Separation anxiety.

jamaeolus · Expire: 2015-08-20

I have a asahi pentax 67 105mm 2.4 that is in very good condition save it has a large rainbow on one of the groups in the bottom halv of the lens. I am going to sell it but I like to give evaluations on my lenses and was curious what the opinions on the site might come up with. I rate each category (optics, function, cosmetics) from 1 to 10 so a mint example would have 30 points. Optically aside from the rather substantial sized separaion, this lens is in darn good optical shape, i might knock it down one point for a bit of yellowing but unsure how far to ding it for the separation. Opinions?

i'll post some photos here in a few minutes.

blotafton · Joined: 08 Aug 2013 Posts: 1552 Location: Sweden

Hard to say, it should reduce value in my opinion.

Judging from my Heligon 50mm f/1.9 with that issue it only shows up with the sun in the frame and in some situation in the bokeh. Otherwise it's not an issue but I wish that the seller would have given that information.

Some only want the "minty" stuff.

jamaeolus · Expire: 2015-08-20

Oh of course it reduces the value. But I haven't seen enough lenses with separation to get a real handle on what kind of points I should mark it down. I have taken photos with it and they were quite good but it has to reduce contrast or increase flair, or both.

Paragon19 · Joined: 26 Dec 2021 Posts: 45

I've seen a fair number of people list different lenses with that kind of separation as "for parts/repair", and priced accordingly. This is what I would probably also do when listing a lens like that. Have you evaluated the impact the separation has on image rendition?

visualopsins · Expire: 2025-04-11

Unknown how fast separation might progress...if at all, or catastrophically fast due to shipping stresses...

If it were mine I'd price it lower than the lowest-selling price of another of that model, and list as-is, for parts, to avoid returns. Somebody would like to try it but has been unwilling to pay the going rate of a lens without separation is my guess; probably about the same as you paid. Smile

Probably about half the cost of a lens without problems, maybe less.

Asking price also depends on how fast you want to sell it. If you're willing to wait and pay multiple relisting fees, you could lower the asking price each time relisted until it does sell...accept offers, choose the best.

cooltouch · Joined: 15 Jan 2009 Posts: 9097 Location: Houston, Texas

I don't know how valid of a comparison it is, but I'll go ahead and share my experience. Some years back, I bought a Tamron 500mm f/8 mirror from a local municipal auction. Got it for a good price, but I was saddened to find it had separation in the small optic that sits in the hole of the primary lens. The construction of this piece forbade any sort of easy -- or even not so easy -- removal of the lens. It had about the same amount of separation as yours -- perhaps a bit less.

I tested it thoroughly before posting it on eBay. I found that the separation did affect sharpness by a noticeable amount. When I listed the optic, I had photos of it dismantled, which I included, with clear photos showing the separation. I put a $50 OBO price on the lens, not really expecting much, but I was surprised when somebody accepted my asking price. So I happily sold it to the fellow. It's worth noting that, these days, the Tamron 500 often sells in the $100 range. Back then, its price on eBay for a clean example was almost double that. Just to put my asking price in perspective.

Pancolart · Expire: 2013-11-18

RokkorDoctor · Joined: 27 Nov 2021 Posts: 1267 Location: Kent, UK

ZoneV · Expire: 2011-12-02

Separation is a very bad thing. It may still give very good images, but one does not know how it will be in the future. Or how it now behaves in critical ight situations, and so perhaps a perfect image is ruined due to additional internal reflections. On of my spearation isuees showed up in the bokeh of the lens.
http://www.4photos.de/camera-diy/Delamination-Separation-Repair.html

So I would give it like 2 out of 10 points. And clearly state the spearation problem and pictures in the descritpion. Probably even rate the lens as " for tinkerer" or something lik that.

stevemark · Joined: 29 Apr 2011 Posts: 3754 Location: Switzerland

Not talking about a-Bay here (I really try to avoid them completely) ...

... on local Swiss auction sites where people usually act reasonably and with common-sense I would describe and depict the issue (with images as you show here). I also would state that the issue isn't visible on images taken with the lens, and that it's caused by temperature shocks (cemented glasses with different expansion coefficients). I would add a few images taken with the lens, and offer to take it back if the customer isn't satisfied. And I would set a starting price of 1.--.

I have done that with several "defective" but useable lenses (e. g. filter ring dented, but no visible de-centering), and never had any returns.

But oh well, e-Bay probably is different ... ?!?

S

jamaeolus · Expire: 2015-08-20

Unfortunately for me ebay is my only option (other than keeping it, which I might do) . I did take it out for a spin this evening and I couldn't detect any image degradation but I don't have an undamaged identical example to compare with. This first one the suns reflection is in the top right corner of the image. Which i would expect to be a worst case scenario.

Pancolart · Expire: 2013-11-18

It should be visible in the flares. But using it full frame, perhaps it only occurs on edges so, yes use it with joy.

visualopsins · Expire: 2025-04-11

Probably best seen in out-of-focus highlights, aka bubbles...these show interior of lens(!) including front element defects and dust.

Knudsen · Joined: 16 Jun 2021 Posts: 115 Location: Indiana

This is just my opinion on buying and selling lenses with issues like separation/haze between elements, ethics, view of the world, etc. I am not faulting you or your plan to offer it for sale.

The separation itself and haze are related in that most buyers will not be able to repair such a lens. The sites I buy from most either list these as inoperable/parts lens and sometime list haze or separation (cemented lens elements or coating). That is with ANY haze. On a 1 to 5 scale, that would be a 1. I have a nice Vivitar 1 I paid very little for, found haze between elements and binned it.

Roughly, lens worth $100 to $250 with free shipping in 4 or 5 condition might sell for $5 to $30 as parts/inoperable.

These places are very ethical.

I am not saying or thinking you are unethical.

That being said, I think as long as you disclose the condition, preferable with the photo's of the lens showing the rainbow, it is perfectly ethical to ask any price and rate it any way you feel like rating it. It's on the buyers end to understand what separation is, does, and what the cure is. The cure does not exist as far as I know, not in DIY land.

You might get your selling price. Someone who knows or learns the limitations will get their money's worth out of it. For the Vivitar hazed lens I binned, I certainly got my moneys worth. It's banned to the basement now. I like working on difficult projects, so I did not discard it. I want to try http://www.4photos.de/camera-diy/Delamination-Separation-Repair.html if I can find the "glue" Very Happy

That will be a long time from now.

Good luck with your sale!

visualopsins · Expire: 2025-04-11

stevemark · Joined: 29 Apr 2011 Posts: 3754 Location: Switzerland

D1N0 · Joined: 07 Aug 2012 Posts: 2491

Separation need not be rainbow like it can also be hazy

visualopsins · Expire: 2025-04-11

Or like snowflake as we have seen recently. :0

Haze and separation are related only by un-repairability by most buyers. Smile