Skywatcher Evostar 150 F8 Refractor

[DRT]

Following a very helpful tip-off from @Chris Lock a couple of days ago I purchased this lovely beast from Astroboot.com at a knock down price of £245

The scope is basically brand new and comes with all of the standard accessories, all of which are unused and still in their original wrappers and boxes. I suspect it was a customer return as there are a few very small scratches on the blackened edge of the objective lens that can be seen at the bottom of the lens in the picture below but the scope looks otherwise perfect.

I fitted a Skywatcher Dual-Speed focuser and an ADM D-Series dovetail when the scope arrived ths morning and here she is attached to my AZ EQ6 GT...

 

I checked the colimation using my Hotech with the diagonal and new focuser attached and the laser was bang on in the centre of the objective.

Now all that remains is to point it at something and report back

 

A big thanks is due to @Chris Lock for the heads-up - I am very please with this latest canon

 

 

 

[John]

Nice Derek

The laser will confirm that the focuser and objective optical axis co-incide. A cheshire will check the tilt of the objective is correct.

Have fun !

[xtreemchaos]

lovely frac Derek, and looks the bizzy with the new focuser.well done.  charl.

[cotterless45]

Nice ! You'll find a 150 opens up deep sky and is a great all rounder. If you get some ca, try a 2" Baader semi apo filter in the diagonal. Wish more folks would get on the frac train !

Nick.

[DRT]

6 minutes ago, John said:

Nice Derek

The laser will confirm that the focuser and objective optical axis co-incide. A cheshire will check the tilt of the objective is correct.

Have fun !

I don't have a cheshire, John. Are you just trying to make me spend more money?

[Chris]

You're very welcome Derek  It looks much better on your AZ EQ6 mount than it would have on my photo tripod .

Fingers crossed the lens is as good as the scope looks!

[John]

7 hours ago, DRT said:

I don't have a cheshire, John. Are you just trying to make me spend more money?

As recommended by our own PhilJ:

http://philjay2000.tripod.com/usefulstuff/adventures.pdf

[FenlandPaul]

Looks great, Derek - worth the wait I hope.  You were looking out for one about year ago, weren't you?!

Hmmmm, that AZ-EQ mount has got me thinking...

[DRT]

Thanks, John, that is the clearest explanation I have read of how to do this. I'll do a star test first and see how it goes. If it's off I'm not sure what can be done given that it has no adjustment in the cell

[ollypenrice]

35 minutes ago, DRT said:

Thanks, John, that is the clearest explanation I have read of how to do this. I'll do a star test first and see how it goes. If it's off I'm not sure what can be done given that it has no adjustment in the cell

Ed Ting's website describes how you can settle the cell (if necessary) by standing the tube vertically and tapping it for ten minutes! I must say that mine, bought very cheaply, gave a good star test. Given their low price, especially second hand, I think these are a very good bet and have that 'proper telescope' thing about them.

Olly

[John]

49 minutes ago, ollypenrice said:

Ed Ting's website describes how you can settle the cell (if necessary) by standing the tube vertically and tapping it for ten minutes! I must say that mine, bought very cheaply, gave a good star test. Given their low price, especially second hand, I think these are a very good bet and have that 'proper telescope' thing about them.

Olly

Yep - I've used that method on scopes where there was no objective tilt adjustment. You need to gently loosen the objective lens retaining ring 1st to allow the lens elements a touch of movement. I use a gentle slapping technique all the way around the lens cell which seemed to work. Don't over tighten the lens retaining ring when finished - just enough to hold the elements in place without them rattling.

 

[nightfisher]

There has been a good few times when i have been tempted with a 150 f8 yard canon but i just dont have the mount, my present EQ5 would have a hernia if i put one of these on it, lovely scope

[DRT]

I've just been to RVO to pick up a cheshire.

I will now spend the rest of today slapping my refractors

[DRT]

Collimation report...

Skywatcher Evostar 150 - dead centre with the Hotech and almost perfect concentric circles through the Cheshire. Unfortunately the retaining ring is so tight I could not loosen it to have a go at slapping it into place but to be honest I don't think it needs it.

