Leaving the cap off?

[AMcD]

Over the past few AP sessions I have noticed when I review the guiding data in the morning that I have peculiar spikes in the guiding for no apparent reason.  I have now found the reason.  I have a homemade automated scope cover to enable me to cover the scope remotely via the focuser port on the Pegasus Powerbox when I have finished a remote session (picture of the mechanism mounted atop the telescope below).  This evening I noticed that when open the cover catches the wind!  Hence the spikes in the guiding.  

Until I come up with another solution, is there any real harm in leaving an achromatic refractor with the cover off in the observatory between sessions?

[vlaiv]

1 hour ago, AMcD said:

Until I come up with another solution, is there any real harm in leaving an achromatic refractor with the cover off in the observatory between sessions?

Possible dust buildup on the lens.

Lens is always exposed to dust - cover or not. Question is how big is the level of exposure. If you leave it like that for a few days - you probably won't notice it, but there will be a bit more of it then otherwise.

That however does not impact quality of the views / images, and can be removed with bulb blower, special cloths and lens cleaning liquids from time to time (just be careful - hard bits of dust when wiped away aggressively can scratch the lens and/or coatings on them - that is not something you want).

[AMcD]

12 hours ago, vlaiv said:

Possible dust buildup on the lens.

Lens is always exposed to dust - cover or not. Question is how big is the level of exposure. If you leave it like that for a few days - you probably won't notice it, but there will be a bit more of it then otherwise.

That however does not impact quality of the views / images, and can be removed with bulb blower, special cloths and lens cleaning liquids from time to time (just be careful - hard bits of dust when wiped away aggressively can scratch the lens and/or coatings on them - that is not something you want).

Many thanks.  I engaged in a bit of mid-session re-engineering last night and removed the cap, which eliminated the guiding spikes.  I will now have to turn my mind to an alternative remote solution...

A