About to buy the 17-40L advice sought

Ok finally decided to purchase the 17-40L,
well im about to pick it up on Friday, and would like to know if the lcd on my 20d is capable of showing if its a good copy,(ie focusing /softness etc).Or does it need to be displayed on my crt moniter?only ask this as it would save me to'ing and fro'ing to the shop and save me time and money(btw they only have 1 in stock at moment so i cant try several).
Also how do you read/interpret the date code (just to ensure its a recent one and not a 'return').

thanks for looking and commenting.

Zooming all the way in on the camera LCD will give a hint. can you get a few hours and take the card home and examine the shots on a pc. doesn't the shop have a return policy?

Camera LCD's are low res and fairly cheap. Best bet is to take pictures at the shop and examine them at home. You could ask them to hold the lens for you pending inspection of the pictures.

Any reputable dealer will have a return/exchange policy. Like Dante and NiceGlass have said you should either:

a)buy a copy, take it home, and run it through the paces. Examine your shots, if you're satisfied keep it, if not, exchange it and try again.

b)try to give the lens a good workout at the store (not the best shooting conditions) and take your CF card home, check it out, and go back and buy the copy you tested.

FWIW, I wouldn't rely on the LCD screen, then again, I'd also buy the one copy they had and if not satisfied, return it. You seem to have a few lenses already philbyuk, what did you do when you purchased them?

The odds of having any problems with your lens are minimal - there are always some horror stories but remember, you can always take it back - that's surely the whole point of buying from a store instead of on-line?
I got my 17-40 from jessops, cost about £40 more than Warehouse Express ( I'm still not 100% sure I was wise but it did mean I didn't have to wait, and I got to play with it before I parted with my £)
Test it thoroughly:
http://focustestchart.​com/
And Jessops have a 30 day no quibble return.
And get on a credit card so you have additional buyer protection.
And finally, enjoy the lens. They are superb!

You can't use the LCD to gauge lens sharpness. Unless it's really, really off (which you'd see in the viewfinder as well).

Great lens though - you'll be happy.

This would be a difficult lens for me to buy now. With the Sigma 17-70 out and Tamron about to release a constant f/2.8 in a 17-50 range, 17-40 seems quite limiting.

thankyou all for the replies. yes the shop does have a returns policy, and is as cheap as warehouse express(cheapest online place in uk) thats why im getting it from here,so no prob with return. was just trying to save myself from taking it back later if its a bad copy.looks like ill have to test it at home.btw anyone kmow how to decipher the date codes?

Negatory on the date code, but I can tell you the 17-40 is a great lens.

quite the contrary if you can see yourself going FF in the near future.

ed rader

Don't worry whether it's a return or not only whether it's shaprp across the ENTIRE View.
My 17-40 is currently back at Canon for adjustmnent under warrenty because it looked fine til I tried it on a FF camera then I co uld see that all of just one side was slightly OOF compared to te other side
Didn't notice it on the 1.6 crop cameras.

So - try it on a tripod on a FF camera! If it's good - it's good!
Obviously there will be some distortion but it should be equal in each corner (don't use clouds to test! )

You will need to use sharpening to see if you have got a good copy - you cant really tell from the viewfindwer unless it's really bad!


If I was buying one now and I didn't have a FF camera here's what I would do, I'd take a CF card into the shop and ask to test the 17-40 on the 5D as that was what I was thining of buying to get really good quality wide shots
They will probably let you shoot outside unless you look shady
Frame a subject so you have details in all four corners OR take shots rotating the camera so all four corners are used (tree, lines on a wall texture etc) ata good shutter speed at ISO 100
If not enough light ask to use a flash too and shhot something close like the film boxes against a wall
make sure the camera is flat to the plane of view and use f5.6 or f8 at 100ISO

Good point. The 17-40 certainly makes much more sense if you plan to move to a full frame camera.

Take a shot and go to one of those digital 1 hr photo booths set up in most stores,,,,view the pictures on that and print them if need be...you will get instant feedback

All Canon superwides are soft in the corners on full frame cameras. As long as they're equally soft and the center is sharp then you've got the best you're going to get.

Like many others here, I would say that using the LCD alone will probably not be enough.....getting some pics onto a monitor would be the best way if poss.

Can I ask where you're getting the lens from and how much you'll be paying? I'm also in Manchester and I've been toying with the idea of getting one of these lenses....