Another silly question

[emyliano2000]

Hi again,

Even though I'm using a dew shield on my sw 200p the secondary mirror keeps dewing up during the course of an imaging session. Would a dew heater wrapped around the stalk of the secondary affect my images? 

Emil

[MarsG76]

It shouldn't... try to add a fan at the back behind the primary mirror blowing at the mirror, might also help with the dew. 

[emyliano2000]

5 hours ago, MarsG76 said:

It shouldn't... try to add a fan at the back behind the primary mirror blowing at the mirror, might also help with the dew. 

I already did that and the secondary is still dewing up.

[wimvb]

I have a small diy dew heater strapped around the stalk, and haven't had dew since. The cable is attached to one of the spider vanes and doesn't affect the image.

[emyliano2000]

1 minute ago, wimvb said:

I have a small diy dew heater strapped around the stalk, and haven't had dew since. The cable is attached to one of the spider vanes and doesn't affect the image.

It doesn't affect the imaging causing weird star shapes or anything else, is it?

Emil

[wimvb]

Not noticed any difference. It may cause shorter diffraction spikes, but haven't seen this in my images.

[MarsG76]

17 hours ago, emyliano2000 said:

I already did that and the secondary is still dewing up.

 

16 hours ago, wimvb said:

I have a small diy dew heater strapped around the stalk, and haven't had dew since. The cable is attached to one of the spider vanes and doesn't affect the image.

Excellent... I got some dichrome and was going to attach it to the back of the secondary in some heat shrink to stop the secondary from dewing up powered by a rechargable 6Ah battery... running the cables same as winvb done, along one of the spider veins.