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Getting a Reliable EQ Mount


Herzy
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Sorry for spamming threads but what should I buy that will give me a jumpstart in astrophotography? I currently have an alt/az tracking mount that doesn't track very well.

I hear everyone saying that I should just get an equitorial mount, and they are suggesting like 2000$ ones. Do I really need to save up to get these or can I get one cheaper? I have about 600$ to spare atm, and I want to get into astrophotography as soon as possible.

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600$ isn't a big budget for a mount. You will probably have to look in the used market for a Celestron CG5-GT or Orion Skyview Pro/Skywatcher EQ5 Pro goto mount. You might also need to budget for a guide camera and scope and possibly a short tube refractor for imaging DSOs. The 90 mak isn't an ideal telescope for DSO imaging so you might want to decide on what objects you want to image before making any purchases.

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4 minutes ago, Herzy said:

What's guiding?

 

OK, this question means the word you need to hear from us is Stop! Firstly read a book on AP. Making Every Photon Count by Steve Richards is available from this site's sponsor.

Lots of thigs about astrophotography seem counter intuitive or even ridiculous. (The equatorial mount being essential and being the most important part of your kit. Aperture not mattering on its own but F ratio being vital. Small pixels not necessariy gaining you resolution. Etc etc.) The last thing you need to do is jump to wrong conclusions or assume anything at all.

To answer your question, mounts costing less than about 10,000 dollars need autoguiding for long exposures. A parallel scope attached to the main one has a small camera of its own shooting short exposures. The exact position of the star on the chip is measured every second or so and, if it moves, a correction is sent to the mount. This allows a guiding precision better than one part in two million, which really is a level of precision very rarely encountered in engineering. That's why mounts are not cheap.

Olly

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Thanks Olly, I've purchased the book. From what i understand guiding is a second optical tube that is hooked up to a computer thing. And it essentially just tracks a star and makes sure it's not drifting at all and when it is, it sends corrections to the mount?

Should I look into this or is just a mount enough. I won't buy anything though untill I've read the book. Also, in all these amazing pictures I see from this website are the people generally autoguiding?

Edited by Herzy
Eh
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48 minutes ago, Herzy said:

Thanks Olly, I've purchased the book. From what i understand guiding is a second optical tube that is hooked up to a computer thing. And it essentially just tracks a star and makes sure it's not drifting at all and when it is, it sends corrections to the mount?

Should I look into this or is just a mount enough. I won't buy anything though untill I've read the book. Also, in all these amazing pictures I see from this website are the people generally autoguiding?

I'll stick my neck out and say, yes, the best images are autoguided. There are very high end 'unguided' mounts but they are not really unguided. They still have a feedback loop. They 'guide' on their own ultra high resolution encoders linked to a planetarium model of the sky. If you want to do AP properly and spend less than about 10K dollars on your mount then autoguide. People make creditable efforts without autoguiding but if your interest has been piqued by the best forum images, then autoguide.

Mounts like the Skywatcher HEQ5, NEQ6 and Celestron equivalents have pretty awful inherent accuracy (maybe 30 arcseconds of periodic error) but with autoguiding this can, with care, be reduced to 0.5 arcseconds. That is an enormous difference. A reduction of 60x in error. A lot.

Olly

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So just an overview... I should get a good equatorial mount first, and then look into autoguiding to improve the results. 

Im still confused is autoguiding to make you get your desired results faster or does it just give you better results? If autoguiding really isn't necessary I'm going to save that for another time and just make-do with a good EQ mount.

I'll just say the only reason I want to get a EQ mount that is reliable is because I currently have an alt/az mount that is HORRIBLE. I still don't know exactly why (it's not field rotation) but like 39/40 pictures are all trailing and just not good, so I'm assuming that an EQ mount will boost my results and allow me to get enough images to stack.

 

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This is just one bit of anecdotal data, but here goes. I have a Celestron Advanced VX mount and with reasonably careful alignment (basically two passes through calibration and their "All Star" polar alignment routine) I can consistently get 60-second unguided exposures with maybe a 5-10% reject rate. Depending on whether your particular mount came out of the factory on a Tuesday or Friday :happy11: and how careful you are in the alignment procedure you might get 90-120 second lights with a tolerable reject rate (say 30% or so). Beyond that, with a budget tracking mount like the AVX, you need to autoguide. With autoguiding on the AVX, I can get 5 minute exposures with less than a 5% reject rate, and could probably go longer. I've done a little mechanical work on it -- gently adjusting backlash out of the motor gears and backing off the DEC axis ring nut a smidge (so it turned a little more easily) -- but you can probably get similar results without opening it up (and, if you look through my post history, you may not want to open it up at all!).

