the mother of all exasperation ...

[David Lyga]

How many of you ever attempted to remove all the elements from a complicated zoom ... and lived to tell the truth?

Case in point: Vivitar 28 - 105 f3.5 - 4.5: this monstrosity has 15 elements!!!

What initially made this so frustrating was the fact that, although spanner slots were on the rear element casing, the obscene amount of pressure needed to budge this set was monumental. Mere maximum pressure was not enough. I had to place a screwdriver into one of the slots and hammer with all my strength to (finally, after multiple tries) get it loose.

Then the fun really started. In the rear, there are TWO element sets. After getting the lid off of the first, the elements were reluctant to leave their abode. THEN, all five came cascading down, ruining the careful alignment order and individual direction!. Then, more of the same with that inner set, which contained three more elements.I had ALL the elements ... but the order and direction?

Luckily, most elements align according to how the metal casing is constructed: they have to fit perfectly, without wobble. But there still are countless ways to order these and I invented new four letter words in getting this accomplished.

It is Sunday morning at 8 AM. I worked on this for SIX hours yesterday and, today, after a needed night sleep, worked for THREE AND A HALF more. Almost ten hours to set right a $20 lens. (And some people think that I am intelligent!!!!)

There are many configurations whereby the lens is ALMOST sharp, but there are tell-tale signs of misalignment when you have halos at the far corners. We KNOW that wide open there will not be tack sharpness in the corners, but we also know that those corners have to be at least reasonably sharp wide open. Two stops down, I can finally say that I 'have a lens' in that it 'justifies' the whole day of work.

NOTA BENE: Always be obsessive when taking apart one of these types of lenses. You will save much time and will not have to require Merriam Webster to modify its lexicon with the colorful terms that you newly invent. - David Lyga

 

[Dali]

Like a lot of things in life,it is question of knowledge and experience, no magic.

https://www.lensrentals.com/blog/20...plicated-sony-fe-70-200mm-f2-8-gm-oss-part-1/

 

[ic-racer]

I dropped my coveted 28mm f2 Distagon in 2009 and spent quite a few hours trying to get it apart. I set it aside and in 2015 I re-assessed the problem. The front ring unscrews, showing the screws for disassembly.
This lens is not a zoom, but it does have TWO HELICOIDS. The second helicoid, for the moveable front element, was difficult to get re-aligned. I had to assemble it and do actual film tests looking at the frame edges, to see if I got it correct. Good news is that when the front helicoid was off by only one groove, the edges were very blurry and it was clearly obvious.

BTW the actual repair of the bent housing was quite easy, it was just a slight bend in one of the three 'feet' holding the inner mechanism together.

 

[AgX]

This lens is not a zoom, but it does have TWO HELICOIDS. The second helicoid, for the moveable front element, was difficult to get re-aligned. I had to assemble it and do actual film tests looking at the frame edges, to see if I got it correct. Good news is that when the front helicoid was off by only one groove, the edges were very blurry and it was clearly obvious.

Did you not learn at Apug to mark that helicoid orientation when coming apart...?

 

[ic-racer]

Excellent question. The main helicoid, was of course marked, but the secondary one is very fine, you can see that in the picture from post #3. My 'index mark' was the "Z" which you can almost see is aligned with the slot right below it. The helicoid was very difficult to detect when it was engaged at the correct spot. In the second picture of post #3 you can see the index lever which engages the slot under the "Z." (looks like a white line at ten-o'clock).

FYI: On this lens the front element spins as you focus, but the outer housing which holds your filters, does not spin.

After that whole experience, I'm not so bothered that my 50mm Distagon for the 6008i has a MANUAL ring for setting the front element (it is not connected to the main focus).

 

[removed account4]

Hi David
That does sound fun !
The funnest lens I have taken appart and barely gotten back together again was a Wollenston Meniscus. Thankfully I took notes !
John

 

[Cholentpot]

I have a perfect condition yashica minister. The only issues is the rangefinder is out of sync. I spent hours and hours trying to move the #&*!^#$ screws to get it set up. I don't what they did in the factory but it won't budge. I gave up and now it sits in it's case shaming me.

 

[NB23]

I’m such a clumsy man, I’m only capable of screwing and unscrewing a rear lens cap. Every time I have tried a repair I either had to throw the whole mess in the garbage, or ziploc the whole mess and send it to a repairman.

Good luck

 

[GRHazelton]

David, you have more courage than I do! I salute you and wish you good fortune in reassembly. Seriously, perhaps looking for another such lens in good condition might be the best option.

 

[Eric Rose]

I fixed an old Olympus WA lens once. Very frustrating. Not my idea of fun.

 

[Vincent Peri]

The only lens I ever took apart was a Nikkor 105 f/2.5 that had a spot of fungus on an internal element. Fortunately, the lens element in question was easily accessible once the lens was apart and I could remove the "fresh" spot of fungus... no lens etching was apparent. Also, none of the elements were jostled out of place. With a little tinkering, I got everything back, good as... well, I was going to say "new." But the jury's still out on that.

 

[David Lyga]

I’m such a clumsy man, I’m only capable of screwing and unscrewing a rear lens cap. Every time I have tried a repair I either had to throw the whole mess in the garbage, or ziploc the whole mess and send it to a repairman.

Good luck

Perhaps you would not feel so singularly clumsy if I showed to you my graveyard of parts, accumulated over the years, from failed repair episodes and attempts. - David Lyga

 

[David Lyga]

David, you have more courage than I do! I salute you and wish you good fortune in reassembly. Seriously, perhaps looking for another such lens in good condition might be the best option.

