EP quality vs FL

[ardbeg74]

Hi Guys,

Planning on filling out some gaps in my ep collection and replacing my stock sw ep's.

In regard to getting the quality balance right im thinking of buying cheaper long fl ep's and increasing quality as the fl gets shorter. In my head this seems logical, i'd imagine that the demands on the optics of a 4mm ep are much greater than say a 30mm?

Im looking at vixen right now, NPL 40mm & 20mm, a NLV 12mm and an LWV 5mm. Tempted to replace the SW barlow while im at it with a vixen one.

Im in Japan right now and these are all half price compared to the UK. Was going to buy just the 40mm and a single pentax or takahashi but i think i'll get more enjoyment out of replacing the stock eps and having a range of ep's to suit seeing conditions.

What do you think? sound sensible or is the LWV perhaps overkill and could be replaced by an NVL?

Cheers

Mark

[Ags]

Its the other way around - the long focal length eyepieces are more difficult to make. It is more difficult to show a high quality widefield than it is to simply give lots of magnification.

[ronin]

My "choice" would be to determine which set offers what you want then purchase from that set, as in all Vixen NLV's or similar.

Reason for this is the they tend to be parfocal (Not on plossl's).

So less adjustment when swapping eyepieces.

[rwilkey]

Hi Mark, the 5mm LVW (?) will give 240x (f/l 1200mm scope f/8) which in my opinion would be way too much magnification.  You will hardly use it.  150x is about right for planets (esp. Jupiter) but can be pushed up on Saturn, Venus and Mars, but only in the best possible weather conditions.  Your 8mm BST hits the right note, you will not get much better than that.  But should you want to push it 200x is doable in this country and I would recommend the William Optics 6mm SPL if you really must go higher!  The Vixen NPL and NLV's get a good press hereabouts but I have not tried them myself, bear in mind that Plossl's have poor eye relief in the shorter focal lengths, no good if you wear glasses.

[ardbeg74]

Thanks for the replies guys.

Interesting that i had that the wrong way round Ags. Parfocal would be good ronin especially for planetary when the seeing isnt great. ( Which is most of the time )

Robin, im generally using the stock 10mm and 2x barlow. While jupiter is at its sharpest with the 8mm on its own, Im finding that the barlowed 10mm is acceptable. However the barlowed 8mm ive never had any success with, way to mushy. Now here is where my thinking is probably wrong, the reason i wanted a good quality 5mm was because i had thought that the stock 10mm wasnt that great and the barlow wasnt helping things, ( i suspect it causes a little ca too). So a good quality 5mm would be preferable and also sharpen up the image a little. But from what you are saying it would appear that the problem is uk seeing, not the stock optics.

Now i fully appreciate why its important to join a club. As a beginner I dont really know how much the image is being degraded by seeing vs optics vs scope etc... and its way to easy to make expensive mistakes finding out

Anyways, i bought the NPL 40mm as i needed that and held fire on everything else for the time being.

As always, thanks for your sound advice guys.

Cheers

Mark

[Tiny Small]

Whilst my scope can probably handle it a bit better, I frequently go upto 400x on the planets. I use a barlowed 6mm wide Fov. Just depends what you are willing to put up with. The skywatcher plossls aren't bad for the money either. Not in the same league as the top stuff but a hell of a lot better than the MA eyepieces the scopes come with.

[ardbeg74]

Hi Tiny Small, 

It looks like my limit is around 240x with the kit ive got and the seeing conditions. But as you said, thats just what im willing to put up with. There was one night back in november where i might have been able to push it a little bit more but never had a night like that since. 300x is certainly too much for me other than doing a star test.

Its now looking like i need a set of parfocal ep's between 6 and 10mm with long eye relief. Just a pitty  BST dont do a 6 and 10 in the same range as the 8.

Cheers

Mark