Vivitar Series 1 135mm f/2.3 - Rear Element Coating Damage

justtorchit · Joined: 12 Oct 2009 Posts: 269 Location: St. Louis, MO

After experiencing a long bout of "seller's remorse", I found myself looking to try and collect (and this time hang on to) many lenses I previously owned and ultimately sold in the interest of trying out new lenses. So in discovering how much I miss them, I have vowed that when purchased again, they shall not be resold to fund newer shinier things.

That being said, I recently picked up a Vivitar Series 1 135mm f/2.3. I am quite familiar with the lens in terms of function and performance. However, what I don't know is, it seems the copy I picked up, while cosmetically impressive, has an optical issue with the rear-most element. While I could have returned it, the rarity of the lens in good cosmetic condition combined with the N/AI mount, had me thinking I would work with it.

At first, I thought it was haze. I read up on some possible treatments and found a lot of recommendations for Isopropyl Alcohol. Fortunately, the rear element is easily removed via three screws and a threaded retaining ring. Once I isolated the element, I treated it carefully with some Isopropyl Alcohol. Nothing seemed to change. When dry, I replaced the element back into the lens.

Honestly, now it looks worse. It looks like I may have affected the coating. Though this could just be in my head. I have no "before" photos. And part of the reason I "went for it" was because when I first shot with the lens, I noticed quickly, a lack of contrast and some overall image softness (moreso than is usual for this optic). So I hadn't really anything to lose.

My question is:

1. What is wrong with this lens?
2. Have I ruined it? Could Isopropyl Alcohol have made things worse?
3. Any recommendations?

Currently, the most likely scenario for me, is to find another copy of the lens, which won't necessarily have to be in N/AI mount (which is what I use), and replace the rear optic with a clean one. Then sell the other optic for parts. But ideally, I would love if there were something I could do to try to fix what I have here. Thanks for reading!

calvin83 · Joined: 12 Apr 2009 Posts: 7495 Location: Hong Kong

I think the coating was etched.

marcusBMG · Joined: 07 Dec 2012 Posts: 1298 Location: Conwy N Wales

Rear elements like this are commonly uncoated anyway, particularly in older lenses. Coatings in any case are unaffected AFAIK by standard solvents like iso-p, certainly I have never seen any effect on the coatings of any of the lenses I've cleaned, even with stronger solvents like acetone.
The spotty nature of the affliction is more fungus like than haze which more usually, but not necessarily, afflicts a lens element more uniformly. One possibility is there was fungus leading to surface deterioration/etching, some types of glass seem to be more vulnerable. Deterioration of rear elements on the classic t-mount 300mm and 400mm lenses is common this looks similar. Bad news I'm afraid.
see the sticky on uncleanable lenses.

Lloydy · Expire: 2022-01-01

It looks like fungus etching to me, sadly irreparable.

justtorchit · Joined: 12 Oct 2009 Posts: 269 Location: St. Louis, MO

Bummer! Well I appreciate the input. So am I to believe then, that because I witnessed no fungus personally, that a previous owner likely attempted to clean the fungus, leaving behind the etched glass? Because I have seen fungus before and what I saw when initially investigating this lens definitely didn't look like fungus. It just looked like a faint haze.

I pulled out the rear element and snapped a few pics. At a distance it does just seem like a coating issue, but up close, it looks like, as you all suggest, the glass is etched.

Crop of Above Image:

A sample reveals I could be making much much more of this than need be. People have made amazing images with lenses in far worse states. The collector and analyst in me just prefers my lenses clean and clear so I can truly see through the lens as the designers intended.

hasan · Joined: 12 Mar 2007 Posts: 315

I don't know about its formula, but maybe it can be exchanged by spare lens?

justtorchit · Joined: 12 Oct 2009 Posts: 269 Location: St. Louis, MO

Does anyone know, on these lenses, how the rear mount comes off? I managed to find a copy of this lens in M42 mount and considered swapping the rear element. Unfortunately, as soon as I got the flashlight out....I discovered the rear element of this lens has issues too! What is it with these rear elements?? Though it doesn't look as serious as the other lens and I haven't attempted any cleaning yet. So if I wanted to extract the rear element, how would I do so? The Nikon version has three simple Philips screws but this one is free of any obvious screws.

SonicScot · Posted: Fri Apr 24, 2015 1:33 pm Post subject:

There are two tiny slots on the inner ring at the back, they are visible in your photos. You need one of those tools (can't recall the name of it) which has two parallel screwdriver-type bits which fit into those tiny slots. Then you just unscrew the ring.

calvin83 · Joined: 12 Apr 2009 Posts: 7495 Location: Hong Kong

SonicScot · Posted: Fri Apr 24, 2015 2:40 pm Post subject:

WNG555 · Joined: 18 Dec 2014 Posts: 784 Location: Arrid-Zone-A, USA

Late reply to this thread, but you can polish away that etching with cerium oxide.
I've had success with two rear elements from Vivitar zooms made by Tokina. Similar looking pattern. Oddly, the etching issue seems to be caused during manufacture in my case. The element was sealed off, and the only possible cause was reaction to material out gassing or assembly.

I used cerium oxide windshield polishing kit from Harbor Freight Tools. You get a tub that would last several lifetimes.

I have this lens too, and I don't think I have this affliction. Although I see fungus and haze inside mine.