In praise of the Vixen 102M

[vineyard]

Hello,

I was going to write this about Mars during this last fortnight, but on reflection the things I wanted to share were really about a much greater appreciation of this beautiful old scope (& mount).

Have had 3 proper sessions on Mars - Night 1 with the Vixen (reported here), then Night 2 when I stripped my imaging rig down to see what the difference would be w a TV102iis instead (& try some rookie planetary imaging reported here), and then tried the Vixen again last night (Night 3).

I know I'm not a connoisseur, but I am seriously impressed with the 102M.  I didn't compare them simultaneously, so this not really a comparison report at all, more some general reflections.

1.  On the first report @Johnhad reckoned that the red & blue fringing I saw might have been dispersion rather than CA in the 102M - you were right John, b/c I noticed that w the TV102iis as well.  It seemed marginally less w the TV on Night 2 but perhaps that was lower magnification or just a different night of seeing, but it really drove home to me the quality of what the 102M had shown on the first night.

2.  Visual through the TV102iis on Night 2 looked a lot brighter - almost painfully bright at times, difficult to see detail.  Perhaps that is better optics, or a better diagonal, or the superior transmission of the Delite EPs I used w the TV...

3.  ...because on Night 1 w the 102M I mostly used a 12T2 and it was easier to see more subtleties w/o filters (other than Baader M&SG for LP).  I've read that 12T2s are meant to have a softer, warmer tone, and tbh when I looked through the Delites, you could tell.  I actually preferred the warmer tone on Mars of the 12T2.

4.  On Night 3 I went back to the 102M and as it was a great night - calm - I thought I would see how far I could push the magnification.  So I took it as far as I could w my kit: to 278x (9mm Delite w 2.5x PM).  The scope & mount did not break a sweat (unlike my eyes where there were some floaters).  The image did not blow up - I could make out Mare Cimmerium, Eridania, Mare Chromium & Cerberus, but it was either too bright for the polar cap, or I couldn't see it.

5.  On that point, the 102M optics are clearly good enough that when it was the Delite in there as opposed to the 12T2 it also seemed v bright - but again I wasn't comparing the two EPs on the same night, but it really vindicates to me how good these 102M optics are for such an old achromat.

6.  I also put some BVs in on Night 3, and the scope held them w/o a problem - BV'ing at 278x was more restful than mono-vision & it felt like I had less floaters w two eyes.

7.  I tried a couple of different filters on Night 3 (stacked on top of the Baader M&SG) - a Solar Continuum (just for kicks) and a 58 greenish (as per Bill P's report).  The 58 was better (quicker?) and definitely allowed more of the regions closer to the pole to be discernible.  Sadly no Baader contrast booster.

8.  I tried some planetary imaging w the 102M given how good conditions were on Night 3, but the focusing was too coarse to be worth capturing.  The 2-speed focusing on the TV was definitely more precise.

9.  Once I was done w Mars on Night 3, I tootled around on some stars, and that 102M scope is brilliant.  Pin point sharpness, no false colour that I could make out.

Special mention should also go to the SP mount.  It held the rig without a problem.  Clearly w such a long OTA when you touch it, it shakes but it damped down pretty quickly (1-2 secs max & that's w a steel tripod).  And the tracking was perfect for visual purposes - Mars didn't leave the centre of the EP.  It did struggle a bit on Night 2 when I put the beefier TV on (the counterweight was not heavy enough) but not a problem w the 102M and 1.1kg of BV & EPs.

Being an inveterate tinkerer, I've often thought around whether I should upgrade, or what changes I should do to the 102M (2" focuser, or 2-speed focuser etc).  And these nights have really reinforced to me the following:

A) No way do I let this scope go.  It performs wonderfully, its got character. It stays.  Given that I already have an old TV102iis, no upgrades necessary for this old Vixen.  (I did the hole-in-a-piece-of-paper collimation check - this thing is 30-40yrs old and its centred!).  In fact it should be invested in.

B) No need to change the focuser.  I did some maths, and unless my optics are wrong (which is entirely possible!), a 1.25" image size is formed about 700mm from the objective?  If the focuser is fully racked in, its end is about 670mm from the objective, but focus on the stars is about 30mm racked out, so its touch and go whether there is any vignetting.  I could make doubly sure by using a lower profile visual back and perhaps a prism diagonal to make it rack out a bit more.  Will definitely change the visual back, not sure yet about the prism diagonal.  Given that, I don't think a 2" focuser would show me anything more at f10 (or am I getting something wrong?).

