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Messages - bolgsorchumsdea

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1
Beginners Forum / Re: Rich field vs. wide field
« on: February 08, 2018, 10:26:12 PM »
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Gee, I've used the term rich field a lot, but kinda loosely without really looking up a definition. For my own application I've meant getting a 3-4 degree true field of view by whatever means (or even more in binoculars). I usually attain that by using a 32mm or 40mm Plossl in my ST80, C80ED, or 120ST refractors. I also use my 2" 32mm Tele Vue wide Field and occasionally my 26mm Orion Q70 for that purpose. I don't own any eyepieces with a wider apparent field of view. I guess I could just as well say that I like low magnification views, but it's purely for the wider true field of view that I, personally, can get with what I have.


What you describe is wide field rather than richest field or rich field. Richest Field or Rich Field is about the number of stars visible in the field of view and is relatively independent of the aperture. A large, fast focal ratio telescope with a 82 degree or 100 degree eyepiece that maximizes the exit pupil will has a narrower field of view than a smaller scope but goes deeper to the number of stars, depending on the exact view, is about the same.

Jon

2
Beginners Forum / Re: Why larger focal length implies more magnification?
« on: February 03, 2018, 07:26:16 AM »
Thank you CB, I'm glad it helped! 

Steve

3
Mounts Questions & Expirience / Re: iOptron AZ Mt Pro Tripod Collapsing
« on: February 03, 2018, 05:20:24 AM »
I got the lever lock knobs and they work great. They should discontinue the star lock knobs.

4
Beginners Forum / Re: Would you rather use a barlow or have 2 eyepieces?
« on: February 03, 2018, 04:55:32 AM »
I use a barlow, TV 2x , The 2.8 KLEE was never one of my favorite barlows ,

5
Mounts Questions & Expirience / Re: Meade LX-850 precision
« on: February 03, 2018, 12:05:21 AM »
Yes. I ignore his comments as long as they are confined to his experience with his scope. But he made a strong and negative statement comparing it to a system with which he has no experience. So I sympathize with you in that regard. Which is why I responded.
I have provided numerous results with my system over the years to show its performance in quantitative terms. Nothing he has ever produced comes close to what I regularly post. And that is with a system he claims is inferior without having any experience with it.
Frank

6
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Hey, there are some interesting (read "depressing") national maps in the link below regarding winter cloud cover:
https://weather.com/...t-month-of-year

Thanks. Looks like Brian Brettschneider, who created the maps, did a nice job of assimilating the data. Here's the collection of maps for every month at his site.

http://us-climate.bl...cloudiness.html

One of the weather stations is right in Muskegon, so December indeed is the worst month. From my experience with frequent drives inland during the winter, a higher-resolution map would show the winter cloudiness falling off much more rapidly away from the leeward side of Lake Michigan, say, in 20 or 30 miles. Still terrible weather inland, but nowhere near as terrible as right along the lakeshore. Since the lake effect is stronger in the Keweenaw Peninsula than anywhere in the country, I'm surprised to see its cloudiness looking better than the Lower Peninsula. Something seems awry with the map, but it's likely due to having data from only one station in Houghton. In his defense, he made the most of the data he has.

Tom

7
Reflectors Telescopes Forum / Re: What is that thing under your Dob?
« on: January 31, 2018, 08:14:58 AM »
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Equatorial platforms are the best things since sliced bread, so to speak. I have 3 of them. You can order them custom-made for your latitude and most are adjustable +/- 5 degrees of latitude. My first I had made for my location. The second and third were gotten used at great prices. Both were made for 45 degrees latitude and I live at 43.6 degrees- easily within the adjustment range.

Why 3 platforms? One is for multiple scopes and is going with me to the Total Solar Eclipse. It will be driving a small tripod carrying my PST for group viewing of the partial phases and any prominences, filaments, etc. The other two EQ platforms are dedicated to my main dobs. This means that those scopes don't even have ground boards. They bolt directly to the top component of their platform. I've included a photo of both scopes. Their stats are in my signature. I built both dob bases with the EQ platforms' heights in mind. I shortened the rockerboards accordingly since I am only 5'8". (Many stock dobs are built over-tall.)

If you get a 16", I HIGHLY recommend a platform, but make sure it is built for the weight. My platform was built for its original owner's 16" with extra reinforcement underneath.

do you know of anyone making them that are more affordable than the link in post#3?
jim

8
Beginners Forum / Re: SCT - narrow FOV
« on: January 31, 2018, 04:55:36 AM »
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... Or I can also examine it much more closely and see the whole thing using a wide field eyepiece in a 20" f/5--something astronomers of the period could not do. And then I can increase magnification to the seeing limits and still examine large swaths simultaneously while resolving stars in the galaxy itself.

Unless the seeing is truly spectacular that night, you probably won't be able to put much more magnification on it than with an 11" f/10 SCT, and then we're kinda back where we started aren't we?
Sent from my D6603 using Tapatalk
You are not really back where you started,. as Red pointed out, that factor of 3.3 in image brightness is big. A week or so back I was out under dark skies and enjoying various galaxy clusters, some of which were on the challenging side. I had spent a couple of nights with my my big scope and gotten use to it's reach. I was using magnifications well within the reach of a scope like the C-11, no more than 400x-500x, mostly less, 200x-300x, But the last night, since I had to leave early the next morning, I switched to the 12.5 inch. I was rather surprised, the galaxies that were easy and bright in the larger scope were difficult or impossible to see. Intellectually, I wasn't surprised but I had hoped to see more in the smaller scope.

