14 replies to this topic

[Tom T]

ED80 StarTest

Finally had some clear skies and a chance to get out with my new ED80.

Before the sun set, I had the 80 out on the moon side by side with my SDF, and was pleasantly surprised with how the 80 performed. Fine detail was very similar in both scopes, with the edge going to the larger SDF – as you would suspect. The image held up very well all the way to around 180x (60x per inch), and there was *extremely* little false color shown on the limb of the moon. I’d suspect that most people would say there is none – or at least none worth mentioning, but I’ve noticed I seem to be a little more sensitive to false color than some people. Please note, I don’t find it objectionable on most of the scopes I’ve seen it on, but I do see it, and I frequently see it when others do not.

Throwing it on a star showed a slightly broken C pattern of the first diffraction ring, and an extremely slight trace of a second at the base of the C, but the airy disk itself was fairly round with little to no signs of elongation. This indicates its *slightly* out of collimation (not surprisingly so, given the way the focuser is attached to the OTA, I’m willing to bet the focuser is not properly centered), but there were no obvious signs of astigmatism, and the intra and extra focal diffraction patters were more symmetrical than I had expected. I noted no signs of pinched optics.

The images cleanly *snapped* into focus with is further indicative of good optics. There is a very small in focus range – a good sign. The focuser works very well, and supported several heavy 2” eyepieces when pointed near zenith.

When you take into consideration the price point, I must admit I’m very impressed with this scope. There are a few things I’d change, but for the money, this is an exceptional little scope.

Tom T.

[Bill Grass]

I broke down & ordered one from Company 7. The gentleman on the phone said that there's really no way to adjust the lens cell, but he collimates those ED 80s by adjusting the focusers. He also said that every single one he's received from Orion needed adjustment.

I'm anxious to get mine! I hope it stays collimated throughout shipping!

[Tom T]

I broke down & ordered one from Company 7. The gentleman on the phone said that there's really no way to adjust the lens cell, but he collimates those ED 80s by adjusting the focusers. He also said that every single one he's received from Orion needed adjustment.

I'm anxious to get mine! I hope it stays collimated throughout shipping!

And mine was no exception to that. Tests with a laser today showed that the focuser was pointed about 1/2 inch or less off center. Unfortunatly, even with the slop in the screw holes the focuser wasn't "quite" able to line up. A quick use of the rotary tool, and the holes were enlarged *just* enough to allow me to properly align the focuser.

I'm anxious to get it under the stars, but according to the CSC, I'll be cooling my jets for a bit. Maybe this week, I'll finally get around to setting up that artificial star I've been telling myself I'd do for years.

Tom T.

[Tom T]

Tom,

Not really. It didn't need much enlargement at all. You just need to be careful that you don't enlarge the holes so they are bigger than the head of the screw - you really just want to elongate it slightly. And it took a fairly long time to enlarge the hole even slightly with the dremel. If you were really worried, you could just use a small round file. I prefer a dremel because I'm lazy. Just don't take off much.

I certainly wouldn't do this on a TV, TMB or the like - but then again, I wouldn't expect to have to do this on a TV. TMB or the like.

Tom T.

[Victor Kennedy]

TT's Synta HotRod Shop - has a nice ring to it, doncha think?

[Tom T]

This Tom's not planning on it anytime soon. <g> The amount of work I'm willing to put into an optic is inversely related to what I've paid for it.

I am considering doing a detailed writeup on the scope tho - complete with tune ups. BUT there is so much information on this scope already out there, I'm not really sure there is a need or intrest. What do you guys think?

Tom T.

[Bill Grass]

Do it!

I'd be interested in reading it. I've got an ED80 on the way.

[Tom T]

Otto,

No. They are the screws that hold the focuser onto the OTA. The holes that had to be slightly elongated were in the rolled steel of the OTA.

Before you enlarge the holes, you should just try loosening the screws and adjusting the focuser, as there is quite a bit of slop already. My focuser wouldn't quite adjust far enough so it was optically centered on the lens - thus just a very little bit more play was required to get everything centered.

Tom T.

[Tom T]

Well, managed to throw the ED80 on a star this evening for a few minutes.

I love it when a plan comes together, and it looks like my efforts at collimation paid off. Even though the scope was taken directly from inside to outside, and the seeing wasn't the best, a quick star test showed the *entire* diffraction ring coming and going around the airy disk - instead of just on one side - a definite improvement.

Detail seemed *slightly* improved on the moon, and held up very well all the way to 200x. Mars was a tiny, but EXTREMELY nice sight.

And then the clouds rolled back in.... <sigh>

Now for a clear night so I can do a REAL star test, and not just the quick stuff...

Tom T.