First Light Report Vixen SP102m f/10

[MjrTom]

Yesterday afternoon I went to look at an SP 102m telescope which was in very good Knick. The optics were pristine. After a quick clean with a micro fibre cloth it was gleaming. Cosmetically the tube had a couple of scuff marks and a bit of chipped paint on the dew shield.

As for the focuser it is a 1.25 inch rack and pinion. What was a surprise was that the focuser is really smooth with no backlash at all.

In addition to the OTA there was the original vixen wooden alt/az mount with slow mo controls. The metal work needs a little work as some of the bolts/screws are showing their age a little with rust spots but nothing major.

Also thrown into the deal was a reasonable quality 1.25 prism and an excellent Vixen Ortho 9mm. I shall have to pick up a diagonal very soon.

I managed to get half an hour in the garden this morning in between the cloud cover.

First target was the most challenging for this scope, Jupiter.

Whilst using the Nagler zoom at 6mm the disc was sharp with a noticeable purple fringing and also some yellow fringing as well.

Not overly distracting but definately noticeable.

With that done I swung the scope round to some DSO targets starting with epsilon lyrae and was very surprised just how much resolution there was and the double double was easily split with the 13mm EP. I decided I would push my luck a bit and dropped the Nagler zoom in and progressively increased the mag from 167x to 333x with a lovely diffraction pattern.

On from there was the Ring Nebula with the 13mm again which was visible with direct vision which is nice the ED80 struggles a little on this target.

I dropped in the vixen Ortho and was lovely and sharp and contrasty at 111x

Lastly I tried a couple of open clusters to see how much field of view I can muster.

Using the 24mm Panoptic I could fit the double cluster in view and just about fit pleiades in the FOV as well. At a guess it would be about 1.5 degrees FOV.

With this in mind I am less concerned about the lack of a 2 inch focuser.

So not much of a session but happy with the purchase and got the lot for 200 quid

[MjrTom]

A proper first light report from the Vixen SP102M

Friday evening the conditions slowly improved over the evening and by 11pm the skies were clear enough and the scope was setup in the garden ready

Earlier in the day I had picked up the new version of Turn Left at Orion (TLAO) and thought since Orion was just clearing the top of the garden fence that this constellation would be todays target.

The main aim of the session was to do a bit of double star viewing and with the help of TLAO I found the dobsonain doubles section and proceeded to work my way through them all.

Starting off with a favourite of mine, the Trapezium. sadly the scope was not able to pick out the E or F components but I suspect it had a lot to do with Orion being low in the sky. At magnitude 11.1 and 11.5 its going to be a challenge under my light polluted skies.

OK so I admitted defeat on this one and turned my attention to the other double stars of Orion.

Firstly was Sigma Orionis, a multiple star system located due south of M42.

With the use of the 3-6mm Nagler at 5mm the four component stars were separated the most difficult being the small C companion at 11" and 8.8 magnitude.

Next 32 Orionis. This was a more difficult target with a close separation of only 1.2" with the Nagler zoom again ramped upto 3mm (333x) the secondary star was almost separated but difficult to confirm due to the seeing conditions.

Alnitak next, wow what a nice double! the colour contrast was quite obvious and a tough target for this scope to resolve with only 2.5" separation but still managed it with the 5mm BGO at 200x magnification.

On from there it was onto Mintaka at the other end of Orion's belt. a very easy double with a large separation (53") and only needing the 9mm to split the double (111x)

Lastly I finished on the double star I expected to be the hardest to resolve, Rigel.

Rigel was a blazing star in the eyepiece of my Nagler Zoom. This is a tricky double as Rigel at 0.3 mag outshines its companion at mag 6.8 The separation is fairly large at 9.3" but with the primary being so bright it took the moments of steady viewing to pick out the much fainter companion, it looked like a planet circling its star, a really nice double which I shall have to look at more often.

No session in Orion would be complete without a look at M42

With the 13mm Nagler and a Lumicon UHC filter the detail visible in the nebula was quite astounding. It looked like a pair of bats wings unfurled in front of my eyes. The more I looked the more detail in the wisps were visible and seem to curve round and fill the full FOV of the eyepiece.

