Buying a telescope...how important is the mount?

I have not read this thread in its entirety so bear with me; I have though read some of the back and forth and mind making of the OP. Here is sum total of my "OWN" analysis thus far from AP perspective and not sure if it helps OP in any regard. Regards




References:
FSQ-106EDXIII F5 Astrograph for Imaging...
Knowing AT65EDQ for AP...
Knowing ZEQ25GT 2" for AP...
AstroPhoto Processing...

I have not read this thread in its entirety so bear with me; I have though read some of the back and forth and mind making of the OP. Here is sum total of my "OWN" analysis thus far from AP perspective and not sure if it helps OP in any regard. Regards




References:
FSQ-106EDXIII F5 Astrograph for Imaging...
Knowing AT65EDQ for AP...
Knowing ZEQ25GT 2" for AP...
AstroPhoto Processing...

Excellent post. :-)

I think the confusion happened when the discussion veered into "learn normal astronomy" as the OP put it. I think the intention was to learn telescope quirks before venturing fully. I am learning and hope that the quirks i experienced could be worked on.

I have not read this thread in its entirety so bear with me; I have though read some of the back and forth and mind making of the OP. Here is sum total of my "OWN" analysis thus far from AP perspective and not sure if it helps OP in any regard. Regards




References:
FSQ-106EDXIII F5 Astrograph for Imaging...
Knowing AT65EDQ for AP...
Knowing ZEQ25GT 2" for AP...
AstroPhoto Processing...

Thanks. The table is quite helpful. I am curious though...a number of people have recommended the CEM60...that isn't out yet, is it? I didn't think that was arriving until March. I also haven't found any reviews of it. While I think it is an intriguing mount, it would be nice to see how it actually performs in the real world first.

Excellent post. :-)

I think the confusion happened when the discussion veered into "learn normal astronomy" as the OP put it. I think the intention was to learn telescope quirks before venturing fully. I am learning and hope that the quirks i experienced could be worked on.

To be precise, my issue was the fact that comments like "just do astronomy and don't bother with AP for now" were based on incorrect assumptions about who I am and what I'd do with a midrange mount if it became "a hassle". Assumptions like "I'd just get so discouraged with a midrange mount I'd just give up." That's a pure assumption, its a pure fabrication. It has absolutely zero relevance to who I actually am and what would or would not discourage me. It's a mistaken assumption, a bad assumption. Offering advice based on what you mistakenly assume a person will do is the best way to give really bad advice.

The kind of advice given based on those assumptions was also actively discouraging itself...to assume someone will be discouraged by using <somemount>, then to actively discourage them from even trying to start astrophotography as a result of your assumption? Which itself was based on an assumption that the person asking for advice had never even tried astronomy before, or had never even tried astrophotography before, and had never tried stacking or processing an astrophoto before? Seriously. It doesn't really get more discouraging than that. I truly didn't come here to be discouraged. I'd have happily offered more information about myself if someone had asked, rather than assuming.

Anyway...

I am curious though...a number of people have recommended the CEM60...that isn't out yet, is it? I didn't think that was arriving until March.

Well, March is not far and we'll find out plenty about it by then.

In the meantime get ZEQ25 and possibly AT65EDQ; supplies of either of these might already be running low, if not sold out alredy, so get 'em while you can. This will give you plenty to do and learn till spring for ~$1600. Regards

I am curious though...a number of people have recommended the CEM60...that isn't out yet, is it? I didn't think that was arriving until March.

Well, March is not far and we'll find out plenty about it by then.

In the meantime get ZEQ25 and possibly AT65EDQ; supplies of either of these might already be running low, if not sold out alredy, so get 'em while you can. This will give you plenty to do and learn till spring for ~$1600. Regards

If you missed it, I am planning on using my Canon EF 600mm f/4 L II lens as an OTA (assuming I can get some parallax rings built for it), so I already have a scope. I just need a mount. I've been warned off the ZEQ25 by a couple people, primarily due to the capacity I think (it only holds 27lb...regardless of what I start out with, I intend to get a larger tube eventually as well (maybe even before I get a better mount), so I want something that can handle more weight than 27lb.)

