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Vivitar 28 2.0 Close Focus Komine Disassembly
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PostPosted: Sat Nov 02, 2019 3:42 pm    Post subject: Vivitar 28 2.0 Close Focus Komine Disassembly Reply with quote

I have never disassembled a lens before. I picked up a Vivitar 28 2.0 Close focus and there appears to be slight haze under the front element or even beyond. I am not sure if I should keep it, try to clean it, or return it. Can anyone give me some guidance on disassembling the lens? I did some searching online, but have not been able to find anything.


PostPosted: Sat Nov 02, 2019 7:47 pm    Post subject: Reply with quote

There is stuff around if you look. The structure of many of the versions is often similar so don't restrict your searches to f2 versions or close focus versions. This is a komine made 28mm:

https://www.youtube.com/watch?v=B0-2B1jiKFQ

This is on this site:

http://forum.mflenses.com/vivitar-28mm-f2-8-a-cleaning-attempt-t73504.html

and there is this:

https://elliotkang.wordpress.com/2012/05/13/disassembly-of-vivitar-28mm-f2-8/


PostPosted: Tue Nov 05, 2019 10:41 pm    Post subject: Re: Vivitar 28 2.0 Close Focus Komine Disassembly Reply with quote

cbass wrote:
slight haze

Don't bother, it's of no practical consequence.


PostPosted: Tue Nov 05, 2019 11:28 pm    Post subject: Re: Vivitar 28 2.0 Close Focus Komine Disassembly Reply with quote

cbass wrote:
I have never disassembled a lens before. I picked up a Vivitar 28 2.0 Close focus and there appears to be slight haze under the front element or even beyond. I am not sure if I should keep it, try to clean it, or return it. Can anyone give me some guidance on disassembling the lens? I did some searching online, but have not been able to find anything.

It's worth having it cleaned, I just don't think it's a good lens to learn on, I recommend a Helios 44-2 as your first lens to cut your teeth on.


PostPosted: Sun Nov 10, 2019 6:25 pm    Post subject: Reply with quote

By worth having it cleaned, does that mean sending it to a professional service? If so, then I am not familiar with too many of those. I have contacted some in the past about another lens, but the prices they quoted I was better off just finding another copy of the lens. I do have a helios, but that lens is pristine, has sentimental value, and it one of my best performing lenses. There is no way I will take it apart.


PostPosted: Sun Nov 10, 2019 8:26 pm    Post subject: Reply with quote

cbass wrote:
By worth having it cleaned, does that mean sending it to a professional service? If so, then I am not familiar with too many of those. I have contacted some in the past about another lens, but the prices they quoted I was better off just finding another copy of the lens. I do have a helios, but that lens is pristine, has sentimental value, and it one of my best performing lenses. There is no way I will take it apart.


I got one with fungus and I opened the front pressing ring and clean it a little bit. The coating on the front has a larger water mark pattern. But the image quality doesn't seem to suffer. Now I got another one and can do a comparison. I think bargains do exist and be patient you will get another one. I've seen quite a few in 2018 and 2019 selling for very reasonable price.


PostPosted: Mon Nov 11, 2019 5:02 am    Post subject: Reply with quote

I managed to get the name plate off and as I was taking pictures I managed to capture the haze very well. Does anyone know what this haze is and if it can be cleaned? It is inside the lens and not outside. Also seems to be only on the front element. Is that what others see?



PostPosted: Mon Nov 11, 2019 10:16 am    Post subject: Reply with quote

cbass wrote:
. . . Does anyone know what this haze is and if it can be cleaned? It is inside the lens and not outside. Also seems to be only on the front element. Is that what others see?


Even in person, it's often difficult for me to know exactly where haze is without taking a lens apart. And in my experience, if I can get to the haze, it usually wipes right off. The hardest part for me is to get the glass free of streaks, smudges and dust.

I searched for an optical diagram of your lens, and I think I found it on a lens box in an ebay listing:
Click here to see on Ebay

Is that one the same as your lens? I hope so because it appears the front elements aren't cemented together. In that case you may not have to worry about haze between cemented elements.

