Optics or Aperture?

[Podger]

Hi everyone,
I'm a newbie and this my first post. I currently have a 150mm x 750 Bintel Newtonian on a Bintel GEQ mount. I am going to buy a GoTo for general viewing (moon, planets, DSO), not too obsessive Astrophotography and Public Outreach use with a laptop. Important that it is portable - i.e 1 person can set up and take down easily. I reckon parts must be no more than 20kg preferred to 25 Kg max. I am down to a Celestron SGE 925XLT, Meade 10"LX90GPS or Meade LX200R 8". I am going off the SGE because too many bits to try to assemble/disassemble in the dark and total weight high. The Meades seem to be about the same weight, the LX90 has bigger aperture, LX200R better optics. Re Astrophotography, thinking of DSI II/III and a focal reducer - can this, with the software, overcome field rotation/ long exposure issues by auto aligning and stacking many short exposure shots? Is autoguiding necessary with this sort of set up? Is the 8" LX200R a better unit for these purposes than the 10" LX90GPS? Also I am not keen to mix and match OTA, mount, software etc. One stop shop preferred.
I have read all the Forums and seen heaps of great advice and information so look forward to comments.
Thanks, Rog

[Zuts]

Hi,

Your question was optics or aperture. You left out the mount. If you really want to do some reasonably serious astrophotography then you will want to image for between 5 and 10 minutes per exposure.

I may be wrong but i dont think 1 minute subs with drizzle will cut it. You can take heaps of exposures and reduce the noise but at the end of the day you just wont have captured enough photons.

For the price of the 10 inch you can get an EQ6 and c9.25.

As far as autoguiding is concerned, unless you spend big bucks on a mount you will need it. You just cant go over a few minutes on an EQ6 without it. I imagine a meade with drizzle is even worse and on an alt az celestron without a wedge forget it (except for planetary of course).

You could get a field de-rotator for the Meade but then you will be limited to certain low portions of the sky and at 500 AUD it's not cheap.

In my opinion and its only my opinion an SCT is a good all purpose scope, an SCT on a reasonable EQ mount is even better. You get visual after a 10 minute setup and can definately do good astrophotography. If you go the Alt Az route i think you will be dissapointed for astrophotography unless you buy a wedge (and drift aligning on a wedge is not easy) but happy with the visual side.

Remember if you decide you like DSO astrophotography there is no escape, you will need to guide, that is a fact.

Paul

[madwayne]

There's a mighty fine 8" LX90GPS going for a song in the classifieds here at the moment :whistle:.

[peter_4059]

Roger,

Here's my opinion.

You can take pictures of deep space objects with shorter exposures than 1 minute - I'm typically using 15 second sub exposures but stacking a lot of them (50). These will not contain the same detail that you get with a longer sub but they will also contain a lot less noise. If you want to see what you can achieve with a DSI II and a 15 sec sub in a 10" scope here is a link to some of my attempts. None of these images are greater than 15 sec subs.

http://www.flickr.com/photos/11730783@N06/

The Meade software is supposed to accomodate a bit of rotation but I have not seen this work so don't know how successful it is. Having a larger aperature scope means you can get away with shorter subs. You can always move to longer guided exposures in the future as I am just about to.

I take my 10" Newt and EQ6 to public outreach events and can set up and pack up on my own in about the same time as the clubs C11 can however the C11 typically needs 2 people. The EQ6 head is about 16 kgs.

I know you don't want to mix/match but if you end up with an EQ style mount this will be hard to avoid. I'd get a HEQ5 pro or an EQ6 pro and a DSI II and try your 6" newt on it first? You won't need a focal reducer with this combo. You can then add a SCT later.
Peter

[dugnsuz]

Thanks for the link to your album peter.
Those are some of the most best DSI type pics I have seen - well done. The fact that they're all stacks of 15sec subs makes them all the more impressive.
Cheers
Doug

[Podger]

Thanks for comments so far. I realisethat the mount is critical to good photos. Peter's shots are great and I would be delighted if I could do near as well. I am not interested in taking 8 hour exposures in LRGB then spending a week in Photoshop.
A guy at the club recommended a Losmandy G!! mount which looks good but where can I get info on the Gemini software that goes with it? I am wary of eg a US mount with software produced in Germany - I've seen too many problems unsolved because of communications problems in such a set up. The Meade LX200 with the Autosuite/Smartdrive (PEC on both axes)/DSI it seems should work well. Another guy at the club gets results similar to Peter with a C11/Fork/DSI II. The EQ6 seems popular - where can I get a spec/review of that and the sofware that goes with it?
Any comments on the LX90 10" vs RX200 8" OTA? The portability/ ease of set up/ good GoTo performance is more important to me than perfect astrophotography.
Hope I'm not banging on too much!
Rog

[Benny L]

in a nutshell go for the best optics..

I'd go for the LX200R.. but thats me :whistle:

[coldspace]

The LX90 is now coming out with the same optics as the LX200R. Its called the LX90 ACF. For general viewing and great goto it would be a good choice and alot cheaper than the LX200 ACF.

Matt.

[Astromelb]

Dear Podger,

You are going for a telescope that is a mix of a visual and photographic. Do you want to do planetary, if so then a SCT is going to have a lot of limitations for you. The Astro Societies tend to steer away from these selections as they are easily beaten in performance by a good Newt (reference grade hand crafted of course) or a really top shelf fluorite refractor such as a William Optics.

