# What to look for when buying a used lens in person...?



## cayenne (Jun 10, 2012)

Ok, I've decided to go try maybe the 70-40MM f/4 lens I posted about earlier.

I'm supposed to meet him and examine the lens tomorrow (Sunday) and if it looks good....buy it for $500.

As you might guess...I'm a 100% noob. I got my first DSLR (5D3) last month.

I've never bought a used lens before...so, what should I look for when examining the lens? What kinds of questions should I ask? As I understand it..this person bought the lens from someone else, so it is at least a 3rd party buy here.

I'm guessing to look carefully at the rear element for scratches? How much is too much? Front lens?

I'm bringing my camera to hook it up..and see how it works, but as a noob, aside from taking some shots to see if AF works....what else should I look for? I'm meeting in a public place....I figure smart for a high dollar item and cash transaction....etc.

Anyway...thoughts on buying a used lens from someone in person?

Thanks in advance, I truly appreciate all the input and advice I've gotten here so far...

cayenne


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## Radiating (Jun 10, 2012)

cayenne said:


> Ok, I've decided to go try maybe the 70-40MM f/4 lens I posted about earlier.
> 
> I'm supposed to meet him and examine the lens tomorrow (Sunday) and if it looks good....buy it for $500.
> 
> ...



Canon stuff is generally bullet proof until you start doing physical damage to it, except for their micro motor USMs on older lenses (does not apply to the lens you're looking at).

Pretty much the only thing to worry about is physical damage. Check it for physical damage, especially bumps and dings, if that's good then check the glass. If that's good then all you have to worry about is the AF. Get a tripod, mount the lens on a tripod and then have it focus on a brick wall, wait until it locks focus and beeps if you have beep enabled then go into live view and zoom in and then adjust the manual focus ring to see if it's in focus, if you can get it any sharper the lens has focus issues, if not it's good. Do this at various focal lengths. Make sure to switch out of live view when focusing because the camera uses a different system to focus in live view where it just tries to guess and check the focus instead of phase detection. 

If the AF and physical condition are good you should have no issues even with a lens 10 years old.

Hope that helps.


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## neuroanatomist (Jun 10, 2012)

Meet outdoors in daytime - better conditions especially for a slower lens. Test AF, shoot sky and see that vignetting looks symmetrical, shoot something flat with detail across the frame and check that the corners are similar (equally sharp or less sharp). Check the zoom and focus rings move smoothly.


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## cayenne (Jun 10, 2012)

neuroanatomist said:


> Meet outdoors in daytime - better conditions especially for a slower lens. Test AF, shoot sky and see that vignetting looks symmetrical, shoot something flat with detail across the frame and check that the corners are similar (equally sharp or less sharp). Check the zoom and focus rings move smoothly.



Thank you one and all...making notes for when I meet tomorrow afternoon.....

Please, if anyone has further suggestions...keep posting them!

C


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## bkorcel (Jun 10, 2012)

Look for signs that it may have been dropped. Check the filter ring for dents. Examine the glass. Should be clear with no haze or spotting. Check the external surfaces for scratches or fungus spots. Small stuff on the front glass may be ok like dust speck sized spots but not too many. Make sure any manual focus rings or zoom rings operate smoothly and dont bind anywhere in the full cycle of the ring. Electronically, make sure the AF will switch quickly from it's closest focus to infinity and back....do that several times in a row. If the lens has IS you need to test the IS capability in landscape and portrait mode (hold the camera with the top facing the left and again facing the right). IS should function smoothly in all three positions and it should hold firmly without jumping or wiggles. Take some shots with the aperture wide open..check the sharpness wide open. Take some shots stopping the lens down each time to F/16 (most people wont shoot smaller than that). Make sure all images are exposed properly. Also check the edge of the images for chromatic aberations (where the colors dont seem to line up in the same place) some call it color fringing. On the wide setting you might see some color fringing at the edges. There should be none in the center of the image.

All in all Canon lenses are hard to break no matter what you do to them. The IS systems are somewhat sensitive so you should make sure that works perfectly if the lens has it. Other things to look for are signs that it might have been in water or if you see ANY and I mean ANY sand particles anywhere. Sand and salt will kill electronics. If you see any sand, walk away.

Good luck...If you can try to stick with L lenses with that 5DMIII. They perform to their full potential with L glass.


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## bkorcel (Jun 10, 2012)

Are you looking at the Canon EF 17-40mm f/4L USM? The 70-40 doesnt exist so I assume that is a typo.


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## TexPhoto (Jun 10, 2012)

1. Visual inspection.
2. Shoot with it on your camera. make sure it auto focuses,, exposures are correct etc. Consistantly.
3. Shoot something flat that has detail, like a brick wall. Examine at 100% for sharpness, check center, and all 4 corners. 
4. As with any purchase online or off, know the going rate. Don't spend $500 on a $700 retail used lens only to find them new for $480, or used for $350. eBay completed auctions is a good place to check.


