Beginner Canon EF , EFS, EFM

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alan
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#1
Please tell me what these lens abbreviations mean and how do they affect what type of lens to buy. Thanks.

I've been off these forums a while now and there used to be a trader on here, was it Ian? Based in Scotland I think. Is he still around?

I m thinking of getting back into it but before, never seemed to get much beyong beginner stage :)
 
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#2
EF is canon mount for DSRL's

EF is full frame and can also be used with cropped sensors
EFS is for cropped sensors only (put one of these on a full frame and you generally wreck the camera)
EFM not one I really know, but think it could be for the canon M mirroless range, which is a cropped sensor

If you see RF, that's for the new EOS R mirrorless range,

Don't know any of the traders
 

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now and there used to be a trader on here, was it Ian? Based in Scotland I think. Is he still around?
You mean Ian Kerr / Kerso.
He's not posted in about 4 years.

EFM not one I really know, but think it could be for the canon M mirroless range, which is a cropped sensor
Spot on, (y) its for the EOS M series which is indeed a crop sensor mirrorless camera.
 
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#8
EFs or EF will both fit your camera
But if he changes to a 'full frame' sensor EOS DSLR (and given the sub £600 price the Canon 6D can be bought for on the second-hand market, why wouldn't someone want to consider that as a possible option?!) or decides to buy a 'classic' old EOS 35mm SLR for some fun with film (and plenty of people seem to be doing that) then the EF-S lenses won't fit; only the EF lenses will fit and work with EOS full frame DSLRs & EOS 35mm film SLRs.

Also, whilst EF lenses will fit crop sensor EOS DSLRs, they'll be subject to the crop sensor 'magnification' effect: In other words, a 50mm EF lens will give a field of view equivalent to an 80mm lens on a 1.6 x crop sensor camera. Sounds good with EF telephotos, but what about wide angle, where a 24mm EF lens will look close to a 40mm lens on a 1.6 crop sensor camera?

So that's a simplified (I hope!) version of how those letters affect the lenses to buy. Unless people sell all their kit to change to another make, they usually want to keep their lenses and change/upgrade the camera body they have. So some thought is perhaps due as to which direction you think you might go in the immediate future before buying a lens? Hope this is useful and if anyone thinks what I've said is incorrect then please let us know!
 
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StewartR

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#9
Also, whilst EF lenses will fit crop sensor EOS DSLRs, they'll be subject to the crop sensor 'magnification' effect: In other words, a 50mm EF lens will give a field of view equivalent to an 80mm EF-S lens on a 1.6 x crop sensor camera. Sounds good with telephotos, but what about wide angle, where a 24mm EF lens will look close to a 40mm lens on a 1.6 crop sensor camera?
Sorry, but that's just not correct. The focal length is a physical property of the lens. A 50mm lens is a 50mm lens. A 50mm EF lens and a 50mm EF-S lens will offer the same field of view when attached to the same camera.
 
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#10
Sorry, but that's rubbish. The focal length is a physical property of the lens. A 50mm lens is a 50mm lens. A 50mm EF lens and a 50mm EF-S lens will offer the same field of view when attached to the same camera.
I'm aware that was not the correct terminology but I was trying to explain it layman's terms. You also seem to have misunderstood what I said. I referred to a 50mm EF lens giving the equivalent field of view of an 80mm lens when mounted on a 1.6 crop sensor camera (50mm x 1.6 crop factor = 80mm equivalent).

Put a 50mm EF lens on a 1.6 crop sensor camera, now does it give the same field of view as it does on a full frame camera, or does it give a narrower field of view on both the image and in the viewfinder? That's what I was referring to. I'm sorry if I got some of my explanation technically incorrect, but hopefully the gist of it got through. I'll edit my post above and try to make it a bit clearer.

If you'd like to explain this more clearly and using the correct technical terms then be my guest; however, please don't tell people what they've said is "rubbish" when they're trying to help someone, as it does come over as being rather rude.
 
