Would you purchase a returned L-lens?

The Dark Knight wrote in post #17246723
BTW, I guess this would count for all lenses, but especially in a situation like this, what are some obvious things to check out? I usually check out the physical build (make sure there's no dust inside the element, the zoom works smoothly), then the electronics (make sure all the apertures can be dialed in correctly, AF works correctly), and then for any IQ issues (lack of sharpness or front/back focusing issues).

Anything else that should be checked out when purchasing a lens?

Other than what you suggest, not really. Unless you want to test the Highly resistant to dust and water. Throw some dust at it, then wash it off in the kitchen sink to see if it passes. Never know, the sealing could be faulty. Of course I'm joking.
If I could afford one, I'd already purchased it. So since you've asked here, you can redirect the blame to us when your wife goes postal on you.

I treat all lenses the same when they arrive at the door. I look them over carefully, check all the zoom rings, focus rings for smooth operation, and listen carefully for grinding noises. Check the switches for distinct clicks (AF on-off, IS on-off and any others)I then check the lens electronic contacts, scrapped up, used, shinny and bright with no scratches, new. I then mount the lens, check for wobble on the mount, power up the camera, look for errors, check zoom and aperture read out, focus close item, at minimum focus distance, then focus at infinity, back to close. Shoot several photos at different zoom ranges, check for proper aperture, check focus using FoCal, set front/rear focus. No problems found, the lens is ready for service, and will be used frequently for trial period.

B

When I inspect a "used lens" I look from the front element, with a small flash light inside the barrel for fungus, debris, and "things" in the glass. I'll then look with the flash light from the rear element, and also check the mount for small chips and snags. I also roll the lens and listen for debris moving around inside the lens. The lenses I have bought "used" have been only from KEH, and I've found every lens in great condition. Some you could not tell it was ever on a mount.

Bill Emmett wrote in post #17248180
When I inspect a "used lens" I look from the front element, with a small flash light inside the barrel for fungus, debris, and "things" in the glass. I'll then look with the flash light from the rear element, and also check the mount for small chips and snags. I also roll the lens and listen for debris moving around inside the lens. The lenses I have bought "used" have been only from KEH, and I've found every lens in great condition. Some you could not tell it was ever on a mount.

Awesomely thorough, thanks!

There isn't going to be any problem with the lens. I've bought use lenses - most of them very heavily used - and never experienced any problems whatsoever. And I'm not particularly "lucky", it's just that hardly anything ever goes wrong with quality lenses. No need to scrutinize the thing to death - just buy it and use it and enjoy it!

if the lens works fine, functions as it should and you want it. then buy it and use it. years from now it will be a non issue.

The Dark Knight wrote in post #17244150
A local camera store offered to sell me a 24-70ii for a decent (but not spectacular) discount. Catch was it was a returned item. But they told me I can take it home, check it out, and if I have any issues with it, just bring it back for a full refund with 14 days.

So I did that, and honestly I could not tell if this lens was even used. I made sure the serial number matched on 3 locations - box, warranty card, and lens itself. The lens case was squeezed into the styrofoam in that factory fresh flattened way that I find really hard to duplicate once the case has been taken out. Same thing with the lens itself, it was squeezed into the styrofoam really tightly.

Couldn't really find any dust or anything like that on the lens either.

The only thing that felt a bit "off" was that there were some small rips on the plastic covering the lens hood and the lens.

I tested the lens and it seems to work well, no issues I can detect right now.

So at this point I'm wondering if I should just keep the lens. It seems like it might have been a true unopened return (maybe buyer bought a couple of copies and found a really good one and decided not to even open this?).

My biggest question would be whether I will qualify for the rebate, the store indicated I would.

My buddy picked up a 70-200 f2.8II that way. Asked at the store about it and was told they had one that was a return (they normally special order) and was told $1900CAN and it was his. Bought it on the spot and I don't think it was even taken out of the box before it was returned.

The Dark Knight wrote in post #17244150
I tested the lens and it seems to work well, no issues I can detect right now.

So at this point I'm wondering if I should just keep the lens. It seems like it might have been a true unopened return (maybe buyer bought a couple of copies and found a really good one and decided not to even open this?).

as for myself, there are only 3 reasons I have ever returned a lens, and in order:

1. I had 2 copies and I returned the one that was slightly less sharp, most often on one single edge. almost never was the middle less sharp.
2. I had 2 copies and one focused better on my bodies
3. it was clearly decentered, more so than in #1. this is rare. I had one rokinon and one canon extender that I returned for this reason.

#1 is the most common. and in this case, if someone bought the one I returned, I would bet 99% of the time they would never ever notice. we are talking about very minute differences, most often only near the edge of the frame.

soooooooooo...........​.... I would bet that your lens is either #1 or #2, or maybe as others have suggested, buyer's remorse.

#2 is usually not a problem--it can be calibrated. #1 is the main thing that would always keep me wondering.......... would you be okay with the chance that your lens was not the best out of 2? that would drive me frickin nuts.

so... if you're anal like me, no, not worth the savings. if you don't pixel peep, I guess it don't matter.

put it a different way: if canon offered a $200 premium for picking the sharpest out of 10 lenses for you, would you pay it? hell yeah I would. $500? yup, I still would. so, if you would, then I guess that answers it for you.