Definitely reading "Making Every Photon Count" or something similar and get a good grounding in the problem you're trying to solve before forking out a lot of cash. But at the same time, be pragmatic. I know there are better mounts than the AVX and I'm lucky enough to be able to afford one, but I also don't have an observatory or a particularly private lot and so I expect to haul it in and out of the basement every night I want to use it. So I'm willing to trade its lighter weight (which translates to less capacity and lighter, less accurate, build) for its portability. It's a conscious choice and despite the fact that it's not a middle- or upper-level mount I can definitely get images that thrill myself and my friends from it. I figure in 3-5 years, if I'm still at it, I can reconsider getting a better amount. But right now my own lack of experience is a much bigger limitation than my mount. I'm learning and I honestly don't feel a much more expensive mount would help much. There is no known compression algorithm for experience.

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Thanks for the great help, I've seen quite a few issues with the AVX but at the same I've seen quite a few amazing photos. Should I get it? 5-10% reject range is certainly a plus side... 

Also do you mind me asking what your autoguiding setup is?

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I would say please do your homework first !  Better to spend a day or two speccing it all up properly and getting what you know will work, than spending now and repenting later.

As others say, it's probably realistic to say that in most cases, a good EQ mount is the most important thing, and yes that needs guiding regardless.

An initial guiding set-up need not be expensive by the way, I started with a Celestron T70 travelscope (£40 off ebay) as the guidescope and still use that, with a Meade LPI used as a guidecam (also £40 ebay).  That meade was a little frustrating since it's not very sensitive, but it definitely worked - I upgraded to a QHY5liic eventually and am as happy as a clam.

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I can't (or won't :-) advise you to get a specific mount. Too much responsibility :-) . The main point is to be conscious of the tradeoffs. Less expensive mounts will have more built-in error -- a $800 mount is simply not going to have the engineering and construction quality of a $4000 mount -- and will probably have less capacity. Your exposure times might be limited; you might spend more time trying to coax out better performance. But there is also what you're comfortable with budget-wise, how committed you are to astrophotography, where you're going to set up and how much weight you want to lug around how often, and so on. I know not everyone agrees with this, but when you're just getting started with a demanding hobby that will take years to master, there might be worse strategies than starting off with decent but not top-end equipment, focusing on learning and pushing what you have, and planning on making a bigger, better-informed purchase a few years down the road when you have a firm handle on what you really want. Yes, maybe you'll end up buying two mounts or two cameras, etc. ... I'd be willing to bet someone will be willing to help take the old ones off your hands.

For autoguiding I use an Orion SSAG and 50mm (I think: not at home to check) finder with a helical focuser, running PhD2 on my laptop. My understanding is that QHY has a very similar guide camera for a little less. I went with Orion package because I made one pass at using an older CCD as a guide camera, failed and decided I wanted to spend more time learning to guide and less time figuring out what individual pieces would work together. YMMV.

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On 23/2/2016 at 21:42, Herzy said:

 

Im still confused is autoguiding to make you get your desired results faster or does it just give you better results? If autoguiding really isn't necessary I'm going to save that for another time and just make-do with a good EQ mount.

 

 

It does both, but I'd say it is more to do with 'better' than 'faster.'  Imagine imaging two points of light (eg a pair of tiny close stars). If you track them perfectly then all the light from the left hand star lands on the same left hand set of pixels and all the light from the right hand star lands on the nearby set of right hand pixels throughout the exposure. This would be great, becase a) you'd have the maximum amount of starlight filling each little set of pixels and b ) the stars would be separated on the image.

If your tracking is not good enough then the chip will wander around during the exposure and the starlight from the left hand star will land on the right hand pixels and vice versa. So you will not cleanly separate the stars in the final result and the stars will both be fainter because their light has been smeared over a larger number of pixels.

Olly

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Thanks! I'll do a lot more research and take time to learn everything. Before I bought my alt/az mount I thought that was all astrophotography consisted of and I didn't have a clue about the problems that come along with it, and now I regret buying it. So I see what your saying, that I could make another big mistake. UGH astrophotography is a VERY expensive hobby!! ;(

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Hi Herzy,

I've recently been through this same exercise.