C) No need to change to a 2-speed focuser (not sure how that could be done without changing the whole focuser anyway).  Because I got in touch w Pavle at DeepSkyDad and he reckons that the variation of the AF3 he does for Taks should reliably generate enough torque to micro-step the single speed focuser  So while tbh manual focusing could work fine for visual, if I can micro-step focus adjustments using a hand-controller without touching the tube, then that is v tempting indeed.

Anyway, sorry this has become a v long report, but these last few nights have really made me appreciate this 102M a LOT.  It punches waaaay above what it says on the tin (or its calendar age), and I think justifies the right type of modest investment (a new visual back to allow a proper prism or 1.25" diagonal w compression rings not set-screws, and ...perhaps... an AF3s+ which can be hand controlled so no need for PCs).

I'll be honest I'm even thinking about the load capacity of the SP to dual mount the 102M and a little wide-field 72ED side-by-side 😂 - if that is stable enough, then w setting circles, wide-field and finders etc, all more that's needed is an atlas, a power pack - needed for the modded Vixen motors anyway - and, oh yes, clear skies).

On which point, time to see if the clouds have gone - stay safe all,

Vin

[vineyard]

Quick update on a gorgeous, stunning Night 4.  This is a keeper.  At the start of the night, I noticed Jupiter & Saturn passing low in the south - couldn't set up quickly enough to get Jupiter before it disappeared behind trees, but got Saturn at 278x.  Boiling conditions (low in city skies, sightline over houses etc) but the scope showed Saturn & its rings fine - Cassini division clear.  (Could this scope possibly handle 330x...?)

Mars itself later in the night when it had risen higher was again gorgeous.  12T2 w 2.5PM and a 58 green filter was the best combination.  And patience was rewarded in terms of just looking and seeing what emerged - Cerberus, Mare Cimmerium, Eridania clear, then Mare Chromium and then eventually ping: the little polar ice cap.  Definitely seems to be smaller than Night 1 - can it change that quickly or is that just bad memory or different seeing?

Spent time w the Pleiades as well now that they are resplendently high at that time.  All of M45 captured & tracked perfectly in a 25mm Zeiss microscope piece.  Maybe just the slightest, slightest of red & blue flashes sometimes on some of the brighter component stars, although when you looked directly at them they were pinpoint white with no colour, so perhaps it was just me seeing things that were not there.

A blissful night.

Stay safe all.

[Alan White]

So pleased that a Vixen scope is bringing you so much enjoyment Vin.
I adore my ED103s, and it has provided me with and will continue to provide endless enjoyment.

Shame the weather and seeing for me has been so poor of late, but that is Astro for you!

[John]

Good to hear that the Vixen 102 achro can still cut it

I used to have one on an SP mount and was very proud of it.

I must give my Vixen ED102SS a spin out soon. It tends to get a little neglected at times

[omo]

The Vixens are really nice, having just passed my SD103 on, its new owner is liking it a lot too

[vineyard]

4 minutes ago, Alan White said:

Shame the weather and seeing for me has been so poor of late, but that is Astro for you!

Argh sorry to hear that Alan.  Yes I think these last few nights have really underscored to me the pleasure that a quick-to-set-up visual rig can bring.  Hope the conditions get better for you for at least a few nights soon.

1 minute ago, John said:

I must give my Vixen ED102SS a spin out soon. It tends to get a little neglected at times

👍🏾It'd be a shame not to!

Just now, omo said:

The Vixens are really nice, having just passed my SD103 on, its new owner is liking it a lot too

I'll bet!  That did look a beauty.

[mikeDnight]

I love the old Vixen's!  I bought a Vixen 102mm F13 back in 1986, and to this day that scope remains one of the best refractors I've ever owned. And yes, it was an achromat!

I probably didn't even get the best out of it, as back then, good eyepieces were hard to come by and relatively expensive. With what I had in way of eyepieces, that scope gave beautiful views of the Moon and planets, but at F13 some might think it would be poor on deep sky. Well theye'd be wrong, as the scope was stunning on deep sky. You may laugh, but my deep sky eyepiece was a 40mm Vixen Kellner. That eyepiece in the F13 was awesome, sharp and utterly transparent. It gave me perhaps the finest view I can recall of M81 & 82 I've had in 40 years of observing in any telescope. I knew when I sold it that I was making a big mistake, but I needed college A level text books, and at the time it seemed the only thing I could do. If I had my time to do again, I'd keep the scope and throw my time at college and university studying mathematics and the natural sciences to the wall instead. 

