Mars 29th Sept

[vineyard]

Hello,

After being re-motivated by @Fozzie's lovely report from earlier this week, I set up the last couple of nights with my old Vixen 102M, on a roughly polar aligned SP mount, previously modded w Vixen motors on both axes (photo below).

Mon night was cloudy & a washout.  But last night around 2300-2330 I noticed the skies were clear enough, though clouds were passing through.  So I quickly set up and am very glad I did!

Ended up using an old 12T2 w a 2.5x powermate for 200x magnification most of the time.  (Did try a 9mm Delite w that but the image wasn't stable enough at 278x - I could see the shadowy shapes of features but could not focus sharply enough - so perhaps I was pushing it too far, or perhaps it was having to rely on manual focusing of an old single focuser: my hunch is electric focusing w a 2-speed could have given surprising results?).

As for Mars itself, I've never seen more or better.  There was definite blue tinge & red tinge to the top & bottom half of the disc, which I guess is the CA from the achromat.  But just sitting w the disc and letting the features emerge really paid dividends, esp as clouds passed by and then seeing seemed to improve.

The SP mount held the rig - and tracked Mars - brilliantly (even with a 12T2+2.5xPM sticking out!).  Some v occasional tweaks with the motor but didn't really need to re-center at all.

I don't know my way around the features so the drawing below is a rough sketch from memory (so the precise relative positioning may not be accurate), overlaid with what I think are some feature names based on other maps & reports which I went & looked at after doing the drawing?  I remember thinking that the darker features reminded me a bit of a chromosome.

The most surprising bit was when all of a sudden I realised that the S Polar cap was sharply & clearly visible.  It just popped as a clean white, sharply differentiated area within the edge of the disc.  Even my wife was easily persuaded to come & see that!  It still feels amazing that there we were looking at ice caps on another planet! 🤩

The 12T2+2.5xPM combination was great.  That is a lovely old EP.  I was v pleased w the SP mount motor-tracking as well.  And I can see why the 102M is regularly called a classic scope - if only I could put a 2-speed focuser cost-effectively on it (Scopestuff in the US seem to be the only people who make something for that, although my scope is one of the older versions with a 111mm inner diameter...).

Hopefully the skies will be clear for actual opposition!

Stay safe all,

Vin

Edited September 30, 2020 by vineyard
typo - the EP was 12T2 not 12T4

[Nik271]

Nice report, Vin! I was observing around 2-3am this morning and I agree with you: the seeing was excellent despite the clouds and Mars was superb. In fact this was the best view I had so far.

I managed to push to x300 with a Skymax180, image was getting a bit soft but in moments of clarity Mars was like looking at it from orbit. I grabbed my camera and took some pics. The overexposed image below is pretty close to my view in the eyepiece with neodymium filter.

I think your identification is correct. In my view from 3am Syrtis Major was on the limb and Sinus Sabaeus in the centre.

  

Sadly the weather forecast for the rest of the week does not look promising here

 

Nikolay

[vineyard]

Thanks @Nik271 - wow 2-3am is dedicated 👍🏾  That's a great picture - I'd be pretty chuffed if I managed to take one like that - I'm going to try once the clear skies come back again.  So far maybe the 8th or 10th Oct look most positive based on conventional weather, but who knows? 🤞🏾

Cheers,

Vin

[Nik271]

Thanks! Let's hope we get some good seeing for the opposition.

By the way this web page shows what Mars features are visible at any given time:

http://www.nightskies.net/mars/mars.html#

I found it more useful than the standard Mars maps. Some people also use SkySafari, but I haven't tried it myself.

 

Nikolay

[John]

Nice report Vin

Great scope and mount - I used to have one !

The red and blue tinges top and bottom might be atmospheric dispersion rather than false colour from the scope.

On the focuser, in an F/9.8 scope I think the stock Vixen rack and pinion works well when properly adjusted. If you feel you really need to change you could put a Moonlite dual speed on the scope as I did for a while with my Vixen ED102SS. Your tube is the same diameter as mine:

 

[vineyard]

Thanks @John. Hmm, is there anything that can be done about the dispersion - I've heard of ADCs but for some reason thought that they were only for reflectors <probably a v silly misconception!>.  @Fozziementioned he used a Baader semi-APO filter in addition to the neodymium in his review - would that help mitigate dispersion too?

I have done some tinkering w the focuser (the slop on it was too much - you had to keep the locking screw fully shut to stop even just gravity drawing it back) - maybe I over-tightened it, I'll see if I can find a sweet spot.  I think what I'd really like is to try and attach something like a DeepSkyDad to it b/c I have a heavy touch w manual adjustments (I've put a DSD on my imaging setup and the difference is palpable) but I think those need a 2-speed focuser?

Thanks re the Moonlite tip.  I think Feathertouch also do one.  I just pause before that level of expense compared to the cost of the scope - if it was an ED102SS like yours or a 102FL then it'd be an easy call!  (Esp as, if I'm going to get a new FT or Moonlite, it'd have to be one for the Lunt 50 first).

