Will these two different cameras make a bigt difference in video quality?

I'm about to buy the nikon D3100 and D5000 but there different qualities will this make a big difference when using them both for my videos but there the only one that can find used and cheap my budget is under 400$ per camera. If you guys know some cheap dslr with changeable lenses and where to find them let me know as well also sorry for punctuation i'm on my ipad

This question might have been better-served over in the "Cameras" category, since you'd find more Nikon shooters over there than here in "Camcorders".

But I know a bit about Nikons in "movie mode", and before you buy, you need to realize three main things about these cameras.

First, being DSLRs, they are limited in how long a "scene" you can shoot (5 minutes in HD mode). Great for scripted filmmaking with short "takes"; not so great for long concerts, sports events, or wedding ceremonies.

Second, 720p @24fps is the only common HD mode between these two Nikons, AND they both shoot in different file formats & compression schemes (D3100 = MOV; D5000 = AVI). The D5000 model came out first, and only shoots HD in 1280x720 @24p. The D3100 was the first Nikon to shoot 1920x1080 @24p, as well as 1280x720 @24p/25p/30p.

Third, the "rolling shutter" effect that most DSLRs (including these two) have. Not great for fast-action shots nor for sweeping pans. Vertical lines (buildings, doors, fences, etc.) will appear jagged or with a "Jello effect" when either they or the camera is moving fast horizontally.

If you insist on using DSLRs and don't already have a stock of Nikon lenses, go find two matched gently-used Canon EOS series and some much-cheaper Canon lenses for your $800 or so budget. Your editing will be much easier with the same file types, compression, & resolution.

Otherwise, just shoot single-camera, get a real $500-$800 miniDV/HDV (low compression) camcorder like the Canon HV40, or one decent DSLR and edit everything together like a regular filmmaker would.

(If you shop carefully, you could find two HV40's for $1000 or less. Canon sells them refurbished online for $499 each.)

Here's a reliable NYC new & used Nikon/Canon dealer (B+H Photo) with this link showing used & refurb DSLR selections in your budget range: http://www.bhphotovideo.com/...RICE_2%7C0

hope this helps,
--Dennis C.