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Topics - Justin Prasad

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I'm considering a Baader Click-Lock visual back for my Nextstar Evolution 8
https://www.highpoin...-for-sct-clsc-2

I already have a William Optics Dura-Bright 2" Diagaonal that came with the direct thread-on adapter for my SCT..This offers the most mount clearance, but it also does not allow for adjust-ability of the diagonal. The good thing is my Dura-Bright diag also came with a conventional nosepiece

I've been seeing a lot of posts about the Baader Clicklock 2" visual back. It looks like it would provide easy adjust-ability and a good sturdy foundation for my diagonal, but my concern is how much loss of clearance will I have?

Does anyone have any photos of mount clearance using a 2" diag. on an 8" Evolution with a Baader Click Lock?

I know the 9.25 already had mount clearance issues, but right now I have quite a bit of clearance using my 2" diag with the direct thread on adapter

Jon

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I am nearsighted with fairly bad astigmatism that requires -4.5 correction. However, I never observe with my glasses because I can't really see a difference with and without them on. My 35 Pan is the lowest power eyepiece I own, and produces a 3.5mm exit pupil in my SCT, but I don't see any difference in the view.

What visual aberrations should I notice with that kind of astigmatism?

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Eyepieces Questions & Recommendations / 15mm UWA 80 deg 2'' eyepiece
« on: January 03, 2018, 08:20:17 AM »
What do you think about this eyepiece:
http://www.ebay.com/...yEAAOSwGtRX1uYd

?

Is it some scam? How does it compare to a plossl / goldline?

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Eyepieces Questions & Recommendations / Filters For Non-Dark Sky Sites
« on: December 30, 2017, 02:56:30 PM »
To use a Celestron 1100 Edge HD in a light polluted area (maybe moderately light polluted ... a small city of approximately 30,000) which filters would I need to purchase to make viewing relatively free of frustration? Would one filter suffice or would a combination of filters be required? Do you have suggestions as to specific brands? Could the same filters be used ... or need to be used ... if astrophotography were part of the equation? Thanks.

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Hi all,

I used to image with a C8 until I was a fool and placed it on an elevated surface.... you can guess what happened. Anyway, since i'm out an OTA, I decided to build a new one. I initially was looking online at OTAs but just didn't think anything was a good fit for what I wanted to do. I am serious about imaging and I wanted the best, so I bought a Zambuto 8" F7 quartz mirror. There's only one problem: I have never made an OTA or even built anything so precise in my life, so now i'm trying to figure out how to best go about assembling an OTA successfully to use the mirror to it's full potential.

I was hoping to get guidance on assembly and my overall plan. When I bought the mirror, the guy I purchased it from threw in nearly everything (I think?) needed to make a Newtonian. He had the supplies but just hadn't put it all together. Here's what I am getting in the mail:

8" f/7 quartz mirror (20mm thick)
1.3" Antares 1/30 wave secondary
Astrosystems secondary holder
Astrosystems secondary heater
Astrosystems spider
Moonlite single speed black focuser
10"x~60" Hastings tube with both ends rolled for rigidity.

Regarding the mirror and mirror cell, the gentleman said this:
"I picked up a Meade 8" mirror cell with the intentions of modifying it for a 6-point cell. This mirror is 20mm thick, so modifying the cell will work perfect with it. The cell has some cork stuck to it. It came that way and I've not done anything to it."What do you all think? Do I have all the supplies needed to make a functional OTA as-is?

I was trying to picture the assembly process in my head as best I could:

Step 1: Using a Bridgeport milling machine to make the holes in the Hastings Tube for the mirror cell screws and spider secondary holder, as well as cut out the hole for the focuser. I had never heard of a Hastings tube before, but I thought I could get a rolled tube from Parallax Instruments if I needed. Any difference in quality? Problem: How do I know the ideal spacing to drill the holes? All these super-precise measurements have me wondering: Some mirrors from Zambuto have the FL in inches on the side. But, does this mean so many inches to the actual surface of the secondary mirror? Even if I placed the mirror surface exactly at the FL distance, how about the need to shift the secondary for collimation? Doesn't that potentially change the distance and mess it all up?

Step 2: After preparing the tube with the holes, I thought that I should spray-paint or flock the inside of the tube black?

Step 3: Do I then install the spider and center the secondary?

Step 4: Attach the focuser on the OTA?

