vineyard

7 hours ago, John said:

I currently use a Baader T2 Zeiss prism diagonal in 1.25 inch mode with my Takahashi FC100-DL. I'm thinking of moving to one of the Baader 2 inch Zeiss prism diagonals with this scope so that I can use my 2 inch eyepieces such as the Ethos with the Takahashi.

Hi John, I can't answer your Q I'm afraid but in case you do make the switch & want to shift your current diagonal, I'm after something like one of those for the 102M so pls can I be v cheeky & throw my hat into the ring early in case you do! 😇 Cheers, Vin

Just now, happy-kat said:

Have you tried a stack with no calibration files as I'm seeing uneven tone across the image.

The flat file shown further up had a dark round middle area.

I've tried without flats & dark flats (in the thread above).  If you mean try w/o darks even, sure can try that w DSS to see what happens - will post later.  Cheers!

Hello,

I took out my new EvoFlattener for a spin on the Evoguide50 earlier this week.  Ever since I got a 2nd hand Evo50 last year I've been tempted to try wide-field AP on it.  At that time, Starizona were the only ones doing it so I put myself on the back-order queue.  But it still showed no signs of shipping, so when SW released one, I switched (the SW one is also a doublet ED w FPL53 elements apparently, and is cheaper - and available - than Starizona).

The photos below show it next to a hosepipe attachment for scale, and then attached to the Evo50 and an ASI294MCPro.  I'd got the mount 3D printed by Philippe at Astrokraken.  He'd actually made it for the Starizona measurements, but as you can see it fits the SW one as well.

Attaching it is very straightfwd - basically thread off the original camera receptacle, and thread the flattener on.  And then thread the camera on - it needs 17.5mm back focus.

My only go-to mount is an HEQ5Pro, so it was definitely overmounted!  But it still need balancing for weight.  The HEQ5Pro weights were too heavy though - luckily I had an iOptron SkyGuider Pro weight which fit, and which balanced it perfectly.  That's a good sign since it means it would work in the field on that.

One mistake I made once mounted was that I tightened the camera holder ring snugly before I focused.  So when I was looking at EKOS focus module and turning the helical, there was no change in star image.  Then I realised what I'd done, loosened the screw on the camera ring, found focus and then tightened it back again.  Finding focus was v easy b/c Philippe includes a bahtinov mask - my first time using one, and so much easier.

A couple of wrinkles I've noticed on first use - fixable in different ways I suspect.

1.  There's no easy way of putting a LP filter on.  There are threads on the front of the Evo, but they are too big to directly attach a 2" filter.  They'd need adapter rings which I guess you can get made from a camera shop?  This would make the aperture slightly smaller though.

Alternatively, you could use a 1.25" filter on a nose attached to the camera, but then the camera won't be able to thread on, and you have to use the three placement rings to hold it, which I don't like the idea of for stray light entry.  I may be missing an obvious fix to that w a different type of adapter.

[EDIT 2: there does seem to be a way if you have a ZWO camera.  Using this which I believe comes as standard w some cameras - thread the filter into that, and then thread that into the camera, and then thread the remaining T2 threads onto the flattener.  I tried that today and was still able to find focus on v distant terrestrial objects so hopefully that will also be the case w stars - in which case, great!]

2.  There is vignetting, at least w an APS-C size chip like the ASI294 has.  I suspect it may be caused by the front edge of the helical focuser in the Evo?  I guess you could crop the image, or alternatively use a smaller chip size - or, if using a front-mounted filter, maybe the smaller aperture will also kill the vignetting.

[EDIT: another possible thing might be to take a bit off the front of the helical...]

There is a test image below of M31 to show the flatness.  Nothing done to it other than DBE in PI.  There is still some curvature in the top right corner (and I think also a bit in the bottom left).  @vlaivalso noticed some slight astigmatism in the corners, in this interesting detour that happened when I first tried to use DSS to stack.  It looks like the edge effects caused by the vignetting, combined w DSS quirks, can lead to weird "halos" in the overall image shape - these are much less present if stacked in PI (a tip from Vlaiv!).  I'll play with this image a bit more to see if those weird halo gradients disappear in processing.  Else it's probably better to use a slightly smaller chip?

