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Helios 135mm f2.8 disassembly
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PostPosted: Mon Feb 23, 2015 9:45 pm    Post subject: Helios 135mm f2.8 disassembly Reply with quote

Hi guys,

I want to open this lens to clean the front glass inside. I screwed the info ring off, but behind it there was no any screws to go further so that I can take the glass off.

Does somebody have an idea how open this lens with the simplest way?

Thank you!

Caitya


PostPosted: Mon Feb 23, 2015 10:49 pm    Post subject: Reply with quote

The front element also screws out, there is no retaining ring. I used a M42 rear lens cap with a 4mm thick rim and covered the rim with double sided tape which I trimmed off with a craft knife just leaving a 4mm ring of sticcky tape. That easily removed the trim ring and the first element.
I used double sided tape as I didn't want to use anything that might slip on the lens and damage the coating, the sticky tape turned the lens easily and the residue of the glue cleaned off easily with lighter fuel.
You might find the element will turn by hand if you wear rubber gloves, it's not tight.


PostPosted: Mon Feb 23, 2015 10:53 pm    Post subject: Reply with quote

Hi,

Thank you for your fast answer. You mean screwing the glass off? Or there is another ring to screw off before the glass?

Lloydy wrote:
The front element also screws out, there is no retaining ring. I used a M42 rear lens cap with a 4mm thick rim and covered the rim with double sided tape which I trimmed off with a craft knife just leaving a 4mm ring of sticcky tape. That easily removed the trim ring and the first element.
I used double sided tape as I didn't want to use anything that might slip on the lens and damage the coating, the sticky tape turned the lens easily and the residue of the glue cleaned off easily with lighter fuel.
You might find the element will turn by hand if you wear rubber gloves, it's not tight.


PostPosted: Tue Feb 24, 2015 12:01 am    Post subject: Reply with quote

there's no retaining ring - there's a ring attached to the outside of the actual glass element. I would try rubber gloves and use your thumbs to push the lens, I think it will unscrew.


PostPosted: Tue Feb 24, 2015 12:14 am    Post subject: Reply with quote

Sorry for my stupidity but still don't get fully what you're saying. Probably I don't understand the technical words. What is the difference between the retaining ring and the simple ring?
Yes, there is a ring outside of the lens. The lens is spinning. What will be unscrewed? The glass itself or the ring?

Lloydy wrote:
there's no retaining ring - there's a ring attached to the outside of the actual glass element. I would try rubber gloves and use your thumbs to push the lens, I think it will unscrew.


PostPosted: Tue Feb 24, 2015 12:57 am    Post subject: Reply with quote

I 've just taken the front element out of mine - it's slightly different to what I described before, it's been a while since I did it before.

The name ring screws out, underneath the name ring the front element does have a retaining ring - which is the ring around the glass about 2mm wide. The ring has no holes or slots for a lens spanner, it has an internal thread so it does not use the same thread as the name ring. So a friction tool has to be used to remove the retaining ring. The lens is convex and is above the level of the retaining ring so a tubular type of friction tool must be used to avoid marking the glass. Which is why I used a thick walled M42 rear lens cap with some double sided tape on the rim. It works for the name ring and the retaining ring. Once the ring is out then the lens and a spacer under the lens will come out

I can post pictures tomorrow if that will help?


PostPosted: Tue Feb 24, 2015 3:09 pm    Post subject: Reply with quote

I see it now. Thank you very much!


PostPosted: Mon Oct 25, 2021 8:01 pm    Post subject: Reply with quote

I'm trying to disassemble the front element on this lens and it's just spinning. I can't seem to get any thread when I turn the lens. Is this normal? Is the thread stripped?