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Trying to decide on Digital Setting Circles

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#1 chtullu

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Posted 29 June 2013 - 03:54 PM

Hello,

I am currently mounting my Stellarvue 105 on a Universal Astronomics Surveyor's tripod on an Unistar Deluxemount (also by Universal Astronomics. It works pretty well althoug since I have moderate light pollution, I have trouble using star-hopping from my back yard. However, I have been thinking about purchasing a GoTo mount - the Celestron VX mount but I've been having second thoughts. First off all, I primarily do visual observations. In addition, I drive a small car so there is the issue of space. Finally, I don't know if I care to be lugging around the auxillary power supply, weights for the mount, as well as the mount and tripod inherent in a goto system. I'm thinking that Digital setting circles might be the way to go. Plus I'd be more apt to take set up the scope in the back yard on the spur of the moment rather than having to deal with a full equatorial system. Below is the price list for the different DSS options that universal astronomics offers. I'm trying to figure out which would be my best option should I decide to go the digital setting circles route.


03216 Micro-Max Computer with Encoder Install $549

03217 NGC-Max Computer with Encoder Install $749

03218 NGC-SuperMax/ArgoNavis Computer with Encoder Install (call for quote/availability)

03219 Sky Commander with Encoder Install $649

03220 Tele Vue Sky Tour with Encoders Install $629

Thanks,

Juan

#2 rmollise

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Posted 29 June 2013 - 04:14 PM

I am a huge fan of JMI, but I just prefer the Sky Commander. No leveling, none of the dratted warp factors, just align on two stars and it is deadly accurate. I believe that with the TeleVue we are back to the same Tangent board as JMI and them dadgum warp factors. ;)

#3 S.Boerner

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Posted 29 June 2013 - 04:20 PM

Or you could make your own for less than $150 if you already have a laptop. Dave Ek site has directions, a hardware list, sources, and an ASCOM driver you can use to turn most mounts into a push to that can be controlled via Stellarium or Sky Chartes.

See:
Build Your Own Digital Setting Circles
http://eksfiles.net/...etting-circles/

I did for my 1972 vintage C8 as well as a cheap refractor I have on a Berry mount. They were easy to make and work well.

#4 rmollise

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Posted 29 June 2013 - 04:21 PM

That works...but you have to have a laptop in the field all the time. Given the reasonable price of the Sky Commanders...they were just a better option IMHO.

#5 chtullu

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Posted 29 June 2013 - 06:13 PM

I may give the do it your own option a shot. It sounds like a fun project

#6 chtullu

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Posted 29 June 2013 - 10:12 PM

I'm now leaning towards sky commander. However, I'll probably change my mind again.

#7 orlyandico

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Posted 30 June 2013 - 02:47 AM

buy an Astrodevices Nexus (cheap), and use your Android or Apple phone with SkySafari.

a much better interface, and the new smart phones have very fast processors and nice screens.

if you don't want that approach, you should also look at the Argo Navis.

#8 John Carruthers

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Posted 30 June 2013 - 03:58 AM

or the Astrofix?
http://www.manortron...auges.com/Astro

#9 DavidTrap

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Posted 30 June 2013 - 07:17 AM

ArgoNavis gets rave reviews down under!

DT

#10 chtullu

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Posted 30 June 2013 - 08:54 AM

I've checked out Argo Narvis but it's over my budget. In addition, I will be using it in conjunction with my 4" Stellarvue refractor, so the large object catalog in Argo Narvis will be overkill for a 4"inch refractor. In addition, I already have The SkyX professional and so can connect the DSC to SkyX and obtain access to additional catalogs as needed.

#11 rmollise

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Posted 30 June 2013 - 10:01 AM

One other feature of the SkyCommander I really like for those humid/cold nights is that when you power it with an external 12v battery, an internal heater keeps the display clear/lively. :cool:

#12 jrbarnett

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Posted 30 June 2013 - 11:33 AM

Let's take this in two parts. The first will be "why you need a GOTO EQ mount" and the second will be "what encoders and DSCs should I use on my existing alt-az mount". But before we do, let's make sure you have the single most important piece of mount equipment for optimal visual observation, irrespective of what mount you use - an adjustable observing chair. No matter what kind of mount you choose, this is a "must-have" accessory for maximizing what you see. Seated your concentration is solely on viewing. Standing, you are also maintaining balance and eye centering which are major distractions from your brain horsepower, whether you consciously know it or not.

