Why would I want a EF-S lens ?

[JZaun]

I have a 20D on order and it will handle the new EF-S lens. I have searched everywhere I can and I cannot find much info on the EF-S series other than they seem to be lighter than standard lens and cheaper for Canon to make because of the smaller glass size. Is there any advantage to having it mount closer to the sensor? I can see the weight advantage and I guess if they are cheaper and (=) in quality to EF lens that would be good. I just can't find out much about them. I guess I am just searching wrong? Any info would be appreciated.

Thanks

Jerry

[robertwgross]

An EF-S lens tends to be cheaper in price, lighter in weight, and will fit and work on that camera. However, you would never want to use it on a film camera or anything full frame.

They are generally thought of as an affordable starter-level lens, but not necessarily the sharpest lens in the bag.

---Bob Gross---

[HJMinard]

An EF-S lens tends to be cheaper in price, lighter in weight, and will fit and work on that camera. However, you would never want to use it on a film camera or anything full frame.

They are generally thought of as an affordable starter-level lens, but not necessarily the sharpest lens in the bag.

---Bob Gross---

More accurately, the second paragraph of Bob's description applies to "it" (18-55 kit lens) rather than "they". The newer EF-S lenses appear to be - based on description, photos and target price - of a higher quality than the 18-55. Few (if any?) members of this board have handled them, so it's impossible to guess their level of build or optical quality at this time.

[CoolToolGuy]

Is there any advantage to having it mount closer to the sensor?

Thanks

Jerry

It is probably easier (read: cheaper) for Canon to make the ultra-wide angle lenses if the rear element is closer to the sensor. In the strictest terms, the '17mm' refers to a standard related to the distance of the lens from the film plane (sensor), and 17mm is only 3/4 of an inch. Today's lenses don't actually conform to the formula, but create an image the same as a lens of that dimension and then project it to the film plane. Prior to figuring out that technique, it was very difficult to get a truly wide lens. Nikon had a lens (21mm I believe) that required you to lock the mirror up before you mounted it, because the rear element occupied the mirror box. When you get down to 17mm (or 10mm in the 10-22) it might be easier to do whatever is required with the extra depth that the EF-S mount allows.

Canon throws around a few hints of this in the press releases and propaganda for the new EF-S lenses.

Have Fun,

[EXA1a]

No doubt, manufacturing costs play always a role. But I am under the impression that some of you are missing the most important point here:
There's a lot of physics involved. It's not only very expensive but close to impossible to produce a high-quality ("L standard") 10mm rectilinear lens for full frame with the given EOS lens register!
Of course, Canon is also trying to get acceptance from the Canon buyers for the 1.6x factor and the EF-S lens line. Whith the new EF-S lenses they made a big step into that direction. If Canon wouldn't get the acceptance for it, they'd quickly move into the full frame direction. But I bet that the acceptance will be high and that 1.6 is/will become the dSLR standard of this decade, with the exception of pure professional cameras.

--Jens--

[ron chappel]

JZaun, EF-s are a nesessity for cost reasons and little else-but it's all to do with the sensor cost!

Affordable full frame digital cameras will be quite a few years away so they have settled on a smaller format instead.Interestingly the wide lenses in this smaller format will cost *more* than their full frame counterparts.It's the huge cost of full frame sensors that make the EF-s lenses nessesary
The cost excuse for smaller format lenses that you quote didn't come from canon -those are some of the marketing slogans from Olympus and others for their 2/3rds format.It may apply to longer lens equivilants but certainly not to the wides!
The size argument also will also apply mostly to the long lenses.

So far canon have:
18-55.This is a cheap kit zoom.An entry level lens that costs *more* than it's full frame equivilant (EF 28-90 usm us$110 ,EF-s 18-55 usm us$150 quoted price) Both are available less when bought with a camera but the difference is still there
The 18-85mm lens is also dearer than it's full frame equivilant ,the 28-135

And the price of the EF-s 10-22 lens is alot higher than any equivilant full frame wide zoom.But it's still cheaper than buying a full frame 1D body and that's where the sense of it all lies

[CyberDyneSystems]

The current EFS lenses are practical for the more cost/cinsumer minded DSLR owners (if such aa person exists)

If you are an L owner ther is not much reason for interest in the paritcular models ... yet. (except of course the 10mm who's range is not reproduced by any Non EFS lens)

[Rayz]

It's my understanding that lenses designed for a smaller format can potentially have higher performance than lenses designed for a larger format, some examples being the Zuiko lenses for the Olympus E-1, some of which have an MTF of 50% at 60 lp/mm. That's better than the best and most expensive Canon L glass.

