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recommendations for video astronomy telescope

Celestron astrophotography EAA solar Maksutov mount imaging equipment cassegrain beginner
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#1 Nicole Sharp

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Posted 14 June 2018 - 02:25 AM

My first-ever post here.  What would be the best possible setup for video astronomy under ~US$1000 (including the cost of telescope, camera, and any accessories)?  My primary goal for a telescope is to be able to film eclipses, transits, occultations, and other dynamic processes (with the ability to record the entire event onto high-definition digital video if possible, or using high-resolution short exposures to compose a video).  From my research, it seems that a Maksutov-Cassegrain would be the best possible design for a low-budget OTA for Solar, Lunar, and planetary imaging and videography?

 

I would need Solar-System Align to find and track Mercury in the daytime (particularly for the Mercury transit next year), so that limits me to either Celestron or iOptron go-to mounts.  I like Celestron's software best of those two, especially since most of their mounts can be easily upgraded to use SkyPortal and StarSense for better tracking accuracy.  I would also like a mount that can handle a short-focus OTA (such as a 500/114 reflector or a 400/80 refractor) if I decide that I would like to use a second OTA to try wider-field short-exposure deep-sky astrophotography in the future (I am fine with keeping exposures under 30 seconds with a go-to altazimuth mount).  I was told by Celestron that the Nexstar SE mounts are only designed to work with Cassegrainian telescopes, otherwise the SE mounts seem a lot better than the Nexstar SLT mounts.

 

If I go with a Maksutov-Cassegrain on the SLT/AstroFi/SkyProdigy mount, it would be either the 127SLT (1500/127, 8.6 lb.) or the AstroFi 102 (1235/102, 5.0 lb.).  The 127SLT would be my top choice, but I am worried about adding 3.3 lb. of payload for a camera and a StarSense to the 8.6-lb. OTA (for a total of 11.9 lb. payload on a mount that works best with 8 lb. payload).  Celestron support told me that 3.3 lb. of payload on the 127SLT would be fine, with no impact on tracking or on the performance of the gears or motor, but I am still skeptical of this.  Has anyone here mounted a smartphone (which actually weighs more than a DSLR) and a StarSense on a 127SLT?  If so, how was the tracking?  For videorecording, I would like to be able to track an object for hours at a time.

 

With the current sale ending June 30, I might be willing to get a Nexstar SE (up to an 8SE) if there is an overwhelming advantage to that mount or OTA over the 127SLT or AstroFi 102 (the 4SE and AstroFi 102 have the exact same OTA).  But I don't like the idea of being locked to just using Cassegrainian telescopes if I decide in the future that I would like to also use a wider-field shorter-focus OTA.  I have also read about a number of disadvantages for the Schmidt-Cassegrain design versus the Maksutov-Cassegrain design, including less contrast and needing collimation more often.  The last thing I probably want is to have to worry about collimation after transporting the telescope by car over potholes the morning of a transit or eclipse.  I also don't think that I need or want an aperture of over 6 inches if I plan to do many hours of Solar videography such as for eclipses and transits, though I am not sure how much of a concern Solar heating is per aperture.

 

I might also be willing to get a Celestron Advanced VX, but I think that could be too difficult for me to set up in the dark.  Any setup I get, I will need carry cases, and will have to be able to carry everything one-handed up and down stairs, and to and from the car, to set up at the park with.  For early-morning events, this means arriving before sunrise and setting up in the dark.

 

What are your recommendations for the best Celestron go-to telescope that is portable; easy to use; has the best possible views for filming eclipses, transits, and occultations; the ability to handle 3.3 lb. of payload on the OTA; and is flexible enough that I could also use a wider-field OTA on the same mount if I wish to?  I would also appreciate any recommendations for cameras, though I was planning to start with just using a mounted smartphone camera for videography, and if that is not satisfying, then start looking for a better camera maybe.  I don't own a DSLR, and was thinking that if the smartphone camera didn't work out, of getting a dedicated astronomy camera, since they seem to be cheaper than DSLR cameras.  Though I should probably figure out my ideal camera now, so that I can check the weight before I buy a mount and OTA for it.  I am hoping that astronomy cameras weigh less than a DSLR though.

