First light with my new dob

[taxman (Matt)]

Took my brand new 8" dob to a friend's house on Saturday. needed a little collimation which I am still finding a pain - probably need some bigger knobs which I'lll try to get from a friend who is a fitter & turner.

My friend lives in a marginally less light polluted area than I (next to a golf course), so I though it would be a good location to see what I could see.

Found Jupiter no problem (of course) first. Seeing was a bit ordinary - the edges were 'boiling', but four cloud bands could be seen, no spot though. Fascinating though, everyone had a look, with the 6 year old most impressed even claiming she could see colours.

Moved on to Saturn - same problem with boiling edges, but the ring showed up brilliantly, and the line in the middle of the planet (cassini division?) was very clear as a thin black line.

My friend's wife did a 'Bart Simpson' slewing it to a random spot in the south south east sky, looked in the eyepiece and said 'what's this cloud thingy?'. I think it was the butterfly cluster according to Stellarium.

We left it for a few hours to cool down, and then tried to find something else. I am very inexperienced, so according to Stellarium, it seemed I would find something if I put Jupiter in the far left of the eyepiece and began scanning upwards to the zenith. I found a very faint cluster, which I initially though was M24, but as it had no bright stars in the centre, now believe it to be M7. Very cool.

Called it night at this stage, as it was about 1ish and very cold (all I wore was shorts and a tshirt.) Spent a lot of time kneeling on wet grass - so I think the next purchase has to be an adjustable observing chair, closely followed by a Baader 8-24 zoom (is it really as good as people are saying it is?), with 50 degrees AFOV at 24mm and 68 nearly everywhere else.

I am glad I went with the 8" dob, as I find the wide field of view much better than my 90mm skywatcher refractor, and the mount much more stable than the eq2 mount. I did get some dew on the mirror unfortunately, so I probably should clean this also. The 6mm GSO was pretty much useless, maybe a burgess 5mm would work better (any advice there?)

All in all, a very satisfying night, glad I spent the money on this. Mainly though, I would like people's thoughts on good observing chair (or plans for one - I am an ex-boilermaker and could probably make one ), the baader 8-24 zoom and the burgess 5mm planetary, if anyone has the time.

Thanks for the help I have gotten on my previous posts - I really am glad I followed the advice people here have provided!

[mrsnipey]

I've got a Baader 8-24mm zoom and I love it (as I've mentioned in a couple of post here). I've had it for a couple of months now and I don't use any other eye pieces. It has a number of click-stops as you zoom in or out but you can stop zooming anywhere you want in between the click-stops.

It's supposed to be parfocal but the 8mm and 24mm settings are nowhere near the middle three settings. Doesn't take much to re-focus though and it's a lot easier than changing ep's all the time. In fact I'm getting pretty good at focussing as I zoom in or out.

It's my first expensive (for me anyway) eye piece but I couldn't be happier with it. (p.s. I bought mine from the US and saved $100)

[erick (Eric)]

Originally Posted by taxman

.......Spent a lot of time kneeling on wet grass - so I think the next purchase has to be an adjustable observing chair, closely followed by a Baader 8-24 zoom (is it really as good as people are saying it is?), with 50 degrees AFOV at 24mm and 68 nearly everywhere else.

...... I did get some dew on the mirror unfortunately, so I probably should clean this also.

........ The 6mm GSO was pretty much useless, maybe a burgess 5mm would work better (any advice there?)

.......the burgess 5mm planetary

Great fun, wasn't it!

A few quick thoughts:-

Yes, I think an 8-24mm zoom is a good addition. There are various makes, from budget to top end. Have a look around at the reviews and put a wanted ad up and see what you get secondhand.

Dew on the mirror - the primary? Just leave it to evaporate during the daytime - make sure the scope is uncapped for a few hours during the day after observing to completely dry out - but watch the cat doesn't move in, spiders, birds etc!

5mm eyepiece. Recommend that you look for a Vixen LV. I saw a 5mm for sale in the classifieds recently. I have a 6mm and an 8mm and love them. Secondhand around $100-120 - well worth it. 8mm is always useful. 6mm only in better seeing conditions. Not sure if the 5mm will be usable most of the time.

Chair. Start with an old gaslift office chair if you get it for free - remove the arms and the back. Not the best on muddy uneven ground, but I push the whels through the mud. Brilliant if you can set up on a large cement pad (around 2.5mx2.5m for an 8" dob). Of course, if the cement is really hot, you'll get thermals rising in the first hours which might cause some seeing problems. There are other designs - search this site and check the Projects & Articles link at the left.

Wet knees - that's a problem - how low to the horizon are you trying to observe? Remember that anything less than about 30 deg elevation and the air column you have to look through becomes considerable - hence seeing worsens.

Keep reporting how it is going!

[taxman (Matt)]

Eric,
I asked about the Baader, because it seems to review much better than any other zoom EP, even the Tele Vue!

So I don't need to worry about dew on the primary? That's a relief - I thought that was a bad blue...

My telescope has a 1200 focal length and I am built like a monkey - little arms, little legs and long body , so kneeling is the most comfortable for viewing at or close to the zenith for me (without a chair of course).

MrSnipey,
Where did you get your baader zoom? I can't seem to find one anywhere and was considering the 198 euros at the baader website - about 330 aus.

[wavelandscott (Scott)]

Sounds like a great night!

Congratulations and I hope you get much more enjoyment.

While I am truly biased, I will say that for me the best accessory (and my wife will attest that I have too many) was an adjustable height observing chair...it made a world of difference for me in comfort which in turn positively impacted my overall viewing experience...can't imagine using a 6-15 inch Dob without one ever again...

[cookie8 (Vincent)]

Originally Posted by wavelandscott

Sounds like a great night!

Congratulations and I hope you get much more enjoyment.

While I am truly biased, I will say that for me the best accessory (and my wife will attest that I have too many) was an adjustable height observing chair...it made a world of difference for me in comfort which in turn positively impacted my overall viewing experience...can't imagine using a 6-15 inch Dob without one ever again...

Agree. Just bought an adjustable height bar stool for $65 for my 12"LB.Should make a huge difference in comfort for all night observation.Still waiting for sky to clear but. Another accessory you might want to consider is a narrow band pass(nebula)filter if you observe mostly in your suburban backyard. Nebulae really stand out as if under dark country sky.
Enjoy your new toy

Vincent

[mark3d]

yeah its enough strain on my back lifting the thing, contorting myself into viewing positions makes it hard work! maybe i need a chair too

[Screwdriverone (Chris)]

Originally Posted by cookie8

Another accessory you might want to consider is a narrow band pass(nebula)filter if you observe mostly in your suburban backyard. Nebulae really stand out as if under dark country sky.
Enjoy your new toy

Vincent

Hi Taxman,

I might add to Vincent's suggestion about the Narrowband Nebula filter and light polluted skies from your backyard. I bought a UHC-S narrowband nebula filter and while it does enhance the nebula that you see, it darkens everything else to the point where its very hard to see many stars at all (its like wearing sunglasses at night).

My suggestion is to get a Moon and Skyglow type filter which reduces the artificial light from streetlamps and glow from the city as well as the moon's light when it is intrusive to viewing. I tried both and trust me, you will use the M&S filter MUCH more than the more expensive narrowband one. I pretty much leave mine in all the time when viewing from my backyard.

FYI: Ba'ader UHC-S is about $129, M&S is about $85.

Cheers

Chris

[erick (Eric)]

Originally Posted by taxman

My telescope has a 1200 focal length and I am built like a monkey - little arms, little legs and long body , so kneeling is the most comfortable for viewing at or close to the zenith for me (without a chair of course).

??? Better get someone to take a photo - I'm surprised that you would be kneeling to see into the eyepiece of an 8" dob pointed to the zenith. If that is the case, perhaps you need to put the dob on a small solid coffee table - get it 30cm up off the ground?

[mrsnipey]

Taxman, I bought my Baader zoom from www.alpineastro.com.
It cost me $279 AU including postage. It's $215 US so with the exchange rate it should be a little cheaper for you. They're out of stock at the moment but I doubt it will be long before they're back in stock.

I thought it was a lot of money at the time, but it improved my viewing so much that I consider it my best astro purchase so far.
Even the views through my old cheapy e-bay 114mm newt are greatly improved.