<blockquote>
<p>If you're on a budget, I'd suggest buying a used DSLR, something like a Nikon D5100 which is now quite inexpensive and widely available, for instance a number of them at <a href="http://www.bhphotovideo.com/c/search?Ntt=D5100&N=0&InitialSearch=yes&sts=ma&usedSearch=1&Top+Nav-Search=&BI=11" rel="nofollow" target="_blank">B&H's used department</a>.<br>
There are several reasons why this is advantageous:</p>
<ol>
<li>You can shoot video and stills while tethered to the computer and see its "Live View" either on the computer screen via USB or an external monitor via its HDMI output port.</li>
<li>It can capture video at 1920x1080 (1080p) which is considerably higher resolution than the 640x480 of your current cameras.</li>
<li>You can (optionally) use a third party firmware from <a href="https://nikonhacker.com/" rel="nofollow" target="_blank">https://nikonhacker.com/</a> to extend/enhance its video and stills performance.</li>
<li>Freeware tethering software is available from <a href="http://digicamcontrol.com/" rel="nofollow" target="_blank">http://digicamcontrol.com/</a> which means no need to buy Nikon's software.</li>
<li>You can record/shoot to the camera's SD card, computer, or both.</li>
</ol>
<p>There must be a Canon equivalent as well but you'll have to research that yourself as I'm a Nikon user.<br>
I bought a used D5100 for similar reasons - to use as a second video camera for microscopy, astronomy, and general video work with a long list of available accessories.</p>
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<p>This.<br>
I owned a Canon t3i and used the Canon specific software to tether to my MacBook for product photography. Just get a cheap prosumer Canikon slr. They record exceptional video and have the tethering function you need. Also, they make them pretty small these days. (i.e. canon SL1)</p>