 

I should add perhaps that I am not interested in producing any publication-quality work, and that creating videos is simply for my own personal recollection of things I can see in the telescope, and the ability to share them with others over social media.  I was initially excited by the idea of doing astrophotography, but after a lot of research, I think it will be too expensive and difficult, especially since I can download much higher-quality images from NASA for free.  I think that focusing on videography will be a lot more interesting and meaningful (as well as a lot easier) for me than trying to do photography of static-appearing objects, and I can still do planetary/Lunar/Solar imaging by stacking the video frames.  I would like to be able to eventually photograph all eight planets though if possible with the telescope (even the altazimuth AstroFi 102 should be able to capture the pale blue dot of Neptune I would hope).


Edited by Nicole Sharp, 14 June 2018 - 03:05 AM.


#2 NaNuu

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Posted 14 June 2018 - 06:32 AM

You already found your way to the EAA subform... there's quite some threads about that question.

 

Taking videos might be not the standard way to do EAA, but doing AP for solar system targets. I guess, keeping the videos as recollection might be a bit disappointing, as those clips per se don't look very nice - it's the post processing which enhances the planets to a nice level comparable or better than what you might have seen looking through the eyepiece.

 

To your questions: I'm using a Nexstar SE with the original scope (6") and also all other scopes I own (see my signature). It quickly turned out, that I wanted a dedicated astro-cam. I chose the ASI 224, which is a colour cam designed for planetary photography, but is very well suited for EAA of deep sky objects as well. If you choose a Nexstar SLT (which is ok) and a short refractor (I wouldn't recommend a Mak, as their F-ratio is a bit too bad for EAA...), you might stay well below the  $1000 limit. Check the EAA subform, you might see cheaper setups.

 

 

hope that helps and you'll find lots of better answers at our subforum!

 

 

Cheers and much fun!

 

micha

 


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#3 hbrunet181

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Posted 14 June 2018 - 08:42 AM

1000 US

 

1) Second hand Nextar 6/8 SE ALT AZ mount 200-300 USD

2) Second hand Celestron 6 Inch SCT reduced to F6.3 200-300 USD

3) ASI 224 MC Uncooled 300 USD

4) White Light Filter 100$ USD

 

That way you can enjoy Planetary, White Solar and DSO's.

 

Hugo.


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#4 nic35

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Posted 14 June 2018 - 09:11 AM

Nicole:

 

I would stay away from the Mak-Cass systems - they generally have too long a FL for EAA on deep sky objects.  Note that I have one.  Although you can get focal reducers, good ones that will cover a wide range of cameras are difficult or expensive to find. I'd second the suggestion for the 6 or 8" SC - it's a very flexible option.

 

The issue with the SE mount (and evolution mount) is that the arm that carries the scope sits straight up, and therefore you can run into issues with the OTA/camera running into the base.  I run a 70mm f6 refractor on my evolution mount by moving the scope far forward in the mount.  But I need to use a diagonal in this configuration, which means I can't use a focal reducer - not enough in-focus. The SLT mounts are angled, so it is not so much of an issue.  But they do not have the same carrying capacity.  I wouldn't try my 8" SC on the SLT I own.  The refractor is fine.

 

IIRC ( I rode the C&O Bike Trail in 2014), Cumberland should be close to some pretty dark skies, which should make EAA all the better.

 

Enjoy


Edited by nic35, 14 June 2018 - 09:19 AM.


#5 bdyer22

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Posted 14 June 2018 - 05:31 PM

I have a 127mm Mak (FL 1540) at f/12.  For Solar, Lunar, and planetary imaging it's focal length (FL), which only affects magnification and therefore your filed of view, is fine for your objectives.  Many here use C8 SCTs, and larger, which are have a FL of 2032mm.

 

Maks will also offer better correction that SCTs and deliver contrasty images.  (better for fine detail)

 

In short, long FL is exactly what you want for planetary or high mag.

 

This will help with small planets but may be more challenging if you what to do full disc images of the sun/moon.

The Focal Ratio of f/12 is slower than an SCT at f/10.  But for Solar, Lunar, and planetary imaging this isn't really a big deal because they're really bright.

I also use mine for EAA of DSOs and it works ok with a .5x FR (focal reducer).  This will speed up your optical train.  So, 1540 becomes 762 @ f/6 (not all that slow).  some like it faster though.

An 6 or 8 inch SCT will give you better resolution "when" the seeing permits because of larger aperture.

I've not tried using an phone camera, but i thought i remembered seeing on of the NV posts talking about phone software that will allow you to do stacking.  This would definitely be helpful for DSO's if you go that route and possibly planetary imaging.   I'll see if i can find what that was called and post it back here.


Edited by bdyer22, 14 June 2018 - 05:33 PM.

