lenses size for canon

Focal Length	Equivalent Focal length on 35mm full-frame	Aperture Range	USM*	Filter Size	Estimated Price	Lens Mount	Distance Scale
17-40	[27-64]	4	Yes	77mm (or rear gel)	$800	Metal	Yes
18-55	[29-88]	3.5-5.6	No	58mm	$100 - with 300D	Plastic	No
20-35	[32-56]	3.5-4.5	Yes	77mm	$370	Metal	Yes
24-85	[38-136]	3.5-4.5	Yes	67mm	$310	Metal	Yes
28-105	[45-168]	3.5-4.5	Yes	58mm	$220	Metal	Yes
28-135	[45-216]	3.5-5.6	Yes	72mm	$400	Metal	Yes
55-200	[88-320]	4.5-5.6	Yes - micro USM (no FTM)	52mm		Plastic	No
75-300	[120-480]	4-5.6	Choice (no FTM)	58mm	$140-$390	Metal	No
100-300	[160-480]	4.5-5.6	Yes	58mm	$270	Metal	Yes
50	[80]	1.8	No	52mm	$70	Plastic	No
70-200	[112-320]	4	Yes	67mm	$550	Metal	Yes

EF 17-40/4L

Though it's a pretty expensive lens at $800 and probably not likely to be high on the list for new Canon EOS 300D owners, many EOS 10D owners are buying this lens. It does give you true wide angle coverage (equal to a 27mm lens on a full frame 35mm camera) and being an "L" series lens it's built to professional standards with high quality optics, a silent USM ring motor, distance scale and comes with a hood. It's certainly a recommended lens if you can afford it.

EF-S 18-55/3.5-5.6 USM

Canon have addressed the wide-angle problem with their 18-55mm lens specifically designed for the EOS 300D (it will NOT fit on an EOS 10D or any other EOS camera). This lens gives the coverage of a 29-88mm lens on a 35mm camera - very similar to the popular 28-90mm lenses often sold in camera "kits". The only drawback of this lens is that it's one of Canon's low end, very inexpensive lenses. Typically they do not perform as well as Canon's mid-range lenses. They usually show lower contrast, especially wide open and lower sharpness, especially at the edges of the image. However, for $100 you get a lens with coverage it might cost you $700-$1000 to get with Canon's better lenses so I think it is a lens well worth considering. You have to buy it as part of the EOS 300D kit - it is not sold separately - so you have to decide whether or not you want it when you order the camera. For $100 I'd say it's probably worth getting. It's not expensive, it will give you a wide-angle lens, and if you eventually decide you want a better lens (like a $700 17-40/4L), I'm sure there will be a market for used 18-55 zooms since those who didn't get one with the EOS 300D might change their minds and wish they had!

EF 20-35/3.5-4.5 USM

This is the least expensive of Canon's higher quality wide-angle lenses. Performance is good, even wide open and it has a ring USM motor giving silent operation and full time manual focus (i.e. you don't have to switch from AF to manual focus). It's well built with a metal lens mount, distance scale and IR focusing marks. It also works very well on Canon EOS 35mm film bodies. The cost is higher than the 18-55 and the zoom range is smaller, so you have to decide whether it's worth spending more. A lot depends on what other lenses you buy since you don't want too much overlap in focal length.

EF 24-85/3.5-4.5

Another higher quality lens with ring USM and full time manual focus. It matches pretty well in focal length with either a 75-300, 100-300 or 70-200mm lens without to much overlap or too much of a gap, so it's a good choice for the semi-wide to semi-telephoto lens of a higher quality lens pair. The only drawback is, of course, it's not very wide on an EOS 300D or EOS 10D, 24mm being the equivalent of a 38mm on a 35mm full frame camera.

EF 28-105/3.5-4.5 USM

This is a workhorse 35mm lens, highly recommended as a relatively low cost, high quality alternative to Canon's cheap "low end" lenses. Much better built, ring USM motor with full time manual focus, distance scales, IR focus marks and a metal mount. It takes 58mm filters. The only reservation is that 28mm isn't all that wide on an EOS 300D or EOS 10D since it gives the same field of view as a 45mm lens on a full frame 35mm camera. If that's not a problem for you this lens is maybe the best $220 you can spend.

EF 28-135/3.5-5.6 IS USM

One of my personal favorite lenses. It has IS (Image Stabilization) which is a scheme which allows you to hand hold this lens at shutter speeds 2 to 3 stops slower than you could without IS and still get sharp images. If you don't like carrying a tripod this is invaluable. It's also a very sharp lens, one of Canon's best mid-range zooms if not the best.. Again the 28mm wide end equates to 45mm in full frame 35mm terms, but the lens also goes out to 135mm - which is 216mm in full frame terms and that's a respectable telephoto.

EF 50/1.8 II

It's under $70, it's small, it's light, it's sharp and it's 2-3 stops faster than any of the zooms. What more can I say. Buy one. You won't regret it.

EF 55-200/3.5-5.6 II

Another of Canon's low end lenses. Originally designed to be sold with APS film cameras and then discontinued since APS never took off, it's now back in a "mark II" version for use with the EOS 300D digital version of the "Rebel". Plastic lens mount, no distance scales, no ring USM or full time manual focus (though it's a USM lens, it's a different type of USM). It does match the 18-55 in focal length (and probably in quality) but it's a lens I'd have a hard time recommending on any basis except for price.

EF 75-300/4-5.6

There are three of these, a non-USM version, a USM version and a USM version with IS (Image stabilization). Though the lens has a metal lens mount, it has no distance scale and the USM motor isn't a ring type so it isn't silent and you don't get full time manual focus. The USM version is probably marginally quieter and marginally faster focusing then the non-USM version. Optically all three lenses are very similar. The two non-IS lenses have identical optics but the IS lens has additional lenses as part of the IS mechanism. All three lenses are very sharp at the short end but start to become a little soft at the long end. They're still not bad - but not as good as a 300/4L lens. The IS version is one of my favorite lenses. You can shoot hand held at 300mm at speeds down to 1/125, maybe 1/90 and still get images which are sharp. At 300mm you have an "effective" 480mm lens compared to the view with a 35mm full frame camera which is very useful for sports and wildlife.

EF 100-300/4.5-5.6 USM

This is an "upscale" version of the 75-300. It adds a ring USM motor for fast focus, silent operation and full time manual focus, plus a distance scale and a front element which does not rotate during focusing (making the use of a polarizer a little easier. You do lose 25mm on the short end though. Optically it performs on about the same level as the 75-300 lenses. Sharp at the short end but starting to get a little soft at the long end. IS is not available on this lens. It's more expensive then the non-IS versions of the 75-300, but cheaper than the 75-300 USM IS.

EF 70-200/4L USM

This is one of Canon's professional quality "L" series lenses. For the extra cost you get better construction, better optical performance, a case and hood included in the price. It of course has a ring USM motor with full time manual focus. It can also take an accessory tripod ring and it will accept both the 1.4x and 2x Canon TCs (teleconverters or multipliers). With the EOS 300D and EOS 10D, full autofocus is maintained with the 1.4x TC, giving you a 98-280/5.6 autofocus zoom (157-448 equivalent). The 2x TC gives you a 140-400/8 zoom (224-640 equivalent), but you have to focus manually. It's a great lens and the price - around $550 - is quite low for an "L" series lens. You can't beat this one for quality, so if the price is within your budget it's highly recommended.