A _good_ designer *knows* that there are _standards_ -- which
describe a base
set of capabilities that =all= web-browsers support; writes _to_
those
standards, *and* employs a 'validator' to TEST FOR COMPLIANCE with
those
aforementioned standards.

A good designer also checks site functionality using a browser like
"LYNX",
which runs on text-only dumb terminals, doesn't attempt graphics in
any form,
and doesn't do Java, Javascript, Flash, or any of the rest of that
cr*p.

Obviously a company has to decide what the ROI is on developing for
every possible combo. I think it would be pretty ridiculous to test
for a non graphics based platform when the OPs website is mainly
pictures of his projects. I agree with Flash and Java issue, but not
on JS.

*GOOD* web designers are _very_ scarce!
Make that very, Very, *V*E*R*Y* scarce.
Unfortunately.

We know how to do it, we just don't have the time to do it. I think if
the OP hits 98% of the viewers out there, he'll be doing just fine.
Here's some browser usage stats:
http://www.w3schools.com/browsers/browsers_stats.asp