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Messages - swittetsakee

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1
Light Pollution Topics / Re: Sometimes It's Hopeless
« on: February 09, 2018, 03:16:26 AM »
Talk to your friends who do not work for your company. Ask them to complain about the safety and security problems associated with blinding lights. Maybe someone will file a lawsuit claiming light trespass.Companies, cities, and counties need to hear about the issue again and again from different sources before the message sticks.Gale

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So, this topic is very similar to my XT6 one, only now I'm asking about the XT8, I have been comparing the scopes for almost a week and I would really appreciatesome reviews.

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ATM, Optics and DIY Forum / Re: Help me figure out what I bought
« on: February 08, 2018, 02:17:48 AM »
Yep. At the very worst, I've got 3 full-thickness pyrex blanks and 3 decent size secondary mirrors, plus the lasers, leds and beam splitters for making test rigs. Plus all that aluminum. They're all on nice, wide and long dovetail mounts, too. What I don't yet know is if the "windows" at the front are simple plane-parallel windows or schmidt correctors. I'll figure that out this weekend if I don't hear back from Aerometrics first.

-Tim.

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Mounts Questions & Expirience / Re: Any NEGATIVES to a Paramount MX+ ?
« on: February 02, 2018, 05:58:02 PM »
Quote
If I am reading your post correctly (and I apologize if I am not) I would not mount your wedge to the MX. I would defork your Meade and put a dovetail on it.

Thanks, Dr.Who - yes, my intention is to ditch the fork & wedge and move my Losmandy dovetail to the underside of the OTA.

To some other points (from various) - yes, I understand there are other options out there for a similar order of magnitude (+/- 50%) in price. I've already investigated some via friends who possess them. What I do not have is a personal friend with a Paramount MX+. I believe the MyT would be a mite underpowered for the kind of potential load I may someday put on it - hence my interest in the MX+ (the ME II seems like overkill).

What I was asking (among other things) is if anybody MX or MX+ owners have had negative experiences with the beasts. I'm not asking for responses like "I would buy an XYZ instead".

Nickel and diming is not on my agenda. But I'm still Scots, so I spend my hard-won money carefully.

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ATM, Optics and DIY Forum / Re: Carbon Fiber Tube Layup
« on: February 02, 2018, 05:20:59 PM »
Look in the "What did you work on today thread"

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Quote
What is the norm expected now vs. where does one cross into narrow or wide based on maximum field that the scope can employ? I am leaning toward a working definition of less than 1.5 degrees as a narrow and 2.5 degrees or greater as wide. Everything else is the normal range.
On the whole, it seems best to avoid these terms -- or use them with caution -- since there is clearly no consensus on their usage. Simply stating the maximum FOV takes no extra space and provides far more information.
Having said that, I can tell you how I classify telescopes in my mind for my own purposes.
In my mind, it's not entirely fair to ignore aperture when defining these categories. For instance, my 7-inch f/5.4 Dob, with its 2-inch focuser, has a max TFOV of 2.7 degrees, which seems very wide indeed considering the telescope's aperture.
My 70-mm f/6.9 refractor, with its 1.25-inch focuser, has a 3.2-degree max TFOV. I still consider that to be a reasonably wide field of view, but by no means extraordinary, considering the scope's relatively small aperture. The wide-field views of my 70-mm refractor are far less impressive than the wide-field views of my 7-inch Dob, despite the fact that they cover a much bigger swath of sky. On the other hand, my 100-mm f/6 refractor, which has a 4.4-degree TFOV thanks to its 2-inch focuser, gives wide-field views every bit as impressive as my 7-inch Dob's despite having a much smaller aperture.

I have seen a fair number of 5x25 finderscopes (stopped down internally to 10 or 15 mm true aperture) with fields of view around 4 or 5 degrees. I consider that outrageously narrow, despite the fact that it's twice the width of the TFOV of my 7-inch Dob.

Likewise at the narrow end. A classic 60-mm f/15 refractor with an 0.965-inch focuser has a max TFOV around 1.3 degrees, which seems exceedingly narrow consider the telescope's small aperture. But the 0.77-degree max TFOV of an 8-inch SCT equipped with a 1.25-inch back and no focal reducer seems only "narrow" as opposed to "very narrow." And a 16-inch scope with a 0.77-degree TFOV wouldn't seem narrow at all.

On the other hand, I do think that absolute TFOV -- ignoring aperture -- plays some role in how I think of telescope. I wouldn't call a 24-inch f/4 Dob a widefield instrument despite the fact that it has a TFOV relative to aperture that's bigger than my 7-inch Dob's.

I think I would place an absolute floor of 2 degrees to consider a telescope to be a wide-field instrument. That's big enough to fit the field stretching from NGC 1981 to M42 (barely), and to fit and frame M44, M45, and Markarian's Chain.

But when you get down to an aperture of 4 inches, I wouldn't consider 2 degrees to be wide-field any more. At that aperture, the minimum to qualify would be at least 3 degrees. And when you get down to 50 mm, at least 5 degrees. I don't claim there's anything scientific about this -- it's just how I perceive it.

