markse68

12 hours ago, John said:

Very interesting report 🙂

It seems a shame to me that the very best high power eyepieces (for the non-glasses wearer) seem to remain in production for such a short time. We have the ZAO's, the TMB Supermono's, the Pentax XO's and now (apparently) the Vixen HR's out of production (for quite a long time in some cases) so fast becoming "unobtainium" for most.

I think the Tak TOE's are still being produced but for how long I wonder ?

Maybe the market for such eyepieces is too small to support production more than a short time ?

 

Ricoh brought back the XW30 and 40 so if there was enough interest, perhaps the XOs could be revived? 🙏

Mark

Done 👍

Mark

Dara Ó Briain was on Desert Island Discs this morning and for his luxury item chose an imaging telescope setup. Every time I hear it I hope someone will chose a telescope but an imaging setup doesn’t sound very practical on a desert island! For me it’d be a decent aperture visual scope on an alt-az mount (or big dob) with nice eps, sketch pads and pencils and a decent paper starchart like Interstellarum (and companion guide). No power worries and plenty of time to learn the sky intimately from glorious bortle 1 skies. The prospect excites! 

His choice of the Feynman lectures to read was good though

Mark

12 minutes ago, Marki said:

Here are the two I still have. A 100RS and a 125R. Both achromats and both lovely to use. I did have a 125 Apolar, but returned it as it has been damaged in transit.

I think the 100RS is a superb f10 achro, and it fired my enduring love of refractors (and Russian glass). The 125R at F8.9 is good too; the example I have needed a fair bit of attention to correct soem aberrations (from the wonderful ES Reid) to enable it to give of its best, but since then its been really good.

 

Lovely scopes Mark  I’ve never seen a 125 come up for sale anywhere since i’ve been in this hobby- must be either really rare or so good that nobody will part with theirs! 

Mark

If I hadn’t already got one i would have gone for that one on Ebay too Magnus- it had the stepper motor driven mount too which would have been nice. Your Intes sounds like it was a real bargain!

Mark

Never heard of a 100RT John- what was different to the R and RS?

I'd love to get my hands on an Apolar-wow!  fascinating scopes though I've read tricky to collimate! There was regular 125mm Achromatic refractor too I think though that was rare as well- I think someone on this forum has one- looks very similar to that Apolar

Mark

Not to be confused with a similarly named thread for some Japanese scopes, this is for the Russian scopes built in Novosibirsk 

These scopes are getting old now, but are characterised by great optics, solid if a little crude mechanics and have always been great value. They have a great character about them - solid and no-nonsense, that makes them very loveable

an old thread about the history of Tal telescopes:

This is my Tal 150p - a 6" f5 newt. It's my current favourite scope. Unusual for a Tal reflector it has a parabolic mirror which although it fails a star test (I don't have the skill to analyse it but it's not quite symmetric about the focus point) it's tack sharp and has given me absolutely stunning views of the planets these last months at powers up to 300x.  The mirrors are showing some aging and I may get them recoated at some point. The mount isn't Tal- it came with a heavy pier mount originally. It has a 1.25" R&P focuser which I plan to replace soon with something a bit more luxurious- justified because I love this little scope and use it all the time.

This is my Tal 200K- an 8" f10 Klevsov-Cassegrain which I bought for planetary but haven't really used that much as the 150p turned up and is working for me so I stuck with that, and I don't have a practical mount for it currently. Comparing it to the 150p it will take higher mag with a brighter image obviously and after collimating it produced lovely pin point stars and with the curved secondary vanes, no diffraction spikes which is really nice. I will at some point use it for planetary imaging I think.

It came with the legendary Tal 8x50 finder which is really a bit special- it has a huge fov sharp most of the way out. I think it uses the same 25mm Plossl that was also quite legendary

it has a 1.25" R&P focuser like the 150p- a bit crude but it works and with negligible slop

This is my Tal 100RS - a legendary 100mm f10 achromatic refractor. I mainly use this for white light solar with Baader film and intend to get a Lacerta Herschel wedge for it this year.

