Thorrulz wrote in post #12159085
...Your lens selection alone may or may not work unless you are using only ef mount lenses. If your lenses include the ef-s mount type you need to know whether you have a
FF,
APS-C or a
APS-H Sensor in the camera you may be looking at.
Since he was asking about moving from "D series" (any Canon "D" series) to Rebel, this point is irrelevant.
Thorrulz wrote in post #12159085
Another
RED FLAG would be not being able to properly place a link to your website. By not knowing or forgetting you don't spell out the dot as in
hereismysitedotnet it doesn't exactly speak much for attention to detail. That is a knit pick and we all have lapses so that in itself can be overlooked....
Trying not to make assumptions here about your web savvy, but lots of people do exactly that to prevent automatic URL address harvesters from picking up the web site and then flooding his email (which many times uses the domain name as part of the address) with SPAM. It is assumed actual human beings are smart enough to replace the "dot" with ".". Of course, if that is what he was doing, you promptly defeated that by posting a live link. If he was trying to avoid posting an automatically harvest-able URL, I'm sure he appreciates your "correction."
I fail to see how it is so impossible to consider the possibility that a working photographer does not keep up with the gadget-freak side of the business.
Besides, even if he is a beginning pro, how is that skin off everyone here's noses?
To the OP... Lenses for the 20D will work on any of the Rebels. Batteries and battery grips will not. Memory cards for your 20D won't work with any of the new Rebels. Other accessories may be hit or miss (e.g. flash triggers).
As far as whether the Rebel line is suitable for professional work, the IQ will be more than adequate, but the mechanical ruggedness (e.g. the shutter) probably won't. Controls on the Rebels are more oriented to amateurs, as are some of the technical aspects, such as the AF system. You may not care about this, but the Rebel line is well known as an amateur, entry-level DSLR, and it won't convey "professional" to anyone who knows the difference.