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#6 bdyer22

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Posted 14 June 2018 - 05:38 PM

Here's the NV article talking about the camera app:  https://www.cloudyni...hy#entry8607953


Edited by bdyer22, 14 June 2018 - 05:39 PM.


#7 PeterWar

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Posted 15 June 2018 - 11:37 AM

I would recommend you to stay away from the 127SLT, the OTA might be ok but the mount and tripod are not up for the job of EAA, the included diagonal is almost like a toy.

 

My recommendation would be a Nextar SE, you may buy it second hand if you want. Once poperly collimated, the collimation should hold well (much better than in a newtonian).

 

It's a much more versatile telescope than a Maksutov in my opinion. Mind that you can equip it with a f 6.3 focal reducer for much wider fields if you ever need it. While Alt AZ mounts do worse than EQ mounts for astro photography, for EAA we're looking at 20-30 second pictures for deep space and much less for planetary, you really don't need an EQ mount.

 

 

A sale or second hand 8" or 6" Nextar SE + ZWO ASI USB 3.0 Camera would be a good combo! waytogo.gif


Edited by PeterWar, 15 June 2018 - 11:38 AM.


#8 Nicole Sharp

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Posted 16 June 2018 - 07:17 AM

Thank you for your advice.  From reading the posts on Cloudy Nights, it sounds like I should not take Celestron's advice that a 127SLT could handle up to 3.3 lb. of payload on the OTA.  The 130SLT and 8SE are also over their published payload limits with just the OTA alone, so I don't think I would trust those either if I want good tracking for hours of video.

 

If I am just going for lots of aperture and lots of focal length for planetary viewing, then it seems like my best options for non-overloaded Celestron Cassegrainian go-to telescopes would be:

 

1.  AstroFi 102 (1325/102 [f/13] Maksutov-Cassegrain, 5.0 lb. on an 8-lb. mount)  ---this is the exact same OTA as the 4SE

2.  5SE (1250/125 [f/10] Schmidt-Cassegrain, 8.6 lb. on a 10-lb. mount)

3.  6SE (1500/150 [f/10] Schmidt-Cassegrain, 10 lb. on a 12-lb. mount)

 

My question then is which of those would perform best for daytime use?  Following up from: https://www.cloudyni...-with-aperture/

 

Most of my decision-making so far has been from internet research and a big stack of astronomy books from the library.  I have two books that state that less than six inches of clear aperture is best for daytime use to avoid overheating the OTA, particularly for observing Mercury in the daytime. Has anyone ever heard of this before?  That might be a good reason to not get the 8SE, in addition to its negative payload capacity (12.5 lb. on a 12-lb. mount).  Another book I have states that atmospheric turbulence is typically on a scale of about 150 mm, so telescopes with an aperture greater than 6" can actually have worse seeing, particularly in daytime.

 

It sounds like the Maksutov-Cassegrain should actually heat more slowly than a Schmidt-Cassegrain (since it has more mass), in addition to providing more contrast and less coma in comparison to a Schmidt-Cassegrain, but the SCTs provide more aperture for less weight.  I would think though perhaps that a 1500/127 (f/12) Maksutov-Cassegrain might be almost on a par with the 6SE, despite it's smaller aperture?  The focal length would be the same, and the smaller size should mean less heat and turbulence in the daytime.  It might be nice to put a 5" Maksutov-Cassegrain on the 6SE mount if possible, or would that not be such a good idea?

 

Is there any good rationale to get the 8SE instead of the 6SE?  It seems like there are a lot more arguments against it.

 

I also noticed on Stellarium that an APS-C sensor cannot fit the full disc of Luna or Sol from the 8SE without using a focal reducer.  I don't want to have to pay for a focal reducer, so that might be another good reason to just get the 6SE.  Though I don't own a DSLR, so that might not be relevant, depending which camera I get.


Edited by Nicole Sharp, 16 June 2018 - 07:28 AM.


#9 NaNuu

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Posted 16 June 2018 - 08:58 AM

Well, if you will stick to only solar system and mainly daytime use, I wouldnt see much of a pro for the 8SE, too.

If you might use it for observing and imageing planets also during the night, the more aperture the better.  When I started again doing astronomy, I was almost exactely at the same point as you are now - and I decided to get a 6SE, for all the reasons you mentioned, except of daytime use. For looking at the sun (of course using that filter!) I only use the little refractor of mine (and only by the help of a camera, as I almost lost my eyesight when I was a kid and the filter was breaking during observing the sun... just by chance I wasnt hit by the focussed light...). 

