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please explain simple EF-S VS EF

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davegregory said:
Robbieduncan is correct. The only reason the EF-S exists is because it's cheaper for Canon to make wide angle lenses with a short focus back (i.e. that the lens is closer to the mirror than EF lenses). It's purely consumer oriented! Lower-end - mid range cameras use the 1.6 FOVCF, making them inexpensive. Canon wants cheaper lenses so they can sell more lenses and cameras. That's it, plain and simple. They are technically identical to any EF lens in every other way but the mount depth.
Click to expand...

Go get a EF lens and and EF-S lens and put them side by side. They are not the same. The mount depth is different, but so is your image circle and the size of the lens elements. With modifications to the mirror on a 5D, you can mount an EF-S lens safely, and your resulting image is a circular image, surrounded by a big black area in the corners of the picture. If your claim was true, you would have an identical image to that on a 1.6 FOVCF camera, which you do not.

Do a bit of research on the subject.

sample from photography-on-the.net of a modified 5D with an EF-S lens mounted

IMG_3314.jpg
 
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robbieduncan said:
They don't and it doesn't. It says you apply the 1.6 crop to EF-s lenses, just like with EF.
Click to expand...

from your same source, the VERY NEXT paragraph:

The EF-S 10-22mm f/3.5-4.5 USM is a great example of a well designed EF-S series lens. It provides a field of view similar to what Canon’s popular EF 16-35mm f/2.8 L II USM and EF 17-40mm f/4.0 L USM do on a full frame camera like the 5D Mark II.
 
thatisme said:
from your same source, the VERY NEXT paragraph:

The EF-S 10-22mm f/3.5-4.5 USM is a great example of a well designed EF-S series lens. It provides a field of view similar to what Canon’s popular EF 16-35mm f/2.8 L II USM and EF 17-40mm f/4.0 L USM do on a full frame camera like the 5D Mark II.
Click to expand...

Yup. So the EF-s lens is providing a field of view of 16-35.2mm in full-frame, 35mm equivalent. So is effected by the 1.6 crop. Which is what I've been saying all along.
 
robbieduncan said:
Yup. So the EF-s lens is providing a field of view of 16-35.2mm in full-frame, 35mm equivalent. So is effected by the 1.6 crop. Which is what I've been saying all along.
Click to expand...

Yep. so you are now using the term Equivalent, not actual, which is not what you have been arguing, but I have.... Actual focal length is 10-22 in EFS. Effective in 35mm terms is 16-32mm.

OK. So, with your logic, take that Equivalent in Full Frame EF 16-35.2mm lens and put it back on your 7D, and your FOV changes again, and your Image changes. It will be using the center of the lens's elements, in effect "cropping" your image tighter, which now gives you an effective focal length of 56.32 mm on the long end, not the 22mm as your argument would dictate.

As stated before, you are comparing Apples to Oranges. You have to have a standard frame of reference which is a 35mm sensor size.
 
thatisme said:
You have to have a standard frame of reference which is a 35mm sensor size.
Click to expand...
That's correct, but you're not using this standard of reference properly: no manufacturer uses effective focal lengths to refer to lenses for dslrs (e. g. it's a 17-55 mm f/2.8 lens and not a 27-88 mm f/2.8 (equiv.) lens), be it a lens tailored for crop lenses or otherwise, but always the physical focal length. I think this is where your misunderstanding lies. This means a full frame lens and a crop lens with the same focal length with produce the same field of view on the same body. A 17-55 mm lens set to 50 mm will produce the same field of view than a nifty fifty on a crop camera (say, a 7D or a 40D).

Note that very often, this is handled differently on compact cameras where you will often find effective focal lengths rather than actual focal lengths, the reason being that sensor sizes can vary quite widely between models.
 
OreoCookie said:
no manufacturer uses effective focal lengths to refer to lenses for dslrs (e. g. it's a 17-55 mm f/2.8 lens and not a 27-88 mm f/2.8 (equiv.) lens), be it a lens tailored for crop lenses or otherwise, but always the physical focal length.
Click to expand...

Correct. Your lens is based in 35mm terms. So by utilizing a less than 35mm sensor'd camera, you are not using the full 35mm image being projected which is where this 1.6 factor comes into play.

Where RobbieDuncan is missing the boat, and most that are arguing incorrectly is that the image will be the same using an EF lens on either a 1.6 sensor'd camera or a FF sensor'd camera. The end result is that it will not. Focal length of the lens has not changed, but your image has.

For the EF-S lenses, since the rear element is smaller, your image circle is smaller, and is tailored to the 1.6 sensors... agreed? Ok. How can this now apply to 35mm? you don't have a full 35mm image circle projected through the lens. So apply your FOVCF to the actual focal length and you will get a hypothetical, imaginary number that equated to 35mm. But since your lens elements cant transmit a full 35mm image, then the argument goes out the window.

