Could not focus with 10mm EP last night

[jonathan]

I don't know if it was just the atmospheric conditions, it was extraordinarily warm last night, but I just could not get my 10mm to focus in the 8SE. 25mm and 38mm seemed fine. Could it have been a bit of mist on the diagonal mirror?

I was able to distinguish two bands and a spot on Jupiter with my 25mm so I don't think there was anything drastically wrong, just with the 10mm. Strangeness.

[Chris H]

10mm ep in your scope gives you x203 so was most probably atmospheric conditions. I find around x130 is just about perfect for Jupiter.

[John]

As well as the seeing conditions there is a lot of dew about at the moment - sometimes you only notice that the corrector has started to dew up when you can't focus properly. A dew shield / dew strip is practically mandatory with SCT's and Mak's in the UK.

[nightfisher]

bad seeing last night, i stuck at 32mm and 25mm ep with my scope (2000mm f/l) dont think i would have done much better

[jonathan]

Ah right, so despite it looking clear there must have been a lot of moisture still in the air? It wasn't dewing up at all, I had my dew shield on and that is usually the first thing to acquire dew on the outside, it was all bone dry; also heaters were on just in case.

I have noticed that despite it being a new moon and devoid of clouds, the sky still looks surprisingly light and grey.

[M4lcs67]

I put things down to poor seeing conditions last night. It has been unbelievably warm these last few days. I was looking at Jupiter last night and I acually had the best view with my stock 25mm ep. I did try using the 9mm with Barlow and if was just a blurr with no definition.

[Stu]

Exactly the same experience for me. Had a good session, but was unable to get above x 150 and even below that there wasn't too much detail to be had on Jupiter outside the main belts, and the Io shadow transit of course :-)

Stu

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[jonathan]

I think it was slightly better seeing last night, but still very warm. Difficult to tell really as I was using my ST80 instead of 8SE.

[Jarvo]

I struggle to get a sharp view with my 8mm Radian / Mak combo - needs to be spot on conditions.