Mirror Cool Down and Thermal Properties

[Black Shuck]

Once I realised early on that the three screws at the mirror end of my Newt were holding on a dust cap/cover. I removed it to reveal the collimation screws. I wondered at the time if there would be any benefit in leaving the end cover off during viewing. I was thinking in terms of cooling down speed. I was reluctant purely on the grounds of vulnerability of the mirror.

I have just started reading the book that Gaz reviewed - "Lunar and Planetary Webcam User's Guide - Martin Mobberley" and he states that there is great benefit to be had by removing the end cap and considers it essential in terms of cooling and thermal/air currents in the tube.

Do any other Newt owning members have views or experience of this and can you offer me any advice?

Cheers

Bill£

[FLO]

I don't think that it serves any purpose other than cosmetic. If it were mine, I'd leave it off.

[Astroman]

Leave it off, unless you want to mount a fan on it.

[Kaptain Klevtsov]

I usually leave mine off except for very long exposure imaging. The computer screen can shine up the wrong end with the cover off and that's not good.

Captain Chaos

[Merlin]

I don't cover the back of my mirror,except when it's stored away to keep spiders out.. I do have a cover over the front surface of the mirror though. This meant cutting a hole in the side of the main tube and fitting a hinged door.