Here's why you need a GOTO mount for visual use (and the VX is a good choice thought the outgoing CG5-GT on clearance for $549 is a better value IMO). Beyond sitting when observing, there's one other major benefit that will help you see more - tracking. The combination of sitting and tracking is like adding an inch of aperture in terms of what level of detail you'll be able to reliably see. Sure, you can get tracking mounts without GOTO but the simple truth is they cost as much or more as the more affordable GOTO options which pretty much makes them utterly pointless if you're a visual observer. Imagers might trade smooth tracking for GOTO, but we visual folk don't care about periodic error and such. You also mentioned that you find light pollution to be bad enough as to impede star hopping. While push-to digital setting circles will help conquer light pollution, they are generally not a granular as a well-aligned GOTO mount. In a crowded field, without a star atlas, figuring out which galaxy is which relying on push-to DSCs (any of them) is frustrating and imprecise.

You also expressed worries about having a small car and not wanting the hassles of set-up and the like for an EQ mount. THe reality here is that a VX or CG5 would fit in motorcycle saddlebags. They are modestly sized, very lightweight mounts. Though there will be a set-up and use learning curve, with a little star time under your belt, your deployment routine will become around 5 minutes. Celestron GOTO mounts in particular offer a wealth of slick features that maximize accuracy and utility. If you're working from a printed list such as those provided by the Astronomical League, Celestron mounts allow you to GOTO a specified RA and Dec which means that even if your target isn't in the onboard (large) catalog, it is easy to find using this feature. Using the two star alignment and 3-4 star calibration routine yields entire sessions putting targets at or near center of your FOV at medium power. No DSCs will maintain that level of accuracy without manual synching throughout the night.

So yeah, you really do need a GOTO EQ mount.

But if you didn't go that route and instead decided to rig your manual alt-az mount with DSCs, I've owned and still own a bunch of different solutions. The Televue Sky Tour is pretty much dedicated to the Televue alt-az mounts. I'd take that option off my list. It's be more trouble than it was worth to adapt it to your current mount. Folks in my club and I have had bad luck with Argo Navis hand controllers and the service from Australia that we've received (others think they're great, so ask around) has been subpar. In my opinion, given that these are the most costly option, I'd skip them too.

The most rugged system I've used is the Sky Commander system, though the green backlit LCD screen is s-t-o-o-p-i-d IMO. You want dimmable red for optimal dark adaptation preservation. Still this would be my first choice. The JMI solutions are pretty basic but okay. The pricing you're quoting for any of these solutions seems to have a hefty mark-up built in though. The cost of the parts would be a couple hundred less I believe, so you have to ask yourself is the labor of installing them worth $200?

Here's something else to consider whether you go GOTO or push-to/DSC. If you have a smart phone (iOS or Android) you're going to want to be using Sky Safari as your in-field atlas and observing list management tool. With the iOS version you can use Sky Wire or Sky Fi (wireless hub) to control the GOTO mount or direct many of these push-to systems to your target. With Android OS you'll need a wireless bluetooth-serial adapter, but will be able then to use bluetooth to wirelessly control or guide your mount using Sky Safari. Sky Safari is way, way, way, way better than any of the catalogs used in any of these onboard or on controller systems.

Whatever direction you go, good luck.

- Jim

#13 rmollise

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Posted 30 June 2013 - 01:54 PM

At low light levels (and the SC display is dimmable), green light is no more harmful to dark adaptation than red. The Navy did rather involved and expensive studies on this when designing new lighting systems for the CICs on AEGIS CGs...

#14 chtullu

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Posted 30 June 2013 - 05:00 PM

Perhaps I will take a second look at the VX mount. I'm going to hold off on my purchase until I think it over more.

#15 pubquiz

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Posted 30 June 2013 - 05:09 PM

Some very long detailed replies here with all mention of chairs etc...

I know you have ruled out the Argo Navis but since it was mentioned in your original post I will coment on my experience with it.

I can only say it is an absolute joy to use! you mention you will not use it's large object catalogue...I think this applies to most things ....only a tiny proportion of what a device is capable is actually used

BUT it is very easy to use (the warp stuff mentioned is a doddle to understand...it's just a word)

It JUST WORKS every time ..the selector wheel is a brill method and the support is fantastic
I have asked a question on the forums a few times and got an IMMEDIATE response from Gary ..the guy himself who makes it.

It may be worth looking for a used one.

I dare say other DSC are good as well but can only say that in about 6 years of using the Argo it has performed faultlessly and would totally recommend one.

Tom

#16 chtullu

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Posted 30 June 2013 - 06:04 PM

I have researched the Argo Narvis and it looks like a great product. However, it is a bit over my budget. I think I will probably stick with the Sky Commander. I've considered again the idea of a goto mount. But I think that the DSC solution would work best for me at this time. I mean if an extra couple of hundred dollars come my way I would be tempted to get the Argos Narvis but I think the sky commander would work out well for me

#17 jrbarnett

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Posted 30 June 2013 - 07:02 PM

Here's one of my DSC solutions. The mount is a DSV-3 with the 7000 tic encoder option. The computer shown is a Sky Commander XP4. The unit works great.