One thing to realize is that for small, faint objects like galaxies, seeing is not critical, the resolution of the eye at such low light levels is very poor. It is not the resolution of the scope that is limiting what you are seeing, it is the resolution of the eye at such low light levels. We can see Andromeda naked eye, but it's 3 degrees x 1 degree and bright. There are numerous galaxies that are greater than 2 arc-minutes, the bright light resolution of the eye, you cannot see them, until they are magnified many times..

Jon

9
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#0. Sunny days don't mean clear nights

I would argue that the reverse, that cloudy days don't mean cloudy nights, is almost more important. Wasting time traveling to your dark site only to have it cloud up is a minor inconvenience. Not traveling to your dark site only to have it clear up, now THAT sucks.

10
Eyepieces Questions & Recommendations / Re: ES 62 26mm vs. Panoptic 24mm
« on: January 31, 2018, 02:10:34 AM »
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Only thing lacking in the 24mm Panoptic is eye relief. If you want both good eye relief and great sharpness, look no further than the 22mm LVW, however, that one is lacking in transmission.

There just is no "free lunch".

Ditto on both! The 24mm Pan is sharp right to the edge and I liked it when I had one but the eye relief was insufficient for use with my glasses so I could only use it with a 3x TV barlow which defeats the point in having a 24mm max TFOV eyepiece. As for the 22mm LVW - great eyepiece but transmission does seem to lag behind.

The 22mm Olivon 70 might be the way to go if one can use a 2" eyepiece. I had one and really liked it. I ended up selling it in the normal buy and sell routine when I was trying out different lines. I have not tried the new APM 24mm 65 deg. I tried the APM 18mm 65 deg and wasn't really excited by it. There was nothing wrong with it necessarily although it did have a bit of EOFB. For me it just wasn't a lively field.

I also tried the 22mm T4 Nagler last winter and didn't like it. Despite the long eye relief I just didn't find it comfortable on the eye.

11
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Stellarium and Sky Safari give real time altitude and azimuth info. Once the scope is referenced to a known object, all other objects are relative. Polar alignment is not necessary, though Polaris may be used. Even a planet may be used. There is a 50 page thread about this, as I mentioned...

Thanks

12
Beginners Forum / Re: New Stargazer here
« on: January 30, 2018, 06:21:58 AM »
The Orion Intelliscope would allow starhopping or computerized object location, but no tracking. Not sure about the goto model. The Dobs are nice for their faster cooldown and wider field of view compared to an SCT. No perfect scope, just a question of which compromises you can live with.

13
Mounts Questions & Expirience / Re: Celestron engineering concerns
« on: January 26, 2018, 03:16:21 AM »
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Sorry to here of your problems but I think you will fix it before Celestron do.

Some alternatives
you might try talking to this guy he makes Nextstar retrofit kits for vixen mounts, and I think his electronics maybe a tad better than Celestron work.
http://www.nexsxd.co...htm#El_Circuito

I have used sitech and its a very good option but you will be tied to a laptop to control , as there is no intelligent handcontoller.


Actually yes there is. It's called Sky Safari Pro on a smartphone or tablet.

14
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Dear Ralph,
I am so thankful for your advice!!
My way of thinking was to firstly buy a mount like star adventurer and then add OAG, modify my DSLR, learn to use and experiment with the software PHD,BYN (also learn to use pixinsight)
But eventually I would upgrade to aGoTO mount,Ifound the skywatcher HEQ5 SKYSCANpro a very good, what do you think?

I believe my hesitation for not spending that much moneyin the beginning is not thatI am not sure if I like it but that my sky current location light pollution map is Greenwith low altitude and it is kinda difficult to find a safe and ideal place to stay all night were I live..

P.S
I know people how achieved good results with light pollution filters, but my opinion is that no filter can ever beat a perfect sky
Buying the Star Adventurer can be a good way to start. I'm not sure can use OAG (Off Axis Guider) with a DSLR and camera lens, because you won't be able to focus at infinity. So for autoguiding you'd need a separate small guide scope, which would be even more weight on the Star Adventurer. I haven't yet tried guiding on the Star Adventurer.

I have no experience with the HEQ5 mount (Orion Sirius here), but I think it would be a very good alternative to the HEQ6 (Atlas). Both are well-built. Another lightweight mount that I have seen favorably reviewed is the Celestron Advanced VX; there is much discussion and people more knowledgeable about those smaller mounts here.

I started out with a big mount (Atlas), then got an even bigger mount (MYT), and finally got a small tracker (Star Adventurer) to have something simple for wide angle tracked shots. You could just as easily start out with the tracker (least expensive option, but more limited), then move up later to a larger GEM and longer focal length lenses and short refractors. You could stop there, or get really hooked and keep climbing up the equipment chain. I've seen some great images using the Star Adventurer with longer lenses. But I'd say the longer the focal length and the heavier the load, the more challenging it will be. Either annoyingly frustrating -- or maybe a fun challenge for you!

Where are you located? Light pollution can be a challenge, but many people get great images from light-polluted areas. Keep working at it.

Ralph

15
Reflectors Telescopes Forum / Re: XT6 Primary Mirror Quality
« on: January 26, 2018, 12:46:54 AM »
My XT6 has a 22% central obstruction. The ergonomics are also great. Excellent bearings. Fine all around.

I am going to send the optics to Majestic next week. The reputation is excellent, and the price is outstanding.

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