Eyepieces, finder, and dew prevention

[scoobymike]

Last night I finally got my new (to me) SW 127 SkyMax on an EQ 3-2 mount out for a few hours. I drove down to Chiddingfold and found a nice dark field to set up in, polar aligned, and went to see what I could see. This is my first scope and I was pleasantly surprised by what was available - the double-double by Vega (JUST!), M13, M56, M31 and one of its' companions, Jupiter with banding in fairly low skies, and more.

My fleabay purchase has shown some gaps in supplied equipment though, and I was wondering if anybody has any thoughts on the following please...

Finderscope - I currently have a red dot finder, which is ok if you know exactly where you're looking, but I really dont! I use binoculars to try and find things, then look for guide stars to get me there in the RDF. What I'd really like is a finderscope that lets me do without the binos. Skywatcher do a 6x30, or a 9x50, but I have no idea what that means, or which would be best for me?

Eyepieces - I have a set of Skywatcher Long Eye Relief EP's in a case, cheap and nasty ish I know, but thats what I got. The 15 and 20 mm are ok, the 5 and 2 are useless as expected. In a scope with such a long focal length, I'm thinking a decent 9 or 10 mm for my high power, and maybe a 32mm for a low power wide view, and then replace the middle power ones later. But which? Will I get much benefit from a 10mm televue nagler at 230 quid over a super plossl at 80 quid? And at that magnification does the extra FOV make much difference? And in the 32mm, should I really be worried over a basic super plossl standard?

Lastly dew prevention... At about 2 am the front corrector got covered in dew. Now I know I'm not meant to wipe this very often, but on your first night out when all that's stopping you is a little water?! So what would be the best way in future to prvent dew from building up? I've read a camping mat foam rolled into a tube could work - good idea?

Lots of questions I know, but then I've had a great first night out, and want to get rid of the obvious headaches before my next one at the weekend.

Thanks,

Mike

[michael.h.f.wilkinson]

9x50 means 9x magnification and 50mm aperture (much better than 6x30). If possible get a RACI finder (Right Angle Correct Image). This will save you no end of back strain or twisting your neck into all sorts of horrible ways.

EPs: Your scope is F/12, so it is quite OK with lower grade EPs. Plossls will show much less sky than a Nagler, however. You could also look at cheaper ultra wide angle EPs. The 2mm is idiotic to supply with any scope slower than an F/4 in my opinion, as it gives WAY to much magnification. The 5mm is less obviously wrong, but the rule of thumb is that an F/12 scope has an optimum magnification at 12mm focal length of the EP, and a maximum at double the magnification (6mm EP). I would think a combination of a 12 and an 8mm decent quality wide angle EP would be great for you scope.

Dew: just make a dew shield from some foam (like a cheap camping mat). I have the official Celestron dew shield (just because my parents gave it to me, otherwise I would have made it myself) and it works a treat, even after 6 hour sessions.

[scoobymike]

Hi Michael,

Thanks for the reply, I found it very useful.

Following your advice I've looked at the following eyepieces; Baader Hyperion 68 degree eyepiece at 8mm, and Meade Series 4000 Super Plossl at 12 mm. I've also decided I will get the SW 9x50 with the corrector. Do you think these EP's are suitable, or if you were looking for similar, would you choose something different? And do you think price point is ok (ie am I spending too much, or would I be better spending more)?

Thanks,

Mike

[michael.h.f.wilkinson]

Hyperions have a good rep, don't know the Meade Series 4000. Plossls tend to have very short eye relief (10mm on a 12mm focal length), which is uncomfortable, especially when wearing glasses. You cold go for the 13mm Hyperion, which has 20mm eye relief. The BST Explorer 12mm (60 deg) has a good rep, and is very cheap.

[deepspacehunter]

I have found that a piece of rolled cardboard (some people may laugh) attached to the end of the tube works very well against dew... the cardboard will attract the dew and I have used them on all of my telescopes for the past 20 years...you can make them where they will fit snuggly on the tube or if you like, you can bungee chord them on... very inexpensive and they do the trick well.....

[michael.h.f.wilkinson]

The only reason to prefer foam over cardboard is that some cardboard gets soggy. Otherwise there is no difference.

[scoobymike]

Thanks,

I've bought the finder scope from FLO, and having read a couple of reviews, am going for the BST 8 and 12, as I can always send them back if I'm not happy!

Thankyou for your time and help, it's been much aprreciated!

Regards,

Mike

[scoobymike]

I can get foam in pretty colours too

[michael.h.f.wilkinson]

I can get foam in pretty colours too

Any colour will do, as long as its black inside. Reminds me of the pink newtonian scope on the forum some time ago.