However, I've actually used red and green illuminated units with my Dob, observing galaxies, to see if I could detect slower recovery time with green versus red illumination. Set to the minimum level necessary for me to be able to read the on-unit readouts, my recovery time with a dimmed, red, LED tangent unit (Advanced Astromaster if I recall correctly) was measurably shorter than with the Sky Commander. For pushing the detection envelope with low surface brightness targets, it does make a difference and red is superior. That said, the Sky Commander is rugged and reliable and is my DSC controller of choice these days.

Posted Image

Regards,

Jim

#18 mantrain

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Posted 13 May 2014 - 11:59 AM

If I can avoid spending $450 I would like to.

This one is much more affordable:

http://www.highpoint...r-netwonian-...

#19 Pinbout

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Posted 13 May 2014 - 10:40 PM

buy an Astrodevices Nexus (cheap), and use your Android or Apple phone with SkySafari.

a much better interface, and the new smart phones have very fast processors and nice screens.



:waytogo:

#20 Eric63

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Posted 14 May 2014 - 08:40 AM


buy an Astrodevices Nexus (cheap), and use your Android or Apple phone with SkySafari.

a much better interface, and the new smart phones have very fast processors and nice screens.



:waytogo:


I assume that this does not work on all alt az mounts. I would probably have to replace my AZ4 to use Nexus.

#21 rmollise

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Posted 14 May 2014 - 10:16 AM


buy an Astrodevices Nexus (cheap), and use your Android or Apple phone with SkySafari.

a much better interface, and the new smart phones have very fast processors and nice screens.



:waytogo:


Well...sort of. DSC computers have real advantages:

--MUCH easier on batteries.

--If the battery goes out, you can just replace it, not hunt for a way to recharge.

--Displays are much more night vision friendly.

--Without a lot of graphics, they are blazingly fast and can track the scope no matter how quickly you move it.

--Many, like the Sky Commander, have built-in heaters to keep the display going in very cold weather.

--Very easy and quick to start up...just mash the button.

;)

#22 Traveler

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Posted 15 May 2014 - 02:44 AM

Hello,

I am currently mounting my Stellarvue 105 on a Universal Astronomics Surveyor's tripod on an Unistar Deluxemount (also by Universal Astronomics. It works pretty well althoug since I have moderate light pollution, I have trouble using star-hopping from my back yard. However, I have been thinking about purchasing a GoTo mount - the Celestron VX mount but I've been having second thoughts. First off all, I primarily do visual observations. In addition, I drive a small car so there is the issue of space. Finally, I don't know if I care to be lugging around the auxillary power supply, weights for the mount, as well as the mount and tripod inherent in a goto system. I'm thinking that Digital setting circles might be the way to go. Plus I'd be more apt to take set up the scope in the back yard on the spur of the moment rather than having to deal with a full equatorial system. Below is the price list for the different DSS options that universal astronomics offers. I'm trying to figure out which would be my best option should I decide to go the digital setting circles route.


03216 Micro-Max Computer with Encoder Install $549

03217 NGC-Max Computer with Encoder Install $749

03218 NGC-SuperMax/ArgoNavis Computer with Encoder Install (call for quote/availability)

03219 Sky Commander with Encoder Install $649

03220 Tele Vue Sky Tour with Encoders Install $629

Thanks,

Juan


There is another route. Not so long ago, Losmandy came out with new DSC's for GM8/GM11 mounts.They don't need the Gemeni system so a (older, even first gen.) Losmandy mount with motors and a 3th part controller is all you need. For example, secondhand the GM8 mount is not that expensive.
With a controller (for example an ArgoNavis, Skycommander or other) you have a compact pushto platform. A friend of mine did buy this new Losmandy DSC's. I did the easy instalation on his GM8 and i must say: they work very fine with an ArgoNavis. Just a small accu is enough as a energysource.

#23 GordonCopestake

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Posted 15 May 2014 - 07:52 AM

You can use $10 manual setting circles and a free iPhone app

Attached Files



#24 rmollise

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Posted 15 May 2014 - 09:51 AM

You can use $10 manual setting circles and a free iPhone app


You can, and this can work OK with a suitably low power wide field eyepiece in a short f/l scope. Close to the accuracy of DSCs? No. I do have alt-az circles on my 8-inch f/5 Dobbie, and they will get me close, if not on the money every time if I take care to level the scope. ;)






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