Seeking advice on 10" scopes (or is that ED80s?)

[DaveO]

Despite protests from the "Minister for Finance", I am planning the purchase of a new scope, and would love to get some feedback from those of you who may have had some experience with the various options that plague me.

While I will primarily do visual work with it, I want to be able to move into some astrophotoghy as well in the future. Nothing obsessive (yet). I also need the scope to be portable, as 3 or 4 unfortunately placed street lights make observing from my house a pipe-dream.

I already own a 4" newt which I have had since 1986 (no prizes for guessing why), and am comfortable with an equatorial mount. I used one of my club's loan-a-scopes, and found out that I really don't like fork mounts - some of the things I can locate without a GOTO happen to be very close to celestial south, and my neck doesn't stretch that far!

My budget is $2500-$3000, and research to date indicates the following candidates:

Skywatcher 10" (SW252Sky) - $2995 from Sirius Optics. Includes GOTO EQ6 mount.
Meade LXD-75 10N - $2750 from Star Optics. This is a Schmidt-Newtonian, which I have never seen.
C10N from York Optical on a CG-5 Equatorial. $2550.I have also been told that Orion make a 10" Newt which is better than the Skywatcher, but about $1000 more.

Can anybody comment on these, especially the quality of the mounts, which reading these forums certainly confirms is as important as the optics.

Note I have steered away from equatorially mounted SCTs mainly because they seem more expensive, but if anybody has suggestions in that regard, I am open to ideas.

[davidpretorius]

ok, top first a c9.25 is a rippa, but really up there in price say $6000 including a really solid mount.

i have a 10" dob which is great and very portable as it is on a mick pinner buggy. it is now motorized, so for $2500, you would have change left over. you would have to fiddle to install etc.

Not many guys i know have reflectors on eq mounts apart from bird, but his bohemoth really needs a titan mount and that is really expensive.

so i know i have not really answered your question, but dob mounts seem to be very flexible and cheap, hence leaving money for cameras for planetary work etc????

the new lightbridges look great and look portable

[DaveO]

Thanks David. ANy advice is always welcome.

I saw another forum where the 9.25 was recommended. But the price is really outside the budget when you add a solid mount.

My main concern with a dob is that there are fundamental problems with tracking, which affect the use in photo work. I know you can motorise them, but the word "hassle" springs to mind.

I'll stay tuned - maybe there are some other ideas out there.

[davidpretorius]

cool,

basically guys are always suggesting at least a eq6 for a 10" reflector

what sort of photo work?

deep space ot planetary?

here is birds 13.1" custom built newt on a g-11 mount. not sure on deep space but definately accurate enough for planetary!!

wind and vibrations seem to be common thoughts on wacking a newt on a eq mount.

[norm]

The LXD75 10inch Meade with autostar would be very nice. In the right budget as well.;)

[DRCORTEX]

While on the subject of 10" Newts and Dob mounts, can someone give me a few details on the pushto's available for dobs. Something that could perhaps be taken off a 10", and then used on a "big mother of all newts" latter on.

I really have limited time to search the skies, so something that lets me align with a couple of stars, check the database, and push until I'm told to stop.

I simply couldn't afford a large EQ6 mount, motors, etc. That might come when I win the lotto and want to get into photography. At this moment - visual only.

Oh, and P.S. - I wouldn't use a Newt on a Dob mount for any photography

Ciao!

DrCortex

[norm]

Hi DrCortex,

The most spoken of here is Wildcard's ArgoNarvis. The unit + encoders (depending on the scope) will set you back around $1000 - probably less.

The beauty is that you can take the unit to your next scope and purchase the relevant encoders to suit that scope.

2ndly its Australian made, delevoped, designed.

http://www.wildcard-innovations.com.au

There is also the Skycommander to my knowledge.

[AstroJunk]

The Meade LXD-75 is a really, really nice scope out of the box. I used one last year and it got a double thumbs up from me. If anything the mount may let it down if you get very ambitious astrophotographically. The EQ6 is a great mount that will take a lot of weight should you plan to hang lots of equipment off it and do autoguiding - but be aware, it probably requires a bit of tweaking to get it up to scratch (my heq5 is fine for a 10" visually).