[vineyard]

10 hours ago, mikeDnight said:

If I had my time to do again, I'd keep the scope and throw my time at college and university studying mathematics and the natural sciences to the wall instead. 

Hindsight is sadly always 20-20 isn't it (unlike at least my current vision).  That's a great evocation of what sounds like a fabulous scope  - memories that stay for decades is pretty much what all important relationships are about, and that scope lives on with you even now in your recollections!

[fifeskies]

It was me that bought Omo's SD103S and I am very happy with it (thanks Omo)

I was using it on Mars just the other night and was getting very nice detail out of it with a 10mm Delos and TV 2 x Barlow.

Currently searching in vain for somewhere that has the matched reducer in stock, no-one can give me a firm timescale for when these will be available again (much like a lot of astro gear at the moment) , keen to try some AP with it at the reduced f stop.

Using it in Bortle 4 skies and it gives lovely high contrast views, will have to get it out to a dark site sometime (thinking Scottish North West Coast) , but no plans for a while at attempting to go anywhere till the world get back to normal.

 

[nfotis]

Regarding dispersion of planetary observation views, wouldn't an ADC help with this? (I suppose that we are speaking about atmospheric dispersion, right?)

 

N.F.

 

[Rob]

Fabulous scope. The CA is almost negligible. I miss mine lots... it only got sold for finance reasons 15 odd years ago! grrrr

Enjoy it.. I know you will.

[vineyard]

5 hours ago, nfotis said:

Regarding dispersion of planetary observation views, wouldn't an ADC help with this? (I suppose that we are speaking about atmospheric dispersion, right?)

Hi, yes that's right.  I guess an ADC would - I don't have one & have never used one, so I couldn't compare with-and-without.  But tbh, it didn't bother me at all on Mars, and is pretty much non-existent to my eyes on stars.  I'll see once M42 is up whether I can make out any dispersion on that.  If not, no need for an ADC for me (which means astro-budget can stay dry for other things ).

Cheers.

[David J H]

I've had my 102M for about 25 years, with a Super Polaris mount. All that is needed to convert the original Vixen fittings to accept 1.25" eyepieces is this adapter;

https://www.firstlightoptics.com/adapters/baader_1.25-36.4_adptr_2408195.html

However, the original 0.965" eyepieces that were supplied (20mm, 12.5mm, and 5mm) still work quite well. Observing Mars with the 5mm in the last couple of weeks has worked really well.

 

Edited October 15, 2020 by David J H

[vineyard]

45 minutes ago, David J H said:

I've had my 102M for about 25 years, with a Super Polaris mount. All that is needed to convert the original Vizen fittings to accept 1.25" eyepieces is this adapter;

https://www.firstlightoptics.com/adapters/baader_1.25-36.4_adptr_2408195.html

However, the original 0.965" eyepieces that were supplied (20mm, 12.5mm, and 5mm) still work quite well. Observing Mars with the 5mm in the last couple of weeks has worked really well.

 

That's the adapter I've pressed "go" on at FLO earlier in the week so that is v good to hear!  I like the compression ring on it (the set-screw on my current 1.25" is starting to become quite unreliable), and also that its got 5mm of fine focus travel.  So I'm hoping that that will effectively also synthesise a nice two-speed focuser - the single wheel for coarse focus, and the EP adapter for fine 🤞🏾

[F15Rules]

Great thread Vin, thanks for sharing!

I note you're a relatively recent member of SGL so you may not have seen some of the other interesting stuff about all things Vixen in previous threads?

Here's a link to a thread I started back in 2018 about Vixen gear..not just scopes, but mounts etc as well:

Hope you enjoy it😊.

I think, for many of us "oldies", the scope that we aspired to own, back in the 70s and 80s, was the Vixen SP102M.. I remember when Orion Optics UK were the main UK dealer for Vixen, they used to offer Vixen refractors and mounts right alongside their own-built Orion reflectors, and they promoted the Vixen SP and GP mounts as being ideal for mounting their 6" and 8" reflectors - but often on a pedestal rather than a tripod.

In those days a complete SP102M outfit, with SP or GP mount would set you back around £750 - a King's ransom at the time!

Your SP102 sounds like a cracking scope...as such, if you want to invest a bit in it, and really extract the very best high power performance from it, you could do worse than look for a nice GPDX mount - the real flagship of Vixens' equatorial range for years, until the Atlux came along to hold their mammoth 6"Atlux refractor.