 

A 6SE is fine for planetary as well as (maybe with reducers) for some DSO observation (via eaa), you might see some of what is possible if you look that “small bore 6” jupiter imageing thread at the solar system subforum). For daytime mercury imaging: you should ask the experts over there, too. I guess it’s a bit beyond the standard eaa stuff done here.

 

In any case: Enjoy! Its an amazing thing to play with, watching the universe. (-;


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#10 bdyer22

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Posted 17 June 2018 - 03:02 PM

Between the three, i'd probably go with the 6SE.  It will get you about 0.76 arc/sec resolution.

 

The 102 will get you to 1.12 arc/sec AND 0.57 arc/sec for the 8SE.  Hope this helps! :)


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#11 Censustaker

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Posted Yesterday, 03:41 PM

I'd also lend a vote to the Nexstar SE 6" and the advice to avoid mak-cas. 



#12 Nicole Sharp

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Posted Today, 03:17 AM

Right now, I think my top choice is the AstroFi 102, simply because the SE mounts aren't designed to work with non-Cassegrainian OTAs.  I think my ideal setup is going to be using two OTAs, one with a large focal length for planetary/Lunar/Solar observing, and a second with a faster focal ratio and wider field of view, for deep-sky observing.  Currently thinking of getting a 1325/102 (f/13) Maksutov-Cassegrain and a 450/114 (f/4) Newtonian for the Celestron SLT/AstroFi/SkyProdigy mount.  Also, if I ever I ever got my hands on a used Coronado Personal Solar Telescope, I doubt I could put that on an SE mount, but it should work just fine on an SLT mount I think.

 

However, I still have a lot of questions about cameras.

 

If I primarily want to use the telescope for video astronomy and electronically assisted astronomy, is all I need a webcam and some Barlow lenses?  Or should I use eyepiece projection with a webcam?

 

I read that eyepiece projection can dramatically increase the effective focal length of the telescope, so would I even want a long focal length OTA such as a Maksutov-Cassegrain for viewing bright planets, Luna, and Sol with eyepiece projection?

 

How do I determine field of view with a webcam at either prime focus or with eyepiece projection?  Stellarium appears to show intense magnification at prime focus with a webcam as compared to an APS-C DSLR (I compared the view with a Celestron NexImage 10, Celestron Skyris 236C, and a Canon Rebel T7i).

 

What would be the best OTA and accessories to get the entire disc of Sol or Luna (0.6 degrees) in the field of view for a video telescope?  Same question for M31 (3.2 degrees)?

 

I am still hoping to keep the cost of the telescope plus camera under $1000.  The AstroFi 102 is less than $500, so what would be the best cameras to use for less than $500?

 

Is there any really good reason to not get a 4" Maksutov for Solar/Lunar/planetary imaging?  Any larger telescope will always have better views, but is there anything specifically that a 4" telescope cannot do that a 6" telescope can?  My impression is that most of the advanced stuff starts at 8" of aperture (such as Pluto or quasars).

 

An altazimuth 4" Maksutov should be sufficient to view and photograph all eight planets at least?  That is probably the minimum goal I would have for a lightweight mount.

 

For anything over 4.5" in aperture without overloading the mount, I would have to either get an SE or an AVX.  I like the 6SE, but I don't like the idea of being stuck only using Cassegrainian OTAs, especially since I would not be able to afford a focal reducer or a Hyperstar (a second non-Cassegrainian OTA is cheaper).

 

I was thinking of maybe putting a little 162/50 (f/3) refractor on the 6SE though as a finderscope.  Orion has one that can use interchangeable eyepieces, and it can also be used for wide-field astrophotography with a webcam (it is basically just a 162-mm telephoto lens, or half of a 9X50 binocular).  But I think that a 450/114 Newtonian or a 400/80 refractor on the SLT mount might be a lot nicer.  Using a webcam instead of a smartphone, the weight shouldn't be an issue on the 6SE.  A 3X Barlow, webcam, and 9X finderscope weigh 1.8 lb. (plus 10 lb. for a C6), which is still less than the weight of a C8 (12.5 lb.).  But if I want to put a StarSense on the OTA also, it starts adding up to too much.  The AstroFi 102 OTA only weighs 5 lb., so I have a nice hefty 3-5 lb. of payload capacity on the SLT/AstroFi/SkyProdigy mount (versus only 2-2.5 lb. for payload with the 6SE).  Also, I do not want to max out the payload either since I would like the mount to keep tracking accurately for many decades; under 75% would probably be best I think.


Edited by Nicole Sharp, Today, 03:22 AM.


