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04-27-2018, 07:54 AM   #1
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Horrible defect in my copy of the FA31

I've recently purchased a second hand FA 31mm lens that arrived today - I put it on my K-1 to snap a few shots and something stood out to me.

There was a ghosting of contrasty objects in all my wide open shots. I do a few lens repairs myself so I checked for decentering - the lens seemed alright. I then looked through the lens to see what the optics looked like and I was amazed to see that there was a defective element. The element was perfectly shaped for over 95% of the total area, but there was a horrible edge to a part of it, sort of like a chord on a circle.

I've snapped some shots of it and the problem is a bit tough to first spot, but it's extremely obvious once noticed. I'm gutted for the seller as I've been told they didn't get on well with the lens - It's now really obvious why. I'm surprised something like this slipped through the QA process. It's an AIV lens by the way.

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Last edited by HarisF1; 04-27-2018 at 08:07 AM.
04-27-2018, 08:01 AM - 1 Like   #2
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Send it back! Send it back!


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04-27-2018, 08:07 AM   #3
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I'm definitely returning it but I wanted to also see if anyone else has stories of wonky elements in premium lenses.
04-27-2018, 08:19 AM   #4
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QuoteOriginally posted by HarisF1 Quote
I'm definitely returning it but I wanted to also see if anyone else has stories of wonky elements in premium lenses.
That appears to be a chip. Is there any indication the lens has been disassembled with the bad element being the result of botched repair? With so many floods and serious storms in the last few years, I would expect a fair number of lenses and cameras to be hitting the market that were purchased as bulk lots from insurers to be hastily cleaned up for sale on eBay.


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04-27-2018, 08:31 AM   #5
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The rest of the lens is pretty clean so I doubt it's a repair job - and from the front (and other angles) there is no sign of disassembly and the elements look perfectly fine. I'm not convinced that it's a chip as it would be more than visible from other angles, and the straightness of the edge makes it seem like it's a production defect. The serial number is 0040xxx, and I've packed it up so no more checking!

Good shout though, I've come across a water damaged item before on 'that auction site'.
04-27-2018, 03:39 PM   #6
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I could see why someone wouldn’t “get on” with that lens well. If you can, add the serial number here as defective.

I hope you find a good copy as the 31 can be an amazing lens!
04-27-2018, 04:26 PM   #7
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I normally have trouble seeing what people are talking about when they point to flaws in their images. Both the ghosting and the defect are extremely obvious here...
I'm amazed the original owner didn't realize something was wrong.
04-27-2018, 11:44 PM   #8
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Something this bad is unheard of in this lens. Over all these years since the lens came out, i've never seen the likes if this. Something happened in its history- who knows what, and now the attempt is to pass it off to some naive buyer.

04-28-2018, 06:38 AM   #9
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QuoteOriginally posted by mikesbike Quote
Something this bad is unheard of in this lens. Over all these years since the lens came out, i've never seen the likes if this. Something happened in its history- who knows what, and now the attempt is to pass it off to some naive buyer.
Luckily I'm not that naive!

It'll be fine at f/2.2 and higher, and can't speak for the impact on CA which seemed stronger than usual.
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