This general trend of lower MTF response, the larger the image circle, is very apparent as one moves up in format from 35mm to LF. This is why I can't help laughing during discussions on DoF when someone makes the point that a photo using a 300mm lens on a 35mm camera at f8 will have the same DoF as a 35mm cut-out from an LF field camera using a 300mm lens also at f8 but with a much larger image circle. At the point of focus, the 300mm lens designed for 35mm format will be significantly sharper than the LF lens, therefore, depending on print size (DoF is always partly dependent on print size), the 35mm shot will exhibit less DoF. However, reduce print sizes to the point where the superior resolving power of the 35mm lens cannot be discerned, then DoF will appear to be the same. But I digress.

Since the 20D sensor with its 8mp should resolve more than the 10D (by about 10%), it makes sense to design higher quality EF-S lenses for it. Theoretically we could then see a 'system resolution' for the 20D which is more than 10% greater than that of the 10D.

[Alexandre Gabriel]

And the price of the EF-s 10-22 lens is alot higher than any equivilant full frame wide zoom.


Actually the only full-frame lens comparable to 10-22 EF-s is the 12-24 Sigma, and it costs 669 USD, or 130 USD less than 10-22's street price (not that much, considering the investments suggested on this forum :wink: :wink: ). As long as you don't know the size of your next body's sensor, I think you should consider the 12-24 instead of 10-22, even considering that the Sigma is slightly darker.

[Rayz]

Actually the only full-frame lens comparable to 10-22 EF-s is the 12-24 Sigma.

It'll be interesting to see how these two lenses compare. When Canon introduced the 16-35 at a considerably greater price than the Sigma 15-30, I just had to test both lenses in the shop (with newspaper taped to the wall) before choosing. I chose the Sigma on the grounds that it was cheaper and actually very slightly sharper, but to a degree that's largely irrelevant.

However, the difference between 10 and 12mm is more than double the difference between 15mm and 16mm, in terms of the effect on focal length, you understand. (I'm not trying to say 1x2 does not equal 2 :D ).

I'd expect the Canon 10-22 to be sharper on the 20D and 300D. If it's not, then 'shame on you, Canon! However, it might well be that edge and corner performance might not be as good as the Sigma 15-30 ... because of the 1.6 crop factor, of course.

[Alexandre Gabriel]

However, the difference between 10 and 12mm is more than double the difference between 15mm and 16mm, in terms of the effect on focal length, you understand. (I'm not trying to say 1x2 does not equal 2 ).


However, 10-22 is EF-s. It won't fit any EOS camera. I see this as a great weakness of tis lens. And the difference between the widest angles are 3.2 mm (16 vs 19.2) equiv. No big deal to a wide-angle, compared to the weakness I mentioned, IMHO.

[Rayz]

However, 10-22 is EF-s. It won't fit any EOS camera. I see this as a great weakness of tis lens. And the difference between the widest angles are 3.2 mm (16 vs 19.2) equiv. No big deal to a wide-angle, compared to the weakness I mentioned, IMHO.

Not sure of your point, Alex. 10mm on a 20D is equivalent to 16mm on full frame 35mm. 15mm (the widest angle I use on my D60) is equivalent to 24mm. For me there will be a huge difference when I get my 20D with 10-22mm lens. I will have the wide angle advantages that previously only 1Ds owners could get with the Canon 16-35mm.

It's true that those who already own a Sigma 12-24 will have less reason to get a Canon 10-22, provided they are satisfied with the quality of their Sigma. However, 3.2mm is greater than you think at those extremely wide angles. Consider it as a percentage. 3.2/16=20%. That's significant.

