Poor viewing last night

[LaurenceT]

I set up last night in the usual way, Evoguide 50ED with dew strap in place, asi224mc with uv/ir cut filter on an Az GTi using Stellarmate. After the usual Stellarmate nonsense I got images of things like the globular cluster in Hercules just fine but any attempt on a gaseous or planetary nebula was an utter failure from an image point of view. Whereas in my last session a few weeks ago I was getting lovely images of these objects very quickly but not last night, just a light fuzz to show I might be there.

Target acquisition seemed perfect and bizarrely I got Jupiter dead centre and although no more than a large dot I saw 3 moons and Jupiter surface features. The one thing I noticed was that everything was quite wet and a quick check showed that humidity here was 93%. Could this have been a factor? 

[Ouroboros]

Certainly, @LaurenceT.  Here in Oxfordshire I decided it was a binocular night. Jupiter and bright stars like Vega were sitting in a halo of glow.  Pity because looking at the long term forecast, last night was the only one that offered the prospect of being clear for the foreseeable. 😐

Edited October 23, 2023 by Ouroboros

[PeterC65]

My last EAA session was as you describe towards the end, and I put that down to condensation on the optics (there was no cloud but the kit was soaking wet when I brought it in).

I do also find that I get the same effect when there is light cloud around. Sometimes the image starts to get fuzzy and the background sky brightens, and when I look outside it's because light clouds have appeared.

 

[tomato]

I couldn’t image from Shropshire last night. The first couple of subs were OK but then the guide star SNR dropped by 50% and the target all but disappeared. Humidity in the dome was 98% when I closed the shutter and the dehumidifier had to work really hard to dry it all out.