28-135mm EF vs. 55-250mm EF-S, please help me understand crop factor.

[klavender]

Sorry for the newbie question but I've searched Google and couldn't really understand this. I have a 40D with a 28-135mm EF lens. I understand this is a APS-C camera and since the lens is an EF that the effective zoom is 44-216mm. I would like to get more zoom but the EF-S telephoto is 55-250mm. 250mm doesn't seem like much more that 216mm and I'm not sure it's worth it. I've also looked at the EF 70-300mm which would be 112-480mm. It's twice as much money and would think I would want it slightly wider at the low end.

Also, if I go with the EF-S 55-250 would the STM be worth it over the standard? I want a quick focus as this will be used mainly for wildlife. How does the standard and STM compare to the USM of my current lens?

[diverhank]

The way the lens numbering is done, it is all based on a 35mm sensor (full frame) so there is no difference for the EF lenses and EF-S lenses in the numbers.  You would still multiply the 250mm by 1.6 to get the actual effective focal length.

[ScottyP]

Exactly. The camera gives the lens the 1.6x focal length boost by narrowing the field of view. Happens on both EF and EFs lenses. 250 is quite a lot longer than 135. And both get "multiplied" x 1.6 the same way. 

What at are you shooting?  Hope it is not birds. Birds are tiny and on my old crop camera a 250mm lens was still not long enough even with the 1.6 crop multiplier to bring them close if they were across the yard. I set up a feeder to bring them right up to within 12 feet from the window and then my upgraded 70-200 worked great. 

[klavender]

Gotcha! Thanks for explaining that! But to answer your question, some pics will be birds probably. What zoom would you suggest?

[Waddizzle]

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@klavender wrote:
Gotcha! Thanks for explaining that! But to answer your question, some pics will be birds probably. What zoom would you suggest?

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The focal length [mm] of lens describes a physical dimension within the lens body.  The difference between EF and EF-S lens rests almost solely with the lens mount.  EF-S lenses do not fit properly on EOS cameras with full frame sensors, just the cameras with the APS-C sensors.  The crop factor [ x1.6 ] for lenses used with APS-C bodies is the same for both EF and EF-S lenses.

Some say that you need at least 400mm to effectively photograph birds.  Or, you can set up a bird feeder about 12 feet from your window and use a 200mm lens. 

[ebiggs1]

"... some pics will be birds probably. What zoom would you suggest?"

As with almost everything in photography, location is the key factor.  Where will you be shooting from?  It is not the lens. Not the camera.  Where will you be and where is your subject.

No lens changes its focal length.  It is what it is and forever will be.  It is the angle-of-view, AOV, that is different.  Learning this is more valuable than focal length.  Crop factor was and is a dumb idea, IMHO, ofcourse.

To give you an idea of what might be required for shooting birds, I offer this.

The data on this shot is: EOS 1D Mk IV.  600mm, f7, 1/400, ISO 800.  The rig is on a heavy duty Manfrotto 546 w/501 head tripod.

Now the critical part, I was about 25 feet from this guy!  Even a 600mm (720mm crop factor) lens will be handicapped by distance.  It s not going to get the job done if you are too far away.  So you must be close, or as I stated above, location, location, location.  It is key.

[RobertTheFat]

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@klavender wrote:

Sorry for the newbie question but I've searched Google and couldn't really understand this. I have a 40D with a 28-135mm EF lens. I understand this is a APS-C camera and since the lens is an EF that the effective zoom is 44-216mm. I would like to get more zoom but the EF-S telephoto is 55-250mm. 250mm doesn't seem like much more that 216mm and I'm not sure it's worth it. I've also looked at the EF 70-300mm which would be 112-480mm. It's twice as much money and would think I would want it slightly wider at the low end.

Also, if I go with the EF-S 55-250 would the STM be worth it over the standard? I want a quick focus as this will be used mainly for wildlife. How does the standard and STM compare to the USM of my current lens?