The fact that EF-S lenses will not fit all Canon DSLRs is clearly a disadvantage. But this is an unavoidable result of much technological progress (aren't you used to this by now? :D ). My eye is on the potentially superior resolving power of the smaller format lens and the 20D is probably better able to use that extra resolution.

Ray

[Alexandre Gabriel]

It's true that those who already own a Sigma 12-24 will have less reason to get a Canon 10-22, provided they are satisfied with the quality of their Sigma. However, 3.2mm is greater than you think at those extremely wide angles. Consider it as a percentage. 3.2/16=20%. That's significant.


Good point. When you need those 20% more than a FF lens, I must agree. But...


The fact that EF-S lenses will not fit all Canon DSLRs is clearly a disadvantage. But this is an unavoidable result of much technological progress (aren't you used to this by now? ). My eye is on the potentially superior resolving power of the smaller format lens and the 20D is probably better able to use that extra resolution.


... I don't think Canon sensors' technology will be dominant enough to make me spend $800 on a 1.6-crop-dedicated lens. But that's just me :wink:
Maybe I think this way because I don't have a DSLR yet. Maybe I will buy EF-s lenses when I buy, say, a DReb. But I don't know if I will buy an expensive EF-s lens.
As always, it's up to the buyer's needs.

[Rayz]

... I don't think Canon sensors' technology will be dominant enough to make me spend $800 on a 1.6-crop-dedicated lens. But that's just me :wink:
Maybe I think this way because I don't have a DSLR yet. Maybe I will buy EF-s lenses when I buy, say, a DReb. But I don't know if I will buy an expensive EF-s lens.
As always, it's up to the buyer's needs.

Alex,
The 1.6 crop factor only has meaning when viewed from the full frame 35mm perspective. It's better to consider the Canon 22x15mm sensor DSLRs as a smaller format which happens to be able to use the same lenses as the larger format 35mm. There's clearly an economic battle going on here. If it ever becomes as cheap (or almost as cheap) to produce a full frame 35mm sensor, as it does a reduced frame sensor, then those EF-S lenses will become a dead-end. It's a risk, I admit :D .

[DocFrankenstein]

1) The two new EFS lenses haven't been tested yet. When they come out, we'll see if it's worth it

2) As long as full frame 17-40 L is around, I'm not even gonna look towards EFS 10-22. But it mysteriously dissapeared from the canon site I hear. :?

[Rayz]

The 10-22mm is still on the European site. Check the following link:

http://www.canon-europe.com/For_Home/Product_Finder/Cameras/EF_Lenses/Zoom_Lenses/EF-S_10-22mm_f-3.5-4.5/index.asp

[HJMinard]

The 10-22mm is still on the European site. Check the following link:

http://www.canon-europe.com/For_Home/Product_Finder/Cameras/EF_Lenses/Zoom_Lenses/EF-S_10-22mm_f-3.5-4.5/index.asp

He's saying the 17-40/4L has disappeared (from Canon USA) - not the 10-22. The 10-22 is also on the USA site: http://consumer.usa.canon.com/ir/controller?act=ModelDetailAct&fcategoryid=148&mode lid=10478

I see that the 17-40/4L is still on the Canon Europe site, however. Interesting.

[Rayz]

He's saying the 17-40/4L has disappeared (from Canon USA) - not the 10-22.


Yes, of course he is. For a moment I thought Canon had changed its mind about the 10-22mm :D .

Nevertheless, I don't think it's good policy to 'refrain' from buying the right lens for the job on the grounds that it won't be suitable for a future camera which you may never buy. That just doesn't make sense to me, unless of course you have good reason to believe that Canon's or Kodak's full frame 35mm cameras are going to become very affordable in the near future, say in the next year or three.

One should also bear in mind that lens technology is also improving over time, although clearly not at the same rate as camera sensors. In 3 years' time, there will probably be better lenses and higher quality zooms with a greater range at a more affordable price.

In other words, the lens you bought today which isn't ideal for your 300D or 20D, but would have been ideal for the camera you didn't yet have, will probably no longer be the best choice for that camera when you eventually get it.