[argoyle]

I just purchased the Vivitar 100mm f/2.8 version of this "legendary" lens. Upon close inspection of the glass, it turns out there is light haze on an interior element toward the rear. In the attached photos, the haze looks much worse than it does under ordinary circumstances. This haze appears to consist of thousands of tiny dots, which I speculate are oil droplets, either deposited by sputtering from the aperture blades or condensed from evaporated lubricant.

I would like to access the affected element to clean the haze off, but I'm stuck. My best guess is that the element is between the aperture diaphragm and the rearmost element. How do I get to it? So far, I have successfully removed the bayonet mount, but I could not figure out how to remove the aperture ring.

Hints, anyone? Thanks.

Attached Images

View Picture EXIF

File Date

 

View Picture EXIF

File Date

 

[stevebrot]

Your lens appears to have severe internal scratches from a botched cleaning attempt. If this is a recent purchase, you may want to contact the seller for a refund.


Steve

[argoyle]

Your lens appears to have severe internal scratches from a botched cleaning attempt. If this is a recent purchase, you may want to contact the seller for a refund.


Steve

The scratches are actually not severe, and I'm not even convinced they are scratches. Like the haze, the circular marks are invisible without a flashlight. (These pictures make everything look a hundred times worse than it really is.) They do not appear to have any effect on images.

[Fenwoodian]

.


If this is a valuable lens, just get rid of it, or have it cleaned by someone who knows what they are doing. If it's not valuable, give it your best shot. Everyone wreaks a few lenses during their lens repair learning process.

---

Last edited by Fenwoodian; 10-11-2020 at 07:57 AM.

[Not a Number]

I would get my money back. It's a good lens but not so rare that you couldn't find another copy in almost pristine condition. The price has come down on these after all the hype raising them to "cult" status. There may even be one listed in the market place at the moment.

Spots and scratches on the rear element tend to have a greater effect on the image than those on the front element.

[argoyle]

If someone can teach me the trick to removing the aperture ring on this lens, I think I can manage the rest on my own (as far as accessing the affected element goes). There is something preventing me from simply lifting the ring off, and it's not obvious what it is.

[GUB]

If someone can teach me the trick to removing the aperture ring on this lens, I think I can manage the rest on my own (as far as accessing the affected element goes). There is something preventing me from simply lifting the ring off, and it's not obvious what it is.

I have the Rikenon version and it is indeed legendary and the go to for "quality with flair" in my stable of macros. There is a pair of slots beside the actual rear element. You need a lens spanner to loosen via these slots. 1 Set Dual Tip Stainless Steel Lens Spanner Wrench Opening Tool for DSLR Cameras|Len Parts| - AliExpress
There should be no need to remove the mount.
The reviews ( Ricoh Rikenon P 105mm f2.8 Macro Lens Lens Reviews - Ricoh Lenses - Pentax Lens Review Database) say 6 elements in six groups. Which is good news because that means no cemented element. I had worried that the mess was lens separation. ie in the cement between two elements.

[stevebrot]

The scratches are actually not severe, and I'm not even convinced they are scratches. Like the haze, the circular marks are invisible without a flashlight. (These pictures make everything look a hundred times worse than it really is.) They do not appear to have any effect on images.

I respectfully beg to differ, based on having evaluated several dozen used lenses over the years. There should be ZERO internal marks. We use a flashlight (torch) with loupe to make them stand out, but turning off the light does not make them go away. When I have seen internal or rear element scratches, it is always reason for return/refund.

If you got the lens for free, it might be worth attempting a salvage for the experience of doing so. If you paid for it, be prepared to be disappointed with the attempt to salvage. Sorry to sound so grim, but when I saw your photos, my heart sank.

Addendum: I spent some time trying to find repair guides/diagrams for you, but with no success.


Steve

(...owns a pristine copy of the Dine version and yes, it is worth getting a good copy...)

[GUB]

I hear what others say about returning the lens if that is a valid option. But if not then take heart - here is the result from a Vivitar series 1 close focus 135mm f2.3 - another legendary lens. But also the only lens that I have taken to the rear element with toothpaste as a grinding paste to remove what appeared to be a coating of scale. Please realize though that was desperate measures not to be done unless as a final resort.

[argoyle]

Mission accomplished. God, it was so easy. The key was found in these very forums:

Vivitar 100mm 2.8 need fixing.... - PentaxForums.com

After removing the aperture ring and the one adjacent to it, the rear element assembly was trivial to remove by manual unscrewing. Luckily, I was right about the location of the haze: it was on the element closest to the aperture diaphragm—and on the outer surface at that. Very easy to clean off, and there were in fact no scratches. The arcs seen in my photos must have been cleaning marks from a previous attempt. They wiped away along with the haze. The glass is now as clean as I could wish.

The cleaning has had no visible effect on image quality. As I had suspected, the haze was too thin to have any effect in the first place. But now I won't have to mention any haze if/when I decide to sell this lens on to the next curious george.

---------- Post added 10-10-20 at 11:18 PM ----------

I spent some time trying to find repair guides/diagrams for you, but with no success.

Thanks for that!

---------- Post added 10-10-20 at 11:19 PM ----------

I hear what others say about returning the lens if that is a valid option. But if not then take heart - here is the result from a Vivitar series 1 close focus 135mm f2.3 - another legendary lens. But also the only lens that I have taken to the rear element with toothpaste as a grinding paste to remove what appeared to be a coating of scale. Please realize though that was desperate measures not to be done unless as a final resort.

That's hilarious. And nice photo!

---------- Post added 10-10-20 at 11:24 PM ----------

There is a pair of slots beside the actual rear element. You need a lens spanner to loosen via these slots. 1 Set Dual Tip Stainless Steel Lens Spanner Wrench Opening Tool for DSLR Cameras|Len Parts| - AliExpress
There should be no need to remove the mount.

I did notice those slots, and right though you may be, I feared that using a spanner on that retaining ring would do nothing more than loosen the rearmost element. That's why I wanted to remove the mount and aperture ring to expose the whole rear element assembly, because I suspected that it would just twist off by hand.

[GUB]

if/when I decide to sell this lens on to the next curious george.

Naa don't sell it -- unleash it.
Rikenon 105 2.8

[GUB]

I did notice those slots, and right though you may be, I feared that using a spanner on that retaining ring would do nothing more than loosen the rearmost element. That's why I wanted to remove the mount and aperture ring to expose the whole rear element assembly, because I suspected that it would just twist off by hand.

Looks like your technique worked for you but normally you can get all the glass behind the iris via my way.

[argoyle]

Naa don't sell it -- unleash it.
Rikenon 105 2.8

Beautiful photo!

Looks like your technique worked for you but normally you can get all the glass behind the iris via my way.

That's good to know for next time.

[stevebrot]

ery easy to clean off, and there were in fact no scratches. The arcs seen in my photos must have been cleaning marks from a previous attempt. They wiped away along with the haze. The glass is now as clean as I could wish.

Cool! Did you recheck using the light?

BTW...thanks for the link. I have a library of that sort of thing.


Steve

[argoyle]

Cool! Did you recheck using the light?

Yup! And thanks again!