text: Celestron Advanced VX Questions - Mounts - Cloudy Nights
  Celestron Advanced VX Questions
  Started by dhayes68 , Mar 14 2018 08:27 AM
  #1 dhayes68
  dhayes68
  I've been goofing off with a C6a on a manual alt-ax mount for viewing and mostly lunar entry level AP. And now I've decided to step up and get a Celestron Advanced VX mount and I have 2 questions if anyone would be kind enough to give their thoughts on.
  1. Buying the mount I have a choice of free accessory depending on where I buy from. A polar alignment tool or a PowerTank Go charger. Any ideas on which is the better choice? Or does it not make a difference since I'll need them both anyway so I should choose the one with the more expensive accessory?
  2. Being a beginner I don't need an autoguider right away correct? It's mostly for really long exposures and I should learn how to operate the VX before getting more advanced tech?
  Posted 14 March 2018 - 08:45 AM
  1. I'd take the polar scope set up. I've had two Celestron Powertanks die on me within a few months. You can get a better power supply on line or at Harbor Freight anyway.
  2. You are correct. Autoguiding and all the gear that goes with it will come later when you really get the imaging fever
  And despite what you will probably hear, I've had my AVX mount for 4 yrs and never had a lick of trouble. Go-To works great every time.
  Edited by petert913, 14 March 2018 - 08:46 AM.
  Exnihilo, mpgxsvcd, grmaximus and 1 other like this
  Posted 14 March 2018 - 08:49 AM
  1. What sort of polar alignment accessory? The battery will be more useful, I think, since the HC has a built in polar alignment routine.
  2. Correct, or, more properly, it's only for long exposures.
  dhayes68 likes this
  Posted 14 March 2018 - 08:51 AM
  I just bought a used C6 and love it. however, I discovered that SCT's on equatorial mounts need rings or you will be craning your neck to look through the finderscope. this will be an issue even with a goto setup since you will need to do at least 2 star alignment each time (I usually do a 2+2 with my CG5 goto). as far as a powertank or polar scope, you really should have both. polar scopes come up used sometimes so I would go for the power tank as I would rather have a new one when it comes to something with a usable life like a rechargeable battery. plus, you can skate by without the polar scope for visual. it helps alignment but it's not totally necessary.
  check out the bay if you want to get some nice rings at a decent price. the bresser ones with dovetail work perfectly. unfortunately, they are white.
  #5 dhayes68
  This one: Celestron Polar Axis Finder for CGEM, Advanced VX, or CG-5 Equatorial Mounts LINK And I'm leaning towards the polar because I will get a battery but most likely a 3rd party one.
  Before you buy, let me check at home. I might have one I could sell you used. I know I have one, just not sure if it fits cg5/avx.
  Edited by Mike G., 14 March 2018 - 09:45 AM.
  Posted 14 March 2018 - 10:31 AM
  1. I would still get the Power Tank. The Polar scope is, IMO, *totally* useless. You will do better with ASPA, and you will do better still with Sharpcap. For visual, you don't need any of this--just eyeballing Polaris through the mount hole is good enough. And you can sell the Power tank for more than you can sell the polar scope
  2. Depends on what you mean by long exposures. 20 secs? With a C6, more will give you trailing unless you are lucky (long F/L).
  If you will do AP for any length of time, you will need to guide, so start early, unless you absolutely can't afford it. Guiding is extremely simple because of PhD2 (free software). You mount the guidescope (the hard part, but you can initially just replace the finderscope). You focus (*once*) the guide camera. You connect to your PC. Fire up PhD2, tell it about your equipment (F/L of guidescope and pixel size of guidecam--often you can just select from a dropdown) and that's all you need to start. Aligning your scope is much more complicated.
  A side benefit of guiding is that (assuming you can see Polaris) you can do pretty much perfect Polar Alignment in a minute or so, using Sharpcap.
  #8 kim.davis
  Posted 14 March 2018 - 12:08 PM
  Curious why the polar cope is useless. Is it because of no illumination, or something else? I am also looking at the polar scope but from my experience with other polar scopes, it was difficult to see the polar axis mark and polaris circle.