The GPDX has even better build, more heft (but still very portable), and even finer engineering tolerances than the SP or GP, and is just a wonderful Japanese built platform for a longish frac like yours.

Thanks again Vin, for a really enjoyable read👍.

Dave

[John]

This was my Vixen SP102M. It was branded Bresser and the model was called the "Uranus". I bought it used around 35 years ago. It had one of the first GOTO systems fitted to the mount - the Vixen Skysensor. Not at all easy to use so I just used it as a motor controller. I used the Vixen .965" eyepieces to start with, then got some Unitron plossl eyepieces in the same fitting, which were better and eventually got the 1.25" adapter and moved on to what then seemed "large" 1.25" eyepieces !

I used this scope for about 4 years until our children came along and I could not find much time to observe so I sold it and was "scopeless" for nearly a decade

It was great to own one of these nice achromat refractors for a while though. I had drooled over them for ages in the "Telescope House" shop in Farringdon Road during my visits to London.

My Vixen ED102SS looks pretty much like a shortened version of the SP102M but with a 2.4 inch focuser and an ED doublet objective lens. I still have a Vixen GP mount as well. I do like Vixen equipment

 

[F15Rules]

10 minutes ago, vineyard said:

That's the adapter I've pressed "go" on at FLO earlier in the week so that is v good to hear!  I like the compression ring on it (the set-screw on my current 1.25" is starting to become quite unreliable), and also that its got 5mm of fine focus travel.  So I'm hoping that that will effectively also synthesise a nice two-speed focuser - the single wheel for coarse focus, and the EP adapter for fine 🤞🏾

It will Vin!

I used one on my Tak FS128 until recently, when I was able to acquire a mint Tak microfocuser to turn my scope into dual speed.

The Baader unit works very well and should really help you to "nail" best focus at high power.

Dave

[Stu]

Great thread Vin, just been reading it all through. Sounds like you’ve got a great scope there; achros they may be, but the figuring on Vixen optics is excellent as you have been finding out. The SP is also an excellent mount; I had one recently with an original single axis drive which I used with my Vixen FL102S, really nice setup. I sold the SP only because I also have a GP with dual axis motors.

I still have the original single speed focuser for my Vixen, but have replaced it with a Moonlite. Whilst that could be deemed to be somewhat sacrilegious, I find dual speed to greatly add to my enjoyment of the scope and a real boon for nailing focus. The fact that it is also rotatable and takes 2” eyepieces is another bonus.

I look forward to reading more about your future sessions with your lovely scope.

[vineyard]

51 minutes ago, F15Rules said:

I note you're a relatively recent member of SGL so you may not have seen some of the other interesting stuff about all things Vixen in previous threads?

Here's a link to a thread I started back in 2018 about Vixen gear..not just scopes, but mounts etc as well:

Hi Dave, yes you're right, I only joined late last year after my astro-bug was rekindled after decades during the summer.  I'm actually quite glad it was re-kindled then & not now b/c (a) it's been invaluable to staying sane in lockdown earlier in the year, and (b) I really wouldn't want to be trying to assemble kit under today's demand-supply imbalance.

So, being a newbie, I had missed that wonderful thread on old Vixens 👏🏾 They really are beautiful to look at, as well as through, aren't they.  I'll try and post a couple of photos to that in the next few days.

That is v interesting on the GPDX.  I sometimes toy with the idea of a dual rig for visual (a wide-field and a 4" side-by-side) and I think the SP mount might hit its limit at that, but perhaps a GPDX...

Great to hear about the fine focus via the EP adapter too - just need that adapter to come w some clear skies now (that's what FLO always pack them with right?).

@John I remember Telescope House on Farringdon Rd, and used to similarly drool!

@Stu I ended up going in the opposite direction from you.  I had a GP2 for a short while which I modded w some belts to make it go-to.  Unfortunately it didn't quite have the load capacity for my imaging rig so - after much deliberation & a certain amount of regret-foretold - I sold it to part-fund an HEQ5Pro.  Can't really complain b/c the HEQ5Pro does its job really well but even so.  I noticed in Dave's Show-your-Vixen thread that you have a Sphinx: how has that shaped up for you?

Cheers all - looking fwd to some fine dark winter nights!

[Stu]

20 hours ago, vineyard said:

I noticed in Dave's Show-your-Vixen thread that you have a Sphinx: how has that shaped up for you?

