Canon EF-S Lens Focal length

[OH2D]

Hey guys i have been wondering something for a while now and i cant seem to find a straight answer anywhere on the internet of elsewhere...

I have been trying to figure out if i have a body with a APS-C size sensor in it (in my case the 7D) and i have a canon EF-S lens (again in my case the EF-S 15-85) am i actually seeing 15mm or am i seeing 15mm x 1.6 which would be 24mm? I know that if i had a 15mm EF lens i would be seeing 24mm but i cant figure out if what is printed on the EF-S lenses is what i am actually seeing or is it still being multiplied.

[crazzy88ss]

It's 15mmx1.6=24mm.

What makes an EF-S lens is that the glass inside is smaller. Focal lengths are comparable to full frame lenses.

[OH2D]

It's 15mmx1.6=24mm.

What makes an EF-S lens is that the glass inside is smaller. Focal lengths are comparable to full frame lenses.

Ok that's what i thought. Thanks crazzy!

[Argote]

Yes, that's basically /thread

An EF lens at 24mm and an EF-S lens at 24mm will give you the exact same field of view and DOF characteristics on an APS-C camera (assuming all else is equal).

The only difference is that if you were to mount an EF-S lens on a Full Frame camera you'd get either vignetting or a cropped image (I don't know how Canon handles this).

And FYI: APS-C is 1.6x in Canon-land only, everywhere else it's 1.5x

[OH2D]

Yes, that's basically /thread

An EF lens at 24mm and an EF-S lens at 24mm will give you the exact same field of view and DOF characteristics on an APS-C camera (assuming all else is equal).

The only difference is that if you were to mount an EF-S lens on a Full Frame camera you'd get either vignetting or a cropped image (I don't know how Canon handles this).

And FYI: APS-C is 1.6x in Canon-land only, everywhere else it's 1.5x

Yeah idk why canon has a smaller "APS-C" sensor thus making it 1.6 not 1.5.

Anyway thanks again guys! :)

[crazzy88ss]

The only difference is that if you were to mount an EF-S lens on a Full Frame camera you'd get either vignetting or a cropped image (I don't know how Canon handles this).

You can't mount the smaller lenses on the full frame cameras. Nikon you can.

Yeah idk why canon has a smaller "APS-C" sensor thus making it 1.6 not 1.5.

The smaller sensors are vastly cheaper to make, and the smaller lenses are vastly cheaper to make. So that's why the cheap cameras are cheaper!

[OH2D]

The smaller sensors are vastly cheaper to make, and the smaller lenses are vastly cheaper to make. So that's why the cheap cameras are cheaper!

Canon's sensor is only a millimeter or so smaller than actual APS-C so there cant be that much of a price difference in manufacturing right?

And Nikon Refers to all if its APS-C sensor and related gear as their DX format right?

[the evn show]

Canon's sensor is only a millimeter or so smaller than actual APS-C so there cant be that much of a price difference in manufacturing right?

Yes it can. The likelihood of a defect destroying a sensor increases with of it's size. Consider going from 15.00 mm to 14.00mm along each dimension. The square area drops from 225.00mm^2 to 196mm^2 13% change in area. The larger the sensor, the more significant a small change in dimensions are.

That's why you see thresholds in sizes of things like LCDs or camera sensors where the next size up costs substantially more. It's relatively easy to make a 23" HD display without defects, it's extremely hard to make a 72" panel which is why the much larger screen costs 10s-100s of times more than the 23" display rather than the 3-4x you might expect for the increased size, enclosure, etc. The size canon uses is probably doubly intrenched. First due to manufacturing concerns (which may not even be a consideration any more) and second due to history. Cameras aren't the sort of thing people take kindly to have changed on them. Upgrading from an early 2000s rebel to a modern T2i shouldn't change the behaviour of my lenses and I suspect that canon sees that as a non-option.

[OH2D]

Ahh ok that makes sense. Yeah I guess I wouldn't want to change if I was a long time canon user.

[crazzy88ss]

And Nikon Refers to all if its APS-C sensor and related gear as their DX format right?

Yes. An easy way to remember is that FX is fullframe, the F in "FX" stands for Fullframe! Process of elimination gets you DX as the APS-C sensor.

I'll throw this out there for food for thought... I wonder if it makes sense at all...

A third sensor size? One that's in between DX and FX. It would require FX lenses but would be a lot cheaper to make and still offer significant improvements over DX. Just a thought.... I'm sure the camera manufacturers have looked into it and decided to proceed with it or not.

[Argote]

Yes. An easy way to remember is that FX is fullframe, the F in "FX" stands for Fullframe! Process of elimination gets you DX as the APS-C sensor.

I'll throw this out there for food for thought... I wonder if it makes sense at all...

A third sensor size? One that's in between DX and FX. It would require FX lenses but would be a lot cheaper to make and still offer significant improvements over DX. Just a thought.... I'm sure the camera manufacturers have looked into it and decided to proceed with it or not.

It's called APS-H, some Canon cameras have it IIRC.

Just for reference purposes, on Sony-land you can mount APS-C (DT) lenses on Full Frame cameras and you can choose to have either a vignetted image or just part of the sensor used.

[crazzy88ss]

It's called APS-H, some Canon cameras have it IIRC.

oh... Uhhh like what?

[remus_lupin]

oh... Uhhh like what?

Just googled, it looks like they did use that size in their SLRs (EOS 1D series)

http://www.dpreview.com/news/1008/10082410canon120mpsensor.asp

"Canon has announced it has developed a 120 megapixel 29.2 x 20.2mm APS-H CMOS sensor - the same size used in its EOS-1D series of professional DSLRs. "

BLAH BLAH BLAH, Ken Rockwell this, Kenrockwell that,

but his was the only site I could find that had a list of the 1.3x crop canon cameras, in the first paragraph there are some of the ones that have that size sensor

http://www.kenrockwell.com/canon/1-3x.htm

[Argote]

Canon cameras using APS-H: 1D, 1D Mk II, 1D Mk II N, 1D Mk III, 1D Mk IV

Source: http://en.wikipedia.org/wiki/Template:Canon_DSLR_cameras

The 1Ds series are the Full Frame cameras for Canon.

Additional info: http://en.wikipedia.org/wiki/APS-H#Multiplier_factors

[crazzy88ss]

oh duh, the 1.3 crop ones... Ok I forgot. But my point is to make CHEAPER cameras. The 1D is still stupidly expensive, competing with the D3.

[Argote]

I agree with the statement that the 1D series is REALLY expensive. I guess it's due to economies of scale...

[crazzy88ss]

They could sell more by lowering the price a lot. But they don't have to because the camera is indeed very good.