What does happen, as indicated by the linked image earlier whereby the 5D was modified to accept an EF-S lens, the image is not complete. Not enough image is sent through the optics of the lens. This shows exactly what my argument has been all along.... the image will be different. What a 1.6 camera is doing is taking that sample image, but only recording the center of it. So, Effectively, it is a zoomed image. So the Effective Focal Length for that image is bigger... say 50mm, where the lens may have been an EF-S 35mm.
 
thatisme said:
Where RobbieDuncan is missing the boat, and most that are arguing incorrectly is that the image will be the same using an EF lens on either a 1.6 sensor'd camera or a FF sensor'd camera. The end result is that it will not. Focal length of the lens has not changed, but your image has.
Click to expand...

I have never argued that. I have argued that an EF and an EF-s lens with the same focal lengths mounted on the same camera will produce the same effective field of view.

You have, of course, argued differently: that the same focal length on the same camera will produce different images. Which is clearly nonsense:

thatisme said:
YOU WILL GET DIFFERENT IMAGES IF YOU USE A 200mm EF Lens on a 7D (APS-C) and a 200mm EF-S lens on that same camera due to the FOVCF
Click to expand...
 
robbieduncan said:
You have, of course, argued differently: that the same focal length on the same camera will produce different images. Which is clearly nonsense:
Click to expand...

Taken out of context yet again. Congratulations!

EF-S 200mm on a 1.6 crop camera will yield the same image as an EF 200mm on a FF camera. If you put that EF 200 back onto the 1.6 camera, the image is different.

How hard is that to understand?
 
thatisme said:
Taken out of context yet again. Congratulations!

EF-S 200mm on a 1.6 crop camera will yield the same image as an EF 200mm on a FF camera. If you put that EF 200 back onto the 1.6 camera, the image is different.

How hard is that to understand?
Click to expand...

It's not. That is exactly what I have said in every post since the start. You are the one who said that a 200mm EF lens would produce a different image than a 200mm EF-s lens when mounted on the same camera. That is the quote is a complete sentence from your post. It is 100% wrong. You are not saying something completely different to what you were saying. It is not "out of context". There is no context in which that sentence contains correct information.
 
robbieduncan said:
It's not. That is exactly what I have said in every post since the start. You are the one who said that a 200mm EF lens would produce a different image than a 200mm EF-s lens when mounted on the same camera. That is the quote is a complete sentence from your post. It is 100% wrong. You are not saying something completely different to what you were saying. It is not "out of context". There is no context in which that sentence contains correct information.
Click to expand...

Re-read THIS POST....YOUR post.

You agree, then you disagree with the exact same statement
 
thatisme....give up.. you are trying in vain to recover from a grave mistake..

effectively you HAVE argued wrong:

Originally Posted by thatisme
YOU WILL GET DIFFERENT IMAGES IF YOU USE A 200mm EF Lens on a 7D (APS-C) and a 200mm EF-S lens on that same camera due to the FOVCF

This WILL in fact create the eEXACT same image... It does not matter what focal length it is, the SENSOR will create the image.. the only difference is that the EFs lens has a smaller image circle.. NOTHING ELSE changes!!! absolutely NOTHING. I don't get what your problem is.. the mm amount on the lens is what matters... if you only get a 1.6x crop out of the resulting image in comparison to a full 35mm frame has no relevance to the lens.

THE MILLIMETER OF THE ACTUAL FOCAL LENGTH ARE ALWAYS THE SAME!

end of story.

A canon 55-200 EF-s and a 70-200L lens at 200mm on a canon 7D will produce the exact same image...the same as if you would mount both lenses on a full frame body and crop the image by 1.6.

end of this meaningless discussion now.. geez
 
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flosseR said:
well, you have a funny way expressing yourself then because you WROTE something completely different...
Click to expand...

ok. this is getting comical.

From your post, blasting me....

A canon 55-200 EF-s and a 70-200L lens at 200mm on a canon 7D will produce the exact same image...the same as if you would mount both lenses on a full frame body and crop the image by 1.6

Don't crop the image, and what do you have? a different image. Want proof? See post #27
 
Thatisme, please read this, and read it CAREFULLY...…


These are the complete comments to all your relevant posts:


"To the previous post about focal lengths, the difference in perceived focal length comes into account when you factor in the 1.6 cropped sensor. Since the sensor is physically smaller than a Full Frame or 1.3 crop sensor, it is essentially taking the image from the center portion of the lens.

So, you WILL get different focal lengths from 2 identically marked lenses where one is an EF-S lens and the other is an EF lens."

--INCORRECT on the same body you will get the EXACT same image

"Nikon also created a FULL FRame camera a while back that also had the ability to create a "cropped" image to increase it's rate of capture to achieve results in FPS that were similar to canon's 1D series bodies. Effectively if it captured less pixels per image, it could do so faster."

-- ALL Nikon Cameras can use ALL Nikon made lenses. And no, that wasn't the main reason to do that.

"YOU WILL GET DIFFERENT IMAGES IF YOU USE A 200mm EF Lens on a 7D (APS-C) and a 200mm EF-S lens on that same camera due to the FOVCF. on the EF lens, the 200mm assumes you are using the ENTIRE image circle of the lens, which you are not. You ARE using the ENTIRE image circle on the EF-S lens, which is a True 200mm for that camera. You have to use the ENTIRE image circle to get a true measure of the focal length. when you use only a portion of that image circle, you have to apply the FOVCF to get the EFFECTIVE focal length."