I sold that too! At one point I had a GP, GP-DX with Skysensor 2000PC controller and the Sphinx. All excellent mounts, I did enjoy the Sphinx but ultimately decided that I didn’t need a Goto EQ Mount. I use the GP also solely for planetary, lunar and solar observing where I just need tracking, and don’t need a huge load capacity so the GP is ideal for that. My one is particularly well fettled, very smooth.

The Sphinx is a very compact and comparatively lightweight mount vs the GP-DX, and needs less counterweights game due to the design which effect my uses the electronics to help offset the scope weight.

[MercianDabbler]

Just found this thread - couldn't agree more. The Vixen is great.

Mine was bought on a Saturday afternoon outing to Telescope House around 1988. I chose a refractor because although my preference is for looking at galaxies and nebulae I knew that I would be an 'off and on' astronomer... and so it has proved but the Vixen can be relied on to lie dormant in its box for ages on end and still perform when I want to drag it out and try to remember how to work it. It's also a suitable size for packing into the car to escape my local light pollution.

I never had the Vixen eyepieces - BC&F traded these up to two Meade Super Plossls (6mm and 24mm) and swapped the eyepiece fitting when I bought it. It does have the original Vixen RA motor drive which still does its job. At the time I thought 'I can always buy the decl motor later'... wrong!

The pic below is a bit rubbish (didn't even have the dew tube on) but the 2016 transit of Mercury was one of the few occasions when the scope has been out in the daytime.

My initial good intentions about photography never materialised during film days but a Canon DSLR now allows me to attempt to muddle my way through some AP.

Since the pic I've added an ADM dovetail on top to piggyback a cheapy Skywatcher ST80. A couple of weeks ago I finally got around to adapting a couple of 1.25kg weight training weights to balance the extra weight ahead of my trip to Exmoor. The scope and its little friend did their job well on the trip - a shame the operator was quite so out of practice!

In terms of future plans...

1. I'm wondering if there is any way to update the polar alignment scope in the mount (or maybe just the diagram from the manual) - the indicated Polaris positions ran out circa 20 years ago... plus I still don't understand how to set the polar alignment scope dials.

2. Two eyepieces seems too few but I'm undecided about what would be a worthwhile addition.

3. Maybe some filters - currently I only have a sodium light pollution one which now seems like yesterday's news.

4. Getting the thing pointed in the right direction can be a faff so maybe a Rigel finder? I'm against sticky pads though so will need to find a better way to attach it.

[vineyard]

I think its brilliant that you can remember what day of the week it was that you bought it - says it all about how important buying a scope should be: a memorable occasion  

It does look naked without the dew shield though!

For polar alignment, I've given up trying to remember how those dials work.  Instead I use a free app on my iPhone called PS Align.  It shows me where on a clock face Polaris should be for my location & time.  And then I just look through the polar scope and try & get Polaris roughly there.  For visual I find that's good enough & things stay where they are meant to be when it tracks.  But I have a dec motor so that does make tweaking things a bit easy in all 4 directions if the alignment is too far off.

I'll defer to others w greater EP knowledge, but if you have 6mm & 24mm then maybe something in the middle?  I really like the way a 12mm works in mine. but I reckon a good 18mm would be pretty decent too?

Cheers

(PS re pointing, I think I'm going to go with a Telrad)

[MercianDabbler]

1 hour ago, vineyard said:

I think its brilliant that you can remember what day of the week it was that you bought it - says it all about how important buying a scope should be: a memorable occasion 

For polar alignment, I've given up trying to remember how those dials work.  Instead I use a free app on my iPhone called PS Align.  It shows me where on a clock face Polaris should be for my location & time.  And then I just look through the polar scope and try & get Polaris roughly there.  For visual I find that's good enough & things stay where they are meant to be when it tracks.  But I have a dec motor so that does make tweaking things a bit easy in all 4 directions if the alignment is too far off.

(PS re pointing, I think I'm going to go with a Telrad)

Definitely a Saturday. That was before the Interweb so you had to actually go and fetch things. Probably 2 hours journey each way... plus I wouldn't fancy driving into London on a weekday then or now. It was well worth a trip to BC&F anyway - I can't imagine having the discussion and swapping the eyepiece fitting on a scope as part of an eCommerce transaction.

I'll check out that app, thanks.

The Telrad does look like a good bit of kit but I'm probably already overloading the SP mount so I'm thinking that the Rigel will add less weight while still hopefully doing a decent job.