Page 1 of 1
Posted: Wed Oct 03, 2007 8:16 pm
I am in the market for a canon. I have an EOS 3 now and its about time to switch to digital. I have been looking at the 40D and the 5D. It may be used for weddings. So my question is, would the 40D be good for this? I don't quite understand the the efect of the lens ratio.
Posted: Thu Oct 04, 2007 6:50 am
I just bought a 40D after shooting with a 10D for several years. Both are excellent cameras. I'm not sure what you mean by the lens ratio but if you mean the 1.6 crop factor, it means that a 100 mm lens will still be a 100 mm lens but 60% will be cropped giving you a lens that is effectively 160 mm. The 5D is a full frame camera, so that 100 mm lens will still be 100 mm. The downside of the 1.6 crop is in wide angle shooting. A 28 mm lens becomes a 35 mm lens so you need a very wide angle lens. I have a 17-40, 24-70 and 70-200 to cover the entire range. Another advantage of a 1.6 crop camera is that you don't have the edge problems that some lenses have when shooting full frame. You are only using the part of the lens with the best optics.
Posted: Thu Oct 04, 2007 10:36 am
Hmn. I don't get it. If you want a camera why would you buy a Canon instead of a camera? (JUST KIDDING
). No intent to start one of those Black Hat White Hat debates here.
"Full Frame" (which is technically somewhat of a misnomer) means 35mm equivalent. Theoretically, the sensor area would be equal to the rectangle of film which is exposed in a 35mm camera. This means that all of your 35mm system based lenses will have the same field of view as they do on your current film body.
For mostly technical/engineering reasons, the sensors in (many -- perhaps most) DSLRs were much smaller, which means that only a portion of the lens optics were used, creating the "crop factor" as Al explained. The problem for many shooters was the loss of wide angle. I never shot extreme wide angle, but did have a 28mm lens. I ended up purchasing a 14mm to get the wide angle I needed. There are some compromises at that length (particularly high cost). At the other end, there are some advantages, if you want length.
For weddings, I don't know -- but you might find that you have a certain lens or lenses that render the look you want and the crop factor will definitely change that.