#13 NaNuu

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Posted Today, 04:54 AM

Just two remarks: I don't follow your conclusion about the SE mount - those days, I'm mainly using it with a (short) refractor, two of my scopes are refractors (well, both sort of short: 460mm for the larger one). Of course, the native SC scopes are some kind of optimal combination of aperture, focal length and that mount, but up to some not too long 80mm (and even my 102/460 is fitting) you can easily deal with other designs. So: you are restricted in what size and length the mount can handle, but definitively you are NOT restricted to Cassegrains. I still would recommend the 6SE (and you can either out that little finderscope  on it or change to a small refractor whenever you want or got another little funding).

 

second remark: you might not want to stick to eyepiece projection - at least my own experiments did suffer from lots of different things: vignetting, additional loss of f-ratio, and so on. It's been sort of ok for some shots of Jupiter using my iPhone but the only picture I ever did like was a shot of the Moon.  BUT you do not need that kind of projection: if you have some cam like an ASI 120 (cheap) or an ASI 224 (not expensive and good) and if you use a 2x to 3x Barlow, you will get to a focal length which is already close to the best you might get from your intended scope. (For the 6SE it's been like that). More focal length without more aperture might just give a bigger blurry spot on the sensor, but not much more detail. (At least as far as my own experiments went). 

 

third remark: M31 is difficult to fit into the FOV of any scope with longer focal length or any of the standard (cheaper EAA) cams. You might get it if you can add a standard cam like a Nikon or Canon (if you own one or can lend one) - but it is HUGE. So any scope you want to use on planets are not very well suited for M31. IF you think about two scopes (maybe the second in the not so far future), then maybe an SC or Mak would be good for planetary stuff, while a small refractor might be good for the widefield things. Both kind of OTAs will be ok on the SE mount. But I can't think of any (cheap, you always can think about hyper star stuff for a C11 combined with an large sensor cam, but that is far beyond $1000...) system, which gives you easily comparable widefield and high focal length planetary FOVs...   



#14 Nicole Sharp

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Posted Today, 05:47 AM

Just two remarks: I don't follow your conclusion about the SE mount - those days, I'm mainly using it with a (short) refractor, two of my scopes are refractors (well, both sort of short: 460mm for the larger one). Of course, the native SC scopes are some kind of optimal combination of aperture, focal length and that mount, but up to some not too long 80mm (and even my 102/460 is fitting) you can easily deal with other designs. So: you are restricted in what size and length the mount can handle, but definitively you are NOT restricted to Cassegrains. I still would recommend the 6SE (and you can either out that little finderscope  on it or change to a small refractor whenever you want or got another little funding).

 

second remark: you might not want to stick to eyepiece projection - at least my own experiments did suffer from lots of different things: vignetting, additional loss of f-ratio, and so on. It's been sort of ok for some shots of Jupiter using my iPhone but the only picture I ever did like was a shot of the Moon.  BUT you do not need that kind of projection: if you have some cam like an ASI 120 (cheap) or an ASI 224 (not expensive and good) and if you use a 2x to 3x Barlow, you will get to a focal length which is already close to the best you might get from your intended scope. (For the 6SE it's been like that). More focal length without more aperture might just give a bigger blurry spot on the sensor, but not much more detail. (At least as far as my own experiments went). 

 

third remark: M31 is difficult to fit into the FOV of any scope with longer focal length or any of the standard (cheaper EAA) cams. You might get it if you can add a standard cam like a Nikon or Canon (if you own one or can lend one) - but it is HUGE. So any scope you want to use on planets are not very well suited for M31. IF you think about two scopes (maybe the second in the not so far future), then maybe an SC or Mak would be good for planetary stuff, while a small refractor might be good for the widefield things. Both kind of OTAs will be ok on the SE mount. But I can't think of any (cheap, you always can think about hyper star stuff for a C11 combined with an large sensor cam, but that is far beyond $1000...) system, which gives you easily comparable widefield and high focal length planetary FOVs...   

Celestron support told me that you cannot use non-Cassegrainian OTAs on the 4SE/5SE mount, but I am still waiting to hear back from them about the 6SE/8SE mount.  I don't have any experience using either a refractor or a Cassegrainian OTA (I only have a Newtonian right now, and the local planetarium also uses a Newtonian).

 

If there is a bunch of equipment at the end of the OTA though, I do not want that to hit the mount.  It looks like there are a few short-tube refractors that are shorter than the length of the 8SE, which I think might be okay like you said.  I have seen a couple of people on Cloudy Nights try to put bigger refractors on the SE mount, but I do not want to deal with slew limits or risk overloading the mount.

