I hope there is no damage

[dugun]

I am told that somebody, let's call the cat felt my lens. Fortunatly the lens is still in its original packing and the landing  was from a short distance and soft. The lens was rattling in its cell, I saw that the fastening rings was loose. I tighted them gently and the rattling stops. But I don't now if the spacers are still  in their original position. I hope there is no damage 

Thanks,
Demir

[nobody]

Hi Demir

It seems very odd that the cell locking ring should have worked loose in the post.
Fortunately, the lens spacers are very unlikely to shift due to vibration.
Nor even the cell being dropped in the packaging by the postal service.
The spacers have no real mass to respond to shaking or even rapid deceleration.
Nor are they likely to have the freedom to move while under pressure from their glass "sandwich."

Don't ever over-tighten the lens locking ring. It is NOT necessary NOR desirable.
There should usually be just a little room for the glass to shake unless the cell is provided with thermal protection 'O' rings.
Otherwise large temperature swings could put pressure on the glass from the enclosing cell.

Glass and aluminium have very different thermal expansion characteristics.
When the cell shrinks in the bitter cold of winter there must always be enough room for the glass.
Glass hardly contracts at all compared with the metal of the cell.
The glass lens elements must always be free enough to exist in their optically perfect form without any external pressure.
It used to be said that you should be able to just hear the glass rattle very slightly when the cell is shaken in the hands.
Enjoy your classical f/15 iStar refractor and let us know how it performs.

[dugun]

Thank you nobody.
I'll post a picture, even the building process of my folding refractor here on İstar Scope Club.

Ragards
Demir

[nobody]

Aug 31, 2015 10:51:51 GMT -5 dugun said:

Thank you nobody.
I'll post a picture, even the building process of my folding refractor here on İstar Scope Club.

Ragards
Demir

Thanks Demir

We'll look forwards to seeing your creation and creativity.