jaylim0512 wrote in post #13326033
I've been reading around and people have been saying some lens' aren't meant for full framed bodies whereas some are meant for it or vis versa with the cropped framed bodies.
Could some explain to me why this is and how I know what to buy for future reference?
Other than the fact that Canon EF-S mount lenses cannot be used on cameras other than those which they were designed for (APS-C format cameras beginning with production of the 300D - the original "Digital Rebel"), the majority of the recommendations that I believe Jay is referring to come from people's personal preferences as to focal length ranges that they prefer to use.
A typical example that we see frequently is "the 24-70 is not a good lens to use on a 7D". These folks suggest, instead, the use of a lens with a range of 17 or 18 mm to maybe 50 or 55 mm because the "24-70 is not wide enough on a 'crop' camera". This sort of recommendation should be totally ignored, in my opinion, because it's really based on personal preference. I, for example, find my 24-70 an extremely useful focal length range for use on my 20D.
Bianchi wrote in post #13326142
if you use a ef lens which is 24 105 for full frame the focal distance on a crop is X 1.6 which in reality for a crop is 38.4 168
For the newbies - this information, as presented, is quite incorrect.