I also grabbed an hour on each of the Perseus Double Cluster & M45 so I will play with those to see what PI-stacked and PI-processed images come out like.  Will post them in the Imaging forum.  If they come out ok, then this is a nice little wide-field AP set up that can be put on a SkyGuiderPro type of mount - and is a lot cheaper than a Redcat!

Cheers,

Vin

You were right!  Here are two images - weighted-batch-pre-processed & then integrated in PI (linear fit).  Only difference between them is DBE (the first one) and ABE (the second one).  Both downsampled for size.  Halo is still there a bit which I guess must be there b/c of the physics of the vignetting (?) but its a lot better than w DSS.  (I couldn't dither as the Evo is normally my guidescope, so I wonder if that might have helped a bit).

It took about 4x the time to stack though but if it produces better results, then so be it - lots of cloudy  nights ahead so plenty of time to work on the double cluster & M45 captures as well 😆

I think in the PI stacked versions, the ABE seems the better image to do further processing on (which is definitely not the case w the DSS versions)?

Thank you again @vlaiv- I would be lost & tearing my hair out without these sorts of tips & guidance so they are highly appreciated.

[EDIT: the ABE version seems slightly 'warmer' in tone than the DBE version so I'm not sure yet which one I'll work more on]

Apologies @vlaiv, I meant the overall shape (I didn't even notice the slight astigmatism in the corners!).

Yes I think you are right on the combination of two different things - stacking & ABE.  Here is the same TIF run through DBE (downsampled just for size here) - the halo effects are less.  Still there but less - and I think its the vignetting that may be exacerbating those, because its basically along the edges of the largest rectangle that would be formed if you stayed inside the vignettes?

Do you think that would not happen if I used a different stacking program (eg PI instead of DSS)?  Or is it better to just crop & take out in post-processing (or use a smaller chip like an ASI183)?

I also thought flats should remove this but it looks like it didn't?  @Stuart1971 here are two images - both without flats or dark flats applied, one run through ABE, the other DBE).

On the flats, when I was taking them (on someone's light box) I did notice the channels were quite different - see attached screen-grab from an example flat FITS.  I just couldn't get them to align w different exposure times - I wasn't sure if again that was from not having any filters in the optical path.

Eventually I need to figure out a way of putting filters in - right now it looks like one way would be to thread a 2" in front of the OTA (w a ring-step down) - maybe that would also remove the vignetting as it would reduce the aperture slightly?  Otherwise a 1.25" further along the path, but there doesn't seem to be a natural place for it (it'll need another adapter!).

Cheers all!

Oops sorry ASI294MC Pro.  I've used that w my larger frac without those halos (but w filters).  Cheers

Hello,

I just got one of the SW EvoFlatteners (gave up waiting for the Starizona one).  Took it for a spin earlier this week.

The image below is 60 lights of 60s - darks, flats & dark flats applied.  Darks & lights done at the same temperature, exposure time, gain & offset.  Flats & dark flats similarly.  Stacked in DSS, and then all that's been done is ABE in PI.

There is vignetting for sure.  And I think this camera & scope combination is quite under-sampled.  But the flattener seems to be working, although top right corner & maybe bottom left corner still have some curvature (vignetting means they'd get cropped out anyway).

But what is going on with the 4-lobed flower-shaped halo?  Is it pinching - but the star shapes seem ok?  Is it a stacking artefact? (I also attach the stacked TIFF & a single light FITS file - if I do ABE on the single FIT the ABE background that's extracted is a different shape from that in the stacked TIFF, and also the single FIT doesn't seem to show a halo although perhaps its there but just v faint?)

Any ideas?

I like the wide-field this flattener potentially allows me to capture (also took some of the Perseus double cluster & M45) but not if this halo will always be there.

Thank you & stay safe,

Vin

(PS - I didn't use any filters, so could it be something to do with that and the chip - some IR sensitivity?)

