John

My school had an 8.5 inch Frank's newtonian in a nice dome. 1st proper telescope that I ever looked through. The illustrations in the Frank's Book of the Telescope remind me a bit of those in the book All About Telescopes by Sam Brown:

The Baader Hyperions don't do so well in an F/4.5 scope. They show quite a lot of astigmatism (distorted stars) in the outer half of the field of view. The Morpheus is a much better range for such scopes. The zoom is not bad but it's field of view at the 24mm end is quite narrow at 46 degrees. You will want at least one other low power / wide field eyepiece, ideally in the 2 inch format to make the most of the scopes potential. This is the challenge with a big aperture and reasonably fast scope - you think the purchase price of the scope is quite high and then find out that you can spend as much again or even more on eyepieces plus a coma corrector to get the best out of it And we have not even started on filters for deep sky observing ......

The XW's do work very well in a big dobsonian. I'm even more irrational / frivolous than you though - I use a Panoptic / Delos / Pentax XW / Nagler zoom set for my refractors and have a Nagler / Ethos / ES 92 set for my 12 inch dob I guess a lot hinges on the budget that @CedricTheBrave has for eyepieces though. At £250 a pop the XW's are not exactly cheapies. At the other end of the scale, the 8mm BST Starguider suggested by @Zermelo is actually a pretty good eyepiece for it's < £50 price tag. On a tight budget it would do a decent job and is not so wide that it makes a coma corrector mandatory. There are lots of options in between as well these days: Explore Scientific 68's or 82's, Baader Morpheus etc, etc.

Really sorry that I missed your question. I use an Altair 180mm dovetail bar: https://www.altairastro.com/altair-tms---vixen-synta-dovetail-bar-clear-silver-182-p.asp I'm sure that other brands will work as well. I use two M8 bolts to hold the bar in place using pre-threaded holes in the Takahashi tube clamp.

With the planets low down (eg: Saturn and Jupiter currently) I've found that my refractors "cut through" the unsteady seeing better than my 12 inch dob does.

45 quid for getting your 1st views of these amazing objects is a bargain and it will show you plenty more besides !

Well, the past few times I've observed, the "window of opportunity" has been short lived thanks to the UK weather. And so it was tonight with pretty solid cloud cover arriving about half an hour after I observed Mars. If the scope had not been quick to set up and cool down (ie: a 4 inch frac) I don't think I would have done any practical astronomy at all recently. So currently, I'm very glad that I have such scopes

The analysis of that material should prove very interesting

Not my scope but this one belonged to the Lowell Observatory. A quick spot of solar H-a observing during our visit there in 2019. I think the scope was a Lunt LS100 - the largest aperture H-a scope that I've looked though

Thanks Michael, I'm only catching them in the gap between two large trees. I suspect I'm going to have to be more mobile when it gets to their closest approach later this month.

Good idea for a thread, especially with the Sun starting to get active again

On Mars now. The disk size has diminished noticeably since I last observed Mars - just 13.8 arc seconds now. At 225x - 300x the south polar cap is just about visible when the planet steadies between wind gusts. Some dark markings showing on the disk including the distinctive snout of the Syrtis Major, the pale "bay" of Aeria and the dark "coastline" of the northern edge of the Sinus Sabaeus. If the wind gusts would drop the seeing could be quite good this evening. Have to break off to make supper now - it's my turn !

I don't do much solar observing but here are a few of mine. Don't have the PST or the Lunt 50 now but they were fun little scopes:

Same scope in the day time

It's as quick to put outside. The Tak needs very little cooling time though. I've used quite high magnifications to good effect with hardly any cooling time whereas the dob needs 30 minutes, sometimes a little more.

First clear evening for quite a few days here. Cold and blowy though. The slim lines of my Takahashi FC100-DL are less bothered by the gusts than my other scopes. I've had a quick look at Jupiter and Saturn before they drop behind the tree branches low towards the south west. These two are around 1.5 degrees apart now so I can fit them into the field of view with the 24mm Panoptic eyepiece. At 38x the image scale is small but exquisitely sharp. Jupiter's four Galilean moons are strung out like pearls all on the same side of the planet. A nice arrangement A couple of equatorial bands are showing but not a lot else at this magnification and with the planet so low. Saturn and Titan shine on the other side of the field with the Cassini division quite clear. Suddenly Jupiter shows some odd scintillation - horse chestnut branches are not a great filter ! Just in case I can't get a decent view when these planets are really close together in the sky later in the month, at least I've seen the pair sharing a telescope eyepiece this evening

First clear evening for what seems like a long time. Takahashi FC100-DL out on the Ercole mount. At the sharp end the Pentax XW 3.5mm towers over the diagonal:

That's a Vixen product I believe. Made in Japan. Apart from the "V" printed on it, it has all the look and finish of a Vixen product.

I used to have some of the University Optics branded versions of these: Over the years I've had them with Celestron, Vixen, Orion (USA), Telescope House and the Circle-T versions too. I spent some time comparing them with Baader Genuine Orthos, Astro Hutech and Fujiyama HD orthos and the Baader Classic Orthos when they came out. I probably posted some reports at some stage.

If and when you start looking, this is one way to tell if an optical finder is RA or RACI:

They are in lovely condition

Hello and welcome to the forum. I think we need to know quite a bit more about the sort of astronomy that you might be interested in to make a recommendation. There are many, many telescopes available for £500 and they all have strengths and weaknesses. The sort of things to be thinking about are: - Does your budget include a mount for the telescope ? - Are you interested mostly in visual observing or imaging with the scope ? - Do you need the scope to be compact / portable ? - Are you more interested in the planets or deep sky objects such as galaxies, nebulae etc ? - Can you use the equipment under dark skies or do you have light pollution to content with ? Give us some more to go on and we will be glad to help

Very interesting thread As well as their thickness, the shape of secondary supports always prompts some interesting discussions. I have curved supports on my 12 inch dob which seem to work well but they are a bit thicker than the straight ones found on most scopes. My vanes are dull black rather than shiny.

That third photo of Stu would be fun to use in a "guess my hobby" competition

My first "apo" refractor was one of the early ED100's. Blue tube back then. Great scope !