EF-S lenses on 1.3X crop and FF bodies? WHY NOT? Plz read

Why can't canon make EF-S lenses compatible with Full frame or 1.3X crop cameras?

I know they won't fit on the current cameras that are FF or 1.3X crop!

But upcoming cameras, such as the 1D Mark IV or 1DN Mark III whatever it is going to be... If it is an issue of the mirror being to close to the rear element, why can't they make enough space and make it work?

Nikon made a camera that is both FF in one made and 1.6x crop in another (or 1.3 whatever, but you get the point). If this were a Canon camera, would you be able to use the lens in 1.6x crop mode, but not FF mode?

Nikon's DX lenses don't extend into the mirror box like EF-S lenses do. They simply have the smaller image circle. The EF-S lenses extend the rear element deeper into the mirror box than an EF lens does, it is only due to the smaller mirror of the 1.6x crop cameras that the mirror is able to clear the protruding rear element without hitting it. If you tried that with the full size mirror of a 1.3x or FF body, it would collide, and cause damage.

Its arguable that if Canon wanted to make it happen, they could bring back the Pellicle mirror of the old EOS-1NRS, but its not likely that this would happen.

Furthermore, Canon is not in the business of making the specialized EF-S lenses go "upmarket". They want the upgrader to upgrade his inferior EF-S lenses to superior EF lenses (both L and non-L).

Then theres the issues of vignetting. Many (if not ALL) of the EF-S lenses would be less than 100% utilizable (is that a word?), as in, you would not be able to use the entire range of a zoom for example because below some focal length you would have vignetting.

I for one don't care for the idea. And chose not to buy lenses that I can't use on my film bodies, so I don't own a single "digital" lens. And unless I breakdown and buy the Tokina 11-16mm f/2.8, thats not gonna change.

-Alan

nureality wrote in post #7024045
Furthermore, Canon is not in the business of making the specialized EF-S lenses go "upmarket". They want the upgrader to upgrade his inferior EF-S lenses to superior EF lenses (both L and non-L).

Then theres the issues of vignetting. Many (if not ALL) of the EF-S lenses would be less than 100% utilizable (is that a word?), as in, you would not be able to use the entire range of a zoom for example because below some focal length you would have vignetting.

-Alan

Ok, but I don't consider the 17-55 2.8 IS that I own "inferior". The only thing that it doesn't have that the 24-70 2.8 L does have is weather sealing and L build.... but then again, the 24-70 2.8L doesn't have IS, so both have their advantages, but i don't consider one to be inferior to the other....

Also, why would we have vignetting? 17mm is 17mm right? Yea, sure the 10-22 may vignette, but so would a 10mm lens that isn't EF-S

nureality wrote in post #7024045
Then theres the issues of vignetting. Many (if not ALL) of the EF-S lenses would be less than 100% utilizable (is that a word?), as in, you would not be able to use the entire range of a zoom for example because below some focal length you would have vignetting.

What he's asking is why Canon doesn't do what Nikon did with their recent FX bodies. You can mount a DX lens on an FX body like the D3 and the sensor will act like a DX sensor. The image is cropped so that you don't have any vignetting... unless those lenses also show vignetting when mounted on a DX body.

The logic behind it would be if you mounted say the EF-S 17-55mm f/2.8 IS to a body like the 5D Mark II. The 5DII would automatically crop so that only the EF-S image circle is shown. This would yeild an image that is a little over 8.2 Megapixels. You'd still have a wide angle to short telephoto equivalent view with 2.8 constant aperture and IS... something that is missing in the current EF lens lineup.

jacuff wrote in post #7024126
What he's asking is why Canon doesn't do what Nikon did with their recent FX bodies. You can mount a DX lens on an FX body like the D3 and the sensor will act like a DX sensor. The image is cropped so that you don't have any vignetting... unless those lenses also show vignetting when mounted on a DX body.