(sorry the files are so big, didn't want to upload compressed files in case the compression created artefacts too!)

Autosave.tif M31 EvoFlat 201009 60s neg10 gain125 offset16_Light_001.fits

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!

Sounds blissful - I need to brush up on my use of setting circles and then I want to check some of those you mention out, thank you!

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.

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.

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

It was a great night wasn't it.  A lovely sketch 👏🏾 & a nice pencil. Someone asked me recently how would you describe the smell of a freshly sharpened pencil - I couldn't put it into words!

Hello,

This was around 0140 this morning. 4" apo (f/8.6), Baader Moon & Skyglow neodymium filter, no ADC, ASI178MC, 2.5x Powermate.  AS!3, best 500ish of 1k frames.  The stacked image was then broken in R, G & B channels in PI, and each put separately through Imppg, before being re-combined in PI.

Focus could be better but I was doing it manually rather than w a micro-stepper.  Conditions seemed quite unstable at times - I couldn't make the icecap out visually at c 175x although it was popping out vividly at 200x last week.

Hope we all get some more chances in the next few weeks.

Stay safe,

Vin

(Rookie planetary imaging errors included not picking a smaller ROI to increase the number of frames captured, not using electric focus, not having a contrast filter...will try & post longer report in observing section 😂)

That's a great drawing.  We must have been out at the same time (myself only with a little 4" frac though).  It was quite unstable wasn't it - I tried some lucky imaging which I've yet to process so will be interesting to see.  I couldn't see the polar icecap last night (did manage last week) - not sure if that was the instability or whether I was running lightly lower magnification last night.  I think your sketch also includes Hellas, which I've subsequently learnt is one of the biggest known impact craters in the solar system!

5 hours ago, GavStar said:

@vineyard I’ve just measured the ota and it’s 23cm without focuser or internal etalon, 29cm with focuser no etalon, and 33cm with focuser and etalon. As Mark says I’m visual only for solar but maybe one of my local club members such as @PeterW may have a go at some imaging in triple stack mode at some point.

Thanks @GavStar - wasn't too far & that's good to know.  I'm going to try a tweak to my Lunt 50 mod with a GPC in the optical train in front of the etalon to try and be able to position the etalon 140mm in from the adjusted prime focus.  Let's see.  I love seeing the amazing images that folks post (such as the one @Nigella Bryantdid above) so I'm trying to see how much I can tweak my setup vs reconciling myself that there's an upper limit to what you can mod to w a Lunt 50 😂).

Intrigued to see the thread b/w you and @Highburymark above about the Lunt 60 vs Solarscope - I was under the impression that Solarscope etalons were hands down in a better league?

Cheers all

2 hours ago, Louis D said:

Probably no worse than a chromed brass barrel.

You're right - I never thought about it that way!  (The existing barrels on these EPs are black and so I just went with that...😂)

1 hour ago, Louis D said:

You might try aluminum foil tape on the insertion barrel.

Hadn't thought of that either - is there any risk of the aluminium somehow creating reflections (even though its on the outside of the insertion barrel)?  Cheers

Oops apologies @DaveL59 - the EPs would be 40mm plossls & 25mm microscope EPs as the ones w the largest ERs (quite distracting).  The inner tube idea is great!

Ah ok re the barrel change - duck tape it is then.

Cheers

Hello,

Cloudy day-and-night tinkering continues.  Two Qs pls for tips!

1.  I'd like to get eye-cups for a few EPs where the ER is quite long - what would folks recommend?  I know Televue have eyeguard-extenders but that will become far too expensive too quickly.

2.  Barrel change.  I have a couple of EPs where the barrel diameter is somewhere between 29.5-30mm (ex-microscope pieces).  So they rattle around a bit - luckily the compression rings can tighten enough to hold them firmly in place, but it becomes slightly annoying when changing them.  I'd ideally like to change them to 1.25" (31.75mm) barrels.  The current barrels thread in - so can be unscrewed off - but unfortunately the thread-size is different from that on normal T2-1.25" adapters (typical!).  I'm leaning towards just putting some black duck tape around the outside of the existing barrels as that should do the job, but thought I would check in case anyone had any other tips from prior experience w microscope EPs?

