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Old Jun 2, 2005, 5:26 PM   #1
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I wonder when Canon will announce the next lens in the EF-S series. Perhaps a 100-300mm IS? This would make a real nice addition to my XT!

Any rumors?

--M
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Old Jun 2, 2005, 6:23 PM   #2
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What's wrong with the EF 70-300mm f4.5-5.6 DO IS USM - it's already a good lens (and small enough)

... and there's already 6 other zooms @ various price points in this range! :?
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Old Jun 2, 2005, 6:53 PM   #3
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yeah... I don't think that'll stop canon from making an efs tele.

there's already a wide, macro, and general efs. Just one more...

But I think the lenses built for full frame are better since you get the best part out of the lens
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Old Jun 2, 2005, 7:39 PM   #4
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my guess would be that it would be something more like a 50-200 or 55-220 or something like that to mimic the focal lengththe full frame 75-300.. since the ef-s line is developed for their consumer line of cameras..

my only hope is that they make it out of better glass than the current consumer tele-zooms such as the 55-200 and 75-300.. if it were on par with the sharpness and the build quality of the 17-85 i would be happy as it would give users a middle ground between the consumer lenses and the L-series.. hopefully the price would reflect this middle ground as well..

but that is pure speculation and who really knows what they are doing next.. but thats what makes the future exciting eh...

best regards, dustin
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Old Jun 3, 2005, 3:09 AM   #5
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BoYFrMSpC wrote:
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But I think the lenses built for full frame are better since you get the best part out of the lens
This is a common misconception and I've even read it in reviews. The size of the sensor has no effect on which part of the lens is used.The light from a point on an object goes through all parts of the lens and is then focused to the a single point on the sensor.That's what lenses do. Exactly the same proportion of light goes through the edge of the lens as the centre of the lens with either 35mm or APS sensor. Theway to prevent light going through edge of the lens is to select a smaller aperture and this can be donewith any lens and any sensor.

It is true of course that you're using the best part of the image, because the light atedges of theimage hits the sensor at a more oblique angle,and digital sensors areallegedly less tolerant of this than film. Howeveran EF-S lens achieves the same result with, usually,slightly less glass because it doesn't generate this bit of the image in the first place.Full frame lenses are to some extent wasted on an APS sensor camera, but the concensus seems to be that there isn't much point in making EF-S tele lenses because they're not going to be much smaller, if at all. Of course it'sa different matter with the wide angle ones.





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Old Jun 3, 2005, 10:28 AM   #6
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NHL wrote:
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What's wrong with the EF 70-300mm f4.5-5.6 DO IS USM - it's already a good lens (and small enough)
You mean besides the price?
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Old Jun 7, 2005, 9:33 AM   #7
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Oldcodgers right - look beyond the hype and read some reviews on Fred Miranda.

General consensus is thatDO's are "OK" for the price - but build quality is missing and they are softer than many can put up with.
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Old Jun 7, 2005, 11:36 AM   #8
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Technophile, I thought I saw where you were going, but then you took a turn to the left and I missed you.

The lens focuses the image into a circle on top of the imaging surface (be that film or a digital sensor.)

A standard EF lens projects an image circle of the same size, no matter what it projects it on to. I think we can all agree there.

But with a smaller-than-film sensor, the light that went through the edges of the lens elements (where most of the distortion happens) does not hit the sensor. So while saying "you get the best part of the lens" is a little non-technical and unspecific (and therefor hard to pin down exactly what is meant) to my thinking it is essentially true.

The parts of the lens that produce the majority of distortions and look the worse (the edges) do not contribute to the picture as produced by a non-full frame digital camera.

I don't know if this inherently means they are "Better" than a EF-S lens. The smaller lens elements in the EF-S lenses mean things like their surface angle is lower (closer-to-flat) which may contribute to better image quality. I don't know, that is just a wild guess. What I'm saying is that EF-S lenses might have their own inherent benefits so the conclusion (that EF lenses are "better") might be false. But I still believe that the worst part of the EF lens glass is not used to make the picture with a smaller than full frame sensor.

As to a digital sensor being more sensitive to light angle vs. film.... This is basically a fact; I don't know anyone disputes this. As sensors are made now (well, CMOS and CCD, I don't know about the Foveon) they are more sensitive. The full frame sensor that Canon uses in the 1Ds family had to be fitted with micro mirrors to "strighten" out the light that strikes the sensor further from the center of the sensor. The light needed to strike the sensor closer to the purpendicular than it was hitting.

I'm sure this cost some serious money both in R&D and making the product more complex to product and more expensive. I'm sure they wouldn't have done it if they didn't have to.

Eric
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Old Jun 8, 2005, 3:05 AM   #9
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eric s wrote:
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But with a smaller-than-film sensor, the light that went through the edges of the lens elements (where most of the distortion happens) does not hit the sensor.
A lot of people believe this and I've even read it in reviews but thepoint I was trying to make is thatit's not true. It's basically simple optical physics. If you draw a diagram of how the light from an object goes through a lens you'll seethe point. Take the light from a single point on an object in the middle of the frame. Some of that light goes straight through the middle of the lens and is unrefracted and hits a point in the middle of the sensor. Some light goes through the edge of thelens and is refracted to the same point in the middle of the sensor. And there's varying degrees of refraction for all light that goes through the parts of the lens in between the edge and the middle. But the point is that all that light gets refracted to the same point on the sensor, provided the lens is focused. By using a smaller sensor you're not discarding light from the edges of the lens. You can only do this by selecting a smaller aperture. If you want to avoid using the edges of a lens it's no good getting an EF lens. You need to buy a lens (either EF or EF-S) with a large aperture and stop it down.


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