John

Looks like there are two versions, according to this supplier at least: https://agenaastro.com/gso-slow-motion-focuser-knob.html I agree that the 8mm size are somewhat harder to find.

I can just make out the Eastern Veil nebula without a filter here tonight - very faint and indistinct - with the 12 inch dob. My word though, with the Lumicon O-III filter it is transformed

I would have thought that would use the 6mm fitting cables ? Those are the type that the supplier is recommending for that mount: https://www.teleskop-express.de/shop/product_info.php/info/p5122_TS-Optics-two-flexible-shafts-for-telescope-mounts-9-inch-and-4-5-inch.html Astroboot usually has them: https://www.astroboot.co.uk/AstroBoot/spare-parts-for-telescopes.html

That's pretty much it. A rough idea of the distance that the drawtube of the focuser needs to move when the barlow is used would be useful when you get a chance.

What mount are you referring to here ?

Looks very nice Have you had a chance to work out how much inwards focuser movement is needed when using it ?

I've come across this photo from 2011. I was comparing the 8mm Ethos + Antares 1.6x Mk 1 barlow with a TMB Supermono 5mm and University Optics 5mm HD Abbe Ortho. I seem to recall that the TMB Supermono won in outright performance terms but not by that much !.

They have no respect for nice gear ....... There used to be an old joke about someone getting splatted like that and his mate asked if he wanted some loo paper and he replied that it would be no good as the bird would be miles away by now...... I'll get me coat ........

I think a number of things changed. I reported on them back in 2014 after finding problems with the Mk II design. I'd owned the Mk I and that worked fine. Hopefully the Mk III (that you have) addresses the issues with the Mk II: https://stargazerslounge.com/topic/229535-would-an-ethos-21mm-and-x16-barlow-replace-a-n31-e13/?do=findComment&comment=2476427 I bought my Mk II from RVO (they were the only source back then as well). They took it back and gave me a refund when I said that I could not bring it to focus in my scope.

I would only be using it with my 12 inch dob and that was the scope where the version of the barlow that I've pictured had focus issues. I've owned the 4.7mm and 3.7mm Ethos SX eyepieces and they are very good and also very expensive. After about 6 months though I concluded that my 5mm and 3.5mm Pentax XW's were slightly sharper and showed a touch less light scatter so I, rather reluctantly, let the 4.7 and 3.7 go to new homes. For £80, if the new design Antares 1.6x will reach focus OK with my dob, it would avoid having two eyepiece cases open when I want to use 300x and more with the dob.

The seeing conditions were rather poor last night and these planets are low in the sky. I don't get great views with my 12 inch dob either at the moment (normally it's as sharp as a tack) so I use my refractors to view these planets currently which seem to do better. You can check your collimation by doing a star test on Polaris: https://popastro.com/documents/PA_jan-mar2009_p12-13_telescopetopics_startesting.pdf More likely than not though it's the seeing conditions and position of the planets that is the cause. Try using lower magnifications ?

Well done Mark !

I'm pleased that you like the Antares barlow and that it obviously reaches focus find with your scopes and eyepieces The last one that I tried had a slightly different design from the one that you have bought and I think that was the reason for my focus woes. It's good that Antares have re-packaged what is a fine barlow optic so that it can be used in a wider range of scopes. I might have to think about getting one of the new designs This is the design that I last used: The above seemed to use far too much inwards focuser movement. Obviously the new body design that you have has addressed that

Absolutely correct. Often I find that the blower brush is all that is needed. I hold the lens surface that I'm blowing upside down so that gravity carries particles away from the optical surface as the air puffs them off.

Very sorry to hear of the loss of your Father. Many congratulations on the superb Tak FC100-DZ. I use an Altair dovetail bar with my FC100-DL and that fits ADM clamps just fine. I also ended up moving to a 6x30 RACI finder to save my neck and back from too much twisting. The Tak 30mm finder is a lovely little thing though. I hate to say this but the Rowan AZ100 will handle a LZOS 130 F/9.2 just fine so maybe that could be in your future still ? But for now, I'm sure you will love using the 100 DZ

That sounds quite normal Marv. It's rare that I get a night when the seeing is steady and excellent continuously. Most often you just get those moments of clarity when you see what your scope can actually do. The answer seems to be to keep at the eyepiece so that you catch more of the good moments

When a bright moon is in the same part of the sky as a planet, I've noticed that this can actually help with enhancing the contrast of features on the planet. Similar to the effect of observing a planet against a sky which still has some sunlight in it I think.

I doubt they sold many. Nothing wrong with them I expect but I can't imagine the market for 20 inch scopes is that big and a proportion of those who aspire to that sort of aperture might decide to splash out a bit more on a David Lukehurst custom job or an Obsession ?

Nice report Doug. I was doing just the same last night: https://stargazerslounge.com/topic/361725-seas-on-two-worlds-lunar-and-martian-mare/

Approximately annually but that's not set in stone. It's probably been nearly 2 years now since I last did it.

My 1st scope was a 1960's 60mm refractor but there a so many better choices now that I would not really recommend one. My 2nd scope, and my 1st "proper" scope was a 6 in newtonian which I made a simple dobsonian mount for. I observed Halley's Comet with that in 1986. Under £250 ? 6 inch dobsonian or, even better, a used 8 inch dobsonian You are probably going to get a wide range of answers to this though, which might not help you in your choice.

Welcome Anthony - nice to have you here

Ahh - that elusive Merope nebulosity And lurking within it is the very, very challenging IC 349: https://skyandtelescope.org/observing/the-merope-nebula-and-its-well-kept-secret/

I have the Aero ED 40mm and it is very good. Even in my F/5.3 12 inch dobsonian (not a scope which I use a 40mm often with) the Aero ED 40 shows good correction across most of the field of view.

Clear skies and quite steady currently here. Got the Tak 100mm out and targeted the Moon. Lots of interest but the Mare Crisium stood out as it was bisected by the terminator and it's dorsa (fine ridges) were well displayed. I also observed at 200x - 300x the two promontories, Lavinium and Olivium that reach out towards each other across a bay on the western rim of the Mare. This was the site of the famous giant bridge spotted in 1953 by amateur astronomer John J O'Neill. He was of course mistaken but it makes an interesting story nevertheless and was used by Arthur C Clarke in his novel "A Fall of Moondust" as explained here by Stephen James O'Meara: https://astronomy.com/magazine/stephen-omeara/2010/05/stephen-james-omearas-secret-sky-oneills-illusion I could see how the small crater between the promontories might, under specific lighting, be mistaken for something else. It is a very interesting area of the lunar surface to explore at high powers under tonight's illumination. Mars is nearby and had risen out of the unstable air. It was showing steadily and sharply at 225x - 300x with the 100mm refractor. The southern half of the martian disk was where the darker detail showed clearly in the form of two distinct bands tonight. These areas include the Mare Sirenum, Mare Cimmerium and Mare Tyrrhenum. The southern polar cap was clearly defined as well. I used some PC editing packages to produce this representation of the view of Mars tonight. Probably the nicest of the opposition so far for me: