Posts Made By: ken pfeiffer

Hi everyone,

I have a newbie imaging question that I hope someone will help me out with. I have an SV TMB-105, and I was attempting some imaging with a Canon Digital Rebel. I got a T ring and adapter, and I was trying to do some imaging at prime focus. I took a few terrestrial pictures and they turned out fine, except that there was some vignetting. That is, the central part of the picture was very nice and clear, but outside of a central circle occupying about 80% of the field,there was considerable darkening.

Can someone explain what is going on here, and if there is something I can do to avoid it? Is this why people buy scopes with larger focusers, or what? Thanks for educating me about this!

Hi everyone,

I have a question about minimizing field curvature in a fast refractor. I have a SV-TMB 105 that exhibits considerable curvature of field with my favorite 19mm Pan eyepiece. That is, when I get the stars in the center of the field in focus, the stars on the periphery are not in focus.

I understand that using a Barlow will minimize this effect. Is there any other way? I am open to any suggestions about what eyepieces, etc. will minimize this.

Thanks for your input!

I have a Lumicon enhanced 2" diagonal
that I believe is a dielectric mirror.

How to clean the mirror? It has
accumulated quite a bit of dust.
I tried using the blower bulb,
but there are still a couple of
spots that won't blow off. Is it
OK to gently rub the mirror with
a microfiber cloth?

What is the recommended method to
clean this? Thanks for any help!

I have done a side by side of those two eyepieces, and the TV is definitely better. Yes, it costs more, but if you want the best...

But I do agree with some of the other replies here. I don't use the 55 much because it is heavy and the contrast in light polluted skies leaves much to be desired. At a dark sky site with a long fl scope it is very nice, though.

Anyone know where to get those plastic caps for the bottoms of 1.25" eyepieces? Mine keep disappearing, and I would like to buy a few extra to keep the "eyepiece gnomes" at bay.

Has anyone seen or done a review of the last AP 155 vs the new 160? Has anyone even done a side by side with these?

That would be very interesting, considering the different design characteristics.

With my 105mm f6.2 APO I like:

30mm Celestron Ultima (nice for terrestrial!)
19mm Pan
3-6mm Nagler zoom

Yes, I know there is a big gap in there between 19 and 6mm, which I fill with a 10mm Radian, but that would make one too many eyepieces, and I don't use the Radian as much as the others.

Has anyone used the IDAS V3 filter? Any feedback or reports about this? I have heard some very good things about it on the Stellarvue Yahoo group.

Sorry, I probably should have mentioned more about the side by side comparisons that are possible at a place like ATWB. I have heard all sorts of stories and read many binocular reviews, but there is nothing like seeing with your own eyes.

I read many good things about Canon IS binos here on this forum, also Nikon Premier LX, etc. I have a pair of Swarovski 10x50 binos, and my wife wanted another good pair for birding. The Canons and Nikons are much cheaper than the Swarovskis, so we were thinking of buying a pair. Going to ATWB, we could compare Swarovski, Nikon, Leica, Zeiss, and Canon, among others. We looked at a gas price sign down the hill from ATWB, hand holding all the binos.

First up were Nikon Monark 10x50s. These threw up a nice view and were very affordable conpared with the other binos, but you could not read the gas price on the sign. Next up were the Canon 15x50 IS, which had been mightily praised here on this forum. These were really nice, and you could read the price! Next were the Nikon Premier 10x42. These had noticeably better optics than the Canons (sharper and clearer, even with smaller aperture), but the IS feature and higher power of the Canons allowed you to see about the same amount of detail. Next were Swarovski 10x42. These turned out to be the best of the lot. They were brighter, sharper, and clearer than the Nikon Premiers, but they also cost about 30% more. Switching back and forth and comparing the Premiers with the Swarovskis several times finally convinced my wife that the difference in price was worth it.

As I mentioned, there is no substitute for side by side comparisons with your own eyes. Thanks, ATWB, for providing this opportunity!

Strange, huh? It would be interesting to know how the Celestron lens is configured.