Captain Scarlet

On 25/11/2022 at 22:38, Dave scutt said:

I started pimping my dob.

New focuser,  80mm RACI , and fan for the primary and fully flocked.

I was going to buy a EQ platform but spent the money on some Telvue Ethos instead.

I have to say, Dave, those are the finest-looking collimation-locking bolts I have ever seen 🤣🤣. Where did you get them, I seem to be missing a few 😁

7 minutes ago, Moon-Monkey said:

Just so your aware the occulting bar has to be at the focal plane of thr eyepiece otherwise it won’t be in focus and may be a bit fuzzy to use 🙂🙂🙂 it’s absolutely possible and great fun although there is a learning by curve it’s all good fun though good luck and can’t wait to hear others reports on this 🙂🙂🙂

Yes thanks. If I choose my sacrificial eyepiece correctly, ie with a focal plane within the nosepiece,  I can operate just on the nosepiece and have it detached when I perform the surgery. It won’t be an Ethos though 😁😁

Brilliant well done. I have several eyepieces or nosepieces I wouldn’t mind doing a bit of surgery to, so I might attempt an occulting set-up myself. I’d always assumed without looking it up that those two moons were out of reach to amateurs. A nice little project-let for me.

Cheers, Magnus

After 3 months in transit via various family members and across a couple of borders I finally received these: an OO cell for a 300mm mirror to go into my Helmerichs tube replacing my old SW 300p cell; and a 50mm elliptical flat to replace the 63mm one in my 200mm newt, taking its CO from 32% to 25%.

Lots of tinkering to come…

Magnus

… after my lamenting that the skies hadn’t lived up to forecast, I finally went out last thing to pack it all up and lo-n-behold it was clear! I decided to stay out while it lasted and managed Jupiter with a definite dark patch in the middle of one of the bands, but seemingly not the GRS; Mars with some dark features, Uranus clearly a bluish disc, M42’s Trapezium with just a momentary glimpse of the E and finally as the dew was intruding Sigma Orionis but no C this time. All at 151x with my Intes M603 and Tak LE 12.5 .

Nice session, Magnus

Supposed to be clear tonight so I set up my 150mm Intes Mak. The 12” would have been out but it’s disassembled in advance of fitting a new OO mirror-cell. However, the forecasts LIED, in fact low cloud, so all I managed was a collimation test on distant radar-dome lights and some images of Poisson Spots:

From Suiter 2nd edition p23:

… and from my own 6” Intes Mak just now:

Elseqhere in the book I recall discussion where certain circumstances yield a vivid bright red spot, and I have observed it, but I can’t immediately recall where or how.

Magnus

PS the bright objects are a set of radar-tower warning-lights on top of a mountain about 16km from me. Extremely convenient non-moving objects for collimating!

I can’t see a spot in your images, but what you describe might be what I have read as (and actually seen through a scope) “Poisson’s Spot”, a diffraction artifact. It can sometimes be bright red from a white point source.

Cheers Magnus

16 hours ago, vlaiv said:

Don't think that is the case.

As far as I can see from the images - all edges on the focus tube are parallel to secondary spider vanes. That would just increase secondary spikes.

Yes you’re right. My thinking was that because the focus-tube intrusion is a solid edge (rather than a thin stripe) it would be brighter shorter and dirtier than the vane-spikes and therefore make them less noticeable. Having said that I don’t think it’s the culprit.

A couple of extra questions: do you wear glasses whilst viewing, which might be fine-scratched in one or more predominant direction  from habitual wiping? Really grasping at straws here.

It’ll be most interesting to see some star images.

M

Very odd. Intrusive mirror clips would produce 3 spikes not two and should not overwhelm the 90 degree ones from the spider. The only thing I can think of is that a protubering (I just invented a word!) focus tube would produce a noticeable spike, and if there is a straight edge on the secondary mirror-silvering at just the correct angle, that might do it. Every non-super-premium secondary I’ve seen has such a straight edge, from where the mirror is held during coating.

Can you show us a photo of your primary clips as seen from the secondary?

I’m intrigued.

Magnus

Could you also maybe show us a photo of your main mirror taken from the open tube end?

Cheers, Magnus (another one )

I had a carbon-copy of that just tonight. An entire day of violent VIOLENT squalls rolling in one after another: hail, thunder, lightning, 50-60mph gusts, a power cut. And then, around 1030 it all stopped, the sky cleared and I had to get at least a pair of bins out. Almost the same target list as yours, wonderfully restoring for a few minutes.

Magnus

4 hours ago, aristotle1954 said:

Many thanks for your comments, in particular those relating to binoculars being banned in certain countries; I'm definitely going to leave the Zeiss ones at home. I'll take a look at the Canon IS range as you've suggested. 

Kind regards

Another word of warning about binoculars being a sensitive topic. I went to Oman a few years ago and upon producing my Leica Trinovid 8x42s, I was asked "do they contain batteries?". They did not, but he told me that had they contained batteries, he would not have let me bring them in. The risk being rangefinders/military use I guess.

My recommendation for a very reasonable but excellent pair of bins would be Meade Rainforest Pro 8x42. I've looked through them and they are very good.

Magnus

Sudden evening rain squalls prevented any proper prior set-up tonight but it was forecast and actually became clear but very windy, so I sat out after midnight on my sheltered side with my Zeiss 15x56 bins. I promised myself I'd go back in on the first meteorite, which I gave up on around 12:30 after none turned up. Then just as I opened the door to go in, Whoosh! from zenith to West.