Thank you & stay safe,

Vin

That looks intriguing @GavStar, looking fwd to hearing more & seeing some images hopefully.

Was wondering if I could ask a quick Q pls?  Would you be able to share what the length of just the OTA is?  I'm going to hazard a guess that its around 275-280mm but can't see that in their manual.

Reason for asking is that I have an FPL-51 f6 refractor (72mm aperture) and was just tinkering to see if I could get it to work by putting my Lunt50 on the back-end - like I am able to w my 4" frac.  And that franken-setup doesn't quite find focus in the 72mm although it does in the 102mm.  Which was puzzling me until I remembered what @Merlin66had mentioned when I was doing my original 102 solar-mod tinkering.  Namely that w a Lunt50, the etalon needs to be around 140mm in from the prime focus point.  Which unfortunately I'm j-u-s-t a few cm short of in my 72mm...

So I'm curious if that Lunt60MT OTA is a slightly shorter than normal one to allow that etalon to be 140mm in from the OTA's 420mm focal length.  I suspect that might be the case b/c their manual also interestingly says that for night-time viewing, 2" diagonals should be used and that if 1.25" diagonals or cameras are to be used then extensions are needed (which would be consistent with a slightly short OTA and only so much travel available on the focuser?)

Anyway, I figured instead of continually guessing, I'd just ask 

Cheers & looking fwd to seeing what a triple-stacked image looks like!

Vin

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

11 minutes ago, Neil P said:

Well I sent my binoviewers off to Denis to be re-collimated and we agreed he would supercharge them while he had them. First class service from Denis they are back better than ever, he even repaired the paint chips on the casing.  Would highly recommend Denis to anyone thinking of supercharging their binoviewers.

Late to this thread.  Sorry to hear that Denis' wife was poorly.  Glad to see he's back in action & that he fixed your BV.  I got mine from him last year I think (time just blurs into one lump pre-virus) and they're brilliant.  He's v responsive so I would echo your endorsement of him for anyone else thinking of BVs.

I have a Pentax K70 (or rather its my wife's which I borrow to experiment with ) and got an Astrotracer module for testing this summer as a v light travel possibility.  The Astrotracer itself is small, light and easy to use.  You have to calibrate it when you switch it on, but its not that problematic (rotation around 3 axes) - for AP they recommend a more sensitive type of calibration which can take slightly longer.

I didn't use it that much in the end b/c I was able to use a Skyguider Pro which allowed much longer imaging time (the AT says up to 5 min exposures).  Also tbh I haven't taken to DSLR imaging that much.  Because infinity focus on the lens isn't actually infinity (it overshoots it) you have to dial back the focus ring (at least on the lens I have) which means focus is subject to driver error wrt heaviness of touch & relying on my eyes on a live-view screen.  The other thing w Pentax I've noticed is that the EKOS driver is still under development so if you want to drive it via a laptop you have to use the older INDI driver which I believe is so-so.  (There are people working on it on INDI forums, but I haven't checked lately how far they've got).

The other thing I've noticed w Pentax is that the images are large in memory terms (but maybe that's with all DSLR images?) so the microSD card can fill up & batteries run low (you can run it off transformer power tbf with a gizmo).

The only other thing that comes to mind re the Astrotracer is that depending on what the skies are like, if you're going to run up to 5min exposures, you might need a filter.  Where I am (Bortle 8) if tried to take a 5 min RAW exposure w/o filters even on low ISO setting I think it would all be blown out?

Hope that's helpful.  It is a very good camera, and the AT function is pretty clever - I think if you can pair it with a clip-in filter, then it makes for a very versatile & lightweight travel kit where you don't want to (or can't) take multiple lights over a longer time-frame.

(Unless they've changed the software - if you use the AT, I don't think you can pre-program it to take multiple exposures; you have to tell it to take another photo again and probably nudge the camera along a bit since the object will have moved while the camera body itself stays static).

Cheers,

Vin

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!