The first session with this scope where I have actually felt like I have accomplished something! Double hunting is quite addictive!

Sorry for the belated report

[John]

Nice report !

I've always loved Vixen scopes, particularly the 1980's / 1990's models which I used to drool over in catalogues / Telescope House, London but could not afford back then

If it's any consolation, I've only been able to spot the F component of the Trapezium with my Vixen ED102SS so far - I've not been able to manage E and F with less than a 125mm. Hoping to beat that with my ED120 this winter.

I use Sigma and Rigel as test objects - if I can resolve all 4 of the former and cleanly split the latter then it's worth having a shot at E & F Trapezium.

If you get some dark skies, it's surprising how well 4" of aperture can do on objects like M42.

Thanks for posting your observations

[MjrTom]

Thanks John,

Yeah this Vixen telescope is not quite from that era, more circa 2005 from what the seller was telling me. Its quite a nice performer to be honest. As much as I would like a 120ED its going to be next year or more before it could be a reality. Although all these ED refractor scopes in the for sale section are not helping me at all!

I shall have to try the trapezium again later in the year when its higher in the sky and maybe from a darker location than the back garden

Since using this 4 inch scope I have come to the conclusion that 4 inches seems to be a minimum aperture to really make DSO worthwhile The 80mm just does not have the same light grasp and resolution.

The 80mm is a nice grab and go but its best suited for widefield star cluster work

[John]

Since using this 4 inch scope I have come to the conclusion that 4 inches seems to be a minimum aperture to really make DSO worthwhile The 80mm just does not have the same light grasp and resolution.

The 80mm is a nice grab and go but its best suited for widefield star cluster work

I came to the same conclusion after owning a string of 80mm / 90mm scopes (including a WO Megrez 90). For me 100mm is the minimum aperture I want to observe with.

[MjrTom]

Thanks John,

Yeah it does seem to offer a good balance between portability and light grasp, 100mm seems to be a nice balance.

I will be picking up my repaired Moonlite focuser from the postal depot this afternoon so I can finally attach it to this telescope allowing usage of 2" eyepieces.

I just hope for the life of me that I dont have to shorten the OTA to take into account the increased light path length which is a major concern

I am relying upon Moonlite producing a low profile flange for this telescope and the light path length remains the same as the stock focuser which they say they do in the company literature.

[MjrTom]

Hello again,

A follow up from yesterdays post. The Moonlite focuser is now fitted and is a far lower profile focuser than the original so the light path should be short enough to use 2" eyepieces and such. here are a few photos of the telescope all setup for some white light solar imaging using my home made filter holder which replaces the standard lens cap

Could do with tidying up the tube rings at some point as they are looking a bit tired.

[MjrTom]

Yes all my eyepieces reach focus when focusing on the solar disk, which can be taken as infinity or as close as possible with lots of draw tube travel in both directions

[John]

That looks superb MrTom

One day I might treat my Vixen ED102SS to one of those although the R&P fitted to that is a pretty smooth unit with a 63mm drawtube.

Does your SP102M have a collimatable objective lens cell ?.

By the way your Vixen and mine share exactly the same logo and colour scheme. Mine dates from around 2000.

[MjrTom]

Thanks John,

Yeah I am pretty impressed with it to be honest. Not that was much wrong with the standard Vixen R&P focuser in fact it is very good!

However being only 1.25" limits the FOV to about 1.5 degrees. With a 2" focuser the FOV increases to a more healthy 2.2 degrees with my 35mm Panoptic

Sadly the lens cell is not adjustable but the collimation is spot on following a recent start test at 200x magnification.

[nightfisher]

wow tom, that vixen looks real sweet with the moonlite mod, look forward to hearing how she performs

[MjrTom]

Hey Jules

It performs like a dream, it transforms the scope!

With the weight of the focuser and using a 2" diagonal insted of the 1.25" diagonal means that the tube rings sit closer to the focuser. This in itself has helped the stability of this long tube refractor. Before when the tubes were centrally located I was finding that the wind caused the scope to form a harmonic resonance. With the tube rings no longer central this has stopped. Still could do with a larger tripod to remove any left over vibrations caused by the aluminium tripod.

As for the function of the focuser itself its a charm. It holds a 2" diagonal and the 35mm Panoptic rock solid and the finest of fine tuning is possible and then lock off the focuser with the shaft lock so the focus never slips.

I am always messing with the focuser just incase its not spot on. With this I spend more time looking and less time focusing lol

Looking at M45 and the double cluster with this scope and a 35mm Panoptic is quite a sight. Pin point stars across the whole FOV with a healthy exit pupil of 3.6mm

I find with large exit pupils my own eyes start to show a bit of astigmatism. its worse in my ED80 of course with its 5.6mm exit pupil

[kev]

Ive had a Vixen SP 102M for ages now, bought it off Astrosystems in Luton!

Still have it, still doing a stirling job, on the original Super Polaris mount - which recently has also been taking my 8" f/6 skywatcher occasionally.

Love the scope.

Also have a set (- the 40mm) of Vixen Plossls.

[John]

Ive had a Vixen SP 102M for ages now, bought it off Astrosystems in Luton!....

That takes me back Kev

I've still got an Astrosystems catalogue back then - oh how I used to drool over the Vixens, especially the 4" flourite

[malc-c]

Brought back fond memories.. In late '80s I purchased one of those on an EQ mount... cost me an arm and a leg but well worth it.... regretfully lost my job at the time and we were saving to get wed, so reluctantly the scope had to go

[kev]

Oh yes the flourite 4" £££££s!

Malc, that takes me back, when you were engaged!!!

Almost back on forum topic....

Do you remember the Harpenden observing sessions, especially the rabbit holes in the field with the deer eyes looking out of the woods. Dark mind you!

Shame about the police turning up that time (someone had reported a strange gathering of folk down at the wood clearing!)

[malc-c]

Kev, remember those sessions well, plus the Nat Astronomy Week spent in Fairlands Lakes Car Park... scraping frost off the OTA's

I also have this image that was a failed experiment with my old SLR - seems people didn't stand still long enough ! - My SP102 is on the left, Rob Towsend's Astrosystems 4.5" reflector far left and another Vixen 102 to the right. This was in Shephallbury park around 1986.

Engaged in '86, wed in '87... next year's the 25th year with no sign of probation

[michael.h.f.wilkinson]

Nice scope and nice first-light report. I have never used any of the Vixen scopes, but always liked the fit and finish (drooled over a couple but was quickly distracted by the arrival of a Celestron catalogue). Sounds like you got yourself a great instrument for a very reasonable price.

I do not quite agree that 4" is a minimum for DSO viewing, and I have had no difficulty seeing the Ring in direct vision with my 80mm (better in averted, but clear on direct), even with the 10mm Radian (48x magnification). I even got the Pelican with the 80mm. I recently got a 31mm Nagler and the wide-field views afforded by the 80mm F/6 - 31mm Nagler combination are awesome. Your 2" focuser upgrade can really open up a range of possibilities for wide field with your 4" scope as well.

I would of course not mind having 20mm more aperture .

[StevieDvd]

Kev, remember those sessions well, plus the Nat Astronomy Week spent in Fairlands Lakes Car Park... scraping frost off the OTA's

I also have this image that was a failed experiment with my old SLR - seems people didn't stand still long enough ! - My SP102 is on the left, Rob Towsend's Astrosystems 4.5" reflector far left and another Vixen 102 to the right. This was in Shephallbury park around 1986.

Engaged in '86, wed in '87... next year's the 25th year with no sign of probation

And the ghost by the Vixen 102, spooky

[MjrTom]

Thanks guys and sorry for the late reply.

Since this initial report I have come to really like the performance of this telescope and apart from a small amount of colour fringing on bright objects it has really sharp and contrasty optics.

Since my initial purchase I have also reflocked the dew shield and also the first section of the OTA up to the first baffle.

Need to get some A3 card to use as backing to flock the central section of the tube and some blackboard paint to repaint the baffles which paint is flaking a bit after so many years.

Its turning into a very enjoyable refurbish of a very nice telescope.