[bullseyebolton]

Hi, I have just bought an older Pentax 10x24. When I look backwards through one of the lenses I can see lots of grime and dust built up on what looks like a mirror or piece of glass in the middle of the unit. So, given that this was so cheap I thought I would risk it and dismantle the case to give the inside a clean up. The problem is that I cant even see where to start taking the unit apart to get inside? Can anyone help? I will post a photo of the unit soon. Thanks.

[bullseyebolton]

some pics of the pentax

[Kevin Purcell]

You can see the seam of the enclosure in the photo. I presume there are either screws under the faux leatherette (which you would have to remove) or the case is cold welded shut (less likely I think).

At your own risk. I don't see eccentric rings on the front (though they may be there) but you will have to recollimate the bins if you can reassembled them. And then you'll need to replace the faux leatherette.

Do they move the objectives to focus?

[etudiant]

What is your time worth?
If you got them dirt cheap, think of the grime as part of the package.
Unless the view is very badly impaired, which in most cases really requires that the prisms be fungus covered, there is no visible gain from cleaning the inner surfaces.

[bullseyebolton]

Well, thank you so much for your advice. Curiosity got the better of me and I just could not resist opening up the unit. I found the screws under the leather patches as you suggested. There were two prisims inside. I could clean one without removing it. The other one I had to remove to clean. Putting back the prisim and getting the alignment right was a real pain and this took me about an hour of mucking around to find the right alignment. After all my efforts I can say that that lenses are cleaner to look through, however, as you mentioned, when looking at objects you cant really tell that the dirt has been removed. Anyway, was an interesting exercise, thanks for the advice.

[Kevin Purcell]

Is the collimation all in the prisms?

Could you just unclip the prisms and then add them back without any movement in their holders?

[etudiant]

Impressive.
You did better than I would ever have expected and you did it quickly.