I wanted to see the difference in the quality L Glass lenses compared to regular glass lenses. Is there a big difference because I know there is a big difference in price? Can anyone post some examples of the difference?

It's not that simple. L lenses are better made in many ways. The L originally meant that it used one or more Fluorite elements that have superior optical qualities. Now it stands for a lot of things.

http://www.canon.ca/digitalphotography/eng...d=180&tid=6

The point is that they use state-of-the-art design and construction to provide the best possible performance for the focal length range and lens speed (with not too much concern about the cost involved).

But a regular prime - like the 50mm 1.4 or 100 2.0 - can still beat any L zoom.

folks, this is quite possibly the most shocking thing i've seen here on OSP ever. lol.

If you do 4x6 printing or low res online pics you'll probably not see much of a difference. However, the L glass has fantastic optical properties. Virtually no chromatic abberation, amazing edge to edge sharpness, and very nice wide apertures. The low chromatic abberation is great when shooting into the sun or in high contrast environments. The edge to edge sharpness is obviously something that you always just want. And the nice wide apertures are always great for low light shooting, indoors with flash etc. The lenses also usually resolve (show more lines close together without blurring) better than the non L alternatives.

Does that help?

I'm with roro and would like to look at samples we can "see" to judge for ourselves?

On a 30D I'm with John. I rented a 24-70L and could not justify the expense to purchase it.

I don't think L glass is the end-all and be-all of lenses. Sure they are great, and for the most part, they are your ONLY choice (no other 2.8 IS tele zooms) but there are non-L lenses that deliver exceptional image quality without the red ring. The EF-S 17-55 2.8 IS is my workhorse lens. I got rid of my 24-70L when I tried one out and realized it's a much better lens on a 30D than the 24-70. Image quality is just superb, sharper than the L, and handholdable at 1/3 shutter.

I also don't think the 85L is worth 4-5 times the price of the 85 1.8.
Also, 35L is not worth 4 times the price of the Sigma 30mm 1.4 in my book. (on a 30D)

Don't become an L-snob! lol

If you want some well respected lens tests to check it out for yourself, go to:
http://www.pbase.com/lightrules/lenstests

They're well respected? That's kind of upsetting. Look at their 70-300 vs 70-200 test they put up results that don't compare usefully, show no comparison of chromatic abberation or any actual resolution charts. Then they do a comparison after throwing in a kenko 1.4x tele in there which is going to mess with the optical properties of the lens and completely ruin the results. They do similar things on other test, but the best test they have is the 80 1.8 vs the 125 f2 L. This does a great job of showing how primes are both very good lenses but the colors you get with the L are a bit more realistic.
The only really useful image in the 70-300 vs 70-200 is this one (bottom images) that shows edge sharpness at the same focal length and same aperture. And that's a great example of what I was talking about. The L lens is far sharper in the edges than the non-L, however you don't need that if you're printing 4x6 or even 8x10 but if you're looking for really A+ results it's all in the details.

You actually don't need stellar edge sharpness for most types of pictures we do. We end up cropping and vignetting anyway.

I do not have any side by side examples to show you. However, I can tell you that I saw a huge difference in sharpness and contrast between my 28-105 f4.5 zoom and the 28-70 2.8L. Yes it's a 28-70, it came out before the 24-70.

On my film Canon it was not as noticeable, but with digital I shoot L glass or a good prime. With the 85 f1.2L you are paying for the L coatings but also the extra f-stop. Sweet glass but a little too much for the amount of time I would use it. I do lust after them though. I guess we all have a weakness.