The logic behind it would be if you mounted say the EF-S 17-55mm f/2.8 IS to a body like the 5D Mark II. The 5DII would automatically crop so that only the EF-S image circle is shown. This would yeild an image that is a little over 8.2 Megapixels. You'd still have a wide angle to short telephoto equivalent view with 2.8 constant aperture and IS... something that is missing in the current EF lens lineup.

YES PERFECT, THANK YOU.....WHYYYYY??? I want to Keep my 17-55 if I can!

what about using an extension tube?

I used my ef-s 10-22 on my MK III.

The reason EF-S lenses were designed the way they were (with the lens allowed to go deeper into the mirror box) is to allow a BETTER (as in optical quality) lens to be made at lower cost. In other words, fewer compromises have to be made in the EF-S lens designs than the third-party "digital-only" lenses that do not project into the mirror box like an EF-S lens does.

I'm absolutely certain that Canon will never follow Nikon's move in making a so-called "full-frame" camera accept EF-S lenses and crop off the vignetting.

However, if you are using third-party "digital only" lenses, you can merely use that lens on a 5D (or other 24x36mm format camera) and crop off the vignetting yourself in post-processing.

I don't see any real utility in this. If you stick a crop lens onto a full-frame body, you get a cropped image. How is this really useful? You just get a lower resolution image than you would from the crop body.

If you really want to use the 17-55, why not just use it on a crop body? If you're going to use a full frame body, why not get the appropriate lens? A crop lens on a full-frame body seems to be the worst of both worlds. Lower resolution, smaller sensor, more expensive.

It seems to me that it would just be a waste of resources on Canon's part to add this feature in an attempt to plug holes in their FF lens lineup. They'd be much wiser to just invest the effort into actually building the missing lenses.

DallasPhoto wrote in post #7023960
Why can't canon make EF-S lenses compatible with Full frame or 1.3X crop cameras?

I know they won't fit on the current cameras that are FF or 1.3X crop!

But upcoming cameras, such as the 1D Mark IV or 1DN Mark III whatever it is going to be... If it is an issue of the mirror being to close to the rear element, why can't they make enough space and make it work?

Nikon made a camera that is both FF in one made and 1.6x crop in another (or 1.3 whatever, but you get the point). If this were a Canon camera, would you be able to use the lens in 1.6x crop mode, but not FF mode?

if it's an issue for you why not buy a nikon?

ed rader

dpark wrote in post #7024583
I don't see any real utility in this. If you stick a crop lens onto a full-frame body, you get a cropped image. How is this really useful? You just get a lower resolution image than you would from the crop body.

If you really want to use the 17-55, why not just use it on a crop body? If you're going to use a full frame body, why not get the appropriate lens? A crop lens on a full-frame body seems to be the worst of both worlds. Lower resolution, smaller sensor, more expensive.

It seems to me that it would just be a waste of resources on Canon's part to add this feature in an attempt to plug holes in their FF lens lineup. They'd be much wiser to just invest the effort into actually building the missing lenses.

+1 and amen to that!!

If you want to use ef-s lenses, then use x1.6 crop bodies.

simple.

Cheaper. Smaller. Optically better.

That's why. Nikon's DX lenses don't have those 3 qualities going for 'em.

bluefox9er wrote in post #7024616
+1 and amen to that!!

If you want to use ef-s lenses, then use x1.6 crop bodies.

simple.

Well, if you , for instance, lived in the bush and had a truck/pick up, .......do you really need another small car to drive around town or you can just use the same truck.........

Filthy McNasty wrote in post #7024729
Well, if you , for instance, lived in the bush and had a truck/pick up, .......do you really need another small car to drive around town or you can just use the same truck.........

I'd just take the truck. But I wouldn't complain that my Geo Metro wheels didn't fit it.

dpark wrote in post #7024751
I'd just take the truck. But I wouldn't complain that my Geo Metro wheels didn't fit it.

BINGO!