 

I also specifically would really like to avoid chromatic aberration if possible.  I think coma is a lot less annoying, which is why I was hoping to use a fast Newtonian on the SLT mount for short-exposure deep-sky imaging.  A 450/114 Newtonian should be able to fit M31 into a low-power eyepiece, but I do not know how that transfers to an image sensor.  Without a focal reducer or a Hyperstar, any Cassegrainian would only be for imaging of Sol, Luna, and bright planets.

 

I still think that a 1500/127 Maksutov-Cassegrain might possibly be able to perform better than a 1500/150 Schmidt-Cassegrain for planetary, Lunar, and Solar imaging maybe.  It also weighs a lot less for better tracking.  If I did get a 6SE, and could find a used 5" Maksutov for cheap, I might want that in addition to a short-tube refractor.  But I don't think there is any way to put a Newtonian on the SE mount, and a Coronado PST would also probably be too long, if I ever found one of those cheap too.  I would like to get one mount that will work for at least 10-20 years if possible, and not have to upgrade at a later point in time.

 

Something else to consider is that the June sale price of a 6SE plus wedge is still more than the current sale price of the AVX.  If I did get an AVX, then I use whatever OTAs or accessories I wanted, since it has a 35-lb. payload capacity.  But I think it might be too difficult to set up and align, and also too expensive.  If I had an AVX, then I would want an EdgeHD with a Hyperstar, and I can't afford that :-O .  With a smaller mount, I can be satisfied knowing that I have the best equipment that is supported by that particular mount, since anything better would be over the payload limit.  I don't want to catch aperture fever, lol!  I think I could be happy with a 4" long-focus Maksutov and a 4.5" short-focus Newtonian, and should be plenty I could see with that.


Edited by Nicole Sharp, Today, 05:51 AM.


#15 NaNuu

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Posted Today, 06:33 AM

Celestron support told me that you cannot use non-Cassegrainian OTAs on the 4SE/5SE mount, but I am still waiting to hear back from them about the 6SE/8SE mount.  I don't have any experience using either a refractor or a Cassegrainian OTA (I only have a Newtonian right now, and the local planetarium also uses a Newtonian).

 

If there is a bunch of equipment at the end of the OTA though, I do not want that to hit the mount.  It looks like there are a few short-tube refractors that are shorter than the length of the 8SE, which I think might be okay like you said.  I have seen a couple of people on Cloudy Nights try to put bigger refractors on the SE mount, but I do not want to deal with slew limits or risk overloading the mount.

 

I also specifically would really like to avoid chromatic aberration if possible.  I think coma is a lot less annoying, which is why I was hoping to use a fast Newtonian on the SLT mount for short-exposure deep-sky imaging.  A 450/114 Newtonian should be able to fit M31 into a low-power eyepiece, but I do not know how that transfers to an image sensor.  Without a focal reducer or a Hyperstar, any Cassegrainian would only be for imaging of Sol, Luna, and bright planets.

 

I still think that a 1500/127 Maksutov-Cassegrain might possibly be able to perform better than a 1500/150 Schmidt-Cassegrain for planetary, Lunar, and Solar imaging maybe.  It also weighs a lot less for better tracking.  If I did get a 6SE, and could find a used 5" Maksutov for cheap, I might want that in addition to a short-tube refractor.  But I don't think there is any way to put a Newtonian on the SE mount, and a Coronado PST would also probably be too long, if I ever found one of those cheap too.  I would like to get one mount that will work for at least 10-20 years if possible, and not have to upgrade at a later point in time.

 

Something else to consider is that the June sale price of a 6SE plus wedge is still more than the current sale price of the AVX.  If I did get an AVX, then I use whatever OTAs or accessories I wanted, since it has a 35-lb. payload capacity.  But I think it might be too difficult to set up and align, and also too expensive.  If I had an AVX, then I would want an EdgeHD with a Hyperstar, and I can't afford that :-O .  With a smaller mount, I can be satisfied knowing that I have the best equipment that is supported by that particular mount, since anything better would be over the payload limit.  I don't want to catch aperture fever, lol!  I think I could be happy with a 4" long-focus Maksutov and a 4.5" short-focus Newtonian, and should be plenty I could see with that.

