EF vs EF-S Lens (Crop Factor)


ssworx

New Member
Aug 24, 2010
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#1
Hi guys,

Would like to know the diff between a 17-40L, 17-55 & 17-85.
At 17mm focal point, are these equivalent to 27mm on a Canon APS-C 400D body?
17-40L is an EF lens whereas the other 2 are EF-S lens.



Thanks!
 

Last edited:

eleveninth

Senior Member
Jan 17, 2006
6,217
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#2
Hi guys,

Would like to know the diff between a 17-40L, 17-55 & 17-85.
At 17mm focal point, are these equivalent to 27mm on a Canon APS-C body?
17-40L is an EF lens whereas the other 2 are EF-S lens.

Thanks!

zzzz see for yourself.

AbelCine - Field of View Calculator

anyway focal length doesnt change only fov.
 

ssworx

New Member
Aug 24, 2010
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#5
Why is the angle of view diff @ 17mm for the 17-40L EF lens?
 

ssworx

New Member
Aug 24, 2010
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#7
Hmmm...sorry I do not get it.
So if the 17-40 is mounted on a crop body, will the 17mm be the same as EF-S lenses (17-55 & 17-85).

Thanks a mil!
 

eleveninth

Senior Member
Jan 17, 2006
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#8

ssworx

New Member
Aug 24, 2010
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#9
yep sorry but i do not understand what you meant & how to use the comparision.
I chose the 7D to compare with a 35mm.
But what i would like to know is EF vs EF-S lenses on a crop body?
Why does the angle differ @ 17mm for EF lenses?

Thks!
 

eleveninth

Senior Member
Jan 17, 2006
6,217
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#10


choose the 5D and 7D ( FF vs APSC )

In the comparison the yellow box is the sensor size from the APSC the rest is what you would see on a FF camera at that focal length.

Anyway what camera u using. I assume it's APSC
 

Last edited:

ssworx

New Member
Aug 24, 2010
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#11
sorry, maybe i confused you.
I know the diff of using the lenses on a FF.
However, I do not know the diff of using a 17-40 vs 17-55 or 17-85 on a cropped body.
the 17mm on the EF-S lenses show the same angle. But not the 17-40 EF (based on canon website)
What i would like to know is would they be the same angle @ 17mm(all 3 lenses on a CROP BODY)

appreciate your patience dude.
 

eleveninth

Senior Member
Jan 17, 2006
6,217
2
38
#12
sorry, maybe i confused you.
I know the diff of using the lenses on a FF.
However, I do not know the diff of using a 17-40 vs 17-55 or 17-85 on a cropped body.
the 17mm on the EF-S lenses show the same angle. But not the 17-40 EF (based on canon website)
What i would like to know is would they be the same angle @ 17mm(all 3 lenses on a CROP BODY)

appreciate your patience dude.

lol. pls refer to yellow box.

I'm not confused. ;p
 

ssworx

New Member
Aug 24, 2010
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#13
sorry i really do not understand.
So will the 17mm on the EF & EF-S be the same on a cropped body, which is 27mm?

thks once again
 

kei1309

Senior Member
Apr 12, 2010
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#14
sorry, maybe i confused you.
I know the diff of using the lenses on a FF.
However, I do not know the diff of using a 17-40 vs 17-55 or 17-85 on a cropped body.
the 17mm on the EF-S lenses show the same angle. But not the 17-40 EF (based on canon website)
What i would like to know is would they be the same angle @ 17mm(all 3 lenses on a CROP BODY)

appreciate your patience dude.
to answer your question:

Yes. they would all look the same on a crop body.

why? because all lenses put the same focal length down on the body. it would be confusing to have one set of focal lengths for FF lenses, and lenses made for Crop bodies

just that, you have to remember to multiply the focal length on any lens by the crop factor to get the 35mm equivalent field of view.

i.e. if you're using a 50mm FF lens, you need to have 50mm x 1.5 (Nikon and Sony APS-C crop factor) which will give you 75mm

and even if you're using a 50mm Lens made for a crop body, you'll still have to apply 50mm x 1.5 to get the equivalent FOV.

and yes. i think this is what you're asking
 

eleveninth

Senior Member
Jan 17, 2006
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#15
lol.

kei so good straight away give answer. bwhahaha.
 

ssworx

New Member
Aug 24, 2010
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#16
to answer your question:

Yes. they would all look the same on a crop body.

why? because all lenses put the same focal length down on the body. it would be confusing to have one set of focal lengths for FF lenses, and lenses made for Crop bodies

just that, you have to remember to multiply the focal length on any lens by the crop factor to get the 35mm equivalent field of view.

i.e. if you're using a 50mm FF lens, you need to have 50mm x 1.5 (Nikon and Sony APS-C crop factor) which will give you 75mm

and even if you're using a 50mm Lens made for a crop body, you'll still have to apply 50mm x 1.5 to get the equivalent FOV.

and yes. i think this is what you're asking
ok i got it now! thks for all ur patience!
 

kei1309

Senior Member
Apr 12, 2010
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#17
lol.

kei so good straight away give answer. bwhahaha.
not so anal tonight :bsmilie: i haven't slept in almost 23 hours :bsmilie:

ok i got it now! thks for all ur patience!
no worries :D

all i want is a cup of starbucks coffee venti size :bsmilie:
 

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