06-09-2013 07:55 AM - edited 06-09-2013 07:56 AM
Basic description is EF lens will work on both full frame and clipped camera bodies while EF-s will only work with clipped.
If you have some like a T4i (like I do) you can use either lens on it while if you have something like 5D mark 3, you only can use the EF lens on it.
To my thinking, if you have a clipped body like one of the Canon Rebels (clipped) and there's a chance you might go FF at some point in the future, it makes more sense to get EF lenses so they can be used on later bodies. They'll cost more now but less over time with a body upgrade.
06-10-2013 09:27 AM - edited 06-10-2013 09:28 AM
EF-S lenses are a slightly different format meaning the sensor is closer to the lens, this is possible due to the smaller mirror with APS-C sensors. The distance from the back of the lens to the image plane is known as the back-focus distance, this is the “S” in EF-S which is short back focus. Sigma has lenses designed for smaller sensors, too, as do others, that have the smaller image focusing but they don't have the same back focus distance.
Moving the lens mount closer makes it easier to design wide angle lenses, but Canon introduced EF-S lenses from scaled down existing lens designs to avoid making new designs.
Example, the EF-S 60mm macro is a 1 to 1.6 of the EF 100mm macro. Sigma and their 50-150mm f2.8 from their 80-200mm f2.8, etc.
As a general rule and probably the best advise, EF-S lenses can not be used on full frame cameras. It can be done but is risky with out certain precautions.
06-10-2013 12:42 PM
To my thinking, if you have a clipped body like one of the Canon Rebels (clipped) and there's a chance you might go FF at some point in the future, it makes more sense to get EF lenses so they can be used on later bodies.
Another nice benefit of using EF lenses on a crop body is that you’re only using the center part of the glass, which is the best parts. Lenses usually suffer on the outside corners, so a lot of mediocre EF lenses perform really well on a crop
06-13-2013 08:14 AM
I hadn't thought about Skirball's comment on only using part of a FF lense on a clipped/cropped body, good info. Makes sense and might allow getting more for less now. I would assume the degredation would present itself if ever used of a FF body at some future point in time.
06-13-2013 09:15 AM
WOW .......I'll give this a go again!
It is called a crop sensor camera, not a crop lens. The sensor is smaller, it is like you took the same image with a full frame camera and “cropped it”.
The lens does not know what kind of camera you are using it on. This means that if you are using a 70mm lens, for instance, on a Full Frame camera like a 5D3, the FOV (field -of-view) will be roughly 34° diagonally. That same 70mm lens on a crop sensor, T4i body, will have an FOV of about 21°.
This is the only difference.
06-13-2013 04:57 PM
06-14-2013 10:28 AM - edited 06-14-2013 10:29 AM
" If you have a 100-200mm lens for EF, the lens will become a 101.6mm - 320mm on a cropped sensor camera."
In reality, the 100-200mm lens is a 100-200mm lens no matter what body it is use on. It will never change it's focal length.
You could put it on a medium format camera and it will still remain a 100-200mm lens.
The only thing that happens is the FOV or angle of acceptance. It makes the 100-200mm lens appear to behave like a 1.6 factor larger lens. (in this case)
All lenses present a circular image to the rectangular sensor. What is not used by the sensor is lost. The focal plane of the lens does not change.
06-27-2013 11:47 PM
With the example of the 100mmx200mm lens I think you mean for it to become 160mmx320mm on a 1.6 crop sensor body such as my 7D & 400D XTI. This is the EFF, effective focal length and the length I use when I think of shutter speed for hand holding, or 1/200 - 1/400 second.
11-30-2013 11:09 AM
I know this is an old posting, but I still wanted to clarify one statement, "the lens does not know what kind of camera you are using it on." While the lense does not know which camera it is on, a full-frame camera, such as the 5D Mark III or a 6D will know if there is an EF-S lense on it.