Ah, I thought we were talking about the 6SE. With that mount, it's definitively possible. The only problem might be a longish refractor will be restricted away from zenith. As to the Mak/SC thing: I own a small Mak and I like it - but I prefer the aperture of the 6" over the smaller 5" - at least if you are not absolutely sure that you only want to observe solar system stuff. I wouldn't think of a Newton for the SE mount, that's true - but the small Newtons you might use with the AstroFI mount to me are not better than a SC and refractor combination. Btw: a Coronado PST on the 6SE mount will not be a problem  (its 400mm) I'm able to manage 460mm with only very little restrictions ( I stay below 85 degrees). My little 360mm Apo has no restrictions at all, And lots of space to add camera and stuff. You might not stick to one mount for 20 years, I bet. Not that it wouldn't be possible, but your needs and wants will change. I.e. you might find yourself doing AP, or simply longer exposures - then you want an EQ-mount. You might find yourself traveling and you will think of a very lightweight mount. You may find yourself wanting some huge aperture - you'll need a more stable mount. And so on. So, planning for some years is ok, but for decades?

 

I don't like eyepiece projections, and without, you easily can simulate the FOV of any sensor - at 450mm focal length, most of the  smaller sensors (which are very good for planetary/solar stuff) will be too small for M31. Visually, that's not a problem! But... 

 

Another remark: I wouldn't get the wedge for the SE mount- all Ive heard about it is not very promising for serious AP, and you will not need it for EAA or planetary stuff. So why add that additional cost and stuff? The AVX is a good mount (even if there are some who may doubt it), at least for what you are planning. And you're right: 4.5" say f/4 Newton and a 4" f/13 Mak will be a nice combination to start with.



#16 Nicole Sharp

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Posted Today, 09:02 AM

I still haven't heard back from Celestron.  If you own a 6SE, maybe you can answer my question about clearance.  Is there enough clearance on the 6SE to use a smartphone adapter and a smartphone for astrophotography?  Or extension tubes for eyepiece projection with a DSLR?  The Celestron website specifically states that an 8SE /cannot/ use a DSLR at prime focus, since it will hit the mount at zenith, which is a really really good reason to not get an 8SE.

 

A smartphone will be a lot cheaper and easier than a dedicated webcam I think, particularly as a beginner.  With a smartphone camera, I can stack video frames for planetary imaging, and I think some smartphones can do 10-second exposures for deep-sky imaging on the altazimuth without a wedge.

 

A short-tube 400/80 refractor is a lot cheaper than a focal reducer or a Hyperstar, but I would prefer not to deal with chromatic aberration if I can avoid it.  How bad is chromatic aberration for deep-sky imaging, or is it worse for bright planets?  I would use the Cassegrain for planetary/Lunar/Solar imaging.  I would much rather have a photo warped by coma from a fast Newtonian I think than have ugly green tinges throughout.

 

I still think the limitation of 4.5" aperture on the SLT mount might be less problematic than the limitation of not being able to use a Newtonian on the SE mount.  I am glad to hear that the SE can use a Coronado though.  Another item on my fantasy wishlist for 2024, lol.

 

The SLT/AstroFi/SkyProdigy costs a lot less though, which is probably an even bigger advantage.  Everything for the SE costs more than for the SLT, particularly the carry case.  Some of the accessories I can probably get used, but overall it should still cost significantly more (probably about $400 more maybe), which means I will not have enough left over to get a decent astronomical webcam.

 

There is also the issue of having only 2-3 lb. payload available on the 6SE, vs. 3-5 lb. payload available with a 4" Maksutov on the SLT.  A StarSense plus a smartphone adapter with a zoom eyepiece weighs 3.3 lb., which on the 6SE would weigh more than an 8SE (which is already overloaded).  I think the SE could handle it, but I don't want to be always maxing out or going over the payload limits.

 

As far as I know though, there is nothing that you can see in a 6" Schmidt-Cassegrain (6SE) that you cannot also see in a 4" Maksutov-Cassegrain (4SE), just at a lower resolution due to the less aperture?  I doubt the 6SE could easily see the moons of Mars during opposition with the light pollution here, and it probably can't see Pluto either.  For suburban light-polluted skies, it seems wiser to save my money with a smaller telescope that is limited to the brightest objects?  Also, using exposures up to 30 seconds with a fast-focus 114-mm Newtonian on the altazimuth SLT mount should be able to pull in better deep-sky images than I could with an 80-mm fast-focus refractor on the altazimuth SE mount (since it has twice the aperture).