The earlier 100R had beautiful purple coatings like the Plossls but tis one has a very pretty golden coloured objective coating

It has a 2" Crayford focuser! With loads of travel too. After adjustment it's really quite nice and usable

the legendary Tal 25mm Plossl- look at those coatings 😍

There must be loads of Tals out there so show us your Tal

Mark

Nice 😊 I’ve got a blue one- my first scope on getting properly onto this hobby and joining this forum. Lovely scopes

Mark

there are slots to allow the pivoting threaded bit to move in and out and stay parallel

Mark

Never gave Ceres much thought before so thanks Ags for making it interesting!

Mark

they should commission @rorymultistorey to do it- imagine what he’d get up to with a bit of a budget

Cooke 6” Toronto 1880

https://www.flickr.com/photos/64866643@N02/38312948121/in/photostream

it works the other way too- planned meets get cancelled due to forecast as keeps happening, only for the clouds to clear revealing gobsmacking transparency and seeing!

Mark

Meteorite protection

Our society meet was cancelled this evening because of the forecast- shame as it’s a beautifully clear night now. The seeing and transparency are really good- e and f of the trapezium easily seen at 150x, Venus earlier was very crisp with a uhc. Mars still showing albedo markings and I saw the pup! Confirmed with several different eps and mags- it was definitely there intermittently  Rigel was a beautiful split with a perfectly sharp pinpoint secondary. Fab

Mark

clouds have cleared, it’s early and Venus is high

Well that cleaned up nice 👌 

Mark

Excellent! Hope the mirrors clean up ok 👌 

Mark

Wow- what a bargain! Did you get the eyepieces and barlow too?

Mark

Galvoptics or Orion if you want their enhanced coatings

Mark

3 hours ago, Ratlet said:

Afternoon all.

I'm wanting to build a nice looking base for my 10" solid tube dobsonian.  The plan is to rebuild with plywood and go for a swish looking varnished finish.

Most of the guides online recommend birch plywood however the prices for it are currently astronomical (£200 per sheet for the 18mm) does anyone have any recommendations for sheet material that would be a suitable alternative at a more reasonable price whilst still giving a good looking finish once varnished.

Scope will be kept in an unheated shed, out of the elements most of the time.

18mm is pretty thick for supporting something that weighs what- 10kg? You could use a thinner ply skin reinforced with timber or laminate layers of ply where necessary

Mark

It does look neat- I like the way the head can be stored in the central tube, but the legs and the bracing look a bit iffy to me

Mark

3 hours ago, TakMan said:

Yes, I spoke with his son Jake after his father’s passing.

I was very fortunate to receive the tracking unit for my mount (possibly the only one outside the States…)

To be honest, I prefer the operation without the tracking as it’s a bit fiddly and doesn’t work as well when out of balance. Perhaps with Charles’ help, it could have been dialled in better after…

I think the Rowan mount will do much better in that regard, but I still won’t be getting rid of my Nova Hitch!

Jake did start a Kickstart campaign, but I don’t think it took off…

Here is a link to one of many FTX CN threads, it gives a god idea what such a well thought out bit of engineering is capable of..!

https://www.cloudynights.com/topic/646341-ftx-plus-alt-azimuth-mount-for-grabgo/

Any idea what that tripod is?

and what do you mean by "the late Charles Riddle’s ‘2-axis’ balance"?- ah the dovetail clamp can slide up and down- nice

Thanks,

Mark

There's also Desert Sky Astro your side of the pond

http://www.desertskyastro.com

Mark

It's very common with switching psu's with their high frequency switching and floating isolated outputs- a phantom coupling somewhere. We use meanwells a lot at work- decent brand but if you touch between 2 systems you can feel a high frequency "hum" and if you touch with your elbow, a tingle. With a meter it measures 60V ac. I don't think it's anything to worry about in terms of safety as there's no current and if you connect the DC GND to mains earth then it's not isolated anymore

Mark