20-35
No Canon service (discontinued lens)
No FTM (No USM)
Noisy AF (No USM)
Shorter focal length
72mm filter size (as opposed to ubiquitous 77mm)

17-40
f/4.0

I don't understand your poll If you're asking if the 20-35/2.8 is a better purchase than the 17-40, then I guess it would depend on how much of a bargain price you can get on a 20-35 and whether or not you need 17mm, f4, USM, etc. Personally, I'd consider the 20-35 (for FF) for the right price.

Omar

I once looked into the 20-35L, but given it's price of $450-600 being asked and the fact the 17-40L seemed to have better IQ as well as the other advantages (other than slower max aperture) I stuck with the 17-40.

I've inadvertently got both. IQ is about equal (maybe favoring the 20-35 a bit).
The extra stop is absolutely brilliant.
Assume you had to sell one, if it were you, which would you sell?

Well if your happy with the 20-35L and the extra stop is of use, I'd probably stick with that.

I love my 20-35L for 2.8, snappy IQ, nice colors, and no filter vingetting at 20mm with a 72^77 step up and 77mm 2stop hard grad. That combo is over 12mm thick! It's also a nice chunk of mostly metal that feels good in your hand.

Every time I consider a 17-40 for the price, I always come back to 2.8 and decide to keep my 20-35L until I can afford a 16-35 I or II.

i'd sell the 17-40, because i'd get a higher price for it, the IQ is (assuming i had your copies) the same with both lenses (so no advantage either way), and because i personally value F2.8 capabilities.

ymmv, but you asked

Has anyone actually needed Canon service and got stuck because the 20-35L was discontinued?

Pixel Perfect wrote:
I once looked into the 20-35L, but given it's price of $450-600 being asked and the fact the 17-40L seemed to have better IQ as well as the other advantages (other than slower max aperture) I stuck with the 17-40.

Both the 16-35/2.8 L II and the 17-40 are excellent lenses. I own both and use them on all 3 sensor sizes with superb results. There is a visible difference in the 1mm at the wise end, wider view, yes its available to you as well as the extra light it lets in wich is the major reason for justifying the cost difference. If you need thr syp of lighy is so very worth the price.

The 17-40 is by no means sharper.

DigiCanon wrote:
The 17-40 is by no means sharper.

It is sharper than the 20-35L, which is what PP wrote, and which is the subject of this thread...

The 20-35 is not a L lens. It is a 3.5 - 4. We are talking about the 20-35 that is no longer made and not supported right? If we are, then it doesn't even touch the 17-40.....I know I have had them both.

jbfaulconer wrote:
The 20-35 is not a L lens. It is a 3.5 - 4. We are talking about the 20-35 that is no longer made and not supported right? If we are, then it doesn't even touch the 17-40.....I know I have had them both.

Well the subject did say 20-35L, so most people assumed that's what we're talking about

I would have to keep the 17-40 for several reasons,
1) It is a current lens and will be supported by canon for a long time to come.
2) It has 3mm on the wide end, where most want this range lens for.
3) it has 5mm on the narrow end giving it a more useful range.
4) once in a while I will need a bigger apeture but seldom use these style lens to blur or in low light, usually want a deeper fov.
5) would have to think since I dont own the 20-36 that the IQ is better with the 17-40, and I'm sure were talkin "L" becayse the standard 20-35, is, USM.

You either want / need an ultra wide or you don't. If you need 17mm, then the 20-35 just won't do, no matter if it is sharper or not. Personally I have the 17-40 for it's wide capabilities.

Easy decision. Do you need the wide angle or do you need the extra stop?

I have the 20-35L, had the 17-40 before. I use the 20-35L on a 5D and it's great. I had a 40D with the 17-40. I can't see much difference in IQ between the two though the 5D delivers better overall due to FF. Not a fair comparison. Still, I'm very happy with the 20-35L.

Just had the 20-35L serviced at Midstate Camera in RI. I realize you're in the UK but would think you have access to aftermarket service companies there. I wouldn't worry too much abut the service issue. I think it's the extra stop and the color/contrast. To me, the 20-35L has the edge.

After all of the above and the poll I am still unclear about this. Both the extra stop and the FL are important. The noise and lack of USM are minor problems for me with the 20-35, as well as the servicability, and the IQ for both lenses is really pretty even.
I got the 16-35L II and hope this will put my dilemma to sleep. (And selling both the 17-40 and the 20-35L.)

Have to add though that if pushed really hard and would have to make a decision, I would go with the 20-35.

Thanks all for the input.

not sure if this is permited ...but here is an OA on ebay for 20-35L

http://cgi.ebay.com/Canon-EF-20-35mm-f2-8-2-8-L-wide-angle-zoom-lens-20-35_W0QQitemZ180430281128QQcmdZViewItemQQptZCamera_Lenses?hash=item2a027b99a8

I know someone with a 20-35L and they wanted a comparison between that and my 17-40mm on the 5D mark II and there was no comparison the 17-40 stomped it into the ground the 20-35mm was soft everywhere in the corners and was much softer in the centre and this was at all apertures. The 20-35 is an old lens and it performs like an old lens.

When you have tried 2.8 and less, you don't want to go back to 4.0 and more... Stick to the 20-35L.... Old lens ? not that important... I own a 28-70mm 2.8L and is marvellous.... Use it in Studio all the time....
Soft because it is old ? Not true... tons of old lenses are brillant.. Softness can hapened to any lens, new or old...