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## Marsu42 (Jun 10, 2012)

BozillaNZ said:


> no matter what you look for, there is always a factor or 'luck' in buying used.





bkorcel said:


> Other things to look for are signs that it might have been in water or if you see ANY and I mean ANY sand particles anywhere. Sand and salt will kill electronics. If you see any sand, walk away.



My 2cents: carefully listen to the usm motor working, if there's any sign of scratching, it might be sand/dust. This was the first early warning sign when my macro lens broke down - in this case, everything works just fine and then suddenly the lens breaks with err01 requiring a $250+ repair.


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## MintMark (Jun 10, 2012)

As well as all that good advice, you can do an aperture test.

Set the lens to f/16, look into the front element and press the depth of field preview button. You should see the blades close to form the smaller aperture. Make sure all the blades close and open again quickly as you press and release the button.

Mark


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## cayenne (Jun 10, 2012)

bkorcel said:


> Are you looking at the Canon EF 17-40mm f/4L USM? The 70-40 doesnt exist so I assume that is a typo.



Yes...typo....17-40mm

C


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## bdunbar79 (Jun 10, 2012)

Absolutely some of the best advice given so far is to take your camera with you. Shoot several shots wide open for sure. Shoot the sky, walls, contrasty scenes. Whatever you like. I'd check each end of the zoom, 17 and 40mm. There will be differences that are normal. Midway some zooms show a bit of barrel distortion, but you won't notice. Physical things have already been stated. I'd try a shot at like f/11 or f/16 and inspect DOF sharpness. Are you able to upload your photos onto your computer from your card prior to making a purchasing decision? I don't see why you couldn't post some on here and have us look at them.


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## Mt Spokane Photography (Jun 10, 2012)

Its absolutely impossible to test a lens mounted to a camera for subtle issues like sharpness or decentering, you can verify te AF works, Iris stops down, manual focus and zoom rings work smoothly, and that the glass is clean and clear, and general condition.

I also evaluate the seller. Does the seller appear to be knowledgable about the lens, why is he selling it. If the seller does nor know anything about it, thats a red flag. You can often, but not always tell if a seller is lying. Do they have the original receipt, etc.


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## bdunbar79 (Jun 10, 2012)

Right. But you can test for subtle differences if you import to computer.


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## cayenne (Jun 10, 2012)

Mt Spokane Photography said:


> Its absolutely impossible to test a lens mounted to a camera for subtle issues like sharpness or decentering, you can verify te AF works, Iris stops down, manual focus and zoom rings work smoothly, and that the glass is clean and clear, and general condition.
> 
> I also evaluate the seller. Does the seller appear to be knowledgable about the lens, why is he selling it. If the seller does nor know anything about it, thats a red flag. You can often, but not always tell if a seller is lying. Do they have the original receipt, etc.



Thank you one and all for the great primer on evaluating the lens.

It is VERY rainy out here in the New Orleans area today...met in a coffee shop to evaluate the lens.

Nice young kid, seemed to be interested in photography...big hobby of his. He's wanting to sell some zooms like this one and move into primes.

Seemed a nice kid.

Front and rear elements on the lens looked nice....motor seemed to move from infinity and back quickly...no discernible noise. Body of lens was in good shape...no scratches or anything. ONly thing really that showed any dings or wear, was the hood itself, and I'm ok with that.

He didn't have the pouch that goes with it....and he forgot to bring the UV filter he had for it...said when he gets back on this side of the lake again, he'd try to remember to bring it and holler at me to meet him for it.

Anyway, I think I'm very happy with my purchase.

As per the other thread, this is the 17-40mm f/4 L. I got it for $500 even.

I had been wanting to save a bit more and get the faster 16-35....but I think I got a good deal on this one, and this will give me wide angle to play with for awhile. I might even look into keeping this one, and saving for the 14mm to get something faster and even wider.

Anyway, from my research and feedback on this forum (thanks guys!!) this looks like a good deal, and likely as not, if I find I want to...I should be at least able to get my money out of the lens if I wish to resell it.

LOL...I'm guessing some of the tables of girls in the coffee shop were getting a little self conscious with me shooting all kinds of pics of them with my big camera, etc....gotta go back through and look at the images to see if any keepers...

Thanks to all!

C


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## Axilrod (Jun 10, 2012)

cayenne said:


> Mt Spokane Photography said:
> 
> 
> > Its absolutely impossible to test a lens mounted to a camera for subtle issues like sharpness or decentering, you can verify te AF works, Iris stops down, manual focus and zoom rings work smoothly, and that the glass is clean and clear, and general condition.
> ...



It sounds like everything went well. People tend to take care of their gear, especially when it's expensive. I've bought tons of lenses used and haven't had any issues at all. The 17-40 is a very solid lens, and unless you shoot in low-light constantly you're not missing much with the 16-35mm. And as well as the 5D3 does at high ISO's you really don't have much to worry about. 

The 14L is a great lens, very sharp, but it's expensive as hell and not near as versatile as the 16-35 or 17-40. It's a good lens to have, but it's definitely not anywhere close to one of the first lenses I'd get if I was starting a collection. It was the last Canon lens I got, there are just more important lenses to get before that one IMO. Enjoy your 17-40 and try not to get too wrapped up in lens acquisition, the more you buy initially the harder it is to master each one.


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## wickidwombat (Jun 11, 2012)

$500 is pretty decent and the 17-40 is a good lens

for you info in the future i wouldn't bother changing it for a 16-35 mk1 but down the track a 16-35 f2.8L mk2 would be the only reason to change out

I shoot my 16-35 at f2.8 alot its a fun lens

I think you are going to be happy with the 17-40 though


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## cayenne (Jun 11, 2012)

wickidwombat said:


> $500 is pretty decent and the 17-40 is a good lens
> 
> for you info in the future i wouldn't bother changing it for a 16-35 mk1 but down the track a 16-35 f2.8L mk2 would be the only reason to change out
> 
> ...



Thank you.

I was never looking at the 16-35 mk I...I was only looking at the mk II.

I'll have this to play around with this summer for a wide lens, but I likely see myself for most new lenses...not buying anything slower that 2.8 in the future.

And, if I decide the extra stop is important to me...I can likely sell this one for no less than even money, and put that $500 to the new lens...whatever that may be.


C


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## Mt Spokane Photography (Jun 11, 2012)

It sounds like you got a good deal. Thats the price I would expect to pay for a used one that is clean and working well. Many sellers will not drop that low, and I pass them by.


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## Jettatore (Jun 11, 2012)

I've bought a bunch of equipment used, but never in person. For a lens, when you get it if there is a return window or if in person, I'd look for the feel of the zoom/focus rings, and inspect the front and rear elements for scratches for miniscule dings in the coating. To be honest, miniscule dings in the coating will not effect normal images and probably won't even show up in a test shot but they might hurt the re-re-sale value if your buyer scrutinizes it ad-nausea. After that just test the switches and it's ability to find and achieve sharp focus accurately and repeatably, you might need to mico-focus adjust it back or forward a notch depending. If you buy a body used, one thing to consider would be to test a long exposure in very dark lighting to see if the sensor has any severely lit pixels, this doesn't effect normal shooting but if you like long-exposure nighttime landscapes, some sensors don't preform flawlessly at 100% crop without fixing some lit pixel areas, my copy of the 7D doesn't, but for normal shooting it's perfectly fine and I rarely ever use images from that body under any circumstances at 100% view. My opinion is that if the seller has a good rating it's probably worth it for you to take a risk and even buy the item sight unseen. Lots of good deals online. Good luck.


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## cayenne (Jun 11, 2012)

Jettatore said:


> <snip> After that just test the switches and it's ability to find and achieve sharp focus accurately and repeatably, you might need to mico-focus adjust it back or forward a notch depending.<snip>



I need to investigate and learn what 'micro-focus' is all about....and how to do it.....

I've seen the term used around here, but not sure what it is or benefits, or how to do it yet...

Anyone have any good links on this?

Thanks again for everyone's advice on this, I think it helped me greatly on this first used lens purchase.

C


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## neuroanatomist (Jun 11, 2012)

cayenne said:


> I need to investigate and learn what 'micro-focus' is all about....and how to do it.....
> I've seen the term used around here, but not sure what it is or benefits, or how to do it yet...
> Anyone have any good links on this?



The basics are here: http://www.the-digital-picture.com/Photography-Tips/AF-Microadjustment-Tips.aspx

Currently, I use Reikan FoCal.


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## cayenne (Jun 11, 2012)

Testing.
Trying to reply on other thread..got a 'security block' error message...anyone familiar with that?

C


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## Marsu42 (Jun 11, 2012)

cayenne said:


> Trying to reply on other thread..got a 'security block' error message...anyone familiar with that?



Using the search is said to help now and again: http://www.canonrumors.com/forum/index.php?topic=6414.0


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## cayenne (Jun 12, 2012)

Marsu42 said:


> cayenne said:
> 
> 
> > Trying to reply on other thread..got a 'security block' error message...anyone familiar with that?
> ...


Thanks...interesting.

Not sure what would have been blacklisted...just was a link about the new version of Apeture being posted...hmmm


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