It's the capacity that primarily has me interested in the CEM60. It'll be interesting to see how that mount turns out in a couple months. If not that mount, then it'll have to be something else capable of handling more than the ZEQ25, though...preferably something that can hold 40lb or more. Hence the CGEM (or even CGEM DX) or Atlas mounts.

Without venturing too far into this discussion, I can report that I have never actually looked at an object through any of my telescopes. I am strictly into astro photography and technical gadgets, nothing visual.

I like to sleep at night, hence my desire to automate everything to the fullest. This also makes my checklist for what is good with a certain mount somewhat different to other people's, and unfortunately I do not always make that totally obvious and clear in the discussions.

Nonetheless, great discussions!

/per

What, exactly, are you complaining about? You came on saying you wanted to go big in this hobby and were expecting to pay what it cost to get the best results, and dropping $12k on a Canon lens didn't deter you. That's a lot more than most of us have spent on an optic. One isn't ASSUMING after reading that when they infer the author is not afraid to pay what it costs to buy the best.

It seems more like YOU ASSUMED we would somehow realize you were greatly overstating your level of interest, level of ability, and budget. However, as each reply came in reading your initial post precisely the same way, you got angrier. Finally, you started going down paths which don't jibe at all with what you claimed you wanted to do in you initial post, and it has become clear hearing anything other than whatever it is you wanted to hear has you furious.

Frankly, you have have become unacceptably derisive to a community which has done its level best to help.

We aren't being paid to listen to you, here. As has been said before, no one here is getting a check in the mail based on what you decide to do.

Think about that and cut out the hateful PMs you've been sending.

-Rich

Excellent post. :-)

I think the confusion happened when the discussion veered into "learn normal astronomy" as the OP put it. I think the intention was to learn telescope quirks before venturing fully. I am learning and hope that the quirks i experienced could be worked on.

To be precise, my issue was the fact that comments like "just do astronomy and don't bother with AP for now" were based on incorrect assumptions about who I am and what I'd do with a midrange mount if it became "a hassle". Assumptions like "I'd just get so discouraged with a midrange mount I'd just give up." That's a pure assumption, its a pure fabrication. It has absolutely zero relevance to who I actually am and what would or would not discourage me. It's a mistaken assumption, a bad assumption. Offering advice based on what you mistakenly assume a person will do is the best way to give really bad advice.

The kind of advice given based on those assumptions was also actively discouraging itself...to assume someone will be discouraged by using <somemount>, then to actively discourage them from even trying to start astrophotography as a result of your assumption? Which itself was based on an assumption that the person asking for advice had never even tried astronomy before, or had never even tried astrophotography before, and had never tried stacking or processing an astrophoto before? Seriously. It doesn't really get more discouraging than that. I truly didn't come here to be discouraged. I'd have happily offered more information about myself if someone had asked, rather than assuming.

Anyway...

What, exactly, are you complaining about? You came on saying you wanted to go big in this hobby and were expecting to pay what it cost to get the best results, and dropping $12k on a Canon lens didn't deter you. That's a lot more than most of us have spent on an optic. One isn't ASSUMING after reading that when they infer the author is not afraid to pay what it costs to buy the best.

It seems more like YOU ASSUMED we would somehow realize you were greatly overstating your level of interest, level of ability, and budget. However, as each reply came in reading your initial post precisely the same way, you got angrier. Finally, you started going down paths which don't jibe at all with what you claimed you wanted to do in you initial post, and it has become clear hearing anything other than whatever it is you wanted to hear has you furious.

Frankly, you have have become unacceptably derisive to a community which has done its level best to help.

We aren't being paid to listen to you, here. As has been said before, no one here is getting a check in the mail based on what you decide to do.

Think about that and cut out the hateful PMs you've been sending.

-Rich

You know what I'm referring to when I say you assumed, and it isn't what your referring to above. I made that very clear in my PM. Your handily ignoring it, but whatever.

I DO intend to spend the money, you know that as well, and again, that isn't the point. Again, your handily ignoring what I' explained to you in PM (and what I also explained out here). But...whatever.

It also isn't the community, it is primarily you, and maybe a couple others (but apparently they aren't as stubborn as either of us). You know exactly what I'm referring to, but again...were still playing games here. Again, whatever.

There is no longer any point in continuing any debate or conversation with you. I used PMs because it isn't the communities issue, it's between you and me. You either just don't understand the point I've been trying to make, or simply don't care. Either way, it doesn't matter anymore. Thanks for the help, good day, clear skies.

My thoughts...

I've gone from a Celestron SLT 130 and it's associated mount (wobbly nightmare) to a CG5 GT with the same SLT 130...hmm, to a CGE Pro Edge HD 1100. I took my time weighing up all of the different mounts and scopes and ended up buying the CGE Pro Edge HD 1100 and I'm very happy with the setup.

There's an absolute plethora of mounts out there. The way I see it is this: mounts like the Paramount to me are boutique pieces of equipment which I've come across when running a studio and the rediculous money people spend for what seems like very marginal gains. I'm sure that there are gains in spending huge amounts of cash on a Paramount mount are there to be had, but this puppy would never part with $350 just for a counterweight from Software Bisque, plus you have to buy a mount and counterweight bar...no thanks.

I heard people moaning about the weight of the CGE Pro and that it's impractical; to who, a midget? Seriously. I'm not the biggest built bloke and I don't find it that heavy to lift the entire mount head on my own and place it on top of the tripod. I could understand if people out there are at retirement age and are a tad weak, but for those of us that are not infirm, it's easily movable, same goes for the Edge HD 1100, it's lightweight and a breeze to lift.

At the time of looking for a new mount, I tossed the idea of a CGEM DX around in my mind, but looking into the future and possibly having an assortment of new *things* attached to the scope, I went for something that would be able to accept new additions without going over 50% of the mounts rated load. Things May creep over in time, but I don't want to be at 90% of rated load like I would be if I went for a CGEM DX, so I went for the CGE Pro instead. I could have easily afforded Software Bisque's top of the range mount, but as I've already said - in a round about way - I don't think that what you get for your money merits paying such large amounts of money for.

Something that I've now found with going down the road of astrophotography is that having an increased amount of equipment leads me in the direction of wanting to have a shed at the bottom of the garden and not have to take everything down night after night as it's an absolute pain. There's cameras, an auto focuser, automatic dew controller, dew heaters, autoguider, remote control leads going into the living room, etc, etc. It takes a whole load of time to set everything up and less time observing. So that's something to take into account.

The best advise I can offer is take your time and weigh up all of the options out there and see which one suits you best.

I would argue that the mount is just as important as the optics. I have several good scopes, but finding better ways to mount them is an endless quest.

While Jon did say he wants a mount that will last the years and has purchased top end photo equipment leading us to believe he is seeking to create really excellent images, he also expressed in interest in widefield work based on his interest in hyperstar. A hyperstar setup means more forgiving pixel scales and shorter subexposures, so for this use a midrange mount may produce as excellent of results as the top end equipment.

If later his interests expand to include narrowband high resolution astrophotography taking advantage of the darkest sites and rare opportunities of great seeing, then those high capacity high performance mounts may be the only way to get those truly exceptional results.

Gale

I would argue that the mount is just as important as the optics. I have several good scopes, but finding better ways to mount them is an endless quest.

Definitely

While Jon did say he wants a mount that will last the years and has purchased top end photo equipment leading us to believe he is seeking to create really excellent images, he also expressed in interest in widefield work based on his interest in hyperstar. A hyperstar setup means more forgiving pixel scales and shorter subexposures, so for this use a midrange mount may produce as excellent of results as the top end equipment.

If later his interests expand to include narrowband high resolution astrophotography taking advantage of the darkest sites and rare opportunities of great seeing, then those high capacity high performance mounts may be the only way to get those truly exceptional results.

Gale

This also came into my thinking when buying a mount. I've got Hyperstar, and as I've already mentioned, when you start adding more weight to your scope/mount setup, with something like the CGEM DX you're way above recommended norms for astrophotography if you've something like an Edge HD 1100 or 1140. Obviously it's a different story if you've a lightweight scope.