  Because for visual you don't need it, and for AP it just doesn't provide high enough accuracy. At best you will have to follow with drift alignment. Celestron provides ASPA (All Star Polar Alignment) in the AVX software, which will do better than you can do with the polar scope. And Sharpcap will do better than either (as will Polemaster).
  mclewis1 and mpgxsvcd like this
  #10 Matt Harmston
  Matt Harmston
  Graduate: Confused State University
  Posted 14 March 2018 - 01:14 PM
  I started doing deep sky video astronomy a couple of months ago, and have been out about 10 times since (a rarity in Iowa). I do not use autoguiding...yet. I have found that by leveling the 'pod, doing a 2+4 align, and then ASPA (a straightforward process, hence no need for a PA scope) on the AVX, the stack-and-align-on-the-fly functionality of my video camera's software really helps. For instance, using my 100mm refractor at f/4.5, I recently I took an image of a section of Markarian's Chain and had 16 individual galaxies come out to play in the final .tif file just by stacking 6 25 second subs.
  If you use a 0.5x or 0.33x focal reducer (beware, they may be scope-specific) and apply stacked shorter exposures (as my MallincamSky software permits me), you can learn a lot and have a great time without being hamstrung by the slower f/10 1500mm system. And, you might be able to get away from having to jump right into autoguiding. That said...I plan on autoguiding eventually, as I'd really like to push exposure limits. So, while not a necessity depending on your goals and equipment (I slept at a Holiday Inn Express, so that makes me an expert LOL), autoguiding is likely something that you should at least plan for, if not jump into.
  Beware...this stuff can really get a person hooked.
  #11 kim.davis
  Posted 15 March 2018 - 12:22 AM
  Sorry to keep asking.. I kind of google ASPA and now know it's software. But my question is whether it is a built-in software in AVX so that I don't need to purchase any extra item or I have to buy some kind of star sense. If latter, price would go up so fast, compared to polar scope unless I want really serious AP.
  #12 JPaulo
  Loc: Sao Paulo / Brazil
  Posted 15 March 2018 - 04:34 AM
  ASPA is software functionality built in the AVX.
  If you download the AVX manual from the Celestron site, you can check more details on it.
  You don't have to pay extra for it.
  Edited by JPaulo, 15 March 2018 - 04:36 AM.
  Posted 15 March 2018 - 06:47 AM
  One more for the powertank.
  Consider this: powertank or any other type of power, you will ALWAYS need it, there is no way around that.
  The polar scope is, like the guys said, useless. Or better, its not completly useless, it is only very bad to use and not precise.
  I have a Avx and a polar scope and i dont really like it. First, to use it, you must use it at the very start of the night, otherwise you cannot see the drawings on the polar scope. Second , you have to be on your knees, and depending were you have your mount, that can be very unpleasant. Third, the precision on the polar star, is only necessary if youre going to do imaging, because, like said before, for visual, you simply point the mount to that direction, and the normal routine for aligning the mount on the mount's software, is more than enough for visual use.
  And i even bought a iluminator for the polar scope, but, it only made my life a little easier, because i could see the polar star through the polar scope, even in the dark. Did not improve the align accuracy.
  I have to remeber you that i bought the polar scope and the iluminator, because i do mostly imaging, and that was the only reason why i bought them.
  Meanwhile, i put them aside and bought the Qhyccd Polemaster, wich is a fantastic tool for aligning the mount on the polar star.
  A cheaper way is to use the Sharpcap, also very good for this purpose. The ASPA procedure can also be helpful, when you learn how to use it.
  And, like i already said, this is only necessary, if you do imaging, otherwise, for visual, you dont need.
  Get the Powertank.
  ASPA (all star polar alignment) is the name we all use for the built in polar alignment routine in the hand controller for all the Celestron gem style mounts. In the hand controller however you will not see something called ASPA, it's just referred to as the polar alignment routine.
  The routine is easy to perform but it requires that you have done a good accurate initial alignment first (it relies on the sky map to calculate the offset for polar north/south).
  There are some folks who are very comfortable using a physical polar alignment scopes (PAS) and can get a good polar alignment done very quickly but for most folks the ASPA routine is fast and easy too. For imaging Stelios has very clearly described what the choices are and why the PAS doesn't make sense.