-- This is pulled out of you mind because it does not make sense at ALL and is so incorrect it's not even funny.. the lens is NOT adjusted to the focal length.. the length is the same.. the EFFECTIVE focal length (or Field of VIEW) comes from the sensor.. NOT the lens!!!

"ok. this is getting comical.

From your post, blasting me....

A canon 55-200 EF-s and a 70-200L lens at 200mm on a canon 7D will produce the exact same image...the same as if you would mount both lenses on a full frame body and crop the image by 1.6"

-- NO YOU WONT!!! what are you? a troll that needs feeding??

I compared BOTH lenses mounted on a 7d to BOTH lenses mounted on a 5d… if you crop the BOTH images from a 5d you have the same as BOTH from a 7d..
If you take BOTH shots from a 7d .. they are the SAME.. and they are the same if you shoot them both on a 5d..


GET
IT
IN
YOUR
BRAIN!

THE SENSOR MATTERS!!! NOT THE LENS..


geezz….
 
QUOTE=flosseR: Thatisme, please read this, and read it CAREFULLY...…


These are the complete comments to all your relevant posts:


"To the previous post about focal lengths, the difference in perceived focal length comes into account when you factor in the 1.6 cropped sensor. Since the sensor is physically smaller than a Full Frame or 1.3 crop sensor, it is essentially taking the image from the center portion of the lens.

So, you WILL get different focal lengths from 2 identically marked lenses where one is an EF-S lens and the other is an EF lens."

--INCORRECT on the same body you will get the EXACT same image. Show me images with EXIF data in tact, and no cropping done in post

"Nikon also created a FULL FRame camera a while back that also had the ability to create a "cropped" image to increase it's rate of capture to achieve results in FPS that were similar to canon's 1D series bodies. Effectively if it captured less pixels per image, it could do so faster."

-- ALL Nikon Cameras can use ALL Nikon made lenses. And no, that wasn't the main reason to do that. Never made any mention of Nikon mounts not working on all bodies. And please do enlighten everyone here what the purpose of "high-speed crop" is on that Nikon body...

"YOU WILL GET DIFFERENT IMAGES IF YOU USE A 200mm EF Lens on a 7D (APS-C) and a 200mm EF-S lens on that same camera due to the FOVCF. on the EF lens, the 200mm assumes you are using the ENTIRE image circle of the lens, which you are not. You ARE using the ENTIRE image circle on the EF-S lens, which is a True 200mm for that camera. You have to use the ENTIRE image circle to get a true measure of the focal length. when you use only a portion of that image circle, you have to apply the FOVCF to get the EFFECTIVE focal length."

-- This is pulled out of you mind because it does not make sense at ALL and is so incorrect it's not even funny.. the lens is NOT adjusted to the focal length.. the length is the same.. the EFFECTIVE focal length (or Field of VIEW) comes from the sensor.. NOT the lens!!! Yep. I made that point a number of times already. The Actual Focal length (the mm) doesn't change.

"ok. this is getting comical.

From your post, blasting me....

A canon 55-200 EF-s and a 70-200L lens at 200mm on a canon 7D will produce the exact same image...the same as if you would mount both lenses on a full frame body and crop the image by 1.6"

-- NO YOU WONT!!! what are you? a troll that needs feeding??

I compared BOTH lenses mounted on a 7d to BOTH lenses mounted on a 5d… if you crop the BOTH images from a 5d you have the same as BOTH from a 7d.. DONT #$@$$ CROP!!!!!!!!!!
If you take BOTH shots from a 7d .. they are the SAME.. and they are the same if you shoot them both on a 5d..


GET
IT
IN
YOUR
BRAIN!

THE SENSOR MATTERS!!! NOT THE LENS.. EXACTLY. NEVER SAID IT DIFFERENTLY. THE 1.6 IS FROM THE CAMERA SENSOR, NOT THE LENS. NEVER DID I STATE THAT DIFFERENTLY


geezz…. END QUOTE
 
sorry man.. i just cannot help you...

you are beyond what we, on planet earth, define as normal...

I tried.. i really tried..please read carefully what i wrote..
the "cropping" was referred to only one camera body.. just to illustrate you the whole crop size thing.

Now on the top of my quote you write to show you an exif intact photo with an EFs and EF lens..

I cannot do that as I don't have my cam but I will have it back on the weekend and I actually own a dx and FX lens (EF-s and EF) in Nikon land that overlap at 24mm, so I CAN show you..

to everyone else: Can someone do this before then to show our poor misguided soul what is going on?.

As far as Nikon goes: The reason was the F- Mount.. High speed crop is a byproduct. the D700 does not have it and some other don't either but they all MOUNT DX lenses in crop mode AND full frame mode.
F Mount has not changed since the 1950's and the reason why they kept it was that they can let people use older lenses.. Canonians for example got forced to EF in the 80's if I am not mistaken.


Now drop it.. you lost.
 
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