So, if you just want it to work and give you a good experience, get the Meade.

If you are a practical sort of chap, then the skywatcher/eq6 has plenty of potential (but is a lot larger than the meade and needs a pier to work best).

Can't comment on the Celestron.

[Starkler]

The kind of mount you would need to carry a 10" newt effectively becomes very expensive.

Whilst a 10" newt is nice for visual work, you really dont NEED that much aperture to do good astrophotography. Check out what many acheive with just an 80mm refractor. :eyepop:

Inside that budget you could maybe get a 10' dob for visual AND a smaller scope on say a motorised heq5 for your photography needs.

[ausastronomer]

The Meade LXD75 mount is the equivalent of an EQ5 and is really inadequte for a 10" telescope. An overloaded equatorial mount becomes nothing more than an excercise in frustration IMO. In addition to that, if planetary/lunar viewing/imaging is your main objective (Dave lives in light polluted Sydney so I assume it would be) the Schmidt Newtonians are not a great choice IMO. The Schmidt Newtonians are inferior to a standard newtonian at high power for lunar/planetary viewing IMO. They are much better suited to widefield low power views of DSO's at which they excel. If you were to go the Schmidt Newt route I would limit myself to the 8" model, because of the mount, I would be avoiding the 10" version. That having been said I know several people who are happy with their 10" Schmidt Newts, they obviously have different standards and expectations than I do.

My recommendation within your budget and the options you have listed would be the 10" F5 Guan Sheng OTA on a Synta EQ6 mount. Andrews can do this combo for you and so can Bintel I believe.

Geoff's recommendation of the 10" dob for visual and a smaller Equatorially mounted scope for imaging is another excellent option and is possibly a better choice than a 10" Equatorially mounted Newt IMO.

CS-John B

[DRCORTEX]

Yes, I've been taking a good hard look at this system. Really is great for what it does. Best thing is that it is swappable, just buy a different mounting kit. That, plus you can buy motors from the states which support it, and turn your Newt into a "goto".

I love the way it is upgradeable. Me thinks my bank account will be depreiciating shortly.

[MarkN]

One thing not mentioned above which may be relevant is the very high central obstruction factor in Schmidt-Newts; up to 40%. Your effective aperture will be much less than the nominal.

Mark.

[robin]

Ive got a 10" fork mounted scope.Yep, sometimes you've got some awkward positions to get into for viewing but after a short time, it becomes 2nd nature.Ive also found myself in awkward/uncomfortable positions using dobs & refractors though.

[DaveO]

Geoff, thanks for the alternative point of view. I have to admit I like the look and portability of the 80mm, but I had been repeatedly told that 8" was a minimum for astrophotography (admittedly this was by people selling me 10" newts!). I will need to investigate further.

[DaveO]

Thanks John. This was what I was looking for. I had read some criticism on the LDX mount elsewhere in a different context, and wasn't sure whether it would cope with this size scope.

[DaveO]

Mmmm.. this is starting to sound ominous. Can you explain further what you mean by "tweaking"? Since owning a house I have become far more "practical" than I ever hoped to be or friends considered possible, but I'm not sure I want to start tinkering with the scope.

[ausastronomer]

Mark,

I already mentioned that the Meade Schmidt Newtonians were a poor choice as a lunar/planetary scope and not as good as a normal newtonian. The large 40% Central Obstruction, which reduces contrast, is one of several factors which contribute to this.

CS-John B

[Starkler]

Absolute rubbish !

I would suggest 8" as a minimum size visual scope to be satisfying (especially for dso's) and I know many will disagree with that statement, but photography can be done with much smaller apertures, especially for widefield work.

For photography the most important factor is the stability and rigidity of the mount, and for larger scopes the costs can be prohibitive. Much better to comprimise on scope size than the mount.

[ausastronomer]

Dave,

To prove that Geoff is correct and what you have been told is RUBBISH !!!!