7
Beginners Forum / Re: How do you deal with the frustration of Weather
« on: January 31, 2018, 05:31:29 AM »
Recently I had to catch up on Game of Thrones while pushing glass and testing them

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Wow, there was a break in the clouds. I just went outside. I could see Aldebaran in Taurus--nothing else. Then I looked in the binoculars and I saw the whole thing...there is no understating how cool these things are. I like how wide the field is. I panned over to Orion and could see a ton of stuff. The Orion Nebula was too dim. I thought I could see a little fuzziness there, but I think I need to wait until I can go to a darker site. Nonetheless, I could see tons of stars--all nice little tiny dots. I'm going to go outside again... =^D

EDIT: Too late, too many clouds and a sudden increase of mosquitos. It's a conspiracy!

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I like it very much. The whole rig only weighs about 30 pounds. I can pick up the entire rig (scope, tripod, and mount) and carry it outside in one trip. I do take at least one more trip for my observing chair and whatnot. It's a really good tree dodger too.

My mount is a Universal Astronomics UniStar Deluxe. Sadly, no longer made, but you might find one used.

If I were looking at a new mount for this scope, I would probably investigate the Stellarvue M002CS mount and tripod for $599. It looks like a good sturdy manual mount, but I haven't actually tried one.

http://www.stellarvu...e-mount-system/

The grand total would be $1368.00.

10
Mounts Questions & Expirience / Re: Alt/Az Mount Options for 6" Refractor
« on: January 30, 2018, 11:56:27 PM »
Thanks...the AZ8 is definitely an option...Tammy's videos look good for settling time even if it will be longer with a 6" OTA.

I could also get more time with my C9.25 in alt-az mode but not sure if that long a focal length is practical.

Both use Losmandy "D" plates...perfect for the AZ8.

11
Thanks for the input Steve! Those thumb screws look nice, is there any downside to using those over the stock screws? What does the milk jug step do?

I seem to have everything pretty well aligned at the moment so I think I am going to follow the "if its not broken, don't fix it" theory and use it as is until the secondary needs adjustment again. Then Ill plan on loosening all 3 screws and try to get it collimated without over tightening. I may replace the stock screws for thumb screws as that point as well.

When I do this, I loosen all three a couple turns and then gradually tighten all 3 one at a time until its aligned and all somewhat tight? And then once I am at this point I should be able to make subsequent adjustments using just 2 screws?

As for the primary issue, your the second person who suggested changing the stock springs. I read somewhere here on CN that it was a good idea to tighten all 3 primary collimation screws until the springs just bottomed out and then back them off 1 and a half turns, and then from there do the adjustments by loosening two of the 3 screws so I went ahead and did this. It resulted in the springs being compressed to about a 1/4" like you suggested. The springs seem to be applying a decent amount of pressure, but the one adjustment screw is still really tight relative to the other two. It still turns and seems to adjust fine, it just takes a lot of force to turn it. Unlike the locking screw thats tight which feels like it has a burr or something, the adjustment screw turns smoothly, it just has a lot of resistance. Im kind of thinking as long as its not hurting anything its probably not a big concern, at least for the time being?

12
ATM, Optics and DIY Forum / Re: Going for 20" (kilncasting)
« on: January 30, 2018, 04:01:15 AM »
I spent another 3 or 4 hours grinding on it today. Trying to get it "flat"... Here it is on one of the kids sleds... looks like a giant peppermint ;-) The colored in areas are the low spots... The "flat" area has been getting gradually bigger and bigger and eating away at the low areas... a few tiny bubbles here and there at the seams where the shelves sat vertical (the parallel lines in the middle) but I may grind past them if luck is with me... otherwise a pinpoint of flat black will do ;-)


13
Light Pollution Topics / Re: Please review my light pollution slides
« on: January 30, 2018, 02:13:57 AM »
Quote
Gary,

Have you had any success in finding some specific narrow-band LED or low CCT (2200K) LED light fixtures that towns and cities can purchase? For example, are there any specific cobra head fixtures with narrow-band LED light sources available?

thanks,
Rob P.

Hi Rob,

I sent you a private message with my contact info for blue-filtered streetlights.

Gary

14
unless you refigure it before cutting it up. sometimes its a cheap way of getting a nice mirror. all the grinding and polishing are done just fix the figure. and since a lot were only figured to 1/2~...strip the coatings and finish the figure.

I'd stick with a full 13" mirror.

on Vlad's site he states that the off axis segment [either cut out or masked off] reduces the wavefront error by a factor of 4. so if the parent mirror starts out as a 1/2~....

15
General Astronomy & Observing / Re: Wasp and Hornet Spray for Protection?
« on: January 26, 2018, 12:51:32 AM »
Some YouTubers were dumb enogh to actually try a pepper spray vs wasp spray comparison test. Wasp spray was useless:
https://www.youtube....h?v=9Uy9MnQfk_0

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