Dew Shield / Hood for Newtonian Reflector

[Bernard254]

Hello - I have recently purchased a Sky Watcher 150P-Ds on an EQ5, I have added the dual motors. Initialy I will only be observing, but eventually I would be looking to dabble with AP. After reading many articles on the internet, I have found confusing information re hoods / Dew shields for Newtonians reflectors. My question is, a hood / dew shield on a Newtonian reflector should not have much influence on the dew aspect becasue of the primary is at the bottom of the tube ? but does it have any benfit with stopping stray light on a Newtonian and is there any advantage in buying one or would I just be wasting my money ?

I look forward to hearing your opinions

thanks Kev

[Gweedo]

I think that the general opinion is that closed tube newtonians don't really need dew shields and that they don't offer any benefit with regard to stray light. On my flex tube I've made a foam shield to fit the middle section as this should stop stray light impinging on the mirror as the lower tube is not that long and close to the ground; so there is the possibility that street lights could shine directly on the mirror.

Flocking the internal surfaces of the tube seems to be the accepted solution for increasing contrast.

[brantuk]

The primary is well protected from dew at the bottom of the tube - but the secondary at the top can mist up quick if it's a dewey night. A dew shield will retard the process quite a lot - but some folks add a secondary heater to keep it clearer for longer

[Bernard254]

Hello - thanks for your advice - much appreciated

Kev