Is this lens OK? (Weird aberration)

[HotToddy]

Hello All,

Hate to use my first post to ask a needy question, but If I don't start posting on this board, I never will.

I just got a 90mm Fujinon lens and was suprised to see this funny looking shape in it. It is in the rear element. The attached photo shows the rear element, detached from the shutter. Will this affect my photos? What is it? Is it a reflection?

I'm still waiting for a lensboard, so I can't try it out yet.

Thanks for any help,

Todd

[Gene McCluney]

I would slap together a cardboard temporary lensboard and try that baby out. Might have to send it back, you know.

[wfwhitaker]

Hard to tell from the photo... Could it be a coating defect? If so, it probably won't have any discernable effect on the ground glass, but under certain lighting conditions/subject matter will affect contrast and flare control. Is this a used lens?

[HotToddy]

I can't believe I didn't think to make a cardboard holder.


Yes, the lens is used. The seller seems nice enough so as to give me some time to see if the lens is OK. Although I must say that the defect is apparent just looking at the lens in normal light after being described as "clear". The lens is still better than the last 90mm I tried to buy. That one had a lot of "crud" built up on the inside-prob a combo of Schneider-itits and mold inside. That seller was good enough to take it back after describing the lens as "clear" also. Both sellers had excellent feedback, actually.

Thanks,

Todd

[Terence McDonagh]

I guess it depends how much you paid for it. If you'd still be happ with the price with a defect, keep it. If not, return it. I hate haggling after the fact because rarely are you at an advantage and rarely does everyone come away feeling good about it.

[HotToddy]

Both were between $300 and $400 a piece.

Thanks,

Todd

[walter23]

It's really hard to tell how significant this is just by looking at your photo. If it looked like that under most conditions I'd want to return the lens. You don't really want something like that inside the lens contributing to flare.

But just to clarify - this shows up in the same spot and looks the same even with different lights around, right? It's not just a reflection of your overhead light or something? If I just looked at the picture without your description I'd assume it was just the normal reflection of your light on the lens surfaces.

[Ted Harris]

Hard to tell from the picture here but it could be coating deterioration, separation or fungus. from the shape my guess would be one of the latter two and that is not good news. If you look at it through a loupe or magnifying glass and see sipdery traces coming out from the edges it is fungus.

[HotToddy]

But just to clarify - this shows up in the same spot and looks the same even with different lights around, right? It's not just a reflection of your overhead light or something?

Correct, Walter. It appears the same under all lighting conditions, even without holding it up to a light. In fact when I took the photo, there were no bare lights around at all, including the sun.

Ted, the shape is very clearly defined, not spidery at all.

Thank you all for sharing your experience,

Todd.

[Doremus Scudder]

It looks like lens element separation to me from the photo. Maybe the lens was dropped or mishandled (thermal stress, etc...). If it looks to be between elements (i.e. below the surface of the lens), that is a definite possibility.

I'd send it back.

Doremus Scudder

[Bobby Ironsights]

looks like something has seeped between the lens elements from the outside edges. Like say....cleaning fluid too liberally applied?

[Juergen Sattler]

Send it back to the seller - there are plenty of 90mm lenses to be had, no reason to keep this one and always having to worry about it. Buy from Jim at MPEX and you'll know what you get exactly. Jim is the most honest sales person I have ever met.

[Phil Hudson]

From the colouring and shape of the defect it looks a lot like some balsam separation I have encountered in various lenses over the years. Starting at the edges, in extreme cases this can leave only a smallish amount of unaffected glass in the centre which looks a bit like what I see in the photo. Does the affected part of the glass look slightly yellow to look through?

OTOH, if this lens is a Fujinon-SW 90mm lens, it uses 6 elements in 6 groups, so if I read this correctly there is no balsam cement used in this lens construction at all (and the lens looks a bit small for the 90/5.6 SWD lens, which does have cemented elements).

Perhaps you could say what type/model the Fuji lens is (which may then rule out balsam faults)......

Phil

[HotToddy]

The lens is a Fujinon SW S 1:8/90. I don't know what else to say about it except that the photo was taken of the rear element only. The affected area doesn't seem yellowish, it seems pretty clear actually.

There does seem to be alot of 90mm lenses around, but this is the second 90mm lens I've gotten from "that auction site" (different sellers), and both have had issues. Both sellers didn't see any defects in the glass.

Todd

[Phil Hudson]

From what I can see this model is listed as having 6 air spaced cells, ruling out a problem with disturbed balsam cement......

As others have suggested, it may be a coating problem, or caused by a previous attempt to clean it internally which has left some residue on the inside. Is there any evidence that the rear group has been opened up (eg. damage/wear to the rear thread slots)?

Finally, there was a problem with "outgassing" that some Schneider owners reported in early samples of the Super-Symmar 80/4.5 XL lens. Over time, there was the appearance of some internal hazing/residue behind the front element which was caused by something in the manufacturing process slowly reacting with the atmosphere (I think, others can maybe correct me here). I have not heard of this in other lenses but perhaps it is something similar?

As others have mentioned, good 90mm examples are found all over so if possible I would arrange to return the lens.

Phil

[walter23]

Correct, Walter. It appears the same under all lighting conditions, even without holding it up to a light. In fact when I took the photo, there were no bare lights around at all, including the sun.

Ted, the shape is very clearly defined, not spidery at all.

Thank you all for sharing your experience,

Todd.

In that case I would return it. It may not affect your image quality but I wouldn't want it hanging over me and/or affecting my ability to sell it later on.