Skywatcher pyrex mirrors ?

[knobby]

Hi all

I've gone really off the rails ... looking at changing my scope for something lighter - maybe a Mak,

My 150 will hopefully be gone by Tuesday so all going well I'll be ordering Wednesday, now seriously looking at the 10" skyliner, i know ... aperture fever strikes again !

What is the benefit of pyrex ? is it lighter? the Skywatcher site mentions faster cool down times too.

Really appreciate your opinions

Many thanks

[paul schofield]

I may be wrong but from what I have read the only difference is they cool quicker. Dont know if the quality of mirror is any better, probably though because they cost a bit more.

[JamesF]

I don't believe the difference is that they cool more quickly, but rather that they are more stable as temperature changes (ie. expand/contract less) and thus are more tolerant of temperature difference.

James

[LukeSkywatcher]

I don't believe the difference is that they cool more quickly, but rather that they are more stable as temperature changes (ie. expand/contract less) and thus are more tolerant of temperature difference.

James

I think its a bit of both to be honest.

[Dave Dubya]

Pyrex changes little with temperature and distorts less due to increased strength over non-borosilicate glass.

I think most telescopes will have mirrors/lens made from Pyrex or other borosilicate glass nowadays.

[knobby]

Cheers all

[knobby]

Also what are your thoughts on fitting cooling fans ?

should they blow in or suck out ? left on or turned off when cooled ?

Are they worth it at all ?

thanks again peeps

[Tinker1947]

They might make a difference, they may cause vibration, they might not do much at all, me i wouldn't bother just stick it out side to cool for a hour...