Planetary Eyepieces

[AJSullivan]

After recently buying my much loved refractor i want to get myself a good quality planetary eyepiece. Now I cant afford to pay the earth for one of these things so looking for a good quality eyepiece on a budget. Id be very happy buying second hand so if you see a second hand add link me to it

Also what mm do you think i should get. I have a 80mm refractor (achromat) with a length of 480mm. I have a 3mm eyepiece that imo is awful, it has such a SMALL FOV though it WAS very cheap. I also have a 9mm (celestron standard) that I have barlowed (2x) which gives ok results but nothing special imo.

So there you have it. Advise me!

Alex

[Ben Ritchie]

I always thought the Burgess/TMB (aka B/TMB) planetary eyepieces were pretty good, comfortable eye relief and quite sharp. Kind of a "poor man's Radian", not quite as good but nothing like the price either. They're not all that common used at the moment, but turn up from time to time at around £40 or a 'wanted' ad might pay dividends.

There are Orthoscopics too, which are very good planetary eyepieces if you don't mind the lack of eye relief. Personally I don't like them much, but plenty do. Reasonably cheap too.

[philsail1]

Alex,

Your scope has a focal ration of "f6" so it should tolerate a wide variety of eyepieces.

It will have a maximum magnification (under ideal conditions) of around 160x

(allowing 50x per inch of scope's Objective lens diameter).

You could try a 6mm orthoscopic which would give a magnification of 80x

(160 with a 2x Barlow). Again, the eye relief isn't great on a 6mm Orthoscopic.

10mm Plossls are good too.

Have you got a decent Barlow? Celestron make a good one in the "Ultima" at around £79.00.

Best wishes,

philsail1

[AJSullivan]

Ive read some really good things about the Burgess ones, being both excellent eyepieces and good value for money. They are a REAL pain to find in the UK though it seems. Ive found this site with a few for sale.

http://www.scsastro.co.uk/it240006.htm

Which one do you think will be the highest mag for my refractor? I JUST made out some banding on jupiter i think but the image was very small due to the eyepieces i have. (i also know jupiter is hard to see at the moment).

Thanks!

Alex

[kniclander]

I have a 9 (or 8?) mm Burgess Optical which is really really nice.

[Ben Ritchie]

I've owned the 4mm, 7mm and 9mm before - all gone now, but they're all very respectable IMHO.

They are a REAL pain to find in the UK though it seems.

Yeah, they're a bit rare at the moment. Might be worth trying Bernard at modern astronomy, I think he was planning on stocking them (or the clones?) at some point. Otherwise i'd suggest a wanted advert for any one of them over about 4mm (120x in your 'scope), I don't think you'd be unhappy with any of them and then if you like it you can watch and wait for more to show up.

[asteria]

Hi - I use the 9mm TMB planetary and it is very good. Very sharp. Good build quality too. Ed

[AJSullivan]

What mm do you think I should get? Will i be able to get away with a very low mm? I have the refractor on a slt 60 goto mount though i personally have found it pretty steady. Would something like a 4mm be to low?

Alex

[thing]

You wouldn't want to be above x160 magnification and personally I wouldn't go above 120. The more you magnify the dimmer everything gets. Also with the conditions we get here in UK it's better to go for a lower mag and a crisper view. Personally I would go for something like a Hyperion 8 mil which will give you a wide field of view, 1.1 degrees, and good eye relief. It will give you x60 and x120 with the Barlow. You won't see 'more' at higher mags, you will just magnify the mush that is there.

I have an 200mil Newtonian and while the theoretical max mag is about x400 I hardly ever go above x150, there isn't much point.

[John]

What mm do you think I should get? Will i be able to get away with a very low mm? I have the refractor on a slt 60 goto mount though i personally have found it pretty steady. Would something like a 4mm be to low?

Alex

I've used a 4mm TS Planetary HR (same as the TMB / Burgess Planetary) and that worked very nicely with my 102mm F/6.5 refractor. They also do a 3.2mm which is supposed to be just as nice. I think you will find them a huge improvement over the short focal length eyepieces that you have already tried. The great thing about them is that the field of view is reasonably wide (58 degrees) and the eye relief is 16mm for all of them - even the short focal length ones.

As Ben says above, Bern at Modern Astronomy stocks these I think. They cost around £50 each.

John

[themos]

I have the 3.2mm but with a focal length of 1500mm, it's only useful for star-testing and the one night when seeing is outstanding. It will be more useful when I get a refractor.

[lunator]

I am an orthoscopic eyepiece fan.

I have an F5 refractor and they work well with it.

The 4mm does have tight eye-relief, but the 6mm is pretty good. You can pick these eyepieces up for around £20 secondhand so they won't break the bank

Cheers

Ian

[AJSullivan]

So taking into account everyones advice (or trying too), a 6mm TS Planetary HR 1.25" sounds pretty good? I could probably stretch £50. I already have a 2x barlow so that will up mag to abuot 150x, which as someone has already commented, is definetly pushing it as far as it can go in the UK. Also are the TS and Burgess exactly the same then?

[iancandler]

Not exactly the same, but the originals of both did originate from the same factory and where of the same design.

As someone who uses the 6mm I would say go for it... I use mine in my little Zs66 (F5.9) and it gives great views both with and without a barlow (the little 66 is very forgiving when pushing the mag)