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Largest possible EF-S compatible Canon sensor

miloblithe

miloblithe

macrumors 68020
Original poster
Nov 14, 2003
2,072
28
Washington, DC
Does anyone know what the largest sensor size is that would be compatible with Canon's EF-S mount?

The actual sensors used in the Canon Rebel and x0D line vary a little, from the 22.2 x 14.8 mm (3.28 cm²) sensor in the 400D to the 22.3 x 14.9 mm (3.32 cm²) in the 500D and 50D to the 22.5 x 15 mm (3.37 cm²) sensor in the 30D.

The sensor in the 2002 D60 was even bigger: 22.7 x 15.1 mm (3.42 cm²), which gets closer to Nikon APS-C size 23.6 x 15.8 mm (3.72 cm²).

So my point is, could Canon develop 1.5x or even 1.4x sensors that would still be compatible with the EF-S mount, or is there just not enough room for the mirror in that case? Also, would that even work well since the lenses weren't designed with a sensor that big in mind?
 
L

leighonigar

macrumors 6502a
May 5, 2007
908
1
I can't answer your question but I will make a couple of observations - when you come close to capturing the edges of an image circle you'll usually get vignetting. So, a lens which doesn't vignette much or at all on an APS-C sensor may be able to support something a little larger (there are a number of Nikon DX lenses which can almost be used on full frame - and nikon don't have any mounting restrictions like canon). The size of the image circle will vary from lens to lens.

It's worth remembering that the D60, as far as I am aware, predates the idea of 'EF-S' lenses, and I don't think they will mount owing to the mirror problem, unless you get creative with a hack-saw. I'm unsure what the maximum mirror size is for an EF-S lens. I also don't know if you can mount EF-S lenses on one of the 1.3x crop pro canon bodies [Edit: 'the internet' thinks not].

Hmm...
 
Kebabselector

Kebabselector

macrumors 68030
May 25, 2007
2,987
1,638
Birmingham, UK
As Leigh previously said the D60 was for EF Lens. EF-s Lenses appeared with the 300D (and probably the 10D? not sure not got my EOS guide on me)
 
miloblithe

miloblithe

macrumors 68020
Original poster
Nov 14, 2003
2,072
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Washington, DC
Right, but I don't think that the mirror in this case was a limiting factor. I think they just hadn't designed the mount yet.

Certainly increased vignetting would be an issue, if not necessarily a problem.
 
T

toxic

macrumors 68000
Nov 9, 2008
1,664
1
If it is an APS-C camera starting with the 300D or 20D, it will accept EF-S lenses. This is because of mirror clearance, not sensor size.
 
C

ChrisA

macrumors G5
Jan 5, 2006
12,578
1,694
Redondo Beach, California
miloblithe said:
Does anyone know what the largest sensor size is that would be compatible with Canon's EF-S mount?
Click to expand...

The mount and flang to film plane distance is the same for all EOS lenses. The proof of this is that any EOS lens fits on the Rebel. It is NOT the mount that limits sensor size it is the lens.

The smaller lenses only project a small image circle. In other words if you were to mound a EF-S lens on a full frame sensor you'd see dark corners in the frame
 
miloblithe

miloblithe

macrumors 68020
Original poster
Nov 14, 2003
2,072
28
Washington, DC
ChrisA said:
The mount and flang to film plane distance is the same for all EOS lenses. The proof of this is that any EOS lens fits on the Rebel. It is NOT the mount that limits sensor size it is the lens.

The smaller lenses only project a small image circle. In other words if you were to mound a EF-S lens on a full frame sensor you'd see dark corners in the frame
Click to expand...

The EF-S mount (S meaning short back focus) has a shorter distance from the rear element to the image sensor.

http://members.cox.net/byteseller/EFS-WEB/EFS-WEB-Pages/Image5.html

If you mount an EF-S lens with a rear element that extends farther than the usual EF mount rear element onto a full frame camera, the mirror will colide with the rear element.
 
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