Luna through a Telementor

[vineyard]

Hello,

I recently swapped my Primaluce 72ED apo w @sungazer's lovely Telementor setup.  Had a chance to sit with it & the moon for a decent chunk of time last night.  It was beautiful.

Being inspired by some of the amazing sketches on SGL, I thought I'd try my hand but am v-e-r-y rusty (don't even have proper pencils) - one thing I've noticed is that sketching definitely makes you pay more attention on what you are looking at.

Anyway, not knowing my way around the moon that well, I instead sat down at the scope w a 2nd hand copy of Cook's Lunar Atlas, and a handful of EPs (the 25-H & 16-O that came w the Zeiss, and a Delite 9mm & Nagler 3-6mm Zoom).

Spent time looking at:

• Copernicus, Fauth A, Reinhold, Mons Wolff
• Ukert, Pallas, Murchison, Triesnecker, Menelaus, Manilius
• Clavius, Rutherford, Longomontanus, Blancanus, Scheiner, Wilhelm, Heinsius

It was really nice. With the CZJ EPs, it was as if there was no glass in the way. Just so sharp - crisp clean pinpoint viewing, and really well framed. The Delite 9mm also held its own v v well - I think v much the same sharp details & subtleties as the 16-O, except w Luna filling the FOV.  I think the 16-O perhaps gave a better overall aesthetic, but to be fair w a LFL comparison, I suppose I should compare the DL9 to a 10-O to see if the higher magnification was slanting the comparison either way (how much does a 10-O sell for these days - oh ok maybe not then 😂)

I also took a Baader Contrast Booster filter with me but tbh I ditched it v quickly.  It really wasn't adding anything (in fact it seemed to be taking away from the image?).  The scope and the EPs were sharp enough straight up - and I guess w the exit pupil being quite small, it wasn't too glaring on the eyes at all - very crisp & cool.

I also played with the Nag Zoom a bit.  There were moments of good seeing when I could take it to 3mm (280x on a 63mm scope!) and it was still v sharp!  But most of the time I kept that at 5-6mm settings (140-168x).

Seeing the lunar maria and the subtle dips and rises and features (and scattered 'newer' smaller craters), and the bigger older craters, the little peaks within the craters, the shadows cast by the mountains, was quite hypnotic.  Need to figure out how to BV it now!

I'm seriously impressed & v happy w this scope.  It should be great for lunar.  The gunsight finder is easy & bang on.  The focuser is also smooth - no backlash.  The TM mount is butter smooth.  Fine control only moves you so far equiv to 30 mins stellar motion I believe, clearly less w the moon), after which you have to reset it, but for general observation that's not a problem.  For sketching I guess it would be helpful for it to be driven like a Telemator mount.

A really nice scope.

Stay safe & clear skies all,

Vin

(PS - I really want to do a side-by-side w the Telementor & my Vixen 102M.  From memory it looked like the Telementor had much better colour (I couldn't see any false colour on the limb or anywhere else) - and the Vixen is no slouch there.  So is it better glass, or longer f/l, or both?  When I looked at the limb through the DLT9 it looked e-v-e-r so slightly more yellow-ish in places...but I could be mis-remembering.  I say this b/c I subsequently came across this post on CN where the comment from Kevin Barker is intriguing and could be consistent w what I thought I noticed?  Only way to make sure is to do a side-by-side!)

[John]

Nice report. I think the Telementor is F/13.3 (840mm focal length). That and the smaller aperture will make a big difference to the amount of CA that the objective produces:

As can be seen from the above, a 60mm F/13 achromat will be producing noticeably less CA than a 102mm F/9.8 (the Vixen 102M). No special glass needed !

[markse68]

Nice report Vin- it is a lovely old scope isn’t it 😊 I must take mine out for a spin sometime soon as it’s been a while. It really is lovely on the moon I remember- so contrasty. I noticed there’s been 3 sold in close succession on ebay lately- like buses they are! (quite a few Tal 100rs too!)  The only time CA became bothersome I remember was on Venus but that was so small and bright and glaring anyway.

Mark

[Stu]

Great report Vin, welcome to the Telementor club. I’m on my second now and will hold onto this one. They certainly do have something special about them, on the Moon and also double stars. Mine is an OTA only, Telementor II but I enjoy using it on either an Ercole or Vixen GP mount.

I can echo your comments about using a Nag Zoom all the way up to x280. It had no right to maintain image quality up to that point but it did, when the seeing allowed. The biggest problem for me is floaters at those exit pupils but still, amazing.

Also amazing that these old scopes are still delivering after so long, built like tanks aren’t they? 👍👍

[vineyard]

Thanks all. @John that table is v interesting - so I wasn't just imagining (or mis-remembering) it!

@markse68& @Stuyour various posts on the Telementor were v helpful when I was researching the swap offer.  I wouldn't be brave enough to take the scope apart like you did Mark, but luckily @sungazerhas looked after it so well, that there is no need.  Yes, I saw the eBay activity too - I wonder if the steamy price that the first one sold for drew the others out?

