Pentax SMC 7mm, barlow to 5mm or just buy another EP?

[Rogering1]

Hi guys,

I have recently purchased a Pentax SMC 7mm on my F10, Newtonian F5 scope.

To get a bit closer than 178.5x I bought a GSO x 2 barlow, this type of barlow allows you to unscrew the lens cell & fix it to the end of the eyepiece, this makes it approximately 1.6x therefore I can get to 4.375mm approx 285.7mag, I have found this image on most nights to be very good but missing a little contrast and definition, so I'm pretty sure that Saturn around 5mm (250x) is my best bet on most nights.

I feel the GSO Barlow could be letting me down & could be upgraded or:

Buy a 5mm Pentax SMC E.P (don't really want to do this if I can find a "high end" low powered barlow) Siebert do make a 1.25x Barlow Cell (5.6mm).

Does Televue have a GSO Type Barlow (1.6x) where the barlow lens can be removed same as this? http://agenaastro.co...ns/category/24/

All input welcome

[John]

If you can find one, the Antares 2" 1.6x barlow is really excellent. I used to use one with Tele Vue Ethos and Nagler eyepieces and it worked really well - it rivalled the image of a non-barlowed equivilent eyepiece. They cost around £85 new but always seem to be in short supply so putting a wanted advert on the UK Astro Buy & Sell website might be worth a try (I realise you are in Australia so maybe try the "Ice in Space" forum classifieds as well).

There are very few quality 1.6x barlows around. The Tele Vue Powermates are superb but 2x is the lowest power one they do and thats a 2" unit which costs nearly as much as a new Pentax XW eyepiece !