I wanted to do some astro imaging with my DSLR and thought the SkyWatcher Star Adventurer would be the bees knees.

I asked about it on the forums and was mainly greeted with silence. More research led me down the path to the EQ3, HEQ5 and EQ6.

I'm and old fart and have learnt from experience that when you think you have found the ideal bit of kit, go up to the next level for a bit of future proofing. I didn't notice what you intend to mount on it, but as a general rule of thumb most seem to advocate not going over 50% of the mounts stated load capacity to avoid putting undue strain on the motors.

I eventually settled on an HEQ5 and it duly arrived, in a less than pristine state, and was promptly returned. The mount, per se, seemed quite OK for my purposes however it was back on the hunt for an affordable alternative. Being retired, and on a very tight budget, the bottom like was very important to me.

In my searching I came across a new EQ6, the bottom of the range, without the stepper motors and SynScan, the built-in alignment and tracking software. The price was right so I grabbed it and have since acquired the motor and SynScan upgrade kit, all up at about 2/3 of the price of a similarly specced new NEQ6 Pro.

I should point out at this time that mounts in this range aren't exactly featherweights with the mount itself weighing in at 16Kgs, so keep this in mind if portability is an issue.

There are always good lightly used mounts coming onto the market from folk who find that they just don't use the gear that they bought in a fit of enthusiasm, so keep an eye on the classifieds.

Good luck with your search.

 

PS: For what it's worth the Celestron CG5 you linked to above seems to be the dearer GT model. Celestron is now owned by Synta who also make SkyWatcher.

This thread discusses the CG5 and the HEQ5.

 

 

Edited by DarkKnight
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Hi Herzy,

I'm an AVX owner/user. And I got into astronomy last year for Astrophotography.

I did about 4 months of intensive learning and comparing before I made my tight budgeted move. I had no less than 3 wish lists I kept grooming until I decided my current path. I finally pulled the trigger on what I now have, and what I've added to get to where I hoped to be.

The learning curve has been like climbing Everest. But with a lot of help from things like You-tube, online sources, and patient friends, I think I'm getting somewhere. The best way for me to grasp and understand things is to break them down to understandable bits.

You have the right idea, you do need an EQ mount, with Go-To capabilities, that is the prime mover for the top gear. And the mounts available can do some amazing things by themselves. But when you start reaching for pictures of things you can't really see at most peoples practical limits, you begin to reach for specialized autoguiding help.

So think of the Autoguiding as the eye for the mount to track where it needs to be, so the telescope and camera gear can do what it needs to do. The Autoguiding "catches" a star, then holds it as tightly as possible for hour upon hour. Meanwhile, the telescope and camera are riding high on the mount collecting the faint light for the image.

Together, the mount and the autoguiding camera/scope can do accurate tracking that is phenomenal. Getting it all to work together can have you tearing out your hair, but when it comes together and you learn your system and how to run it for your telescope and camera... you'll be amazed.

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Thanks DarkKnight, it was mentioned that the mount has a small maximum weight limit, but I've also heard that aperture isn't really that's big of a factor in astrophotography, so I don't need a 10" optical tube to be held up.

Ive looked into the EQ6 and its far out of my price range. Recently I've been researching the AVX mount. So far I can't find to many issues. If I auto track and use the PEC feature on the mount I should be able to achieve several minute long exposures. This mount is slightly out of my price range but I can save up.

As for the AVX mount I've been seeing so many issues with it that people are complaining about. What are your thoughts on this mount?

Oh BTW you mentioned portability, but that's not an issue really. Unless it's too heavy to carry and you can't strip it down into multiple pieces, then I don't mind taking multiple trips to set it up.

Edited by Herzy
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Thanks

6 hours ago, SonnyE said:

Hi Herzy,

I'm an AVX owner/user. And I got into astronomy last year for Astrophotography.

I did about 4 months of intensive learning and comparing before I made my tight budgeted move. I had no less than 3 wish lists I kept grooming until I decided my current path. I finally pulled the trigger on what I now have, and what I've added to get to where I hoped to be.

The learning curve has been like climbing Everest. But with a lot of help from things like You-tube, online sources, and patient friends, I think I'm getting somewhere. The best way for me to grasp and understand things is to break them down to understandable bits.

