Wanted:Planetry EP

[blinky]

I am in the market (in the next week or so) for a decent EP for high powered views of the planets. I dont want to spend a fortune so on looking around the forum it seems that Ortho's are the best price/performance compromise. I have an 8" F5 Newt and a TV 3X Barlow Lens. I am thinking that something around 7-10mm would be the best, as I could use the Barlow Lens when the viewing is exceptional.

As you might have guessed I dont want to spend a fortune, was hoping to get one for under 20quid, or is that asking a bit too much? Any sellers?

[GordonCopestake]

You might find a 6mm japan ortho for that but to be honest you get what you pay for and you are better looking at the £40-£50 range. Look at the TMB/Monocentrics as well as the TV plossls (at 8mm it's a bit tight but still pretty good)

[GazOC]

Theres a 7 and a 9 half way down the page below.

http://www.astrobuysell.com/uk/propview.php?minprice=0&maxprice=1E15&cur_page=2&sort=id+DESC

TBH £25 delivered is a very fair price.

[GordonCopestake]

They are pretty good prices, jump at them heh

[blinky]

I think I might just do that, what ones though?

9mm would give X111 and X333 with the Barlow

7mm would give X143 and X428 with the Barlow

Going on the X50 per inch of aperature for my 8" Newt that gives 400. so........the 7mm one?

What about the quality of these EP's are they OK (For the money!) Unfortunatly I dont have (Or want) £100 plus for a TMB EP.

[GazOC]

On planets the seeing will limit you to x250 on most nights in this country, you'll only get to use x300 rarely and x400 practically never.

[blinky]

I also found this on Astrobuysell: Telescope House 5mm Ortho (Japan), nice eyepiece in good condition (and still available new for £50.00) - £20.00

The same guy also has Meade series 3000plossls for round about the same price. I take it the Ortho would be best for Planets? and is this a better Ortho than the Antares one?

[GazOC]

Both those eyepeices would be a lot more useful in a 1000m scope with a x2 barlow, the x3 barlow is too much for both of them TBH.

[Brass n glass]

I've used Japanese orthos for years, but never below f6.3. The Orion Optics website says they "prefer" to operate at f6 to f20.

[GazOC]

I also found this on Astrobuysell: Telescope House 5mm Ortho (Japan), nice eyepiece in good condition (and still available new for £50.00) - £20.00

I'd go with that, it gives you x200 without messing with a Barlow. One of the reasons orthos are rated so highly is that the only have 4 glass elements so they give good contrast, putting a Barlow in the way negates some of the benefits IMHO.

The ortho should be far better on planets than the 3000s

[GazOC]

I've used Japanese orthos for years, but never below f6.3. The Orion Optics website says they "prefer" to operate at f6 to f20.

I've used them at f5, they are fine on axis and thats whats important for a planetary eyepiece.

[blinky]

I knew this would happen Now I am totally confused. I had a look round the forum and everythign seemed to point me to Ortho's now I hear that they need a slower scope! HELP!!!

Gaz I was thinking that with a 5mm I would not need to use the Barlow?

So what is it then? Antares or Japanese or go for the series 3000Plossl?

[blinky]

Gaz you replied while I was replying. Thanks for that piece there, I think my scope is pretty well setup for Polar alingment so if I get it slap bang in the middle of the EP I should be OK with the Japanese one.

Can I just confirm though....Deff the Ortho over the Plossl?

[GazOC]

Deff the Ortho over the Plossl?

Without a shadow of a doubt.*

*Definate enough?

[blinky]

OR....A series 4000Plossl 6.4 or 9.7mm for 25quid.

Maybe this post should be moved to equipment discussion?

[blinky]

Gaz, the same happened again! You posted while I replied. So its down to the Antares or the Japanese 'no brand'. Thoughts anybody????

[Brass n glass]

I'd go for the Japanese orthos. I've compared a Nagler 9mm with an 18mm Circle T ortho coupled with a Meade 126 X2 Barlow and there isn't that much difference in resolution, but there definitely is a difference. The Barlowed ortho's field is about half the size of the Nagler's and the image isn't as bright.

[GazOC]

Gaz, the same happened again! You posted while I replied. So its down to the Antares or the Japanese 'no brand'. Thoughts anybody????

I've had several 'no brand' Jap orthos and they've all be really good eyepieces, I've got a couple of Antares as well (the 7 and 9 funnily enough) and they are fine as well. But I'd go with the 5mm as purely for the reason that it'll give x200 without barlowing.

[blinky]

Just mailed the guy regarding the 5mm Ortho. Lets hope he still has it

[Brass n glass]

O'm not sure there are any no brand Japanese orthos any more. The ones that look like no brand are usually Circle Ts where the sticker has fallen off. They've been supplied by KK since the 1960s. The KK website will reveal (in English) the limited eye relief of the high power orthos. I often use a 6mm and I don't find it a problem. I think it would be if you wore glasses.

[blinky]

Luckily I dont wear glasses so hopefully this will be the EP for the job

[John]

I think there is a danger with these discussions that people could go away thinking that there were huge differences between some of the eyepieces mentioned and they could make a disasterous decision - I note the slight tone of panic in one of blinky's posts earlier in this thread . In reality IMHO the differences in views between the Antares Ortho's, the standard Japanese Ortho's the Meade 3000 Plossls, the Meade 4000 plossls and a few others is very little apart from the field of view of orthos which is usually a bit less than plossls due to their design, not a fault - everybody will have their preference of course but from my experience, having tried a number of these in a number of different scopes, for £20-£30 you can't really go that far wrong with any of these.

I have ended up using Meade 3000 Plossls over Orthos becasue I like the rubber eyecups they use - the views seems pretty much the same to me !.

John

[GazOC]

TBH I can see a pretty noticable difference when using my orthos over my Expanse/ Sirius / Hyerions. If I didn't I wouldn't put up with the narrow FOV and tight eye relief.

[blinky]

I have often wondered if you need to be an experienced observer (of which I am not one!) in order to notice the differing views offered by the many designs out there, it seems that this is indeed the case from what you are saying. That is quite interesting and something I will bear in mind for future purchases. I do already have a 6mm and 4mm Plossl, unbranded and very cheap (£35 including delivery from China for 5 Plossl EP's) and have been wondering if I would get a much better view from buying an EP desinged/suited to planetry viewing, I guess I will find out (assuming the EP is still for sale).

[Brass n glass]

Differences in eyepiece performance are often very small, and thank goodness SGL isn't one of those forums that imply: "If you don't want to spendat least £200 on each of your eyepieces, you might as well not bother." But astronomy is all about getting the best possible performance out of a telescope. I have a few Televue and Celestron Ultima clone Plossls, and the cheaper orthos always beat them all on resolution on the moon and planets. I think that bit of extra performane is worth having if it's on offer at a bargain price.