Considering Williams optics flt132 - anything to look out for?

[yoda776 (Matt)]

Thanks John for the review reference.

Originally Posted by John W

Hi, I have a WO 81 mm GTF refractor and its been great. A really solid scope and terrific optics. See review on this web site under Equipment reviews > Telescopes. Cheers, John W.

[casstony]

Originally Posted by yoda776

... the steel tube in the new version is better than the aluminium due to coping with temperature ranges better. .

It's the cell which the glass elements are mounted in that's either steel (newer) or aluminium (older models). Since Aluminium shrinks more than steel in falling temperatures, the Aluminium cells can pinch the glass in cold temperatures. I think they switched to steel in 2013.

[Wavytone]

Well ... there's now one for sale right here on IIS classifieds...

[yoda776 (Matt)]

Thanks for the heads up.

[yoda776 (Matt)]

Thanks for the clarification on the 'steel' component.

Originally Posted by casstony

It's the cell which the glass elements are mounted in that's either steel (newer) or aluminium (older models). Since Aluminium shrinks more than steel in falling temperatures, the Aluminium cells can pinch the glass in cold temperatures. I think they switched to steel in 2013.

[Wavytone]

Williams aren't the only manufacturer aware of differential expansion between glass vs lens cell - both my APM scopes have cells with temperature compensation and I would expect others do likewise for premium scopes.

[yoda776 (Matt)]

Thank you for the info. I have found that out in my investigations / research of various manufacturers. It has been a great learning experience.

Originally Posted by Wavytone

Williams aren't the only manufacturer aware of differential expansion between glass vs lens cell - both my APM scopes have cells with temperature compensation and I would expect others do likewise for premium scopes.