Focusing Australian Optical Co. Model 1918 Scope?

[jayhovers]

Thanks for the detailed description. I'm still stuck at my original problem, i.e. not being able to unscrew the sunshade. I've even got rubber bands around the base and shade to get a better grip with no luck. Assuming its not cross badly threaded, any ideas on getting it unscrewed?

[Warren]

check, as some have a small grove on the sun shade retaining collar. You can make a spanner wrench out of good steel to hold the shade while you CAREFULLY warm the shade at the rear. It should come off this way. Be careful with the heat!!!!!

[Peter Laidler]

Let me reiterate what Wheaty has said. Be VERY careful with the heat...................

[jayhovers]

Success - Finally. Didn't make a spanner, but instead took a piece of spring steel and shaped it around a socket. Cut the diameter to about 75% of the diameter of the scope tube then cut the male ends. Opened up the ends of the piece till it popped around the tube, then slid it up against the base. I wrapped a piece of paper under it to protect the finish. I gently clamped the steel piece then used a hair dryer on the sunshade. Now to see if I can get on target.

[Warren]

PERFECT...I should have said hair dryer or heat gun and not open flame such as a torch (and not the UK type. You'd be there along time with that type of torch..) :-)##
Assuming everyone knows what you think mean can get embarrassing. Assume: makes an *** of me and an *** of U
Sometimes it is amazing how little heat it takes to free up the brass and hardened oil etc.
Ya done good !!!!!

[Rowdy]

Yes , clearance from the lens prism is mandatory - however they played it very safe with the original tool - but very hard to make.

[Peter Laidler]

Maybe the left hand tool should be concave too. Only my opinion..........

[Craig Eberhardt]

Ah, you've all missed the IMPORTANT point chaps............. What do you want to focus RobD? If it's the grat that needs focussing, then do exactly what you have been told above, but with a degree of care.

THEN mount the telescope onto something solid, aim it onto a distant aimimg point (a DAP in Artillery parlance) such as a telegraph pole of something similar. Then move your head and eye left and right across the ocular lens and effectively across the field of view. The tip of the grat MUST stay on the same point of the DAP at all times. If it doesn't, or appears to move to the left/right or up/down, you have parallax and you'll need to focus the telescope onto the IMAGE. (Because don't forget, you are actually looking at an image that's now out of optical focus)

Then it becomes a bit more complicated.....................

Hello there,

My pattern 1918 scope is just a little out of focus. How do you suggest I go about focussing it and how will I deal with with any parallax issues? I don't want to touch it if this is going to be difficult. What range should it be focused at?

[Peter Laidler]

The answer to all your questions are contained in the thread Craig. Focus using a DAP 'some distance away'.

We focus them on a wall chart to an optical focus and you'll be suprised at the amount of pewople who say that '......it's still not focussed' You tell them that it is OPTICALLY focussed for perfect vision. They don't like to be told that even when they're in their 30's or so that it's their eyes that need looking at and not the telescope!

[Craig Eberhardt]

Thanks for you reply Peter. I will get my eyes checked and look again!