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The "crop factor" refers to the fact that with a lens of a given focal length, a camera with a smaller APS-C sensor uses less of the image the lens produces than does a "full-frame" camera with a 24x36mm sensor (by a factor of about 1/1.6, in Canon's case). The effect of this is that a lens of a given focal length is less of a wide angle (or more of a telephoto) on, say, a 40D than on a full-frame camera like a 6D or a 5D Mark III. You can, if you wish, use the crop factor to compute the "effective" focal length the lens will exhibit on one type of camera vs its behavior on the other. Many people use that computation, but I recommend against it. I think it's easier to simply learn how a given lens behaves on a camera of either type. For example, a 50mm lens is "normal" on a 6D, but a mild telephoto or portrait lens on a 40D. On the 40D, a "normal" lens would be about 32mm. Similarly, on a 6D anything below about 24mm is considered pretty wide; on the 40D that figure is about 17mm. On a 6D a 200mm lens is a pretty long telephoto; on a 40D it's even longer. Once you get used to this approach, you can pick up any camera and know which lens to use in any situation, without worrying about what lens you might have chosen if you were using a different camera. The bottom line is: Compute or memorize effective focal lengths if you find it useful to do so, but there's nothing mandatory about it.

[klavender]

I bought this camera years ago for a good deal from a friend who was upgrading to a full frame. This was before I really understood the difference. This camera is better than my ability. I guess I have too many exspensive hobbies without the matching funding. I've toyed with the idea of buying a used full frame instead of buying a zoom lens. But then I'd still be without a zoom. It's hard for me to justify spending the money when this is a once in a while hobby for me. Combined with that fact that I tend to overthink things. Just trying to get the most out of my dollar. It sounds like I just need to get the 55-250mm EF-S STM lens and be happy with it. I just wish it came in USM. Or they had a comprable USM for about the same money. It's $300 versus $450 (for the 70-300mm EF). Thank to everyone for their insight. I really appreciate it.

On second thought, maybe I should just spend the extra $150.

[Waddizzle]

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@klavender wrote:

....  ....  ....

On second thought, maybe I should just spend the extra $150.

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Yes, perhaps you should.  I would advise not being any EF-S telephoto zoom lenses.  I would also advise doing a little more research into camera lenses, and gaining a bit more experience with your camera before splurging on a new lens.

There have a couple of different vesions of the EF-S 55-250mm, and all are currently discontinued, AFAIK.  I picked one [in pristine, factory refurbished condition] for my son from the Canon Online Refurbished Store for under one hundred U.S. dollars last year.  That should give you some idea of what those lenses are really worth.

[TTMartin]

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@klavender wrote:

I bought this camera years ago for a good deal from a friend who was upgrading to a full frame. This was before I really understood the difference. This camera is better than my ability. I guess I have too many exspensive hobbies without the matching funding. I've toyed with the idea of buying a used full frame instead of buying a zoom lens. But then I'd still be without a zoom. It's hard for me to justify spending the money when this is a once in a while hobby for me. Combined with that fact that I tend to overthink things. Just trying to get the most out of my dollar. It sounds like I just need to get the 55-250mm EF-S STM lens and be happy with it. I just wish it came in USM. Or they had a comprable USM for about the same money. It's $300 versus $450 (for the 70-300mm EF). Thank to everyone for their insight. I really appreciate it.

On second thought, maybe I should just spend the extra $150.

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Nope, the 55-250 IS STM is a much better lens, and STM focus for still photographs, while not as fast as USM, is fast enough. STM focus has to be slowed for video, it's not always slow.

As for needing a longer lens, yes it seems like you can never have too long of a lens for birding. A good budget lens for birding with the 40D is the Sigma 150-500 OS, my wife used this combo until getting my hand me down 7D. She still uses the Sigma 150-500 OS with the 7D. The Sigma 150-500 is not their latest and greatest, but, is still a pretty decent lens.

The other thing you can do when you are focal length challenged is get closer to the birds. You can do this by setting up a feeding station so they come closer to you, or camo or blinds so you can get closer to them.