Skywatcher ED120 - Perfect, no adjustment required.

Altair Starwave 152 - Perfect, no adjustment required.

Altair Starwave 102 - Three perfect circles through the Cheshire but a confusing pinpoint bright spot on the edge of the outer circle. Further inspection revealed this to be a flake of paint stuck to the inside surface of the objective. Once removed the bright spot was gone and perfect collimation maintained despite the disassembly and re-assembly of the front end of the scope.

Tele Vue Pronto - Almost perfect so left alone otherwise I would have had to disturb the sealed screws that hold the front cell in place.

Skylight Carton 60mm - Oh dear! Three separate circles with no overlap Twenty minutes later I had them all in the right place using the adjustment screws

Polarex Unitron 60mm - Even worse!!     - On inspection of the lens I spotted the beginnings of fungal growth between the lens elements so decided to break the rules and disassemble the entire cell to clean the lenses and re-assemble it. Job done, nice and clean, re-assembled but still miles out. I checked the alignment of the focuser using the Hotech and it was off by about a centimeter. Once fixed that improved the view through the Cheshire but still not anywhere close to being properly collimated. After messing around with the screws and slapping it around for a while I decided to try a new tack. I slightly unscrewed the lens cell from the housing that holds it to the tube. This provides some movement due to the threads being quite loose fitting. A few tweaks here and there and I have everything lined up and three nice concentric circles. I then fixed the cell in place using masking tape around the join between the cell and the housing, replaced the dew shield over the masking tape and bingo!

A fun way to pass a cloudy afternoon

[DRT]

Now ready for a little solar action. 

This picture gives a fair idea of the size of this thing when mounted alongside an ED120

Now I just need some blue sky!

[Davey-T]

Well that's no way to get it 

Dave

[DRT]

5 hours ago, Davey-T said:

Well that's no way to get it 

Dave

You were right, Dave. No clear view of the sun all afternoon

But I am now watching the Europa shadow transit through the Evo 150 and 8mm Ethos just before sunset and it is beautiful

[Davey-T]

Just now, DRT said:

You were right, Dave. No clear view of the sun all afternoon

But I am now watching the Europa shadow transit through the Evo 150 and 8mm Ethos just before sunset and it is beautiful

I'm still waiting for the clouds to clear to get a view of Saturn through the Tecnosky 152mm.

Dave

[DRT]

Hope it clears. That will be a small target in that big wide field so I hope you get some nice clear sky as it will be stunning.  

The only way I can see Saturn would be to point my scope straight through my neighbour's house. I might get arrested if I point this thing at someone's bedroom window!

[Davey-T]

1 minute ago, DRT said:

Hope it clears. That will be a small target in that big wide field so I hope you get some nice clear sky as it will be stunning.  

The only way I can see Saturn would be to point my scope straight through my neighbour's house. I might get arrested if I point this thing at someone's bedroom window!

I only get a small window of opportunity between some trees, can't see it at all with the SCT from the obs'y due to trees.

Dave

[Stu]

Excellent results with your collimation efforts Derek, well done!

How do you find the CA on Jupiter in the f8?

[A McEwan]

Those big scopes in the black diamond colour scheme are very stylish!

 

[DRT]

50 minutes ago, Stu said:

Excellent results with your collimation efforts Derek, well done!

How do you find the CA on Jupiter in the f8?

There was none at all until it got dark and then only a slight purple hue around the disk of Jupiter. I then fitted the Baader Semi-APO to the diagonal and it is now barely noticeable, which might have something to do with the thick cloud that appeared ten minutes ago

i managed to get some brief views of Mars and Saturn with the Altair F11 102 by placing a tripod in some strange positions just before the cloud came. Probably the best view of Mars I have ever had, but very brief. 

[spaceboy]

That looks a cracking set up Derek and even better when you think you got the EVO150 at an absolute steal.

[DRT]

1 minute ago, spaceboy said:

That looks a cracking set up Derek and even better when you think you got the EVO150 at an absolute steal.

I must say I am very pleased with it. It could have been an absolute dog given the provenance but I think I have picked up a gem. A brand new scope of this size and capability for the price of a good eyepiece - what's not to like about that!!