crop factor of canon


rockdhop

New Member
Mar 11, 2008
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#1
hi.
ihave read that canon crop factor is x1.6 while nikon is 1.5.

so what exactly does it meant?

if let say im using a canon 550D,looking through the VF, when my zoom on the lens is at 18mm, does it mean that in fact im looking at 28.8mm far, and when i shoot,the image captured will be of the view of at 18x1.6 = 28.8mm?

if not, can anyone tell me what exactly does it meant?
 

Octarine

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Jan 3, 2008
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Pasir Ris
#2
if let say im using a canon 550D,looking through the VF, when my zoom on the lens is at 18mm, does it mean that in fact im looking at 28.8mm far,
No. The physical characteristics of focal length remain unchanged.
and when i shoot,the image captured will be of the view of at 18x1.6 = 28.8mm?
Yes. Field of view is what gets changed.
More to read: DSLR Magnification Factor (vulgo: crop factor)
 

zac08

Senior Member
Feb 21, 2005
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#3
hi.
ihave read that canon crop factor is x1.6 while nikon is 1.5.

so what exactly does it meant?

if let say im using a canon 550D,looking through the VF, when my zoom on the lens is at 18mm, does it mean that in fact im looking at 28.8mm far, and when i shoot,the image captured will be of the view of at 18x1.6 = 28.8mm?

if not, can anyone tell me what exactly does it meant?
It's the sensor size. The smaller size of it compared to the original 35mm gives it a cropped ratio of 1.6

So while the lens focal length is still the same as when you use it on FF, the cropped end result is smaller and thus it seems as if you have a longer focal length.

So if you have a sensor which is at 2.0 crop (using a different format to explain), what you see at the end of a 18mm lens will instead be at 36mm equivalent of the 35mm format.

Hope you can get the picture.
 

rockdhop

New Member
Mar 11, 2008
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#4
oh okay, regarding the 18mm at crop factor x2 resulting a 36mm.

in other words, it also meant a "closer" shot (narrower) but at a further zoom, yeah?

am i right to say that in fact, we dont have to bother too much about the crop factor because eventually what i see in the VF = what i get.
 

juste_millieu

Senior Member
Mar 17, 2004
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#5
oh okay, regarding the 18mm at crop factor x2 resulting a 36mm.

in other words, it also meant a "closer" shot (narrower) but at a further zoom, yeah?

am i right to say that in fact, we dont have to bother too much about the crop factor because eventually what i see in the VF = what i get.
yes :D
 

rockdhop

New Member
Mar 11, 2008
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#6
hmm got it. since what we see in VF = what we get when we print out, then why is there still people making it sound so chim, and confusing the masses? hahaha
 

kazumi

New Member
Sep 10, 2009
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#7
The field of view changes, but the focal length don't. using crop factor 2 as example, if u use a 20mm lens, ur fov is 40mm but everything else remains the same at 20mm. its like u take a photo with 20mm, use PhotoShop and cut out the center portion. that's y its call crop factor, cos ur camera crops out the center for u.

It's a disadvantage, cos ur camera crops yr photo everytime. It's like losing 50% of ur photo everytime u take a photo.
 

rockdhop

New Member
Mar 11, 2008
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#8
okay i got that. so my dslr will auto crop for me yeah? hmm in other words, what i see in on the VF does not equals to what will be produce, isnt it??i see a 100% view of an apple. but turns out, probably will only be 70% since its crop?
 

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sinned79

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Jun 18, 2009
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#9
okay i got that. so my dslr will auto crop for me yeah? hmm in other words, what i see in on the VF does not equals to what will be produce, isnt it??i see a 100% view of an apple. but turns out, probably will only be 70% since its crop?
u still see what you get on VF.

just that everything looks more narrower. if u compare the same lens on a FF VF.
 

Rashkae

Senior Member
Nov 28, 2005
19,105
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#10
okay i got that. so my dslr will auto crop for me yeah? hmm in other words, what i see in on the VF does not equals to what will be produce, isnt it??i see a 100% view of an apple. but turns out, probably will only be 70% since its crop?
Your DSLR viewfinder already compensates for the crop. Your viewfinder is not a "100% full frame coverage" viewfinder where you then need to figure out the crop. It's pre-cropped. Of course, you could have found this out by just taking a picture!!
 

android17

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Sep 27, 2009
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#11
The easiest way to test this is to hold both a full frame and crop factor dslr in your hands and look thru the viewfinder. You will see the huge difference.
 

zac08

Senior Member
Feb 21, 2005
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#12
Dun forget there is another factor.

VF coverage of scene. Not all cameras have 100% viewfinders. Most only have 95% or so...

so this can cause another form of error, do note. :)
 

Sep 17, 2008
3,656
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#13
Dun forget there is another factor.

VF coverage of scene. Not all cameras have 100% viewfinders. Most only have 95% or so...

so this can cause another form of error, do note. :)
wads vf?:think:
 

takafan

Senior Member
Nov 26, 2008
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#15
Dun forget there is another factor.

VF coverage of scene. Not all cameras have 100% viewfinders. Most only have 95% or so...

so this can cause another form of error, do note. :)
I think Canon 7D is the only APS-C camera with 100% viewfinder. Correct me if im wrong.
 

rockdhop

New Member
Mar 11, 2008
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#18
so whatever we see through the VF, is already a cropped image (x1.6) uh?
 

zac08

Senior Member
Feb 21, 2005
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#19
so whatever we see through the VF, is already a cropped image (x1.6) uh?
yes, for Canon cropped DSLRs and also with a factor of 95% viewfinder reduction as well.
 

Octarine

Moderator
Staff member
Jan 3, 2008
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#20
so whatever we see through the VF, is already a cropped image (x1.6) uh?
Yes. Reason is that not only the sensor is smaller but also the mirror and viewfinder optics. Target is a smaller / cheaper sensor and an overall reduction of camera size.
 

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