I am too frugal for such 'waste'. - David Lyga

 

[David Lyga]

NOTA BENE: My 'success' with success might be a bit off. The problem is that there are multiple configurations that present a decent image. For example, whether the real element closest to the aperture is turned one way or the other, presents about the same level of resolution. Thus, there is a quandary of whether it is 'this way' or 'that way'. And there are other configurations which seem to also be OK. I want as much correction as I can get and, other than undying and ongoing frustration, the alternatives with 15 elements are somewhat overpowering. But, until I get sick of this, I will persist, taking careful images with each new configuration (noted carefully on paper). Most alternatives are not even attempted (for example), putting two convex elements together without there being a metal spacer, is impossible and not even attempted. Putting a concave lens next to a convex protrusion larger than the space allowed for in the concave lens creates wobble and, thus, is not possible. So, at least I have something to start with but one thing I will banish, forever, with such future attempts, is to NEVER rush taking apart one of these monstrosities. - David Lyga

 

[KN4SMF]

Throwing away a piece of photographic or radio gear, or any other such "vintage" equipment completely goes against my religion. At the same time, there's a lot of third party zoom lenses that should have never been manufactured in the first place. They are such total junk. On occasion I've been known to just chunk them on sight, unless I'm selling a camera and can just "throw it in" with the deal, just to get it out of the house. In general I would never even bother to carry or use any zoom lens. To me, they're ALL 43-86 Nikkors.

 

[benjiboy]

How many of you ever attempted to remove all the elements from a complicated zoom ... and lived to tell the truth?

Case in point: Vivitar 28 - 105 f3.5 - 4.5: this monstrosity has 15 elements!!!

What initially made this so frustrating was the fact that, although spanner slots were on the rear element casing, the obscene amount of pressure needed to budge this set was monumental. Mere maximum pressure was not enough. I had to place a screwdriver into one of the slots and hammer with all my strength to (finally, after multiple tries) get it loose.

Then the fun really started. In the rear, there are TWO element sets. After getting the lid off of the first, the elements were reluctant to leave their abode. THEN, all five came cascading down, ruining the careful alignment order and individual direction!. Then, more of the same with that inner set, which contained three more elements.I had ALL the elements ... but the order and direction?

Luckily, most elements align according to how the metal casing is constructed: they have to fit perfectly, without wobble. But there still are countless ways to order these and I invented new four letter words in getting this accomplished.

It is Sunday morning at 8 AM. I worked on this for SIX hours yesterday and, today, after a needed night sleep, worked for THREE AND A HALF more. Almost ten hours to set right a $20 lens. (And some people think that I am intelligent!!!!)

There are many configurations whereby the lens is ALMOST sharp, but there are tell-tale signs of misalignment when you have halos at the far corners. We KNOW that wide open there will not be tack sharpness in the corners, but we also know that those corners have to be at least reasonably sharp wide open. Two stops down, I can finally say that I 'have a lens' in that it 'justifies' the whole day of work.

NOTA BENE: Always be obsessive when taking apart one of these types of lenses. You will save much time and will not have to require Merriam Webster to modify its lexicon with the colourful terms that you newly invent. - David Lyga

Why oh why do photographers think they can also fix photographic equipment ?, I consider the costs of having my equipment professionally maintained occasionally as part of the expense of being a serious photographer which is probably (although it was all bought second hand) why it's still working fine after using it for more than thirty years.

 

[Luckless]

Haven't played around with a complex zoom yet myself, but I greatly enjoyed watching a friend trying to clean one up a few years back.

Forget the model, I think it was a semi-recent Nikon, but he learned the hard way while trying to unscrew a set of elements that threading comes in both left and right styles...

Why oh why do photographers think they can also fix photographic equipment ?, I consider the costs of having my equipment professionally maintained occasionally as part of the expense of being a serious photographer which is probably (although it was all bought second hand) why it's still working fine after using it for more than thirty years.

Because some of us are mechanics, engineers, and other professions with similar backgrounds, and are more than capable of working in and learning about more than one subject in life?

 

[choiliefan]

I've read that some manufacturers use a thread-locker which must be thinned with solvent before the elements can be unscrewed.

 

[AgX]

Because some of us are mechanics, engineers, and other professions with similar backgrounds, and are more than capable of working in and learning about more than one subject in life?

... or have tinkered with mechanics since childhood days. This of course does not make you a camera repairer but is a good starting point to be added by textbooks, service manuals and ... trial & error.

 

[AgX]

I've read that some manufacturers use a thread-locker which must be thinned with solvent before the elements can be unscrewed.

Worse than that are screws that are reverse threaded.

 

[Dali]

Worse than that are screws that are reverse threaded.

Why would someone would do this in a lens?

 

[AgX]

I do not remember such at a lens (but would not be really surprised either) but at camera bodies there are such.

The main reason for such is a screw that holds a lever or similar that only in one direction is moved under such force that it may by friction turn loose a standard screw.

 

[bernard_L]

Save the elements for some future tbd "project"; Save the focus helicoid for your next DIY camera. In that way, you can rest assured that this zoom has not lived and died in vain, and you sleep without remorse. Bonus: lessons learned.

 

[MattKing]

Why would someone would do this in a lens?

To prevent one thing from loosening while another is being tightened?

 

[Luckless]

To prevent one thing from loosening while another is being tightened?

They can also serve to help sell a new lens to someone who was too cheap to send a slightly damaged example off to be seen by qualified service techs...