HC48 plus the dock included. It seems easy to work with this one, but is new and there's not much reviews out there about the Sony one. I definetly between any of these but as always you guys have the last vote in my electronics decisions!! hahahahaha!! Help!!
The confused one!!!