My own Vivitar 28 f2.0 is the same as the one on ebay. I've never worked on my lens before, but I just took the name ring off to have a look. It appears as though the front element retainer might (?) simply unscrew - if you can get access to it. Or if you have a lens spanner, I see slots in the chrome ring below.

If you proceed, go slowly and note the orientation of parts before you remove them. Heat can help loosen stubborn rings.


PostPosted: Mon Nov 11, 2019 2:03 pm    Post subject: Reply with quote

Is that haze in the lens or on the top element? It's hard to tell from the pic but it does look a bit like coating deterioration/wear. If so that can't be fixed.
Won't be that of course if it's in the lens. I would expect it to clean off in that case. I use basic optical wipes dipped in acetone.
Scratches on the lens spanner slots on the lens suggest it's been opened up before, or s/o tried to.


PostPosted: Mon Nov 11, 2019 7:51 pm    Post subject: Reply with quote

That is the same as my lens and indeed the correct optical diagram. It does look like the front element is not cemented.

What is a front element retainer? Is that the silver ring? I followed the Vivitar 28 2.8 video and in that one the group just unscrewed. I tried the same with gloves and had no such luck. I didn't really crank on it, but I think the silver ring needs to come off. So it seems to be slightly different.

There are scratches on the silver ring and it appears somebody already put a spanner wrench on it and had it apart already. This worries me as I wonder if the haze is left over from someone cleaning up fungus and the haze is coating damage.

The Haze is inside the lens, not outside. I already cleaned the outside of the lens. When I shine a led light the outside coating appears fine. It will see a uniform and even green reflection.

Lens performs great when it comes to sharpness, but it takes a hit when it comes to contrast.

Do I need to mark anything for alignment? Do I need to make sure anything is aligned? Aperture closed? Aperture stopped down? At minimum or maximum focus distance?


PostPosted: Mon Nov 11, 2019 8:28 pm    Post subject: Reply with quote

cbass wrote:

Lens performs great when it comes to sharpness, but it takes a hit when it comes to contrast.

Do I need to mark anything for alignment? Do I need to make sure anything is aligned? Aperture closed? Aperture stopped down? At minimum or maximum focus distance?

Looks like a simple haze to me.

You don't need to mark anything, lens retainers are pretty much a centering apparatus for an individual lenses.
If you plan to remove several lenses, optical diagram can be handy as to avoid putting a lens back in upside-down position.
It's often obvious if you do, but sometimes it isn't.

Get a lens spanner. Looks like the previous attempt to open it was made with a screwdriver, using only one slot.


PostPosted: Tue Nov 12, 2019 1:29 am    Post subject: Reply with quote

cbass wrote:
. . .
What is a front element retainer? Is that the silver ring?
. . .

To add to what aidaho said, sometimes the front name plate is used to hold the front element or group in place. And sometimes there's a black, threaded ring / retainer below the name plate which holds the front element(s) in place. In this case, I just assumed the black ring on top of the element or the ring surrounding the element were retainers and might screw off. I know you already tried, but I wish there were a way you could gently, but firmly grasp the ring(s) around the front element.

I can see now that bulbous front element makes it difficult to try to loosen the (retaining?) ring on top of it. I just used the open end of a small bottle with a rubber glove to try to loosen that ring, but mine wouldn't move either.

Next, I'd use a lens spanner to try to loosen the slotted, silver ring - whatever it may be. When I try to clean lenses, it's often trial and error to find the correct pieces to loosen.

In fact, I just gave the silver ring on my own lens a try with my spanner, but it wouldn't budge. And since my lens is already clean, I'm not going to try any harder.
Heat and or solvents might be needed if the retainers / rings are cemented in place.

I think a dedicated lens spanner is the best tool, and they don't cost much on ebay. But there are alternatives:
https://www.pentaxforums.com/forums/114-maintenance-repair-articles/199396-spanner-wrench-substitutes.html


PostPosted: Wed Nov 13, 2019 4:23 am    Post subject: Reply with quote

Well I failed. The lens is still fine, but I can't get anything apart. I put on a latex gloves and tried to unscrew the lens elements. Then I borrowed a lens spanner and tried to remove the silver ring. Nothing will budge and I am applying a good amount of force. I'm not sure I want to apply anymore.