interpreting Canon MTF chart with 10D camera

[gordeaux]

Am I getting the right idea if I conclude that with a 10D's 1.6 "multiplier" (or cropping in my book), I'm not using anything to the right of about 14 on the charts (21.5/1.6)? So I shouldn't pay the extra $ to get performance between 14 and 21.5, etc.? :?:

[TimmyG]

I too am wondering if the 1.6X crop factor applies to the MTF charts. I see in photo.net's review of the Canon 18-55mm lens (can be used on digital cameras only) that the MTF chart only goes to 13.
Go to:
http://www.photo.net/equipment/canon/efs18-55/review/
and search for "mtf" to find the charts.

Can anyone second the assumption that 0-13 is the only valid range for MTF charts when used on digital cameras?

[gordeaux]

I too am wondering if the 1.6X crop factor applies to the MTF charts. Can anyone second the assumption that 0-13 is the only valid range for MTF charts when used on digital cameras?

Since this was originally posted I've found several sources confirming the 0-13.5 being all that matters on a 1.6x cropped camera. I can't remember those sources, however.

[Tom W]

I think you can calculate roughly based on the ratio of sensor size to actual film size. IOW, if you take the useful chart range of a lens and divide it by 1.6, you will have an approximate range of the actual lens used for the smaller sensor. The 18-55 stops at 13 due to the actual diameter of the lens being smaller.

As for the portion of the lens not being used, future cameras will most likely have larger sensors as this is the only way to produce higher megapixel cameras without producing higher noise. If Canon has intentions of staying with the 1.6X sensor size for all its consumer cameras, then the company will probably start producing more EF-S type lenses. But they aren't going to develop new lenses if there aren't going to be cameras to go with them.

Photokina will answer that question.