# Lens mount for Rebel XS



## sunlou (Jun 8, 2009)

Hello, I have a Rebel XS and i've been seraching e bay for cheap lenses to strat building my gear,

But I can't figure out wich lense will fit or not. I figured at first that my safest uneducated guess was to buy canon lenses. do they all fit.

For example I won my bid on :
 
Canon FD Mount 75-205mm f3.8 Macro Zoom Lens

Will it fit 

(I think not from what i've read but i am all lost)

how about this one

Canon Mt. 80-200mm f=3.5 macro zoom lens AE-1 A1 fin

thanks


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## Steph (Jun 8, 2009)

FD mount lenses (as used on the AE-1 and other manual cameras) won't fit on your Rebel XS. The lenses need to be EF or EF-S mounts to fit. Both lenses you looked at will NOT fit your XS.


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## Overread (Jun 8, 2009)

However I belive there are mount adaptors cheapy availble on ebay for most mount conversions. Some have glass optics in them others are just ring adaptors - depending on the mount chances. If your going with a glass containing mount do some research and get a good one


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## Big Mike (Jun 8, 2009)

I wouldn't recommend buying the incompatible lenses and an adapter.  It will be much easier to stick with more 'modern' lenses.

As mentioned, and Canon EF or EF-S lens will work...also, any off brand lens that says it's for 'Canon Auto Focus' should work as well.


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## sunlou (Jun 8, 2009)

Thanks


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## iadubber (Jun 8, 2009)

also keep in mind that if you buy EF lenses that you have a 1.6x crop body. So you  need to multiply the focal length of the lens by 1.6 to get the actual focal length on an aps-c sensor.


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## Baaaark (Jun 8, 2009)

iadubber said:


> also keep in mind that if you buy EF lenses that you have a 1.6x crop body. So you  need to multiply the focal length of the lens by 1.6 to get the actual focal length on an aps-c sensor.



Which makes that 50mm 1.8 that's just a little over a hundred bucks AWESOME for portraits.


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## johnj2803 (Jun 8, 2009)

also you might want to know that the"older lenses" will not AF an you will have to manually focus.


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## Dao (Jun 8, 2009)

iadubber said:


> also keep in mind that if you buy EF lenses that you have a 1.6x crop body. So you  need to multiply the focal length of the lens by 1.6 to get the actual focal length on an aps-c sensor.




Well, the actual focal length of the lens will not change.  If the focal length of the lens is 50mm, it will be 50mm when mounted on any EOS cameras (digital or film).  However, when it is mounted on a cropped  body, the Field of View will be smaller when compares with the full frame body or  35m film body.


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## musicaleCA (Jun 8, 2009)

Which is why the effective focal length is changed, by a factor of 1.6. A 50mm EF lens on an APS-C body will have the equivalent field-of-view as an 80mm EF lens on a full-frame body. Since focal length is directly related to field-of-view, I fail to see the difference you seem to be trying to point-out...


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## Dao (Jun 8, 2009)

"Actual" focal length of a lens will not change.  A 50mm lens is always a 50mm lens.


A 50mm focal length lens is different (optically) from a 80mm lens.


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## Steph (Jun 9, 2009)

musicaleCA said:


> Which is why the effective focal length is changed, by a factor of 1.6. A 50mm EF lens on an APS-C body will have the equivalent field-of-view as an 80mm EF lens on a full-frame body. Since focal length is directly related to field-of-view, I fail to see the difference you seem to be trying to point-out...



By definition the focal length is a characteristic of the lens: the focal length of a lens is the distance from the optical center of the lens to the focal point, which is located on the senor/film plane when an object at infinity is in focus. No mention of the camera or size of sensor/film in the definition. The focal length of a lens does not change according to the camera you use it on. There is no such thing as effective focal length by definition. Of course the field of view will change because of different sensor sizes but not because of a different focal lengths.


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