Revelation Astro 12" F4 Imaging Newtonian- first impressions

[laser_jock99]

A new Revelation Astro 12" F4 imaging Newtonian arrived today from BCF. This is the first new scope I've owned all the others being used kit.

First impressions- it's BIG and heavy, 20Kg a lot of scope for the moneny. I'm getting more couterweights made 10Kg+ plus extension bar is not enough to balance this scope. If you're not confident handling heavy scopes then it's not for you. You'll also need at least an EQ6 to carry this. A carbon tube would be better, but they are not on offer yet.

Revelation 12" F4 beside my 8" F6 scope.

Revelation 12" F4 besides me at 6' 2"

The overall fit and finish is okay for this class of budget scope. The focuser seems nicely made and quite sturdy and has 1.25" , 2" and 3" options and graduated markings. The scope is supplied with a 2" x 35mm extension tube.

The rear mirror cell looks like standard GSO fare, comes with a cooling fan. The adjuster screws could be upgraded but I need to study these more closely to see if its#'s worthwhile?

The adjuster screws in the spider cell might also benefit from Bob's Knobs or similar to make tweaking collimation easier?

Looking down the tube there are no baffles, but it might be worth flocking the inside at some point?

The scope rings seem beefy enough and it comes with an 11" Lossmandy style mounting bar. A longer (15") Lossmandy bar might be better to counteract any tube bend as the scope moves. So that's a possible future upgrade. I will increase the mechanical strength of the scope cradle by adding a top bar.

Not much else to say at this point since it was too cloudy to test, and I have no eyepieces here! Needless to say after 3 days in the care of Interlink it looked a bit out of collimation.

[cotterless45]

Wow! Lovely.

Flocking would e good. The focusser is lovely. I've always found Bobs Knobs or heavy compression springs better for collimation than those supplied.

You might also like to upgrade the supplied latitude adjustment bolts, available on fleabay.

Nick.

[Teslar]

That's a biggie. I'd check those mounting bolts on the scope rings. The ones on my Quattro were soft as cheese. I had to change them for Hi Tensile bolts. Also try and get hold of a third scope ring it will make rotating the scope easy for visual use and also make it easier to load the scope onto the mount. Good luck

[SamAndrew]

Wow that's a monster!

makes the EQ6 look small

I look forward to hearing how it performs

[laser_jock99]

That's a biggie. I'd check those mounting bolts on the scope rings. The ones on my Quattro were soft as cheese. I had to change them for Hi Tensile bolts. Also try and get hold of a third scope ring it will make rotating the scope easy for visual use and also make it easier to load the scope onto the mount. Good luck

Yes some of the bolts on the scope rings (hinges & the retaining pin) didn't look up to the task but could be easily upgraded. A third ring might be a good idea too. I'm also looking at getting the longest 350mm(15") Losmandy saddle as the supplied 11" saddle looks a bit short on the big tube. Getting the thing on the scope wasn't as bad as I had thought it might be, I fitted the saddle and scope ring assembly onto the EQ6 first and then dropped the scope into the rings using red tape marks to show the pre-determined balance point. Trying to carry the scope in one hand whilst attempting to fit it on the dovetail grove wouldn't have worked.

[fwm891]

As this is an imaging scope have you tried imaging through it yet - any results...

[laser_jock99]

As this is an imaging scope have you tried imaging through it yet - any results...

Still waiting for the clouds to clear- maybe tonight........?

More importantly though, I'm waiting for other essentials to arrive- anoher 10Kg of counterwieghts and a coma corrector/focal reducer. On the plus side though I think

I've mastered the collimation procedure, as suspected the scope was a bit out when it arrived. The mirror springs will have to be changed for sure to something longer and stronger. The locking screws need changing for ball ended M6 x 20 knobs. Bizzarely the supplied knob screw ends have cup points which are more commonly used on set screws for locking shafts. I filed the cup points down flat but ball ends would be better. More engineering thought needs to go into these mirror cells.

[fwm891]

Still waiting for the clouds to clear- maybe tonight........?

... More engineering thought needs to go into these mirror cells.

I think that comment goes for a lot of equipment that's built to a price rather than built for a function!

Glad to hear you have your collimation sorted

[Chris]

holy smokes thats huge compared to your 8", I bet that was fun to mount, I struggled mounting my old 8" without making noises like an Olympic weight lifter:)

[Damo636]

Lovely setup, not for the faint hearted lifting that up onto to mount!! My GSO has the same mirror cell and agree the oem springs are nowhere near heavy enough. The Bobs Knobs aftermarket parts are so effective I was able to remove the locking screws altogether.

http://www.bobsknobs.com/Newt/page22/MLB12.html

[nightvision]

Very nice, I also have the old F5 dob version, primary figuring got very good reviews in independent tests. Looking forward to your testing/imaging. I believe you are going for the ASA 0.73 corrector/reducer, F2.9 on a 12" scope! .... They're just mind bending numbers, the effective focal length shouldn't stress the mount tracking/guiding too much. I might get the same reducer for my 200PDS ....once funds are available.

[laser_jock99]

Lovely setup, not for the faint hearted lifting that up onto to mount!! My GSO has the same mirror cell and agree the oem springs are nowhere near heavy enough. The Bobs Knobs aftermarket parts are so effective I was able to remove the locking screws altogether.

http://www.bobsknobs...ge22/MLB12.html

Thanks for the Bobs Knobs springs link they look just the ticket. I'll stick with stock screws for now, but the springs need to go!

. I believe you are going for the ASA 0.73 corrector/reducer, F2.9 on a 12" scope! .... They're just mind bending numbers, the effective focal length shouldn't stress the mount tracking/guiding too much. I might get the same reducer for my 200PDS ....once funds are available.

That's the plan- as and when funds allow. A decent coma corrector would be a couple hundred pounds anyway- may as well go the whole hog and get the ASA Keller coma corrrector/focal reducer I figured? Trouble is they cost more than the scope! I need to check carefully if it will work first.

[pete_l]

That's the plan- as and when funds allow. A decent coma corrector would be a couple hundred pounds anyway- may as well go the whole hog and get the ASA Keller coma corrrector/focal reducer I figured? Trouble is they cost more than the scope! I need to check carefully if it will work first.

Wise move. The Boren-Simon Powernewts use this corrector. I believe that the supplier also replaces the secondary mirror with a larger one and that they specify a 1/12 PV primary mirror.