Canon Digital Rebel XT and the EF lenses

[michael_g.]

Hi,

I finally decided to switch to Digital (I still own and really like my

Elan 7e!) I have several EF lenses and was wondering if the Digital

Rebel XT can automatically compensate the focal length differnce

(x1.6) when used with the EF lenses (especially for the flash-enabled

shots)?

Thank you in advance.

[kiestphoto]

Define "compensate". If you mean make the lens behave as they did on a 7e in focal length,

no. If you mean adjust flash-metering and such appropriately, then yes.

[carl_weller]

A 100mm lense will by and large behave 'like' a 160mm - I say 'like' because there are

subtle differences. If you take the shot from the same place as you would with the 100mm

on a FF then it is simply a crop of the picture in effect. If you move to get the same

framing you will increase the distance to subject and thus the DOF.

 

As for flash, the newer 430ex and 580ex are supposed to automatically sense and

compensate for the magnification effect.

 

Other flashes - probably the built in on the rebel as well - don't.

 

Your pictures should still come out OK a long as you realise that the camera will be setting

the flash for a shorter focal length than the 1.6 effective length.

 

This means that you will get good coverage (100 is WIDER than 160) but you will lose

some range on the flash and you will use more power than you actually need to, increasing

recycle times on the flash.

 

good luck,

[paul -]

<i>"wondering if the Digital Rebel XT can automatically compensate the focal length differnce (x1.6)"</i><p>Other than zooming in/out an external flash head to match focal length, there are no differences to be compensated. Even newer bodies which are supposed to zoom the flash head according to the "1.6x" effective focal length are said to have problems doing that at times. It doesn't really matter, as a wider flash spread can often help soften the flash by bouncing off walls/ceiling.<p>The "1.6x" simply means the image you get will be a cropped version of the image you would get using the same lens on a full frame/35mm camera.