Quote:

---

Ok, just saw a reference to this thread from another forum. I saw the 5 star gadget mentioned elsewhere, and promptly went off to ebay to see it. What can I say, at that price, it was impossible not to hit the 'buy now' button. I cant praise the shipping / delivery enough, from your side of the pond, delivered to my doorstep in Canada, in less than a week. timing was very fortuitous, we were leaving for a weekend at a very dark location, and the little gadget arrived in the mail about an hour before we left.

My sct was collimated better than it's ever been that night, and, I did the collimation in broad daylight.

But, I do have a question now, after reading about the overheating issue on earlier ones. When mine arrived, the diffuser and the little 5 hole faceplate did fall out when I was putting in the batteries the first time. When re-assembling, should the black side be on the inside facing the leds, or on the outside facing the telescope? I'm wondering if the black paint is part of the 'heat fix', and, it needs to be inside? I put it the other way around when I re-assembled, and haven't noticed any problems yet, but if this is a problem, I'd like to pre-empt it now.

---

Yes, black to the inside.

--------------------
Jim

Post Extras:

Quote:

---

Hi Kevin,

The formula M = 336 D / F^3 (D is in inch, F is the focal ratio) was derived by Roger W. Sinnott (Sky and Tel, May, 1991) based on Ray trace for Newtonian reflector, included in Suiter's book. Actually, as Suiter pointed out in his book (5.3.4), this will give "incorrect distance" for SCT. Suiter suggested M of 24 for a 8" f/10 SCT for a real star test. Our experience and Ray trace indicate that you do need at least this far for a real star test but not nearly as this far for an excellent collimation. To do a perfect collimation, you do need to go as far as to see the Airy disk! This has to be done by experiment for your scope.

However, you still can go much closer to do a (at least a preliminary)star test as long as you can focus on the star, and as long as you know what kind of impact/aberration the closer distance will introduce (yes, spherical aberration!)

We will make a clarification on this formula on our web site. Thank you for raising this question.

-Tong

---

I picked one of these up from AgenaAstro (Manish), and got to play around during the day with my SCT. I setup my scope in the shade of my "porch", which is elevated about 10 ft above the sidewalk, and pointed down the street. I mounted this artificial star by taping it to my grab-n-go mount and had my kids tend to it while I setup and aligned.

I could clearly get everything in focus at >130ft, and had to us a 80mm extension tube when I pushed it close to 70ft, but it was really difficult to see any diffraction patterns because of the daylight. Now, I wasn't really expecting this to work in broad daylight, but I thought I read some had had success and figured to give it a try (and it was a way to keep the kids out of my wife's hair for an hour or so).

My question: can this be used in the daytime, but not out in daylight? Or do I have to wait for dusk? I'll give it a whirl at dusk tonight when the sun is not quite set, but our street is cast in shadow.

I'll also try and figure out how close I can get with my setup for those who may be interested in SCT land.

--------------------
Clear Skies,
Jim
--
"Do, or do not. There is no try."-Jedi Master Yoda

Scopes: CGE925, 80ED, NP127is (w/ADM acc.)
EPs: Naglers: 31, 22, 17, 9, 3.5 Pan’s: 15
Misc: Telrad, 2x&4x Powermate, Sol/OIII/UHC/Var Pol. Filters
Imaging Gear: Pentax K100D, SPC900NC

Post Extras: