Dobsonian to something else?

[GeoffW1 (Geoff)]

Originally Posted by mbyrr

Well I just spent a few minutes collimating the dob, following a tutorial video I found on YouTube.

I can't find anything about setting up the Finder properly tho, anyone?

Hi,

This worked for me...

Mount your lowest power EP and in the daytime at twilight, swing to a distant distinctive object on land. In my case there was a lady used to sunbathe on her balcony........um, she was upside down tho.

Focus the finder and scope for that distance and centre the object in the EP. See where it is in the finder and centre it there as well.

This will nudge it out of the EP so repeat all this. Then mount a medium power EP and repeat again.

Wait now for a bright star to appear (no confusion with others then) and do all that again on the star. If you have to refocus the finder do so carefully as it is easy to push it out of alignment.

Then go to your highest power EP and repeat.

Cheers

[mbyrr (Antony)]

Thanks Geoff. I got it centered on a signpost across the street but will need to do it on a star for proper alignment I imagine.

I'm seeing alot of talk re the Telrad Finder, it sounds like a good investment, is it?

[noeyedeer (Matt)]

best to use something a few kms away. across the street will have your finder wayyy out

[mbyrr (Antony)]

Originally Posted by noeyedeer

best to use something a few kms away. across the street will have your finder wayyy out

Yeah it was wayyy out already.

So after some consideration of everyone's much-appreciated comments, I'd really like to make the dob work. To that end, if I can make it easier to use that would entice me to use it more often. Consequently:

1. Any recommendations for this Telrad finder? I watched a video about it and it seems to be highly recommended for finding things (one of my issues).

2. Another upgrade option is a 2x Barlow. I noticed that Bintel have a couple of branded options, the ED and non-ED version. Is it worth it for planetary viewing?

3. I saw a video on YouTube where a guy attached a webcam, has anyone tried that? I took some pics of the moon awhile ago, but it was a pain to line the camera up to the EP.

[dannat (Daniel)]

i personally dont like using barlows too often,but for planetary they are ok -the ED versions can degarde the image less

telrad is good -you dont like the optical finder? both have ADV/DISADV, some peole use both

webcams can work -to take pics or live view?

[mbyrr (Antony)]

Originally Posted by dannat

i personally dont like using barlows too often,but for planetary they are ok -the ED versions can degarde the image less

telrad is good -you dont like the optical finder? both have ADV/DISADV, some people use both

Yeah I was thinking of using both.

webcams can work -to take pics or live view?

Either/or I guess.
I saw a video of a guy converting a Creative webcam with a film cannister, seemed like a cheap and easy way to get the job done.

[mbyrr (Antony)]

Hmm it seems I've managed to align my finder using Syrius.
I really like this SkEye app on my phone too

[barx1963 (Malcolm)]

Sirius, good choice for finder aligning.
Telrads are either a love em or hate thing. I have used one but gave it away as it dewed up very easily and craning the neck is a pain. Some use them very succesfully with no other finder but I only used them to sentre on brigh naked eye stars then use my main finder to star hop. One advantage to living in the bush is green lasers are a bit less obviou here so I prefer that to a Telrad, but in the city it may be you best choice.
A comment on collimation. I was reading another guide today (see here http://www.garyseronik.com/?q=node/169 ) which has a little FAQ section that explains what collimation achieves and puts things into perspective. The lesson is that a scope that is a little out will still work OK, just you may lose a little light and get more aberrations. But perfect collimation is not such a big deal (at least for visual observing).
And a further comment on goto. Many think that Goto will solve all their issues with finding objects. IMHO it is often a false economy. In mosr case you still have to align the scope each time you setup which requires some basic knowledge of the sky. I found when I used a goto for a little while I spent more time fiddling with aligning and setuo than actual observing. I would setup, do the alignment, then slew to some bright familiar object, not be happy with the accuracy so start again, make a mistak, start agin and 45 minutes would go by and all I have seen are a couple of alignment stars and one bright object. In that time I could have nabbed 5 or six objects with my dob!
Also with go to you are trading aperture away for electronics.
This is not to say that goto has no uses, but it is not a panacea.

Anyways, glad to hear you are persisting with the dob and making progress!!

Malcolm

[barx1963 (Malcolm)]

Oh and a note on barlows. Some recommend them on the basis that it doubles your eyepiece collection.
I used a Televue 2x Barlow for some time and well as a Televue 2.5x Powermate and frankly never saw better images with them than I could get with an equivalent stand alone EP.
I tried numerous times but always went back to stand alones.
Good quality EPs are the "gift that keeps on giving" they are an investment is future viewing taht will outlast your scopes if you look after them. IMHo they are a much better investment than barlows.

Malcolm

[mbyrr (Antony)]

Yes I might wait on the Telrad for now, at least I have an aligned finder now, so that helps!
If not a barlow, what other sizes should I get to complement the ones I already have? (15mm and 9mm Fully Multi-coated Plossl Eyepieces (1.25"), 26mm Wide View Eyepiece (2"))

[barx1963 (Malcolm)]

Plossls tend to be OK at the longer lengths. The 26 and the 15 should be fairly easy to use. In your scope they will give 38x and 67x respectively and the 9 will give 111x. In most situations you do not need much over 100x and in an 8" pushing much beyond that on most nights is asking a bit.
So I would persist with the EPs you have and try to do as much with the lower power ones as you can. Best thing is to try and get to observing nights and ask to try others eyepieces. In most cases, observers are happy to oblige and it will give you a good idea what works.
I know it is a bit in the future but as you are in Melbourne, think about coming up to the Snake Valley camp, first weekend in November. We are a very friendly bunch and you will get to see losts of scopes and try lots of eyepieces. The website is here http://ballaratman.wix.com/svaa#!events The other suggestion of the MPAS is good also.

Malcolm