John

There is no need to "sacrifice" a PST to convert it to a larger set up. If you cut off the "gold" tube a few inches in front of the tuning ring the back half becomes a Ha eyepiece. With a suitable sleeve, the front half can be rejoined to reconvert it to standard....

I stand corrected Peter - I did not realise that this could be done

It can be done with a refractor of the right aperture / focal ratio. The Vixen 80mm F/11 refractor is considered a good "donor":

First Light Optics - Vixen A80MF Refractor

But you need to sacrifice a PST (for the Etalon filter) and to purchase a suitable ERF filter (which are not cheap !) so the cost will exceed that of a PST or the Lunt 35. The prize is a larger aperture HA scope of course but you have to "do it right" - you can't take any chances or cut any corners when it comes to the sun.

One of our members, Merlin66, has a lot of expertise in undertaking such work.

I've recently come across this further guide to eyepieces which I thought was well written and useful :

Robins Eyepiece Guide

I used to have a Konusky 150mm F/8 refractor. It was exactly the same as the Skywatcher Evostar 150 refractor, except that the colour scheme was yellow.

I believe that the Konusky 200 is pretty much the same as the Skywatcher 200P:

Reflectors - Skywatcher Explorer 200P EQ5

Except that the yellow (older) Konusky versions have the older style (and more wobbly) aluminum tripod legs.

Magnification: focal length of scope divided by focal length of eyepiece

Exit pupil: focal length of eyepiece divided by focal ratio of scope = exit pupil diameter in mm.

Focal ratio: focal length of scope divided by diameter of primary mirror or objective lens = focal ratio, expressed as F/5, F/7 etc, etc

True field of view = Apparent field of view of eyepiece (eg: 50 degrees) divided by the magnification that it gives in a particular scope = the true field of view in degrees (how much sky is shown).

I think I've got those right

Hope it helps a bit !

how much did those cost you? im a total beginner and that big fat green one made me drool.....

Too much probably, although most of them were bought used

Quite a lot of the low power, very wide angle eyepieces are pretty fat, and heavy - they seem to need big lumps of glass in them to do their stuff.

Another approach, simple and functional, a £4.99 plastic component box from Maplins. Works perfectly well for regular sized eyepieces.

I like Japanese volcano tops:

Nice set Simon

I like those classic orthoscopics too

Great review Mr Spock - thanks for posting it

I'd heard from several sources that the C9.25's were something a bit special and yours seems to underline those rumours. I believe their specification differs slightly from the other Celestron SCT's - is that correct ?

To be able to use 300x plus with ease under UK skies shows that the scope is a top performer.

If I were thinking of moving to a SCT, I think the C9.25 would be at the top of my list

So, to get a slightly larger view of Jupiter, I would need a 2x barlow and to complement my range a 18mm EP...At the moment I have a 9mm and 25mm EP that came along with my scope....

Yes, the 2x barlow would turn the 9mm into an effective 4.5mm.

Pressed into John?

I now have the small Maplins case and was wondering how some people have got the 'tight fit' around their Eps?

I lay the item in question on the foam to see which cubes need to be depressed. I then, as tight a spossible around the item, break the cubes free, in a block, down to a depth of a couple of inches or so. You should then be able to press the item down onto the cube block, which will then depress forming a hollow for the item. The foam points in the lid hold the item in place and over a little time, the depression becomes established. When you want to move things around you can always pull the cube chunks back up and they will, with a bit of fidlding, go back to their original place, more or less.

Your Celestron collection is a good deal bigger than what I started out with (a 10mm, 26mm celestron Plossl, and a Vixen "silver top" 36mm Plossl). I thoroughly enjoyed observing with them. Yours should give you very good views.

This was my collection a few years back - and I was dead pleased with it :

What a great set

Interesting that you still have a place for the 2 TV plossl's in there - but they are really great eyepieces as are the Nagler zooms.

When I move away from the "black and green" it will be towards Pentax XW's - the only EP's I've tried which surpassed (only by a tiny bit mind) my TV's

Reading this thread has inspired me to get a case for my eyepieces so far I only have 1 that came with telescope and I have one ordered and a barlow.

As this thread is old, Where would I get a case like this with foam?

I got mine from Maplins - it was around £15 I think. It has that cube-cut foam which is easy to pluck out as needed or, as I do, to push down into indentations in which the eyepieces sit. There is foam in the lid as well to keep the eyepieces in place when the case is shut.

Niiicccceeeeeee!!!!!

I'm just wondering what your doing with the eye lens caps? I've seen a few people do this but I fold my eyecups down and the TV cap fits nice and snug. I just tested this method on my 13 ethos and its dead wobbly. Each to their own though.

They are snugger with the eye cups folded down but I didn't want to fiddle about near the eye lens in the dark so I keep mine up (as I use them when viewing) and the indentations in the foam seem to keep the caps in place. The 20mm T5 Nagler eye end cap is the worst offender for falling off too easiliy !.

I might try and store them folded down for a while and see how it goes though - thanks for the suggestion

...Can you post an update? I'm just curious on what you're using now.

Heres my current set minus a Skywatcher Aero ED 40mm which won't fit in the case !:

These do tend to fill up faster than expected...

And change their contents rather rapidly as well - I'm rather shocked to find that I've only one eyepiece left of the 9 I posted a picture of on 14 January this year

Fascinating looking scope - thanks for posting the pics

It looks rather similar in style and finish to my Intes mak-newtonian - functional but very well engineered. The coatings on my corrector are purple as well !.

The (V) symbol does mean Vixen I believe - nice quality eyepieces in their day.

Good idea about changing the mount - the aluminum tripod will shake somewhat I would think with a 6kg OTA on board.

Look forward to a report on the views through it

hello all first time on the site but wathched the nights sky every clear night i could for years love it any advise on telescopes for rookies thanks

Try posting this in a thread of it's own in this section - you will get plenty of suggestions then

The Skywatcher Nirvana 16mm might be worth considering - at £135 new they are good value IMHO and work pretty well even in fast scopes - 90% as well as Naglers at a lot less money. If they are not exactly the same as a UWAN, then they are pretty darn close

One of these years i will bite the bullet and invest in a TV Plossl of 32mm or so because i really do like widefield views.

What is the apparent FOV of this EP?

It's 50 degrees - it's a standard plossl design, just well executed.

For wider fields of view you have Radians = 60 degrees AFoV, Panoptics = 68 degrees AFoV, Naglers = 82 degrees AFoV, Ethos = 100 degree AFoV and now the Ethos SX = 110 degrees AFoV

....The reason I'll go for the Televue is that all my eyepieces are Televue, and it's just a little quirk that I have.

I have that quirk too ......

Interesting, I have the 8,11,20 and 32mm notch-sided TV plossls and wouldn't call them remotely parfocal - in fact I've just put some parfocalising rings on them to save me re-focusing. Also the notch drives me nuts and I'd much prefer if they had smooth sides. Maybe the old ones would have been better for me!

Thats odd - the two TV plossl ranges that I've owned were spot-on par focal (with the exception of the 40mm as already mentioned). That's one of the main reasons I bought them

I agree about the undercut barrel though - I much prefer the smooth ones but that seems to have gone out of fashion !.

I've owned a set of the smooth-side TV plossls and a set of the later versions and they are really well made eyepieces. Personally I don't think I'd invest in the 40mm again though - it's a fine quality eyepiece but it's way off from par-focal with the rest of the range and shows no more sky than the 32mm does. It's long eye relief is good for glasses wearers (it was designed for this purpose I believe) but can make it awkward to find the right eye positoning if you don't wear glasses.

I have a 10" F/4.8 Orion Optics newtonian optical tube. Normally I use it on an alt-azimuth mount (rather like a Giro) and it's really easy to set up and use - almost a 10" "grab and go" in fact (apart from a bit of cool down time of course).

I put the scope onto my CG5 mount, which has the 2" steel pipe tripod legs, to see how it fared. The mount could handle the scope for visual use fine (the OTA weighs around 10kg which is relatively light for a 10") but, as a package, I found the whole thing very unweildy - the pleasure seemed to have gone right out of it.

I've a 6" refractor which I also use on the same mount but with that you can easily rotate the diagonal to get the eyepiece in a comfortable position - it's just not as simple with the newt unfortunately.

I have a lot of admiration for those who can manage a 10"+ newtonian on an equatorial mount but personally I'll be sticking with dobsonian / alt-azimuth mounts for scopes in that aperture category in future.

I tried to do that with my C8 when I had it. I was advised that Celestron don't keep records of the serial numbers as well, which was not much help !. Rod Mollise's guide to buying an SCT might be of interest if you have not already seen it (free download):

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