My thoughts...

I've gone from a Celestron SLT 130 and it's associated mount (wobbly nightmare) to a CG5 GT with the same SLT 130...hmm, to a CGE Pro Edge HD 1100. I took my time weighing up all of the different mounts and scopes and ended up buying the CGE Pro Edge HD 1100 and I'm very happy with the setup.

There's an absolute plethora of mounts out there. The way I see it is this: mounts like the Paramount to me are boutique pieces of equipment which I've come across when running a studio and the rediculous money people spend for what seems like very marginal gains. I'm sure that there are gains in spending huge amounts of cash on a Paramount mount are there to be had, but this puppy would never part with $350 just for a counterweight from Software Bisque, plus you have to buy a mount and counterweight bar...no thanks.

I heard people moaning about the weight of the CGE Pro and that it's impractical; to who, a midget? Seriously. I'm not the biggest built bloke and I don't find it that heavy to lift the entire mount head on my own and place it on top of the tripod. I could understand if people out there are at retirement age and are a tad weak, but for those of us that are not infirm, it's easily movable, same goes for the Edge HD 1100, it's lightweight and a breeze to lift.

At the time of looking for a new mount, I tossed the idea of a CGEM DX around in my mind, but looking into the future and possibly having an assortment of new *things* attached to the scope, I went for something that would be able to accept new additions without going over 50% of the mounts rated load. Things May creep over in time, but I don't want to be at 90% of rated load like I would be if I went for a CGEM DX, so I went for the CGE Pro instead. I could have easily afforded Software Bisque's top of the range mount, but as I've already said - in a round about way - I don't think that what you get for your money merits paying such large amounts of money for.

Something that I've now found with going down the road of astrophotography is that having an increased amount of equipment leads me in the direction of wanting to have a shed at the bottom of the garden and not have to take everything down night after night as it's an absolute pain. There's cameras, an auto focuser, automatic dew controller, dew heaters, autoguider, remote control leads going into the living room, etc, etc. It takes a whole load of time to set everything up and less time observing. So that's something to take into account.

Thanks for the new perspective, chapskins. Appreciated.

I've looked at (and, honestly, drolled over) the CGE Pro 1100 HD package a few times. The mount definitely looks pretty.

I'm curious...do you use autoguiding with the CGE Pro, or do you just use PEC? Either way, how is your tracking? P2P PE performance (I guess in RA and Dec, if you guide in both)?

Since I first asked this question, I went on a guiding research binge. While it does not sound like you can get down to the very fine sub-arcsecond (P2P PE w/ PEC) precision performance of a $10,000+ mount, it DOES sound as though with good polar alignment and good tracking (which involves using a guiding scope of adequate focal length relative to the main scope), you can get down to around a couple/few arcseconds P2P PE with a lesser mount.

It seems like 7 arcseconds P2P PE without PEC is the target for high end mounts. That would be +/- 3.5 PE. With PEC and/or high precision encoders, Software Bisque, Astro-Physics, and 10Micron mounts all seem to reach the sub-arcsecond range (<+/-0.5 PE). The CGE Pro has +/- 5 PE without PEC. According to a conversation I had with Celestron, their mounts offer PPEC, or programmable PEC. Once programmed, Celestron mounts can offer very good performance, somewhere between +/- 2 to +/- 1 PE (2-4 arcsec P2P PE).

When it comes to using PEC, Celestron recommends you guide while programming to get the best results (their manuals actually state you should use the hand controller to manually guide, however numerous YouTube videos and forum threads show people autoguiding with a SSAG during CGE/CGEM pec programming). If you have less than 4 arcsec P2P (+/- 2) PE with PEC, then guiding with a sufficiently long guidescope (or OAG, I guess) should help reduce that even further.

If I could get that kind of performance out of a guided mount that cost less than $10,000, I would be pretty happy. Even if the unguided performance of the mount is still 4-5arcsec P2P PE or so, so long as I can get round stars with guiding up to 10 minutes, I'll be pretty happy. Once I move into 20minute 3nm-5nm narrow band imaging, that's when I figure a high precision mount with sub-arcsecond P2P PE would really be necessary.

For reference:

CGE Pro PE charts:
http://www.celestron...-pro-mount.html
(Scroll down to the bottom for charts)
- Normal unguided: +/- 7 (14 arcsec P2P)
- PEC unguided +/- >2.0 (4.5 arcsec P2P)
- Autoduiged: +/- 2.0 (4 arcsec P2P)
- Autoguided w/ PEC: +/- <2.0 (less than 4 arcsec P2P)

The best advise I can offer is take your time and weigh up all of the options out there and see which one suits you best.

Aye, indeed. Still looking, still listening.

I may still just pick up an EdgeHD DX 1100 package deal this year (even not on sale, it's $4400, and on sale it's $4000...less than the $7000-8000 I was originally planning to spend, so I'd still be able to save), then sell off the mount at some point in the future when I decide I need a larger scope, and therefor a better mount. Seems like a personal observatory is pretty critical once you get into scopes larger than about 8" and mounts heavier than a CGEM DX. For portability, I've also thought about just getting the EdgeHD 800 package deal, which uses a CGEM rather than a CGEM DX. That would be ok, though...the EdgeHD 800 deal is $2500 (which is only about $500-600 more expensive than buying decent used gear off cloudynights and astromart anyway), and once I upgrade the scope and get a new mount, the I'd just reemploy the CGEM for wide field tracking with my DSLR and shorter lenses.

While Jon did say he wants a mount that will last the years and has purchased top end photo equipment leading us to believe he is seeking to create really excellent images, he also expressed in interest in widefield work based on his interest in hyperstar. A hyperstar setup means more forgiving pixel scales and shorter subexposures, so for this use a midrange mount may produce as excellent of results as the top end equipment.

Aye, I figure hyperstar would be pretty forgiving. I don't suspect I'd start with hyperstar though...I'd add that sometime later, next year. If I started with an f/6.3 focal reducer on an EdgeHD, which would reduce the 11" from 2800mm to 1764mm, or the 8" from 2032mm to 1280mm, how would a midrange mount, with good guiding, perform? Acceptably?

If later his interests expand to include narrowband high resolution astrophotography taking advantage of the darkest sites and rare opportunities of great seeing, then those high capacity high performance mounts may be the only way to get those truly exceptional results.

That pretty much sums up the long term goals.

The only way to train PEC effectively is to use PEMPro. Forget about training with an autoguider or (heaven forbid!) by hand.

At the end of the day it doesn't matter if your PE is +-5 or +-3.5 or +-1" - you will still have to guide. Because of the King rate / atmospheric refraction due to airmass / declination drift due to polar misalignment.

I know I said 20 minutes unguided is possible - yes with perfect polar alignment and close to the local meridian. Where airmass and thus atmospheric refraction is minimum. To go longer, unguided, you need a mount with modeling Like a Paramount, ASA, 10Micron, or theoretically an AP with the so far nonexistent APCC Pro.

Any other mount, you'll have to guide.

A trivial point but decidedly non funny. This piece of cr*p azimuth adjuster screws on lower end mounts won't let you align to better than about 10-20 arc minutes off the pole. The threads are too coarse and the azimuth axis have too much stiction. So. You will guide.

As to the question of 1700mm guided with a mid range mount. If that mount is a Losmandy G11, CGE, or CGE Pro, yes certainly. A plain CGEM or DX.. my money's on NO. An Atlas or EQ6... maybe.

One alternative. Of you're not averse to spending $4000 and can wait for a potentially unbounded amount of time, a Takahashi NJP used is a very capable mount. AP900 class and $4000 used.

It was pointed out to me that even the lowly CGEM is capable of 20 minutes + guided even at ridiculous focal lengths. With an adaptive optics unit. The SBIG AO8 is only $800, but requires a rather expensive camera.

Aye, I figure hyperstar would be pretty forgiving. I don't suspect I'd start with hyperstar though...I'd add that sometime later, next year. If I started with an f/6.3 focal reducer on an EdgeHD, which would reduce the 11" from 2800mm to 1764mm, or the 8" from 2032mm to 1280mm, how would a midrange mount, with good guiding, perform? Acceptably?