  Remember, you don't need to have done any sort of accurate polar alignment for visual goto work. The initial alignment routines (goto alignment) simply do not require that the mount be polar aligned.
  A polar alignment does make doing the initial alignment routine a little easier to do but (the initial alignment stars will be a bit easier to center and if you taking the shortcut of doing one star alignments a polar alignment first will help). Overall the question becomes does it make sense money and time wise to use a PAS? The answer for most folks is no, you're better off spending the money on something more useful.
  Edited by mclewis1, 15 March 2018 - 08:32 AM.
  #15 kim.davis
  Posted 15 March 2018 - 10:40 AM
  Thanks a lot for all answers/comments. One more question
  Is it possible to use AVX as a manual GEM using slow motion control? I am not saying all the time, but occasionally when I want to do star hopping or battery is gone.
  #16 Emanuel
  Posted 15 March 2018 - 11:33 AM
  Yep, it is possible, but, you will loose all the alignment proccess . You just simply unclutch both axis, and as long as everything is balanced, you will have no problems. The huge problem that you will have, is no tracking at all, which means that a object viewed at a moderate or high power, will go out of the field of view , very very fast, which will be very annoying, you will have to be centering the object over and over, so you can see something.
  Not recomended at all. I had this experience and it was bad, really....
  Posted 15 March 2018 - 01:58 PM
  Well, I do use my polar scopes every time I set up. It only takes about 5 minutes, and gets fairly close. Still not close enough for long exposures, but good for short ones, such as lunar/planetary. If power tank is the only other choice, I'd take the polar scope. I never had that choice myself.
  Posted 15 March 2018 - 05:42 PM
  If the battery is gone, you would have to operate with loose clutches. It's doable, but there's no slow-mo control--you're in effect nudging the mount. Sometimes I'll look at the moon that way, before aligning. It's nothing you would want to do for an observing session. No star-hopping.
  If the battery's there, you can definitely loosen the clutches and send the scope anywhere you want, then tighten them again and use the arrow keypad to move and track. However, all your star alignment (but not polar alignment) would be totally lost, so GoTo's would not only not operate but be dangerous until you redid a star alignment.
  There is not many sane scenarios where you'd want to do the above. GoTo with the AVX is very accurate, and there's nothing you'll find manually that it won't find easier. The only case I can imagine, is when you want to observe a bright planet at dusk or dawn, before you can achieve a star alignment.
  In this case turn the mount on, do a "last align" to enable tracking, and GoTo the planet. It will be way off, so you'll have to use the arrow keys to get to it, but at least you'll be able to track it.
  #19 dhayes68
  Posted 16 March 2018 - 08:29 AM
  Thanks for the offer but given my noobess, I wanted a new one just to make sure I've got full Celerant support.
  #20 AhBok
  Posted 16 March 2018 - 08:38 AM
  I'll be a contrarian and recommend the PA scope. I've had 2 17a Powertanks and both lasted about 6 mos. And yes, I charged it after each use and no, I did not leave it on the charger too long 😀. I agree that for visual, you don't need it and for AP, ASPA will be sufficient for many folks.
  But, for AP the PA scope is a super easy first step in getting a coarse PA when using SharpCap or A Polemaster. It's simpler and faster than ASPA. I find using a well aligned PA scope makes it easy to get within 5-10 arcmin of the NCP and then SharpCap or Polemaster will get you the rest of the way. You may not need it now, but if you get into AP, the PA scope is a "nice to have".
  Best wishes. Either choice is fine and neither choice will make much difference in your overall purchase, IMO.
  #21 dhayes68
  Posted 16 March 2018 - 08:39 AM
  Thanks again for the responses. I ended up getting the AVX with the powertank because the one with the polar scope didn't pan out. But it turns out the powertank being offered was just a tiny "Celestron Elements PowerTank GO Charger" which I didn't need so I asked the vendor, can I skip the elements, get a PowerTank 17 and subtract the cost from the price the cost of the Elements charger and they said yes. So I got a PT 17 for 65 bucks.