At the Astro Soc of Melb we do not have any member whom owns a SCT, there is a reason for this, as they are well known for their capability. We recommend a really good Newt or Fluorite refractor. Hope this assists.

[Podger]

Hey guys, this is getting really interesting - I said I was a newby.
I found the gen on the EQ6 and see an EQ6PRO which is EQ6+drives+SkyScan software and think this looks good. Then in another thread someone is expressing disappointment in SkyScan! So what is a good software/EQ mount combo for GoTo and control a la Meade Autosuite? Thanks Astromelb - I'm now thinking a big Newt plus modest APO on the EQ6PRO will give me great viewing of Moon, Planets and DSO plus Astrophotography. Can one use either telescope as a guidescope while shooting with the other(might be a stupid question!)? With a set up like EQ6PRO and a guidescope, how difficult and critical is polar alignment?
Wow, my head hurts!
Roger :eyepop:

[peter_4059]

Roger,

You can get great views of moon, planets, DSO's plus astrophotography with just the newt, good colimation and the right eyepieces and a camera capable of "long" exposures. You don't need guiding for modest exposures but even with the guiding, polar alignment is important. It is quite easy to drift align once someone explains it. You can guide through either scope while imaging through the other.

The EQ6pro, big newt+modest APO combination won't come cheap but this is similar to where I've ended up.

What is your budget?

Peter

[seeker372011]

Roger

if you do decide to spend the big $$$$$ that a Losmandy G11 involves then Peter Ward who is an IIS member is also an australian dealer for Losmandy and can answer any questions you have

if it is an EQ6 with goto then it is less than half the price ..and there are plenty of threads in IIS that debate the price value quation

Narayan

[seeker372011]

The EQMOD(google it) gives you great functionality for an EQ6-downside being you need to be hooked to a laptop

yes you can have a Newt and an ED 80 and image with one and guide with the othter-I do it all the time

IMHO polar alignment is mount independent..you gotta learn how to it and if you want to image you gotta drift align or something similar. all the polar scopes in the world can get you close but I think no banana

for visual-no big deal at all

narayan

[Podger]

Peter, Looks like your gear is similar to where I'm heading - do you have GoTo? My budget is ca $10K, flexible - I owe myself. I'll have to learn the drift alignment method - precise polar alignment scares me.
Narayan, where can I get info on the Gemini software that runs the Losmandy?
I'm hoping to make the SPSP on Saturday and see some of this stuff.
Does anyone have comments on the SkyScan software that goes with the EQ6?
Roger
:screwy:

[peter_4059]

Roger,

I chose not to get goto because I wanted to be able to manually move the optical tube back to a horizontal position - mainly because I wanted to be able to rotate the OTA to get the eyepiece in a comfortable position. With the goto version you would need to slew the OTA using the handcontroller.

Instead I added an Argo Navis (at about the same cost as the goto upgrade) so now have "push to". I've also added a Shoestring Astronomy autoguide port to the hand controller. Now that I've got interested in imaging the eyepiece position is less important and some nights I wish I'd got the goto - I may still upgrade one day and have both!

You should be able to get a nice setup for 10k - possibly look at getting the Losmandy G11 instead of the EQ6.

There is a very good explaination of drift alignment here:

http://www.iceinspace.com.au/index.php?id=63,405,0,0,1,0

Peter

[seeker372011]

at peter wards site

http://www.atscope.com.au/gemini2.html



I'd suggest you visit these yahoo forums as well for some owners views:


EQ6

http://tech.groups.yahoo.com/group/EQ6/?yguid=150343216

Losmandy

http://tech.groups.yahoo.com/group/Losmandy_users/?yguid=150343216

[Podger]

Thanks Narayan.
I read the guff at the links re EQ6 and Losmondy.
Went to SPSP on Saturday - my first visit. Interesting, lots of gear but difficult to see. During the day half of the set ups covered up and most others the owners either eating or sleeping. In the night it was too dark to see and scared of falling over someone's mount. Surprised at the popularity of Argo Navis (must be good). Conflicting opinions on EQ vs Forks but it seems either can be used for visual and Astrophotography quite satisfactorily unless really seriously into it. Software - heard only positives re Meade, some negatives re Synscan and Gemini. Next move is to the showrooms. I feel that there are a number of options all of which would be fine so I can't go too far wrong. Thanks everyone for all the help so far.
Roger

[Ian Robinson]

Both.

Apeture (bigger is better) is key , but the optics and the mount need to be good too.

You might save a few dollars by buying cheaply now , but you'll regret it at your leisure.

Russian maksutov-Cassegrains are a very option for a beginner I think (esp the 6' and 8" f10 and f6 versions.

I've never been overly impressed with either Meade or Celestron SCTs , I've read widely about them and viewed through some at starnights. Maybe the bigger ones they make are better quality (11" , 12", 14' and 16" but they are pricey , they are done in f10 for a reason, ie, viewing and imaging at f10 is more forgiving).

[Ian Robinson]

I'd stay clear of the show rooms until you know exactly what you want.

I've never ever bought a telescope or mount other than by mailorder. (in fact and most the astro-gear I have I bought I have bought from overseas and imported myself).

[seeker372011]

roger

pick any mount you want but please -make it a GEM!
talk to you tomorrow!
Narayan

[Ian Robinson]

A poor GEM is as about a useful as no GEM , so make it a good GEM with a study pedestal or study tripod.