what to note when buying a new lens?

[Murcielago]

most likely i will be going down with my dad to get a lens later and i would like to know what to note when checking the lens at point of purchase for any defects?

so pls share with me and the rest on tips for checking the item when buying.

thanks.

[megaweb]

- bring your camera body down
- test it with your camera for the focusing accuracy
- check for exterior condition
- see thru the lens (from front) against the bright light source (ceiling light) for fungus and dust
- shake the lens to check for any internal loose part
- lastly, ensure the price is similar range to other recommended shops

[ortega]

also check the moving parts for smooth operation

[cjyong]

better to bring along a laptop if u have to check the quality on the spot.

[Snoweagle]

Originally Posted by cjyong better to bring along a laptop if u have to check the quality on the spot.

If no laptop, try the shop's computer.

[acupofkopi]

what's the laptop for ?
how to check ?

[raptor84]

Shoot wide open, test for calibratio issues, sharpnes...

[Snoweagle]

Originally Posted by acupofkopi what's the laptop for ? how to check ?

Zoom in and check for any spots which may be caused by dusts or dirt.

[ipin]

Also :
1) have a look to see if the apeture opening is round. You don't want a lens with a stuck apeture blade.
2) Check the zoom, focusing and/or apeture rings for excessive stiffness or looseness.
3) check the contacts too. Have seen a new lens with a bent pin!

[Culés]

OK based on the input on this thread and my personal experiences, here is the list of things one should do before buying lens, chronologically, if I missed something please add:

1) Fungus/ dust test by holding to light
2) Shake test for loose parts inside
3) Aperture open /close for sticky blades test
4) Contacts check
5) Shoot wide open
6) Check for focusing errors, sharpness, corners light fall off, Chromatic Abberation on laptop
7) If price OK, BBB!

[wind30]

wah you guys check so many things? I usually buy from a familiar shop. I just take one shot wide open and check sharpness in the shop. The more extensive tests I do at home immediately after purchase. If not happy just go shop again to exchange on the same day.

[Culés]

This list is for buying new and used lens, especially used lens from a stranger whose address you dont know. If you only buy new from a shop you know, I guess you're ok.

I would still do all these checks on the spot though. I once asked CP (Peninsula) whether I can just take a new lens and bring it back the next day if faulty and whether they would exchange for a good one. They immediately said they can't do that and send the lens first to the manufacturer. Other shops may have different policies. But this thread is about checking lens, not shop policies, before we get OTd.

Originally Posted by wind30 wah you guys check so many things? I usually buy from a familiar shop. I just take one shot wide open and check sharpness in the shop. The more extensive tests I do at home immediately after purchase. If not happy just go shop again to exchange on the same day.

[lsisaxon]

Originally Posted by Snoweagle Zoom in and check for any spots which may be caused by dusts or dirt.

Dusts and dirts inside the lens will never show up in the image.

[hongjone]

OT a bit, is there a way to check on the aperture if it's a Nikon G lens or equivalent? No aperture ring. Can advise? Thanks

[ipin]

Originally Posted by hongjone OT a bit, is there a way to check on the aperture if it's a Nikon G lens or equivalent? No aperture ring. Can advise? Thanks

There is a lever that you can pull back the apeture. Look for it, it's a flat piece of metal.

[hongjone]

Originally Posted by ipin There is a lever that you can pull back the apeture. Look for it, it's a flat piece of metal.

Hmm... Interesting, will give it a try. Thanks

[Snoweagle]

Originally Posted by lsisaxon Dusts and dirts inside the lens will never show up in the image.

Yes they will, larger particles and with a greater DOF at wide angle.

[Youhong]

Check serial number with warrenty...

[lsisaxon]

Originally Posted by Snoweagle Yes they will, larger particles and with a greater DOF at wide angle.

Never had this problem before. Not even with Fisheye unless the blob of dirt is so huge it can be easily seen with naked eye on visual inspection of the lens, why even bother to use an image to evaluate?

Unless you're mistaken and talking about dust on the sensor?

[ianpaice]

Indeed checking shop policies is just as impt if not more when buying a new lens.

Often, we only get to realise problems with an equipment after we get back home. Testing in the shop can be flawed due to limited time and other interference.

Originally Posted by Culés This list is for buying new and used lens, especially used lens from a stranger whose address you dont know. If you only buy new from a shop you know, I guess you're ok. I would still do all these checks on the spot though. I once asked CP (Peninsula) whether I can just take a new lens and bring it back the next day if faulty and whether they would exchange for a good one. They immediately said they can't do that and send the lens first to the manufacturer. Other shops may have different policies. But this thread is about checking lens, not shop policies, before we get OTd.