Here are 2 links to some images taken by my friend in the USA Kevin Dixon, with a 60mm (yes 60mm same size as the department store Tasco) Takahashi APO refractor.

http://www.kevindixon.westhost.com/Rosette_H-alpha.htm

http://www.kevindixon.westhost.com/Rosette_Nebula-NBI.htm

http://www.kevindixon.westhost.com/Horsehead_only_NBI-FS-60C.htm

Here are a couple of images Kevin has taken with a 106mm refractor (4")

http://www.kevindixon.westhost.com/M16-narrow_band.htm

http://www.kevindixon.westhost.com/Bubble-narrow_band.htm

As you can see from those images what you have been told is absolute RUBBISH in the 1st degree. Keep in mind that Kevin is using very high end equipment in every aspect of his imaging but notwithstanding it is only 60mm and 106mm of aperture only.

In terms of Geoff's comments about an 8" scope being the minimum size for pleasing visually astronomy, I would also agree with this and add a rider in that a skilled observer under dark skies can achieve a lot with a high quality 6" scope.

CS-John B

[Striker]

Apperture is not needed for starting out into astrophotography...just look at Eddies images with 6" Mak/Newt.

http://astroshed.com/observatory/equip.htm

[DaveO]

:jawdrop:
OMG! Well if I wasn't convinced before, I am now. Thanks for the feedback. I am finding this most useful.

To answer a previous question, my main interest is DSOs. While I know the greater aperture of newts is useful in this regard, my prior assumption that large aperture was a prereq is now shattered.

I have also spent the morning at one of the local astro shops (Sirius Optics). At the risk of taking the thread completely off-topic, I am now going to look at 80-100 EDs in a little more detail. One thing I like about them is the portability and the reduced storage space (something the "Minister for the Interior" is also interested in!).

Sirius have an 80ED with EQ5 GOTO mount for $3240. Only one of the 2 lenses in the doublet are actually ED glass, but allegedly it is pretty good. Anybody able to comment on this or equivalent gear?

[ausastronomer]

Dave,

Thats a really good little scope. Shop around, you can buy this OTA only for about $500 to $600 and a suitable GOTO EQ mount is about $1600 so they are $1,000 off the pace.

CS-John B

[[1ponders]]

You're getting some great advice here DaveO.

I have both Orion 80ED and an 8" meades sct (and am thinking of getting an 8 or 10" newt for imaging). Atm most of my imaging is done with the 80. Many of the DSOs you will probably start out trying to image will be close on size to a full moon or bigger, (moon - 30 arcmin, M42/43 - approx 1.5 deg, Keyhole (Eta Carina) - over 2 deg, Tarantula - 40 arcminutes, Silver Coin Galaxy (ngc253) - 25 arcmin). Do an advanced search in the Deep Sky section for the 80ED and check out some of the imaging being done with it. Hopefully if you aren't already convinced you will be.

You will eventually want a longer FL scope to start on the smaller DSOs but there is a hell of a lot out there to break your teeth on and lessen the slope of the learning curve. The longer the focal length the bigger the challenge. About the only time I use my 8" now is for moon shots and planetary imaging if the night is worth it (few and far between atm). And there is another thing. If you get a mount that has lowish periodic error and you polar align really well you may be able to do unguided shots for a minute or so with the 80. That will be much more difficult with an 8 or 10 inch scope. And btw, don't forget you might want a guide scope at some time so the 80 doubles up for that as well. Wack in a 4Xbarlow for visual guiding or as it is for autoguiding.

IMHO to get you up and running? EQ6, 80ED (guiderings and any old 60mm tasko for a guidescope) camera and reticle (for guiding) and away you go. (Sort of :P)

Once you've got that and played with it a bit you will definately have a better idea of where you want to head next.

[[1ponders]]

DaveO have a look here http://www.iceinspace.com.au/forum/showthread.php?t=8103

Yes it is more expensive than the 80 on it's own, but this is an exceptional setup with the focuer and guiderings.

[DaveO]

Paul, yes I agree, the advice her has been as good as I could have hoped for. And truly appreciated.

