First light(ish) with forum bought 150PL

[tallstevef]

Hi All,

After a couple of familiarisation setups I finally got around having a proper attempt at viewing using my forum bought 150PL (Thanks to Pete for all the notes and advice on purchase - a credit to the forum!).

On the plus sides - I did manage to see Jupiter and the 4 moons - this was (I think!) using the 25mm eyepiece which gives a lower magnification? What I saw was broadly the same as the view I had at a local astronomy club viewing session through their 200 Dob.  I think I could just make out the cloud bands but the image was v.small when I was viewing last night.  Somewhat confusingly when I swapped to the high mag (10mm eye piece?) I couldn't see / find Jupiter at all - maybe it had moved, or maybe something else?

What I have learnt is that alignment of the finder scope is critical - my first attempt didn't use one at all and I couldn't see anything.  I thought that wherever the scope was pointed I should see something, but the astronomy club viewing session showed me otherwise.  I've also learnt that the adjustment of the scope, either by "nudging" the Dob or the 150 mount (i.e. twiddling the adjustment cable / knob thing) is pretty sensitive and takes patience!

Am thinking I might be more suited to the dob - the viewing adjustments seemed a bit easier, and the setup less involved.  Will have to see if I can find a place to see if a 200P Dob is easy enough for me to handle / set up...

Steven 

[ronin]

You will find that whatever you get if it is manual then you have to learn your way around using the scope. It always sounds like you walk up to a scope, put your eye to it and see exactly what you want with it bang in the middle. It don't happen like that.

Dobsonian or EQ is difficult,  you are sort of in contact with the dobsonian more but there may be greater options with the equitorial. Usually people want to put a camera on and rivel Hubble. Not easy but with an equitorial it is easler then with a dobsonian. Also simple motors mean you can find something and let someone else look - it should stay in view.

Not seeing Jupiter when swapping eyepieces can be it moved (sneaky things are planets), you moved the scope even a little, it was still there just well out of focus. Likely (2) as getting one eyepiece out then another in results in the scope being pointed a little off of where it was. This is where wide angle eyepieces come in, and a collection of expensive ones being acquired. Just think that that 10mm ES82 may have been wide enough to have kept Jupiter in view, even if it did try to sneak off.

 

[rockystar]

you've already learned the importance of an aligned finder - does it have crosshairs? When you've got Jupiter in your 25mm EP, check that it is exactly over the cross hairs of the finder, swap the EP for the 10mm and then get Jupiter back over the cross hairs.

you will most likely need to adjust the focus also.

 

[Stub Mandrel]

I use my 150PL for imaging which means pointing it with incredibly silly accuracy. I find that the best strategy is to align the finder so Jupiter or a bright star is in the 'armpit' of the cross hairs and just visible.

Jupiter will wander out of the FOV of 150PL quite quickly if you use a barlow. if you have an EQ tripod aligned 'more or less right' then twiddling the RA knob will let you track it. if Jupiter disappears, just twiddle the knob a little and it should reappear.

With a barlow it helps to go something like 25mm ... 10mm ... 10mm + barlow - re-centring at each stage and being prepared to wind the focuser in or out more than you expect. Some people mark the approximate focus points on their focus tube.