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Posts Made By: David Vandervelde

December 18, 2002 12:12 AM Forum: Equipment Talk

Celestron Star Pointer... how does it work?

Posted By David Vandervelde

Hello all, I just purchased a Celestron Star Pointer off Ebay and I'm not sure the thing is working properly.

When I turn it on there are two lights, one is a very small and dim point in the centre, and there is also another much brighter light (which is oblong and is not at all a circular point) that moves around as I move my head. How is this thing supposed to work? When those two lights are in alignment is it aligned?

Thanks.

Dave

December 19, 2002 10:28 AM Forum: Equipment Talk

Short vs. Regular SCT Adapter

Posted By David Vandervelde

Hi all, I am looking at moving into the 2" diagonal world and am looking at the available TeleVue adaptors to fit a 2" diagonal into my SCT.

What is the difference between the short and regular version besides the length. I have an equatorial mount so clearing the fork mount isn't an issue. Is the image quality different? Is it easier to bring some ep's to focus with the short version? Anyone know the actual measurement and weight differences?

Does TeleVue even sell their regular anymore? The few sites I've looked at only list the short adapter.

Thanks for any help you can offer.

Dave


December 20, 2002 03:33 AM Forum: Equipment Talk

December 20, 2002 01:07 PM Forum: Film Astrophotography - Imaging and Processing

Best piggyback shot without a drive

Posted By David Vandervelde

Hello, I was just curious if anyone else out there has ever done any piggyback astrophotography without a drive on their equatorial mount. I can't afford a drive, so instead I do it manually.

I took this 20 minute exposure of Orion by continually adjusting the scope every five seconds or so using the manual slow motion controls. I used my 8" SCT as a guide scope and centred on Alnilam, then brought it out of focus so it was easier to determine drift, both in RA and Dec (I didn't properly polar align my scope either).

Just curious if anyone else out there has any piggyback shots from such a painstaking method?

December 20, 2002 01:46 PM Forum: Equipment Talk

Using a 1.25" Barlow on a 2"/1.25" ep

Posted By David Vandervelde

Hello, can you use a 1.25" Barlow on a 2"/1.25" ep in a 2" diagonal? I have the Celestron 2x Ultima Barlow and am curious if I could use it on the Panoptic 22mm? I have a 2" diagonal that will accept either 2" or 1.25" eps.

Thanks!

Dave

December 30, 2002 08:47 AM Forum: Equipment Talk

24mm Pan or 22mm Pan

Posted By David Vandervelde

Hello, I have an 8" f/10 SCT and am looking for a Panoptic or two in my main magnification range. I was going to buy the 22mm Pan, but now I'm thinking about going with both the 24mm and 19mm Pan.

What is the difference between the 24mm and 22mm, other than weight? Is the quality the same in the 24mm, which is only a 1.25" ep? Are the 24mm and 19mm far enough apart in magnification to be useful?

Thanks for any advice out there.

Dave

December 31, 2002 03:20 PM Forum: Equipment Talk

Nagler vs. Panoptic

Posted By David Vandervelde

Hello, I have an 8" f/10, and am looking to buy one premium eyepiece in the "sweet spot"for my scope, around 20mm. Since I've always liked lower power, sharper and wider fields, I'll most likely get a 22mm ep... the question is: Panoptic or Nagler (or otherwise, I suppose)?

Has anyone directly compared the 22mm Panoptic and Nagler? I realize that the Nagler will have a wider field of view, but I've also heard that they appear about the same because you can't take in the entire Nagler field at once (ie. You have to look around to see the entire 82* field). What about performance outside of the FOV? Does one perform better in terms of edge sharpness or contrast?

From all I've heard I think the Nagler would be a better ep, but I'm just not sure it is worth the extra money.

Thanks for any advice...

Dave

January 9, 2003 07:27 AM Forum: Equipment Talk

Williams Optics 2" Diagonal and UO MK-70

Posted By David Vandervelde

I just upgraded my 8" SCT to a 2" diagonal, and purchased the Williams Optics 2" diagonal. I was very happy with it until I received my first 2" eyepiece, the University Optics 40mm MK-70. They are an extremely tight fit. It's so tight that I really have to force the ep in, wiggling and twisting it as I go. Last night in the field I wanted to change eps, and I couldn't get the MK-70 out of the diagonal. I was pulling and twisting very hard, and I still couldn't get it free; efforts this morning give the same result. I am worried that in trying to free the ep I'm going to damage something.

Has anyone ever experienced this with a diagonal and ep? Should I be contacting either company and questioning them about it (I have acess to a digital vernier and could measure the dimensions very accurately)? Are there any possible solutions to this problem? For the first time in my life I got really frustrated while observing.

Thanks for any advice anyone can offer.

Dave

November 2, 2004 05:41 PM Forum: Equipment Talk

Help purchasing a new scope

Posted By David Vandervelde

Hello! I am a current 8" SCT user and I'm ready for a new scope. Having done the SCT thing, I'm looking at purchasing either an Apo refractor or a good quality Dob (Obsession, Starsplitter)... and I'm looking at spending a few thousand (up to about $5000).

Based on what I know about my SCT, this is what I want in a scope...

I love crystal clear images. My favourite objects are star fields, open and globular clusters, and the planets. Of course I like deep-sky too, but a rich open cluster always amazes me. I also always seem to gravitate back to my MK-70 40mm, because of the wide-field (relatively speaking, for an SCT) view with tons of pin-point stars... I also have a 22mm Nagler and 12mm Radian but don't use them as much as my MK-70. I don't like the dimmer, hazier views given by my higher powered pieces, although perhaps in an Apo this wouldn't be an issue.

So, I'm thinking I'd prefer quality to aperature... however, I think a scope like a 15" Obsession could give pretty clear images and everything would be much, much brighter. ANother selling point for an Apo would be the portability... just taking a scope and going helps me get out more often. I love the thought of getting a 4-5" Apo, but $5000 for an OTA? Wow... is it worth it? I should also mention that I do want to experiment with astrophotography, but right now it's not a big concern.

I know a lot of you are going to say "visit star parties", but I'm not in an area that has star parties... I'd have to drive a ways to get to one. So in the end will anyone really be able to help me out? Everyone has their own favourite scope, I'm sure... I guess this just come down to personal preference? Probably... but any advice would help! Thanks!

Dave

November 4, 2004 12:52 AM Forum: Equipment Talk

Dobsonian Mirrors

Posted By David Vandervelde

Okay, so I'm thinking about a Dob now...

I have a quick question about mirrors. I have gone over past posts, and realize that everyone will have different opinions about the mirrors in top quality Dobs (Obsession, Starsplitter,...), but I noticed that they list different coatings. The Obsession mirrors claim to have an enhanced primary coating at 96% and 98% (primary and secondary, respectively), while Starsplitter lists 88% and 96%. Does this mean that the Obsession mirrors will give a brighter image? Am I missing something here?

Thanks!