Help with Planetary & Lunar eyepiece's

[prova]

So I'm all set to buy my first 'good' quality eyepiece for both planetary and lunar observation.

My choice's have been narrowed down to the Vixen LV series in either 4mm or 5mm

Having said that, are there any other recommendations for similar money (other brands?) and which of the two magnifications above would suit my 8" reflector best, I want this to be the right purchase so it will last years to come!

Cheers

[Stephen65]

Assuming your scope is an f/5 that gives you a focal length of about 1000mm.

In my 925mm FL refractor the EPs I most commonly use for detailed lunar observing are between 7 and 5mm, seeing has to be good to justify using a 3.5 or 4mm EP.

For that reason I would get the 5mm Vixen LV.

[ausastronomer]

I would agree with the recommendation of the 5mm as opposed to the 4mm.

Cheers,
John B

[erick]

Prova, I also have an 8". It's an f6. I have two Vixen LV's 6mm and 10mm. I really don't think you'll get much benefit going below 6mm. That's 200x in my scope and several nights that's more than the seeing allows. The problem with going 4mm or 5mm, it seems to me, is that if seeing is poor, then you cannot use these eyepieces, for anything at all.

I suggest you don't go below about a 7mm or 6mm, then get yourself a good 2x barlow to get to the magnification you desire when seeing is good. In that way, if seeing doesn't support 340x to 400x, you maybe can still use the eyepiece at 170x to 200x, whereas the 4mm will just stay in your case.

Which barlow? Well Janoskiss has often said:- " Best barlow for high powers IME is the fully baffled Orion Deluxe 1.25". Got mine for $99 from Sirius Optics in QLD. An absolute bargain." It's on my list for a future purchase. (Just checked - I think it's $120 now.)

I'm sure others have views as well, and they may well differ :)

[Solanum]

I have a 6mm Vixen LV and it's my most expensive eyepiece. It's an absolute pleasure to use (especially compared with the GSO Plossl of the same focal length which was awful). No doubt it doesn't compare to a Nagler though!

I would however also advise not going below the 6, as I find that whilst I use it a lot more than my GSO 6mm, it only reveals more detail than my GSO 9mm Plossl on nights of reasonable seeing (doesn't need to be excellent seeing though).

The smaller the focal length the less often you will use it. I intend to get a 9 or 10mm LV at some point which I suspect I will use every night I'm out there.

[janoskiss]

5mm on good nights will do you well. But the fairly narrow FOV of the LVs makes them not so well suited to Dobs, esp at such high magnifications... Maybe better off with a TMB/Burgess planetary EP instead.

[Stephen65]

According to his sig he has reflector on a driven equatorial mount. The TMB/Burgess planetary EPs are well regarded and do have a wider AFOV (60 v 45) but I do not know how they otherwise compare with the Vixen LV's for transmission and sharpness.

When viewing the Moon I usually start with a 10XW which frames the entire Moon nicely with a 70 degree AFOV and then work my way down from there - next to the 7XW and on some nights that is all that the seeing will allow. If the seeing is reasonably good I use 6 and 5mm EPs, if its excellent then 4 and 3.5mm EPs.

When it comes to barlows I think its hard to go past the Televue 2x barlow at the current sale price of $139.

[prova]

thanks for all the replies so far, at the moment I the standard 10mm and 25mm Plossl ep's that came with the kit, so they're just your standard quality although I am quite happy with the 25mm to be honest.

aside from that, my high mag views have been with my 10mm in a rather generic branded cheap 2x barlow and it's ok but i really wanted a higher quality high mag ep for looking at planets and the moon as it's one of my main enjoyments

and reading the above posts i am sliding towards the 5mm Vixon

any further comments welcome

:thumbsup:

[Solanum]

I find my GSO 2x barlow totally useless. The image is so poor you are better off with the lesser magnification of the eyepiece on it's own. You won't be disappointed with the LV in comparison to the GSO Plossls.

[janoskiss]

:doh: thanks for the correction.

[prova]

well i'm pretty much sold on the Vixon LV 5mm, I'll re-visit this thread after I've given it a good run

:)