A not very impressive M27

[powerlord]

Hmm, so clear skies last night, and clear outside app said dew point much lower than temp.. but within an hour tons of dew all over C8. cleaned/dried and made a dew sheld from a couple of bits of paper, but only got 30 1 min subs before it dewed up again.

is app wrong ? For my 72ED, I have a dew heater but I can't see even a bigger one working with the Celestron C8... is it worth getting one ? would have thought a wee usb mini fan or something might work better ?

Anyway.. ASIAIR crashed on AP too so took me 90 mins to set up.. and couldn't work out why it thought my FL was 1258mm.

It was only at 3am when I came down and cleaned off dew and had a go at saturn that I realised I'd left the fecking reducer on it...which also explained the vignetting with my 6d. duh.

I was getting nice clear view of saturn then but tiny, so thought I'd flip 120mm mini over from guide duty and try for some shots.. took a while to get focus, and then asiair kept crashing every time I put it into video mode. I then bumped asi120mm off focus and decided I'd had enough and went to bed. Pity though - but I'll be prepared next time and have pre-setup my asi224 for saturn.

anyway - 30 mins on M27 with a full moon at nearly the shortest night of the year, with an OTA I've only just bought and this is it being used at first time.. with antares .67 reducer.

Frankly I'm surprised I got anything with that comedy of screwups.

And today all my new asi1600 related toys arrived!!! but that's another story.

[Padraic M]

Treat yourself to a dew heater and shield for the C8 🙂 . On my first night with my C8, I was completely dewed up after about 20m minutes. Bought a heater strap and shield and haven't had an issue since.

Enjoy all your new kit!

[tomato]

Considering your trials and tribulations, that’s a nice M27, great colour. It does look to me like the data is black clipped, though no doubt shooting on the shortest night of the year and a full moon, you were battling the light background.

On my Celestron RASA which has the camera attached to the corrector plate, the fan in the camera is enough to keep the dew off, so a fan built into the dew shield could work. I bet a SCT owner has already tried this…

[powerlord]

oh yeh, sorry it was so poor I didn't do much processing - I just used affinity remove background and didn't do my usual of pulling the black up - there was no much light pollution, especially at the bottom that it I just hacked into it basically.

I resent paying more that 5 quid for a 'dew shield' - which is just of plastic with velcro on it - I'll make one myself.

dew heater - huh. wouldnt have thought it could do anything useful with that big top glass. Ill have a look then - though does feel to me a wee fan would work as well if not better.

 

[powerlord]

Dew Shields - I've ordered a 2mm black sheet of correx. Can make dew shields for all 3 of my main scopes with one 15 quid sheet. will just sew some velcro onto it.

40 odd quid for a dew shield... they're 'avin a larf.

[Tiny Clanger]

£15 ? Pfft 🙂

Wickes Proplex sheet £3 https://www.wickes.co.uk/Proplex-Black-Surface-Protection-Sheet-1200-x-1000-x-2mm/p/151157

Not that  I'd use corriflute type stuff myself, I don't like the not-a-proper-curve thing as it bends only along the channels ,  being a plastic version of corrugated card.

Instead I went with 3mm closed cell foam https://www.efoam.co.uk/closed-cell-polyethylene-foam.php  1m x 1m for £11 (except, who could resist a second 1m x 1m for just another £3.71 ? Not me . Handy stuff to have .)

Heather

[powerlord]

that looks better to be sure. well its ordered now. Plus you seem to have linked to some sort of establishment which requires my physical presence, and then requires some sort of manual exchange of goods at that physical location ? I can't see that ever catching on personally. 😜

Do you wrap dew heater inside of dew cover or outside ? I mean, inside best, but then gonna make dew cover more wobbly ?

[Padraic M]

fwiw, I put my dew strap behind the plastic rim, and under the vixen plate; and the shield over the plastic rim. It may also go over the dew shield depending on how you make it. Hopefully this makes sense with the picture below - strap in blue position, shield in red. Doesn't seem to make sense to have the strap outside the shield.

You're right in that the shield can be a bit shakey; it will stay in position as long as you don't use it as a handle. I haven't resorted to sticking velcro to the scope itself.

[jacko61]

I have one of RVOs 12 volt heat bands on my C8 - RVO Heater Bands With Integrated Controller - Rother Valley Optics Ltd  Works a treat. Keeps the front glass perfectly clear even without the big plastic dewshield. 

It fits just behind the front ring under the 2 vixen rails so not underneath the dewshield at all (although I'm thinking of extending the slots for the vixen rails an extra inch to make the shield a bit more stable.

edit: Padraig's picture shows just what I meant except I have a second vixen at the top for my guidescope.

Anyway, your M27 looks pretty impressive to me

Graeme

Edited June 24, 2021 by jacko61