I dropped my lens, is there a professional way to know if it's damaged?

I recently dropped my 24-105 lens on the ground, but it only damaged the telephoto ring.
I managed to fix it and seems in perfect condition.I fell on it's side, not on the top or bottom, on the side.
BUT I want to make sure, is there a way to identify any problems, but not only by looking
at it, I mean a real test done by pros.

That way I'd be sure, as long as it's not expensive.

As long as it works/focuses/etc a "pro" isn't likely to tell you anything else. Service it if/when you have issues.

Try shooting some pics with it...Make sure that the AF and aperture work properly...Check the results very carefully.

If all passes your inspection then don't worry any further about it...If not send it to Canon for an estimate of repair.

As long as it works, keep using it. Are you a CPS member? When/if you have problems, then send it to Canon.

rrblint wrote in post #14866637
Try shooting some pics with it...Make sure that the AF and aperture work properly...Check the results very carefully.

If all passes your inspection then don't worry any further about it...If not send it to Canon for an estimate of repair.

The autofocus works fine, I have test it, so is the aperture and the only problem with it is that the ring was crushed lightly, so it was hard to turn, I fixed it by taking a thin knife and lift the ring, it took me a hour, but I did a good job.
So it turns as smooth as normal.

But I might sell it cause I never really find it real sharp. and another friend of mine also had one and did not liked it.
So before I sell it, I wanted to make sure that I do the right thing by asking this question on this forum.

I'm thinking of selling my 7D to get the 5dmark III, so i'll need cash.....

Good advice so far. I'm no expert; but, the thought occurred to me that you should shoot various pictures at various apertures and then check the EXIF data to see if it matches. I guess if it does it won't necessarily mean there is something wrong; however, if it doesn't match you will know there is something wrong. Just a thought.

sega62 wrote in post #14866674
The autofocus works fine, I have test it, so is the aperture and the only problem with it is that the ring was crushed lightly, so it was hard to turn, I fixed it by taking a thin knife and lift the ring, it took me a hour, but I did a good job.
So it turns as smooth as normal.

But I might sell it cause I never really find it real sharp. and another friend of mine also had one and did not liked it.
So before I sell it, I wanted to make sure that I do the right thing by asking this question on this forum.

I'm thinking of selling my 7D to get the 5dmark III, so i'll need cash.....

I didn't realize that you were planning to sell the lens.

In this case I think that the right thing to do would be to send it to Canon for inspection, cleaning, and repair(if required)...This will give you peace of mind, knowing that you have sold the lens with it working as it should be.

If you choose not to send it off, you should inform all potential buyers of what has happened to the lens and reduce the price accordingly.

Accidents do happen and this one may cost you some money, but you wouldn't want to sell a potentially faulty lens to an unsuspecting buyer.

if you're selling it, you'll probably want to mention you dropped it...and you'll probably lose a good chunk of cash because of it...

The camera store I go to (Tempe Camera in Tempe, AZ) gives free quotes for repairs. I feel like lots of camera shops do this, so it wouldn't hurt to call around and see if you can get a free quote.

Shake it really, really hard for 2-3 min and listen for rattling.

Unregistered.Coward wrote in post #14869584
Shake it really, really hard for 2-3 min and listen for rattling.

...And if it doesn't - drop it again until it does - then you'll know it's broken!

Unregistered.Coward wrote in post #14869584
Shake it really, really hard for 2-3 min and listen for rattling.

It does rattle a bit, so does my 70-200 !
But it's not damaged

sega62 wrote in post #14869848
It does rattle a bit, so does my 70-200 !
But it's not damaged

See, not damaged.

The impact may decenter an element. I would probably test for decentering by shooting a flat plane of field or test charts and then pixel peeping the sides.

riotshield wrote in post #14870554
The impact may decenter an element. I would probably test for decentering by shooting a flat plane of field or test charts and then pixel peeping the sides.

Yep, about those test charts, How do we get them and use em???