I can't tell you from experience, I am still a newbie myself. For DSO's you are not likely to get better images from the C11 than a C8. If it is an average night the seeing will prevent you from taking advantage of the C11's higher resolving power. If the mount is low end like the CGEM it will have more work to do overcoming the momentum of the larger and heavier C11. Take a look at www.astrobin.com using their "advanced search". You will see a lot of images taken with CGEM/C11 mounts that look great on the full screen view, but open up the high resolution view and you will see star trails. You can get the same detail plus more field of view with the C8 because the C8 is better matched to the CGEM for DSO AP. The CGE Pro or a Losmandy Titan may be the best midrange mounts for the C11, I would call the CGEM low end.

Also, if you decide to get the C8, you can't use a DSLR with it in hyperstar mode, you will need to get a hyperstar compatible CCD for it right away. Hyperstar may be redundent to some extent with your 600mm lens.

Aye, I figure hyperstar would be pretty forgiving. I don't suspect I'd start with hyperstar though...I'd add that sometime later, next year. If I started with an f/6.3 focal reducer on an EdgeHD, which would reduce the 11" from 2800mm to 1764mm, or the 8" from 2032mm to 1280mm, how would a midrange mount, with good guiding, perform? Acceptably?

I can't tell you from experience, I am still a newbie myself. For DSO's you are not likely to get better images from the C11 than a C8. If it is an average night the seeing will prevent you from taking advantage of the C11's higher resolving power. If the mount is low end like the CGEM it will have more work to do overcoming the momentum of the larger and heavier C11. Take a look at www.astrobin.com using their "advanced search". You will see a lot of images taken with CGEM/C11 mounts that look great on the full screen view, but open up the high resolution view and you will see star trails. You can get the same detail plus more field of view with the C8 because the C8 is better matched to the CGEM for DSO AP. The CGE Pro or a Losmandy Titan may be the best midrange mounts for the C11, I would call the CGEM low end.

Also, if you decide to get the C8, you can't use a DSLR with it in hyperstar mode, you will need to get a hyperstar compatible CCD for it right away. Hyperstar may be redundent to some extent with your 600mm lens.

Thanks for the info. I have done some searches on astrobin. I haven't found shots with trailing yet...but it does seem that some of the C11 shots (which, honestly, mostly seem to be CGEM DX, which I thought was just a CGEM with a heavier duty tripod, but maybe there is more to it than that) have kind of a funky flare around the brighter stars. Not a nice four point or six point like you get with open-ended tubes that use 3 or 4 support bars. Is that just a consequence of a central obstruction and a correcting meniscus?

As for my 600mm lens...I dunno if that's going to happen. I've been trying to contact Parralax Instruments for over a week. Several emails, and attempted to call just a couple days ago. Haven't received any response from them. Outside of finding a way to manufacture my own rings, I guess...I dunno if I'll be using my lens as a scope. I'm a software engineer...but that doesn't help me all that much with physical engineering of say a pair of parallax rings.

The only way to train PEC effectively is to use PEMPro. Forget about training with an autoguider or (heaven forbid!) by hand.

At the end of the day it doesn't matter if your PE is +-5 or +-3.5 or +-1" - you will still have to guide. Because of the King rate / atmospheric refraction due to airmass / declination drift due to polar misalignment.

I know I said 20 minutes unguided is possible - yes with perfect polar alignment and close to the local meridian. Where airmass and thus atmospheric refraction is minimum. To go longer, unguided, you need a mount with modeling Like a Paramount, ASA, 10Micron, or theoretically an AP with the so far nonexistent APCC Pro.

Any other mount, you'll have to guide.

A trivial point but decidedly non funny. This piece of cr*p azimuth adjuster screws on lower end mounts won't let you align to better than about 10-20 arc minutes off the pole. The threads are too coarse and the azimuth axis have too much stiction. So. You will guide.

As to the question of 1700mm guided with a mid range mount. If that mount is a Losmandy G11, CGE, or CGE Pro, yes certainly. A plain CGEM or DX.. my money's on NO. An Atlas or EQ6... maybe.