Step 5: Assemble a mirror cell

Step 6: Put the mirror in the mirror cell and firmly attach it to the back of the OTA using screws to keep it in place?You can tell by all these question marks that I have very little idea of what i'm doing, lol

Just want to know if my overall plan or order is missing a bunch of stuff, or if I need to change the order.

It will definitely be a big undertaking for me. A Newtonian isn't too complex with parts, but I think what is daunting is making sure the measurements are absolutely precise and that I make -or purchase- a really good mirror cell.

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Beginners Forum / Star Party for Newbie with new telescope
« on: December 27, 2017, 01:08:31 PM »
Well I purchased a new telescope for my wife's birthday present two months ago- a Scientific Explore 16" dob. I wanted her to be able to actually see something than just a dot in the sky. Being new we first looked at the moon from our driveway but since it was very low and close to the trees we couldn't make out much so we decided to go to a star party in upstate NY where it was darker and in a field without all the trees. Having never been to a star party we showed up a half hour before dark to set up but no one else was there. We wondered if we had the right date. Well after about 15 minutes others started to arrive. Since we have no idea where anything is in the sky we used the iPhone app to locate Jupiter which it said was up but not visible since it was still too light out. Finally it was dark enough to see Jupiter with our eyes and try out the new scope - first time ever trying to look at Jupiter. I pointed the telescope towards Jupiter and lined up the Telrad and looked though the scope to see Jupiter. There was no Jupiter to be found. Double checked everything and tried again - still no Jupiter. During this time people were coming over to have a look through the telescope but there was nothing to see. I didn't realize that guests would show up to look through the telescopes that were set up. I guess that is what you are supposed to do. Of course during this time I am getting more and more frustrated. Others with telescopes, who may have been able to help were showing the sky to other visitors. It was a pretty clear night and I could see Jupiter clearly with my eye but not through the telescope. After about an hour went by and just before I was going to pack it in a savior showed up named Joel. He didn't bring a telescope but told us he would try and help us out since he did have experience with telescopes. He was able to find our problem was that the Telrad was way out of alignment and showed me how to fix it. He found Jupiter and had us take a look. There it was, clear as a bell, moons and all. We gave him total control of the scope and he found some galaxies to look at. I am sure it will take us a while to find them again once we get more experience. So we didhave funat the star party and will be trying it again in the future. We have a lot to learn.

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Beginners Forum / Looking for ep's for a 8" dob
« on: December 25, 2017, 10:06:22 AM »
I would like to buy a super wide field/low power eye piece for a 8" XT8.

Suggestions?  I live in Toronto Canada and am willing to invest 250-300.00 CAD.

Thanks.

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Beginners Forum / Light Pollution, Nebulae and Visibility oh my!
« on: December 24, 2017, 12:52:43 AM »
Good day sky gazers!

The spouse and I have been getting very first light on our newest scope here this week.  And I am interested in LP and size of DSO objects.

I thought I understood LP but it's even more defined for me today that we have glass to look through.   I've noticed two items in our first exploration of the skies.  One, the Orion Nebula appears to be the *only* DSO thing I will view off our rear deck.  I discover that... curious.  There are many nebula to see and research in and around the Orion constellation.  However, for some reason which seems to be the only nebula we can view.  I am curious if that means we just live in REALLY lousy LP skies?  Or are nebula just very difficult to see to start with?  Since Orion is quite visible, albeit feint but it's clearly defined.  When it wakes up and we can get out to a darker spot this summer and spring I am sure it's going to only get better.  But I am curious why it is the only nebula we seem to be able to see.

Along with two, and this might be related and clarified by the response to one, I got up this morning and went outside to look at Jupiter in 3:45am.
I left the scope out monitoring Orion and went to bed, woke up a couple of hours later and went right to Jupiter.  It seemed great.  I found the four moons, and the two bigger bands of gas.  I could not find the GRS though.  I began using the 35mm Panoptic (our favourite piece of glass so far btw), then moved to some 23mm Luminos EP, then just checked using a 10mm Ethos.  I moved back into the 35.  The 23mm appeared to be pushing it, it was somewhat less comprehensive and more difficult to get focused.  The 10mm was not able to focused at all on it.

Can someone explain the above to me?  Can it be LP that I am facing?  Preventing me from seeing DSO and seeing more detail on things like Jupiter?The scope in question, 1100 EdgeHD, along with the zip code 64133.  Kansas City.

Thanks for taking the time to school me .

Chris

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