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StewartR

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#11
I'm aware that was not the correct terminology but I was trying to explain it layman's terms.
I appreciate that. But when you said
a 50mm EF lens will give a field of view equivalent to an 80mm EF-S lens
that's not an acceptable simplification, that's not putting it in layman's terms; it's just wrong.

And it's wrong in the worst possible way, because it appears to confirm a misconception that many people have - namely that 'crop sensor' lenses have different fields of view than 'full frame' lenses with the same focal lengths. You know and I know that that's not the case, but the way you tried to explain was ... unfortunate.

If you'd like to explain this more clearly and using the correct technical terms then be my guest; however, please don't tell people what they've said is "rubbish" when they're trying to help someone, as it does come over as being rather rude.
Fair point, well made. I apologise for my intemperate language and I have edited the post in question.
 
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#12
I appreciate that. But when you said

that's not an acceptable simplification, that's not putting it in layman's terms; it's just wrong.

And it's wrong in the worst possible way, because it appears to confirm a misconception that many people have - namely that 'crop sensor' lenses have different fields of view than 'full frame' lenses with the same focal lengths. You know and I know that that's not the case, but the way you tried to explain was ... unfortunate.

Fair point, well made. I apologise for my intemperate language and I have edited the post in question.
No problem, and it's good of you to say that. Thanks for the correction too. I found it quite difficult to explain what I was trying to say. It's a lot easier to show people in real life!

To avoid doubt can we agree that (and I'm trying to word this carefully!) an EF-S 10mm lens mounted on a 1.6 crop sensor camera will give an image with a similar field of view to an EF 16mm lens mounted on a full frame DSLR (or 35mm film SLR) camera?
 
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#13
Ian Kerr...….Kerso, that's the guy. Used to do some good deals.
Thanks for all your help. I just needed to know what lenses I can put on my 50D. Thanks again
 
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#15
Sorry, but that's just not correct. The focal length is a physical property of the lens. A 50mm lens is a 50mm lens. A 50mm EF lens and a 50mm EF-S lens will offer the same field of view when attached to the same camera.
Personally I think this sort of exchange can be very misleading for people just getting into this. It's hard enough to follow the argument for me and I bought into DSLR's back with the 300D and had the 5D.

It may be wrong to say that a 50mm FF lens will act like an equivalent 80mm lens when on APS-C but it's near enough to give a newbe/relative newbe enough of an inkling to get by and if they want to do some further reading up on crop factors and sensor sizes then all well and good.

Just sayin.

:D
 
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#16
Have these lenses in mind
24-105
85 prime?
In your place I'd have a look at zoom lenses starting at 17 or 18mm as 24mm isn't really very wide on APS-C unless you're willing to accept this for the extra reach at the 105mm end.

Prime wise with an 85mm you're going to get quite a tight shot unless you've got some distance between you and your subject. I'd take a look at prime lenses in the 20 to 50mm range as well and then decide if 85mm is for you or not.
 
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#17
I seem to remember people saying the lenses I mentioned produce sharp images which is why I mentioned them. Possibly also the 135 prime and the 100 prime if I remember correctly.
 
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#18
I seem to remember people saying the lenses I mentioned produce sharp images which is why I mentioned them. Possibly also the 135 prime and the 100 prime if I remember correctly.
The lenses you've mentioned (such as the 24 105 if you mean the EF L IS version) are good. However, as I tried to explain, and as Alan says above, an EF 24mm won't give a very wide angle of view on a 1.6 crop sensor camera. So do be aware of the effect the crop sensor on your camera will have if looking at EF lenses.
 
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#20
I think the best way to see this is in practice. If the op can mount a zoom lens (a zoom lens would be nice because it's easy to set it at various focal lengths instead of fiddling with lots of primes) on his camera and take note of what the various focal lengths look like all will become clear.

I think it also depends what the subject is and at what distance. For example I'd think a 50mm lens on aps-c was pretty good for people pictures but a 135mm would be too long as for a whole body shot I'd be too far away, for me.

Another way to see the effect of focal lengths would be to look at a field of view comparison on line. I've seen these from time to time and googling might find one for the op's camera and lenses.
 
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