5mm eyepiece?

[davo]

I know there must have been a million questions on eyepieces but am still a bit confused and wouldn’t mind a bit of advise on my particular set up.

I have

300mm 12” F5 Dob 1500FL

32mm 2”

15mm 1.25”

x2 Barlow

They are all inexpensive eyepieces yet am pleased with the views I get. I’m wishing to purchase anotherr eyepiece for getting a closer look at the planets purely for visual observing and was thinking of a 5mm? Is that reasonable? I hear that some EP’s are not suited for fast scopes? Can anyone tell me which ones are suited? Does it have to be a wide angle?

Being a high mag piece I guess it needs to be of reasonable quality? I was looking to spend no more than £100. Can anyone suggest an eyepiece.

Many Thanks

Dave

Edit by lunator to remove formatting

[lunator]

Hi Dave

An issue you might face is the that tracking object at x300 might be tricky.

Cheers

Ian

[russ]

I agree with Ian. I find things move too fast with the 5mm. But the 7mm mark seems a good compromise between image scale, image quality and not having to nudge the scope too often.

Being a dob, a widefield eyepiece is hugely desirable. Something like a TMB Planetary 7mm with 60deg afov is good and only half your budget. I did have the TMB but recently swapped to the William Optics UWAN 7mm. Field is a huge 82deg and i can just let Saturn drift across the field while taking in the view. It's bliss.

Orthos and Plossls are top planetary eyepieces but with a very limited 40-52deg field, you'll be forever nudging. Not to mention tight eye relief. I tried a Meade Series 4000 6.3mm in my 12 and it was a nightmare. Couldn't relax and enjoy anything.

[davo]

Like the idea of the WO UWAN... but would a 5.5mm Meade Series 5000 Super Plossl be a bad purchase? 60deg FOV. I like the price @ £64.

:scratch:

[russ]

Dave, that was the sort of thing i had in mind. For some reason the 5000 escaped me. There's an excellent review of that eyepiece at this link:

http://www.astromart.com/articles/article.asp?article_id=359

Although that was reviewed in relatively slow scope. I quick look round the web and i notice people are not so happy when the focal ratio hits f5 or faster. Still sharp on axis in the middle of the field but quality tails off towards the edge.

Another option could one of the TS Planetary HR from Modern Astronomy:

http://www.modernastronomy.com/eyepieces.html

Same field of view as the 5000. Designed from the outset to be used in fast dobsonians. And even cheaper at £54. Loads of focal lengths to choose from.

Russ

[russ]

Or how about the Baader Hyperion. They do a 5mm and the fov is larger at 68deg. I preferred my TMB's to the Hyperion but that's personal preference and there's plenty of people who prefer the other way round.

http://firstlightoptics.com/proddetail.php?prod=hyperion

And another option could be these:

http://www.scsastro.co.uk/it020007.htm

They are getting a lot of attention on the other side of the pond. Specs are good and the price is right. Initial reports i've heard is they work very well in scopes as fast f4.5. Which gives them an immediate leg up on the Hyperion and 5000.

[davo]

Now i like the Baader Hyperion. Hang on the Astro-tech is sounding good too. Thanks for the choices i'm gunna have to have a good think.

[davo]

The Baader looks good with 68deg and i'm glad you didn't right-off the 5.5mm Meade 5000. Distrortion at the edges is something i am used to owning inexpensive eyepieces and in a way it could complete the cheap set off quite nicely. You would have thought it would be easy to choose a cheap one? I'm glad i'm not spending £300 i would never make up my mind!

Thanks for the info. I'm much more informed than this morning.

Dave

[acey]

I have a dob with a lightly shorter focal length than yours (ie slightly lower magnification) and the highest power I use is a TeleVue 8mm Plossl - excellent eyepiece. I have a 2x barlow but never use it with that eyepiece - everything speeds past too quickly and there's no improvement in resolution (in fact the reverse). Costs just under £60 these days - quite a bit less than I paid for it several years ago.

http://www.telescopehouse.com/acatalog/TeleVue_Plossls.html

Andrew

[athornett]

I have a 1500mm F/L Lightbridge 12" and own 10mm, 8mm, 7mm, 6mm, 5mm, and 4mm eyepieces. To be honest I wasted my money buying them all - I only ever really use the 7mm Televue Nagler - which is great!

Having said that, most of the rest are Vixen Lanthrums - excellent optics and very cheap on the 2nd hand market if you can find them.

Andy

[John]

I have a 1500mm F/L Lightbridge 12" and own 10mm, 8mm, 7mm, 6mm, 5mm, and 4mm eyepieces. To be honest I wasted my money buying them all - I only ever really use the 7mm Televue Nagler - which is great!

Having said that, most of the rest are Vixen Lanthrums - excellent optics and very cheap on the 2nd hand market if you can find them.

Andy

I have a 12" Lightbridge as well - and Naglers are great (but expensive) with it. The Ethos 13mm is even better

I find the 9mm Nagler a particular "sweet spot" with my LB 12.

John

[JAO]

Dave

I agree with previous posters about Naglers and Ethos's, they are superb eyepieces but they consume the £££s! I regularly use 7mm and 9mm Naglers with my 12"f 4.5 and 18" f4.5 dobs (I only use a 4.8mm Nagler with the 18" when its on its Equatorial Platform), I am lucky enough to have these in my eyepiece box. I also own and use Takahahi LE's at 5mm and 7mm fl's. Although they are not wide field oculars they deliver excellent performance for the money, the compromise being their 50 degree apparent field. They come up second hand for around £120ish (sadly with recent price hikes mean the new price has gone from £150 to £205 in the last 9 months) so this might be an option to consider, they are IMHO excellent eyepieces that are often over looked.

Adrian

[philsail1]

Hello "Dave,"

Re a 5mm eyepiece.

I have a Vixen Lanthanum 5mm eyepiece I could let you try out on your Dob - if you want.

I bought it last year from Orion Optics at Crewe, but found that it doesn't really perform that well on my Orion Optics 8" f4.5 Europa Newt, or mt Celestron C8 SCT. (Well I don't think so anyway!). I found it a bit too powerful really.

If you want to try it out I can send it over. Keep hold of it for a couple of weeks and if you find it doesn't "work" on your Dob, just send back. If you find it is OK, I would be willing to sell for £50.

Anyway, let me know if you want to try. (I won't be offended if you don't!).

Regards,

philsail1