#17 Nicole Sharp

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Posted Today, 09:39 AM

Wow!  Maybe I stand corrected: https://www.cloudyni...e-in-it/page-2/

 

However, Celestron did mention that torque is an issue with longer OTAs on fork mounts.  It isn't just the weight of the OTA, but also how the mass is distributed for moment of inertia.  So compact Cassegrainian telescopes should still always have the best tracking and put the least amount of strain on the motor and gears, compared to a longer OTA of similar weight.  A lighter wider-field 114-mm Newtonian though should perform better than a heavier longer-tube 130-mm Newtonian.

 

It looks like that OTA is 25.5", whereas the Celestron Cometron 114 is 18", and a C8 is 17".  So it might actually be okay!  Hm.  But if I get the 6SE, I will probably just have to use a smartphone camera.

 

https://www.celestro...14az-telescope/

 

https://www.telescop...39/p/118161.uts


Edited by Nicole Sharp, Today, 09:40 AM.


#18 NaNuu

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Posted Today, 11:57 AM

I try to answer at least some of your questions:

 

I do own a 6SE - and I did use it with a stack of reducers and an ASI cam, both with and with our diagonal - it's never been a problem with clearance except for very long extension tubes (which are not necessary...). I have used the mount together with my 102/460 achromat and here I did use a dslr, but this may lead to a bit restrictions for the max angle you can reach (as I remember, its about 85degrees, so almost Zenith good enough for me).

 

I have used three scopes (6SE, 102/460 and the little 60/360) with the smartphone adapter and never had problems with it. BUT I wouldn't recommend a smartphone. Even if there's at least one guy getting astonishing good results using an iPhone, my experience is, that smartphones used as a cam are just for a quick pic, not for any better stuff. For that, if you buy say a ASI 120S, you will get a nice little cheap planetary cam which may allow for some DSO, too. I would recommend a ASI224, though. Its a bit more money but a very good planetary as well as DSO cam - you pay for it, as the sensor is rather small, hence your fov will be smallish, even if you are using a short widefield telescope.

 

Some DSLRs are very good, but if you don't own one of those, you might have not much fun with it (my samsung NX is not worth much as an astrocam...) - and buying one of the good ones will be more expensive as a 224. 

 

Achromats are ok for EAA - but it depends a lot how your personal feeling is. So I do like my 102/460 achromat, but it's rather colorful (you will find pictures on the Astro Video thread taken by the Bresser AR 102/460, look at those and decide your self. A 80/400 might be much less colourful, though! For planetary stuff it might be too colorful - anyway, its more of a widefield, so you don't want to do planetary imaging with that! For DSOs I find it rather acceptable, bright stars will sometimes show some colour - you wouldn't want to use it to challenge Hubble... but...

 

I think the 6" aperture is a nice compromise of aperture, weight, size and price. I didn't use it to capture Mars so far, but it's been rather good for the big planets - and with eaa tools you will see Pluto, I'm sure. If you will catch Phobos? Maybe, I can't tell. I guess you're right, theres not much you can see with 6" which you can't see with 4.5", too - but resolution. This might or might not be important to you (i.e Jupiter looks nicer with higher resolution...) And DSOs like more aperture, even if you are using EAA tools. BUT I find myself using more often my mini (60/360), as it'S very easy going and gives very nice pictures to watch. Only it takes a bit more time to get the fainter stuff and sometimes I love the smaller galaxies with the 6" over those tiny fuzzies on the widefield.  

 

To me, the biggest con for SLT (I do own one...) is the limited weight, though. You MAY put the bigger refractors on it, but its getting rather shaky... So it might not be ok for most of what you want. Thatswhy I would prefer the 6SE over the 8SE (same mount, less weight and cheaper).

 

So much for now. I might find more time to answer more later on... (-;



#19 Censustaker

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Posted Today, 12:28 PM

I would not recommend the SLT mount, its OK, i had a scope with one, but it's nowhere near as stable or sturdy as the nexstar SE mounts. 



#20 NaNuu

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Posted Today, 02:46 PM

Just one more thought: I got the feeling you want to design and buy the one perfect system or combination for all needs, wants and so on (even for decades).

 

While I very much understand that, I think it's something you never will be able to do. Just because if you don't can spent MUCH money, you simply can not guarantee that any system or any combination is best suited for all what you might want to do. So the best recommendation I could think of is: start with one cheaper system keeping some of your money back and wait how things turn out. Try to get a dedicated eaa cam (as almost any scope takes advantage from eaa, maybe except really slow ones).

 

While in principle many cams (even smartphones) are able to get you pictures and videos, the pain if you try to do so with the "wrong" one is much frustrating, while the easy going cams offer so much joy, you will spent much time with that, regardless of how small or how "not best in all cases" your little scope will be. 




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