Stu, yes I won't be letting this go - especially after seeing that CA table.  I might tinker with it though  incl possibly putting some rings on it so that I can mount it on my driven SP for when I try to be brave enough to sketch (I somehow think a Telemator mount will be too rich & rare for my taste!).  The floaters were quite noticeable, but hopefully once I can figure out BV'ing this, then they'll reduce.  And for sure re the build quality - the thought that has gone into all the little things on the mount - it really is as smooth as butter, and the setting circles work (I had to learn the hour angle method but it's quite straightfwd & now I can get more or less where I want to get to!).

Here's a pic of the setup from earlier yesterday evening  v happy to be part of this club!

Stay safe all,

Vin

[vineyard]

Great conditions last night until the fog eventually rolled in.  Stayed at 3mm on the Nag Zoom all evening - 280x was crystal clear & effortlessly sharp - even the floaters calmed down after a while, wonder if could have gone even higher?

Spent most of the time around Montes Harbinger (was able to easily & clearly see features as small as 3km across) & J Herschel areas. Some very poor sketches below (some relative placements could be better, esp the features at 2pm in the Montes sketch).  I've used quickmap.lroc.asu.edu to help identify features.  Is there a way (or an alternative source) where you can put in your location & time, and it shows you the moon in the orientation and w the terminator location as you would see it?).

Stay safe all.

[markse68]

Hi Vin, wish i’d gone out last night as by all accounts the seeing was excellent too but by the time i got home it was already quite misty. 

Moon Chart app is pretty decent and the SkySafari  pro moon is great- you can search features and click on image to get names. Both can be orientated to scope view and show terminator.

Your sketches are great— I want to start sketching the moon. I have an ambition to do a detailed full disk like the antique maps of Cassini etc 😉

Mark

[vineyard]

Thanks Mark - that's v kind. Not a patch on some of the sketches other SGLers share, but hopefully w practice they'll improve.  I want to get to the stage of being comfortable using black paper (feels like there's nowhere to hide w that!).  That's a great idea on a hand-drawn full disk map.  I'm finding that sketching really makes you observe better - I notice & appreciate more things.  And the way the features change their appearance depending on the angle of sunlight is quite something.

Thanks too re those app suggestions - will check those out!

Cheers & stay safe

[F15Rules]

Great report Vin..and lovely sketches too! The Telementor is a cracking scope, I've owned several, and yes, you can binoview with them.

I'll see if I can dig out a few pictures of the setup I used and how I set it up, and post them on this thread😊.

Dave

[F15Rules]

Vin, I've found some detail that might help you..so as not to deflect your thread I'll send you a pm with the info..👍

Dave

[Stu]

1 hour ago, F15Rules said:

Great report Vin..and lovely sketches too! The Telementor is a cracking scope, I've owned several, and yes, you can binoview with them.

I'll see if I can dig out a few pictures of the setup I used and how I set it up, and post them on this thread😊.

Dave

That’s interesting Dave. Can’t recall if I’ve managed that successfully with mine or not. I do have a Baader Clicklock on the back of my Telementor though so that may take up some backfocus. Will give it a go next time the skies clear.

[F15Rules]

Hi Stu,

Sending you a pm..

Dave

[estwing]

Fantastic little scope..

[Stu]

Thanks for the inspiration @F15Rules, I’ve just tried the Telementor with my Mark IV Binoviewers and can reach focus using a x2.6 GPC. This is with a T2 Zeiss prism and 25mm Orthos. This reaches focus fine and I can fit the whole Moon in with a bit to spare. It would be more comfortable for full disk with a slightly bigger fov so I need to experiment to see if I can lower the power at all with a different barlow combination or just use 32mm Plossls.

I also rediscovered my Unitron alt az mount which is perfect with the Telementor, very good slow Mo controls which are easy to reach.

[F15Rules]

Hi Stu,

Looking good!👍

Yes, it does look as if your click lock will use up some backfocus.. below are pictures of my bv setup in the Tak..I did previously have a Tak Clicklock, but was advised by others that this setup would free up some precious backfocus...even a few mm can make the difference between getting focus or not.

The M72/M68 adapter has 10mm optical length.

The Ultrashort Clamp M68-2" has 12.4mm optical length.

Total backfocus consumption is therefore 22.4mm.

I should add that the Maxbrights MKI bv I was using has direct T2 connectivity: the total optical length of these bvs is 110mm.

Therefore, total optical length of that setup was 132.4mm.

Your MK IV  is T2 compatible Stu, but I don't know what it's optical path length is?

Also, I can't recall what the optical length of the Zeiss visual back to Clicklock adapter is? But if you know it, and add that to the optical path of the Clicklock and that of the MKIV binoviewer, it will be interesting to see what the total backfocus consumption of your system is?

Dave

[Stu]

Thanks Dave, very useful.

I’ve just had a nice little session using the barlow element of the AP Barcon on the front of the prism and that worked well. Not sure if the GPC would be better quality as it corrects for the binoviewer prism CA I believe?

At the moment my adaptor for the Telementor is stuck in the Clicklock so I’m a bit stuck until I can free that, but I’m pleased with the views I’ve just had so any further improvement can only help matters. Floaters well controlled although I guess the power wasn’t crazily high anyway. To be continued....