Btw I have to say that I came thiiiiiis close to pulling the trigger on an ED102SS that was up on UKABS recently.  Driven in v large part by your review of it, and similar feedback from our transatlantic brethren.  But it'd have meant letting the 102M go (can't really justify both) and - as another SGLer posted recently about the dilemma of letting old kit go for something fancier - I really struggled with the idea of seeing the old 102M go!  (Probably just as well that I've never looked through an ED102SS - you can't miss what you haven't experienced )

Cheers!

[John]

An ADC is the tool to use if it is atmospheric diffraction and it bothers you. Personally I don't use one.

The Feathertouch is in a different class again from the Moonlight - I have one on my LZOS/MB triplet. But the price tag is a heck of a lot I appreciate that.

I now have a Vixen R&P back on the ED120SS and find it quite OK.

Here are Vixen's instructions for tuning up their R&P focuser and if followed carefully, they do work well:

vixenfocuser.pdf

[chiltonstar]

I've found that even with Mars as high as it is, there is some atmospheric dispersion (using a 180 Mak) and an ADC helps, certainly the N and S polar areas look a lot better/clearer than without. With my 102mm Vixen objective f13 frac, there is less apparent AD although if I wind the magnification up to the same levels I would use with the Mak, I think there's probably not much in it.

Chris

[F15Rules]

Great report Vin👍😊.

Although a reasonably experienced general observer, I am a pretty much complete novice when it comes to Mars to be honest, so I found this thread very helpful, thank you.

It's really whetted my appetite for more prolonged and detailed studying of Mars...now I'm retired, and we have the best opposition of Mars for several years imminent, I just hope we get some really still, steady skies to make the most if it in coming weeks!

You have a great setup there, btw. I owned a couple of SP102Ms in the past, and really enjoyed them, and the Vixen equatorial mounts IMHO are still today far superior than the chinese clones.

I did "graduate" to a later Vixen ED103s (very similar to John's ED203SS, but operating at F7.7 rather than F6.5), and honestly, it was a revelation, a real step up from the SP102M in every way see below).. The later ones also come with a very good dual speed R&P focuser. When you think that these had a retail cost of c £1700, yet you can get a good used one for around £600-£700, they represent great value and willi last you a lifetime.

I was eventually lucky enough to acquire a Tak FS128, but the two ED103s scopes I owned were both superb, and incredibly potent when matched with a GP or GP/DX mount.

Thanks again for a great post 😊.

Dave

[vineyard]

Thanks for the v kind words Dave @F15Rules - I still can't get over seeing ice on another planet with my own eyes.  And thank you also re the setup - yes I love the well-engineered stuff.  There's a craft to it which I think lives on in the objects.  I used to have a GP2 which I modded for go-to for imaging purposes.  In the end I had to let it go v reluctantly b/c my imaging kit was undermounted on it so I had to switch to a belted HEQ5Pro.  If their equivalent of that was a bit cheaper, I would definitely have stuck w Vixen.  I can't envisage ever letting go of the SP though - its perfect for visual for me.  The Vixen motors (swapped on from the GP2) are so quiet, and its great to be able to just focus on what I'm looking at and let the mount and scope do their thing.

Btw you're not supposed to say such nice things about the Vixen EDs pls - I'm trying to avoid non-buyer's remorse re that ED102SS 😂!

In fairness, I'm lucky in that my imaging rig is an old TV102iis (w the 102M used as the visual).  The TV is a lovely scope - I really like that it is designed for BV'ing.  Eventually I'd like to be able to use it for visual as its meant to be & have an even better imaging scope.  But until then its drafted in for imaging & I can't really complain about that.  Wow re the FS128 - I can only imagine the views!  One day maybe I'll have a Tak 🤞🏾

And that's a beautiful setup you have in that photo - is that an original Vixen wooden tripod?

Here's to some good seeing coming back for us all soon, and looking fwd to your report on Mars through the FS128 then!

Stay safe all,

Vin

[Alan White]

Nice to read that you had a good view and enjoyed yourself Vin, I too was out and enjoyed similar views and conditions.

I was using my fine ED103s Vixen, which I highly rate, it’s a stonking scope and a bargain used.

Mars is truly giving this time round, not a dust storm in sight......thank goodness.

 

Edited October 2, 2020 by Alan White

[F15Rules]

4 minutes ago, Alan White said:

Nice to read that you had a good view and enjoyed yourself Vin, I too was out and enjoyed similar views and conditions.

I was using my fine ED103s Vixen, which I highly rate, it’s a stinking scope and a bargain used.

Mars is truly giving this time round, not a dust storm in sight......thank goodness.

 

Yes, Alan, my "stinking" ED103s gave "stonking" views!😂🤣😂

Vin, the wooden tripod isn't a Vixen, it's a home built (not by me) affair which I've had about 10 years, fixed height and very robust - in fact, these days it carries the FS128 on a Tak EM2 mount. The fixed height isn't a problem as I use a variable height observing chair.

Your TeleVue scope sounds great, I'm sure it would probably match the ED103s in a head to head. I really like the Vixen oversized aluminium tubes though..they look impressive but are actually very lightweight.

Clear skies all!

Dave

[Alan White]

Darn autocorrect strikes again....

Clealy stonking not stinking was my intended wording, it nearly corrected again as I typed this!