One alternative. Of you're not averse to spending $4000 and can wait for a potentially unbounded amount of time, a Takahashi NJP used is a very capable mount. AP900 class and $4000 used.

It was pointed out to me that even the lowly CGEM is capable of 20 minutes + guided even at ridiculous focal lengths. With an adaptive optics unit. The SBIG AO8 is only $800, but requires a rather expensive camera.

I figure on guiding pretty much regardless for the foreseeable future. I actually downloaded PEMPro2 a few days ago (I noticed that several of the used mounts for sale I was looking at were PECed with PEMPro). Seems like a handy little utility!

Unguided is an interesting capability, but I don't think I need it to start...probably won't need it until narrow band. I dug into the specs of ASA mounts...seems they get +/-0.35 without any kind of PEC (!!), which is pretty phenomenal. They start at $17,000 for just the mount and another $5000 or so for essential accessories. (It also seems that they only grantee the 0.35 PE when you use one of their scopes, which are another $35,000 on the low end and $310,000 on the high end...no info on how precise it is with a different scope.) If/when the day comes that I'm pointing 24"+ worth of aperture at the sky on a super long focal length, I might spend that kind of money (but it's highly unlikely ). I think an Astro-Tech 16" RC Truss is probably the largest OTA I'll ever use, and Paramount or a 10Micron mount (and Astro-Physics, although their stuff seems more expensive to start, and are lacking the high precision encoders unless you spend almost double the money) seem quite capable of supporting one of those for unguided tracking.

I'm happy guiding in the interim, though. There seem to be plenty of things you can do to tune mounts for better performance than you get off the shelf, for CGEM, Atlas/EQ6, and even Losmandy (although if I was going to spend $7000-9000 on a losmandy plus the cost of parts for a tuneup, I'd just buy a Paramount MX or 10Micron mount anyway.) If I pick up say an EdgeHD 8" deal (mainly because its a really good deal, and not much more expensive than the combined price of the used pieces of equipment I've been looking at), and the CGEM mount just doesn't support up to 10 minute exposures, I'll probably hypertune it first. If that still doesn't work, then I'll sell it and pick up an Atlas/EQ6 and use that until I decide to go narrow band. I plan to start with wider field stuff, rather than narrower field, and eventually hyperstar (or my 600mm lens, if I can find a way to get some parallax rings for it) will support some of the much larger nebula, galaxies and star clusters.

Interesting about the SBIG AO8. It doesn't look like a mirror...is it some kind of lens? I didn't know they made adaptive optics for such small scale imaging. I know they use AO in 8 meter and bigger scopes like Keck. Well, another thing to throw on the list of future accessories. Seeing is always pretty bad here...we get a few short periods a year where seeing improves on average, but fall, winter, and spring we usually have the jetstream either directly overhead, or nearby and mucking up the works. Regardless of the OTA & mount, adaptive optics would be pretty useful here in Colorado.

As for my 600mm lens...I dunno if that's going to happen. I've been trying to contact Parralax Instruments for over a week. Several emails, and attempted to call just a couple days ago. Haven't received any response from them. Outside of finding a way to manufacture my own rings, I guess...I dunno if I'll be using my lens as a scope. I'm a software engineer...but that doesn't help me all that much with physical engineering of say a pair of parallax rings.

Does your lens not have the tripod mount attached to it? If it does, just attach the dovetail rail to it. No rings needed. Then just use a dual saddle side-by-side setup with a guide scope in rings and you're good to go. That's how I've got my 400 f2.8 set up. Works fine.

Charles

Thanks for the info. I have done some searches on astrobin. I haven't found shots with trailing yet...but it does seem that some of the C11 shots (which, honestly, mostly seem to be CGEM DX, which I thought was just a CGEM with a heavier duty tripod, but maybe there is more to it than that) have kind of a funky flare around the brighter stars. Not a nice four point or six point like you get with open-ended tubes that use 3 or 4 support bars. Is that just a consequence of a central obstruction and a correcting meniscus?