I enjoyed Orion; the Pleiades; the "S" around Mintaka; I Iooked for M1 Crab which I've seen through these bins before but not this time, I wasn't sure of the location; I noticed the Beehive become naked eye first time this season; Meissa ("Luger" asterism in my own parlance); I hunted around for M33 having forgotten where it was for a while then eventually found it, and in the process noticed a nice Open Cluster and bright wide double near Triangulum which I later ID'd as NGC 752 and 56 And. I finished off with M81/2 and just about found M51 in the lower-down murk.

Nice session with bins, same tomorrow without the rain or wind apparently so I hope to get my Helmerichs 300mm out for the first time in 3 months.

Magnus

That last photo ... Intes M603? I have one which I restored. Lovely scope.

Magnus

15 hours ago, PeterW said:

Stop it, I’d have trouble finding it shelf space! Maybe one for the Xmas list…

 

Peter

Space wouldn’t be the only constraint: you’ll need shelf reinforcement too!

I have a set, but need to dig it out of storage.

M

… currently for sale on that popular auction site. One an old gold-tube offered for £600 and the other a newer one with start bid at the same level (having progressively reduced it over successive re-listings after no interest).

Not mine I hasten to add, I’m keeping that!

Magnus

For we Western Europeans, this is as good as a weather forecast: heavy cloud and rain on the morning of 8th December!

Nevertheless, it’s in my diary and I shall be up early!

Magnus

We all have the virus, and luckily it’s quite a benign one!

More seriously: I often get asked “why d’you need more than one telescope?”. My answer these days is always “why does a photographer need more than one lens? - for different focal lengths and apertures.” That usually learns ‘em!

Cheers, Magnus

16 hours ago, josefk said:

…

I guess from your sig your also a birder?

Very much so. Not only do I use my Kowa (like your Svarowski) for astro, I have also used my MCTs for birding. Very high FL scopes are superbly useful across wide mud-flats in cool still air.

3 hours ago, josefk said:

Thank you. It's Burghley Park Stamford - it's a great spot and i'm lucky it's on my doorstep. It is a spotting scope and i use it for grab and go - i can't justify an astro scope in this size while i have the spotter. The IP rating was handy tonight! i sometimes wish i'd looked harder at Kowa a few years ago as it would have given me EP freedom. Do you bump up the power on yours or stick to wide field? Cheers

I've just migrated onto my laptop where I can see your sig, and as I suspected from the silhouette your spotting scope is a Swarovski, very nice! My GnG is a Kowa TSN-883, and yes I did get their astro adapter and regularly use my other eyepieces. It can take 150x quite happily, I haven't gone higher yet but I have just acquired a 1.6mm Vixen HR and plan to see what 319x looks like through it in decent seeing. Changing between non-Kowa eyepieces is a bit of a pain though, involving unscrewing the threaded 1.25" adapter, undoing the concealed grubscrew/s, swapping the eyepiece and vice versa.

EDIT: I also notice you have the Swarovski 15x56 bins. I have the Zeiss Conquest 15x56s, which are superb ... it would one day be very interesting to compare side by side.

12 minutes ago, scarp15 said:

Just caught the final stage of tonight's Io shadow transit afore the cloud swept in. 

Well done. I’d too noticed that was due but no chance for me tonight, solid cloud to South.

10 minutes ago, josefk said:

...erm. Doubles i think tonight 😉

I jest by giving you a “haha” emoji but that’s a really moody photo, very nice. Crop out the red lights and you could hang that.

Also, a spotting scope I see. I too use a Kowa scope from time to time.

Magnus

Weather here in SW Ireland the last few months has been terrible, and tonight has been my first more-than-a-moment session since the end of August. I've just come in from finally having taken advantage of Jupiter's altitude these days, and although I observed only Jupiter, it's been one of my more memorable sessions. I  had it in my diary as Europa & Ganymede double transit (thanks @Simon128D ) with shadows to follow plus GRS in prime position. I saw it all, though I did have to drag everything back in hurriedly while a violent squall came through.

I had my LZOS 105/650 on SkyTee2, initiually tucked right under my East wall to shelter from the 60kph wind gusts (it calmed right down a little later). The LZOS has a weird finder-mounting bracket, and it was only a few days ago that I got around to sorting it out and attching a finder: my APM 8x50 RACI . It does make navigating a bit easier ! And I also finally attached my slo-mo extensions(after 2 years of ownership), and they too make life so much easier. I mainly used my Ethos 4.7 to give me 138x.

I saw Ganymede and Europa approach and merge with the disc, while simultaneously Io disappeared around the back on the other side. At one stage there were three bright white pimples attached to Jupiter's disc. Once the two moons were in fornt of the planet, they disappeared from view, I couldn't make them out against the bright disc. But the rest of Jupiter was far better than I've ever seen him before, lots of detail and subsidiary bands, and for the first time (for me) the GRS was RED! Amazing. Then the squall came and I rushed everything back inside.

An hour or two later, all was clear again, so I quickly got it out again to see if I could discern any shadows. I could! And what's more, Ganymede had turned into a silhouette: I could see one sharp tiny black shadow, and Ganymede as a slightly less dark but nonetheless distinct disc.

So: double transit, GRS as red, lots of detail, a shadow and a silhouette. A wonderful short double-session.

As I write shortly after packing up, there's now heavy hail drilling against the window. I was lucky!

Cheers, Magnus

before the squall:

second session after the squall:

Getting ready for the Jupiter double transit tonight. Sky is clear, but 60kph Westerly gusts abound, hence the scope hiding as close as possible to the lee of the house. No comments please about the state of the wall!

First time I’ve ever used any sort of finder on the LZOS (weird mounting bracket), and first time I’ve attached the slo-mos to my SkyTee. They both make such a difference!