Revelation Astro 8" Dob First Light (& second & a bit of third!)

[Darren27]

Well its been a couple of weeks since my new scope was delivered and since then I have had a few opportunities to get outside and the sky.

The first night that offered clear sky took a few days to arrive, but as soon as it did I was straight out into the garden full of expectation of how great the 8" was going to be.  However first light was a bit of a disappointment.

First target was Jupiter, but the scope just would not focus, the image was bright but there did not appear to be enough movement on the focuser draw tube to give a nice sharp image.  I checked the collimation and it was a bit out but not by a massive amount,but a few minutes had it tweaked and ready for a second try, but again the image just would not reach focus.  By now I was getting both cold and to be frank a bit disheartened, so I called it a night and went in to warm up and sulk over a large glass of cognac.

The following day I had a chat with a colleague at work who has a few scopes and asked his opinion and to be honest I was both surprised and a little embarrassed by his suggestion.  He suggested not inserting the eye piece all the way into the focuser as this would effectively give the additional focuser movement required to bring the image to focus.

The next clear night I was straight out and pointing at Jupiter, I inserted the 9mm and again tried to focus to no avail, so I released the screw and slid the eyepiece out of the focuser by about 5mm and then slowly racked the focuser back in, WOW there was Jupiter looking stunning, I could clearly make out several bands of colour, in with the barlow and again a slight adjustment of the position of the lenses and focus was crisp and clear and the longer I looked the more detail I could see.

Now was the time to go hunting for some of the DSO's which I had been hankering over and the reason for the Dob.  Soon the next issue raised its head, or more rightly mine.  The finder gives a very crisp clear image, however I found it very hard to get behind it as there was not a huge standoff between the finder and the main tube, which resulted in me having to contort my neck to get a clear view.  Probably more of an issue with my strange anatomy that the fault of the scope, but at some point I think a right angle finder would be a good upgrade.

The next issue came in the shape of my total inability to star hop, or even to figure out what (not) on earth I was looking at.  I could see a star with the naked eye, but once I moved to the finder I could see loads of stars and couldn't work out which was the one I could see and my very basic star atlas (only down to mag +6) didn't have enough detail to allow me to make sense of what I was seeing, very frustrating.

So overall what have I learnt?

Well the scope is much better than me and I am at the bottom of a learning curve!  

The base turns very smoothly on its bearing, if a little noisily as the lazy susan bearing is between two metal plates.  The adjustable altitude bearings are very easy to adjust and hold the scope well regardless of position or eyepiece size.

The 2" 30mm gives a great wide angle view with a comfortable eye relief, the 9mm is nice although I feel is not an ideal size to match the performance of the scope.  9mm offers x133 mag which is not quite enough to get the best out of Jupiter, but barlowed to x266 its a bit too strong.  I think if you only had a single eyepiece to chose from an 11mm or 12mm would be a better fit, just my personal opinion.

I've ordered a decent atlas and I'm looking at either a RACI finder or a Telrad (or both) and making plans to go DSO hunting once the cloud and the moon clear.

Overall I'm very happy with my choice and I can see many good nights ahead.

[DomDubois]

Barlowed would make the 9mm a 4.5mm and I'm definitely no expert but thats on the upper end of magnification for the scopevunless the seeing is extraordinary.

I just got a 10" dob with the same size eyepieces, I wish the 30mm had been a 26 or 24 but its still pretty nice for the DSO's. Were your eyepieces the same brand as the telescope? If so they are probable GSO's, they make eyepieces for orion, zhummell and many other manufacturers.

My scope came with a right angle finder, its really nice not to have to contort your head in such an unnatural posotion.

[Paul73]

That's what we like. A good honest first light report. I remember the disappointment well....

You are getting the gremlins out of the way now and every time, barring the odd car crash session, you will see more and more.

The star hopping will suddenly click as well. It makes a hell off a difference when you swap from the finder scope to the eye piece safe in the knowledge that your target will be in the field of vision.

Paul

PS. My star hopping only works like this sporadically. But it is definitely getting there!

[estwing]

Lots of great nights ahead! Nice report clear skies

[rory]

Can recomend getting the telrad or Rigel finder . You won't need BOTH though , either or.

They will make searching a much easier experience .

Did you have to lift all your eyepieces out of the focuser or just one in particular ?

[floppygoose]

Hi Darren and welcome to SGL.

I think most people struggle with the 'straight' finderscope that comes supplied with a new dob, and quickly change to something more suitable. I remember similar confusion when first trying to star-hop, but you will soon get the hang of it. In my case it took a while to get accustomed to the inverted image when viewed through the main scope, but it didn't last too long

Good luck with the scope and enjoy the forum

Phil

[Darren27]

Dom, yes the EP's are both branded Revelation, as is the Barlow. I'm happy with the quality, especially considering the price I played for the whole package, but I think a 12mm instead of the 9mm would have made a better balance, especially for someone buying this as a first scope.

Sent from my phone, any spelling mistakes I will blame on auto correct (apart from the ones I make!)

[Darren27]

Rory, yes if I leave a gap of about 5mm between the focuser and the plastic body of the EP then they all work great. The brass compression ring is still within the undercut on the larger 2" 30mm so it's still held securely.

Sent from my phone, any spelling mistakes I will blame on auto correct (apart from the ones I make!)

[Myopicus]

I highly recommend 'Left Turn at Orion' as it explains not only how to find objects, but also what they are, how best to view them and why they are interesting.

Clear skies!

[Peter Drew]

Is there not an extension piece that increases the outward travel of the focuser to save you having to withdraw the eyepieces. ?

[Darren27]

Peter, yes there is an extension but it moved things too far and again I ran out of movement on the focuser.

Sent from my phone, any spelling mistakes I will blame on auto correct (apart from the ones I make!)