When looking at the full resolution images also check arcsec/pixel in the technical section to determine if the image was binned when captured or reduced before uploading. If so, it is possible there were star trails. Or star bloat which has nothing to do with tracking accuracy and is normally present to some extent in all full res images.

Gale

Interesting about the SBIG AO8. It doesn't look like a mirror...is it some kind of lens? I didn't know they made adaptive optics for such small scale imaging. I know they use AO in 8 meter and bigger scopes like Keck. Well, another thing to throw on the list of future accessories. Seeing is always pretty bad here...we get a few short periods a year where seeing improves on average, but fall, winter, and spring we usually have the jetstream either directly overhead, or nearby and mucking up the works. Regardless of the OTA & mount, adaptive optics would be pretty useful here in Colorado.

The SBIG A08 works like image stablization in digital cameras rather than by deforming the optics like in the Keck scopes. It is much easier to follow the image using the A08 than it is to move the entire telescope to follow the star's image.

GDD, I've looked at a good number of CGEM images on astrobin now. In full size images, I do see what your talking about. Image scale around 2 arcseconds or less and exposure times of 300" to 600", and stars, while they may not get oblong, do just kind of lose the aesthetic appeal of really nice pinpoint stars. I even found a couple hyperstar images with 60" exposures, and there was actually some noticeable trailing...I guess that can only be chocked up to operator error?

Interestingly, I did look up a bunch of Paramount MX shots. SOME, and a very few SOME, look phenomenal. Most, however, still seem to exhibit that loss of precision in the stars...they get a little soft, FWHM grows larger, and in some cases you still get slightly oblong stars.

Here are a couple examples. Without looking at the specs, you can't really tell the difference...the CGEM and Paramount MX shots all seem to exhibit the same fundamental issue at small pixel scales and longer exposure times:

http://www.astrobin.com/full/2268/B/
http://www.astrobin.com/full/66031/0/
http://www.astrobin.com/full/32905/0/
http://www.astrobin.com/full/65961/0/

I guess this is my justification in a nutshell for starting "cheap". ;P By the time I spend $10,000 or more on a mount, I want to know exactly how to use it so I can extract the maximum potential. If I can't maximize the performance of a midrange mount by perfecting my skill at polar alignment, goto alignment, PEC and guiding, then in my mind, I don't see how I could possibly get the most out of a high end mount. It would be $10,000 wasted.

Here is one of the better shots with a Paramount MX:

http://www.astrobin.com/full/59386/0/

The stars look pretty good in this one.

As for my 600mm lens...I dunno if that's going to happen. I've been trying to contact Parralax Instruments for over a week. Several emails, and attempted to call just a couple days ago. Haven't received any response from them. Outside of finding a way to manufacture my own rings, I guess...I dunno if I'll be using my lens as a scope. I'm a software engineer...but that doesn't help me all that much with physical engineering of say a pair of parallax rings.

Does your lens not have the tripod mount attached to it? If it does, just attach the dovetail rail to it. No rings needed. Then just use a dual saddle side-by-side setup with a guide scope in rings and you're good to go. That's how I've got my 400 f2.8 set up. Works fine.

Charles

It does have a tripod foot. It is actually built in to the 600mm f/4 Mark II...it cannot be removed. I had a pretty lengthy chat in PM about using the 600mm as a scope with a member here who has done it. He seemed pretty certain that supporting the large front element was critical to maintain stable tracking. The 400mnm f/2.8 has a pretty large aperture and a large front element (almost as large as the 600mm), but it is a fair bit shorter as well. I have used my big lens on a tripod with a gymbal, and even locked tightly down the thing still suffers from camera shake...IS is pretty much a necessity for anything but birds in flight when it comes to normal photography. No harm in trying, though...do telescope dovetails work with the Canon tripod foot? No modification necessary?

I'm curious about the side by side setup. How do you balance that? The guidescope and guider is going to be so much lighter than the lens and camera... Would a lower end mount like a CGEM or Atlas be able to handle that? I ordered an Orion SSAG Mini Guider kit. I think it might be more effective to find some way of mounting that onto my lens, even if I don't have parallax rings.