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View Full Version : thoughts about buying a 2nd hand lens with previous decentering repair history



ivans75
08-09-2017, 5:23pm
Hi guys
I am looking at a 70-200 f2.8II from ebay with previous decentering history (repaired), any thoughts with this in regards to future re occurence? I heard some lenses dont perform the same after repair than when it was new out of factory but then again, I also heard decentering happens out of factory in brand new lenses..

ameerat42
08-09-2017, 5:28pm
Reputable seller? - Ie, can get money back?
Is it significantly cheaper than a new one?
Is there any (real) warranty?
Prepared to take the risk?
Will it cost a lot to return if it's crook?

--And as a preface, do you really need it?

/Stray thoughts.

arthurking83
08-09-2017, 6:21pm
My take and my understanding of this issue is:

1/. don't for a moment think that because it came out of the factory, it's gong to be perfectly aligned setup and working to it's fullest potential.
if you believe this, I'll refer you to get into reading up on Len Rentals blog about the fallacy that Canon, Nikon, or any other 'first party' manufacturer's effluent smells of flowers or pot purri or something.

2/. if the repairer cares enough, they can repair the lens to a condition better than the manufacturer can build them. That includes alignment and subsequent optical working order.

Think about it: manufacturer needs to make a set number within a set time frame .. or they'll start losing money on the venture.
Lets say they need to make 1000 units per hour, they do this in batch lots .. so they make about 10K units for a day's shift on the assembly line. The assembly line may then revert to another lens model and the process is repeated.
From here it gets blurry as to what happens exactly, but some lenses, even the uber expensive models can be trashed! And that doesn't mean pulled apart and repurposed, but literally junked, destroyed and so on.

Not all lenses will be built to specs. and to specs doesn't mean to be exactly aligned to the nth nanometer, with absolute perfect resolution scoring!
To spec means that they have a minimum resolution standard they try to maintain. The built lens will be quickly tested and if it achieves the res target it's passed.
Where it gets murky is that if it doesn't pass, some have commented that most lenses get literally trashed after being destroyed. You'd think that if a lens isn't within specs, they would:
a. could be easily recalibrated to spec.
b. pull it apart and reuse the bits.

I've read that a. can happen, but b. is an expensive proposition, in terms of labour hours required to achieve an end result of little financial gain.

A repairer tho, they charge by the hour, they'll then quote a price to fix a lens based on that premise.
eg. $50/hr, 3 hours work to fix something easily fixed and a couple of hours to calibrate the lens.
Lets say the price to repair and calibrate the lens is then 5x $50($250) + about $200 in parts .. all up $450+GST = about $495 all up. Joe Photographer thinks, well this is the price they have to pay to maintain a quality lens, so they do.
The repairer tho, they promised a set level of workmanship, so will usually go above the call of duty to make sure customer is happy with the work .. so if the calibration needed an hour (or even two) more to get spot on, then Joe Repairer will do so without charging more.

I know if I were a repairer I would!
I may delay the job for a day or so, so that the cost of that extra time required doesn't bleed into other paying jibs that are urgent too. If the repairer did that, then they'd potentially lose money. But to do 2 hours more work but not charge for it isn't necessarily a loss making process.
it is if it cuts into other work, but if the extra time can be delayed and made up for in terms of down time or extra time, then there is no loss .. just more work for no gain.
But the repairer won't want to lose credibility .. more important in the long run than working for 2 hours more and not making that extra $100!

This assumes an independent repairer, not a factory or warranty approved repair facility(like the importer will have) .. those facilities cost money as the repairer is paid by the hour.

I remember Lens Rental's blog describing that Sony prefer to scrap a lens, than to repair it, simply based on the premise that it costs money per hour. So any warranty work is usually a replacement job(on lenses at least).
Lenses costing about $1500 or so, Sony replace a lens where the focus system has broken.
I dare say that such lenses cost them about $500 max. Lets assume a 5 hour process to pull apart, inspect, replace broken bits and then calibrate lens.
Facilities and labour hours probably cost them about $250 at least for this job. Then the risk that it's not perfect .. so for the sake of $250 to them .. it's simple to just send out a new lens and be done with it.

Like Am said, consider who repaired it. If it was Canon HQ here in Aus .. I'd be weary.
If it was Joe CanonGuru in Upper Outer Hillside West working out of his own little premises, I'd go for it(at the right price).
If it's from Gumtree ... avoid. If it's from Ebay ... avoid! :p .. unless you can pick it up in person and can take all your mates as witnesses/protection/backup.
(been hearing a few scam stories of people buying stuff off ebay and or gumtree, where the scam is for the perp to sell some multi K dollar item, and then there's nothing for sale and the buyer is ripped off of their cash at knife point).

ivans75
09-09-2017, 10:41am
Thanks guys, i ll stay out of it

- - - Updated - - -

Oh forgot to mention he did mention it was repaired at CPS, i assume thats canon service centre?

That canon guru is interesting, might be handy to have his contact if you have, Arthur?
thanks again

arthurking83
09-09-2017, 7:57pm
....

Oh forgot to mention he did mention it was repaired at CPS, i assume thats canon service centre?

That canon guru is interesting, might be handy to have his contact if you have, Arthur?
thanks again

Probably best to do so until you get more experience with gear.

The comment Joe CanonGuru was just a generic joke name to indicate a well reknown Canon repairer.


But, I do now have a guy I could refer you too if you ever had gear issues.
He's in Lonsdale St opposite Michaels Camera up in some rabbit warren building that you'd never find without being told he was there.
He fixed my D800 for me .. not cheap, but did a good jo(considering Nikon make it nearly impossible for independents to work).

I can't remember it off hand, but I could locate it if needed one day.