I had already looked at that scope you identified, but with my limited experience, I was not sure exactly what I was looking at! For example:

Is this the same as what I would be buying now?
What is a "traveller focus"? I understand the difference between R&P and Crawford, but this is new.
Why are Losmandy rings so special?
I have no idea what a reducer is or a compression ring!Any enlightenment would be appreciated.

[[1ponders]]

Hi DaveO. The optics of the scope are the same, though the focuser is a dream (I did a bit of research on it when I was thinking I might need to upgrade my 80 focuser for upgrade. I didn't need to but I still thought long and hard about it. See here (http://www.astro-physics.com/index.htm?products/accessories/focus_adap/focus_adap)

I have two sets of losmandy rings and if I needed another set of rings I wouldn't think twice about getting another set, even at that price. They are weighty though and you need a losmandy dovetail to mount them but I wouldn't be without mine. Check them out here (http://www.losmandy.com/secondary.html)I've not compared them to other topend guiderings.

The compression is a brass ring inside the eyepiece sleeve that takes the place of the one or two thumbscrews that tighten on eyepieces to hold them in. Pretty much a standard for higher quality focusers etc. Tensions evenly around the circumference of inserted fittings rather than having the thumbscrews push it up against the other side of the sleeve. Much more secure, and you can rotate the eyepiece etc without loosening the compression ring (as long as its not too tight).

The focal reducer field flattener speeds up your scope (less exposure time) widens the field of view (can be a + or a - depending on what you want to image) and flattens out the field curvature of the imaging lense. Often highly desireable for medium to slow f/ratio scopes, particularly SCTs and Refractors. From what I understand Newts use coma correctors which are similar (flatten the field) but don't change the f/ratio (Don't know newts so I'm only assuming here. Is this correct anyone?)

[AstroJunk]

Don't spend a cent till you've been out with us on a DSO or LPO night Dave - I see you're a fellow member of the AAQ. We have a very representative sample of scopes which are regulars in the field.

Play first - Pay later, that has to be the best advice ever!

[[1ponders]]

;) :thumbsup:@ AstroJunk

Best advice yet!

[MarkN]

"I already mentioned that the Meade Schmidt Newtonians were a poor choice as a lunar/planetary scope and not as good as a normal newtonian. The large 40% Central Obstruction, which reduces contrast, is one of several factors which contribute to this".

I see it now John, don't know why I didn't see it before. 'umblest apologies.

Mark.

[AstroJunk]

How can we possibly cite eddie's permanent observatory as a benckmark here ($20-30K?) with many thousands of hours dedicated effort to get those results. Get back to the original requirement guys! Mainly visual with photography as a potential, not the other way round.

You may lose contrast with a schmit Newt, but with 10" to play with, it's not so bad. If 80mm is so great, why do we all own 10"+ scopes?

We're not all pro's here, some of us just dabble!

(Sorry for being a bore:shrug: )

[[1ponders]]

You're not being a bore AJ.

All viewpoints are welcome.

Besides you know us imagers. We hate to see a potential candidate get away. :lol:

[DaveO]

All

Thanks for all the advice, suggestions, counter-advice and so on! After much navel gazing, I finally made a decision.

On Friday I ordered a SkyWatcher 10" Newt on an EQ6 GOTO mount. :D

In the end I decided aperture was most important to me at this time. the cost was about $2700, which was well within the budget (if one conveniently excludes all those little "extras" one can start spending money on....).

However a telling factor was that the ED80's where "only" $600! My thinking is get the 10" now for DSO work, and but the ED80 later when I get more serious about the photographic work. The mount I am getting can deal with either scope, so I am set up in the short term with options for the longer term.

I'll post the outcome when I get the scope. Hopefull Brissy weather will improve by the time the scope gets here!

[DaveO]

Possibly the most amusing and honest comment I saw in this thread!!!! Think of me as not so much getting away, as saving up for the REAL show!

[acropolite]

Nice to see another one lured over to the dark side.:fight:

[AstroJunk]

Yeah, and us AAQ members don't settle for anything less than a 5" Tak!

Looking forward to playing with your new toy - and thanks for the clear sky's over Qld. I assume you putting in an order caused them. It's just a shame it has to cloud over as soon as the scope arrives, but thems the rules of astronomy.