TV Powermate?

Hi!

Last night I was out using my new AP130 Gran Tourismo. Extremely cold and clear, but the air was surprisingly steady. My usual routine is to take a look at the trapezium for E & F; E was easy but I had trouble with F.

The point is; my shortest FL eyepiece is 6mm, giving only 140X in this scope. Conditions were screaming for MORE POWER!!

So I was thinking today of looking for a shorter FL eyepiece, or a 2X Powermate.

In my collection I have AP SPLs of 6, 8, and 10 mm, which would give me 3, 4 and 5. Although I have astigmatism, I can leave my glasses off at these short FL's.

So, do you think the Powermate would degrade these in any way? Should I look for some shorter FL eyepieces, or would you recommend the Powermate? Your experiences are solicited!

(as an afterthought, I also have a 12mm SPL. Doing a comparison with my 6mm, and 12mm + Powermate, would be interesting!)

Thanks,

Steve

140X should be enough to see the E & F stars in the Trap. I think you might have overestimated the seeing conditions, or your lens wasn't cooled down.

I've used the 2X Powermate as a focal length doubler for photography and it works very well in that role. The build quality and coatings are top notch and I doubt it will limit the performance of your AP130GT in any way.

Oops, it's "Gran Turismo". You'd think after waiting 8 years I could spell it correctly. Roland, could you name your next line of scopes something like "Bob"? Thanks in advance,

Steve

So I was thinking today of looking for a shorter FL eyepiece, or a 2X Powermate.

Steve,

I am going to take a slightly contrarian point of view regarding the Powermates. A year or so back, I compared a couple of the TV 2X PowerMates to several 2X Barlows.

The conclusion I came away with was that the PowerMates added some slight Spherical Aberration to the star test image. The plain TeleVue Barlow did not seem to add any aberrations that I could detect. This was on artificial star in a controlled environment as well as on Vega outside. The telescope was a very fine Vixen Fluorite.

The difference was noticeable in the star test, but did not seem to make a material difference on Jupiter.

The PowerMates are useful for the webcam/astrophoto crowd as there is no vignetting. But visually, I would tend to stick with a shorter focal length ocular, simple TeleVue Barlow or use the Nagler 3-6 zoom. The Nagler zoom adds no SA to the image whatsoever.