You have the right idea, you do need an EQ mount, with Go-To capabilities, that is the prime mover for the top gear. And the mounts available can do some amazing things by themselves. But when you start reaching for pictures of things you can't really see at most peoples practical limits, you begin to reach for specialized autoguiding help.

So think of the Autoguiding as the eye for the mount to track where it needs to be, so the telescope and camera gear can do what it needs to do. The Autoguiding "catches" a star, then holds it as tightly as possible for hour upon hour. Meanwhile, the telescope and camera are riding high on the mount collecting the faint light for the image.

Together, the mount and the autoguiding camera/scope can do accurate tracking that is phenomenal. Getting it all to work together can have you tearing out your hair, but when it comes together and you learn your system and how to run it for your telescope and camera... you'll be amazed.

How do you like your AVX, has it worked for astrophotography? Have you ran into any problems with it? 

And thanks for he run-down on autoguiding, it seems to be a necessity if you want amazing photos. 

Edited by Herzy
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Hi Herzy,

The new Celestron Advanced VX mount seems to review quite well with no real problems reported. SonnyE (up 3 posts ) seems quite happy with it.

They state the carrying capacity as 30lbs and if you look at this thread ...              

 ....... it confirms that you don't need a very expensive monster 'scope to get excellent photos of the night sky.

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On 2/25/2016 at 05:30, Herzy said:

Thanks

How do you like your AVX, has it worked for astrophotography? Have you ran into any problems with it? 

And thanks for he run-down on autoguiding, it seems to be a necessity if you want amazing photos. 

Hi Herzy,

Sorry I'm late getting back to you. Unfortunately, I have had issues with my AVX. The motor drive has failed twice. Celestron replaced the entire mount the first time, and replaced the motor the second time.

I think I found a permanent fix though. I now have a large AGM type deep cycle battery I power it with, and I never charge the battery while the mount is connected. I think the Celestron AC power supply I was using when the first, and second, motor drive failures occurred may have been the culprit. So far this time, with the over sized battery supplying it, it has had no problems. I think it is fixed and has been bringing many hours of flawless operation.

It has been great for my imaging. I have an entirely Orion top end on my mount. I use an Orion SSAG camera on their 50 mm Magnificent Mini Guide Scope. And PHD 2.5.0 on my laptop. It took me forever to finally get everything working together, but persistence and perseverance has payed off. And some really good YouTube video's helped tremendously. PHD Basic's 1 & 2. Also I use Stellarium as my finding and slewing program. But between the mount working smoothly, the guide camera feeding PHD2 good data, and PHD2 being able gently tick along, the camera and telescope are just along for the ride. And that smoothness and accuracy is especially important to me, because I do very long, one shot color imaging. Up to 1 hour on a single image. On Wednesday night, I pushed my imaging out to 1 1/2 hours on a single image. As it turned out, the one hour (3600 seconds) was better due to my camera. But being able to do that requires the guiding and mount to operate very well.

In spite of the motor drive problems I have experienced with my AVX, I still think it can be a good mount at a reasonable price. Mine is performing well for me now. Here's a couple of shots of The Flaming Star Nebula. 3600 seconds, and 5400 seconds.

3600sPPw.jpg

5400sw2.jpg

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Why don't you stack shorter subs? In both images overexposure is obvious. I don't know what camera/telescope combination you use, but any camera reaches full well long before that exposure time on an object like that. The banding in you images is a sure indicator for that...the colorings around the stars also. these are blooming effects.

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5 hours ago, Waldemar said:

Why don't you stack shorter subs? In both images overexposure is obvious. I don't know what camera/telescope combination you use, but any camera reaches full well long before that exposure time on an object like that. The banding in you images is a sure indicator for that...the colorings around the stars also. these are blooming effects.

That is a very good question. Mine would be why can't I get my subs to stack?

A Friend of mine had me send him a series of images taken with my camera and he could not get them to stack either. So I sent the camera in under warranty and the company replaced it.

I'm still learning and trying to figure this all out.  I'm using an Orion ED80T CF telescope, and Orion Imaging Flip Mirror Box, and an Orion G3 Color CCD camera. Oh, and a filter wheel which carries many filters, but mostly I use my Baader Sky and Moon Glow, or for Nebula my Baader Ha7nm.

So besides being a beginner, I really struggle with processing my images. Here is a 1200 second untouched exposure. Same camera, same night, same series, just earlier in the evening.

Any suggestions gracefully welcomed. A lot of hot pixels to deal with?

1200s.jpg

Edited by SonnyE
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