celestron 9.25 or meade 8" lx90 or lx200r

[want a be]

:help: Can someone give me some advice on buying a new scope for viewing and light photography in the furture. I have narrowed it down to the cpc 9.25 celestron gps w/xlt and the meade 8" lx90 or lx200r. I've read so many reviews on all 3 scopes. I'am kind of leaning towards the cpc 9.25 because of it costing a couple of hundred $$ less. Also the weight is a factor also as I have a bad shoulder:shrug: . I know the tube + mount of the cpc 9.25 is 58 lbs, lx200r is 54 lbs,and the lx90 is 33 lbs. The 8" lx90 is by far the lightess but I've read it is not as good for photography as the other two. I also thought of a eq mount w/goto instead of the fork tube because I can break it down in lighter loads to carry and still get a larger ota. I don't know if I want the hassel of setting up a eq mount vs. the fork mount as I never set one up before.:( I want to make a good decision on the scope that is also the most dependable in the long run that has a good track record on repairs....

[g__day]

Some suggestions from someone who was were you are a year ago.

Thought 1 - mount matters more than scope at the end of the day

A decent (say eq 6) mount may give you more joy than a reasonable quality fork mount + star de-rotator you'll need. Plus a fork mount might not allow you to photograph at the zenith position (the gear not fitting between the bottom of the scope and the top of the mount).

An alternate is to buy a wedge so that the fork then acts like an equatorial mount set for your lattitude. But forks and longer than 2 minute astrophotography may prove challenging.

2. Suit your scope to what you wish to view

There are many objects in space and different scopes to different ones better.

If you wish to snap wide or bright objects (e.g. bright clusters Pledaides / Eta Carina or planets Mars, Jupiter, Saturn) a small 3" - 5" APO refractor will be kinda unbeatable, its contrast will be excellent, focus razor sharp and light gathering ability fine for use. It will also be alot easier to learn on. Many folk might go for even a $600 80mm ED refractor and get great results on these targets.

If you wish to image very faint, very narrow objects (many nebulae - e.g. the Omega Cluster) than aperature is needed and a mount solid enough to carry this weight and point very precisely for longer duration - much more expensive.

For the second option it is likely you may need option 1's scope too, piggy backed on the larger scope, and acting as a guide scope for the bigger scope to keep it dead centred (i.e. less than a 1/10 of a CCD pixel off target at any time) on the target for > 2 minutes.

So you can now see why point 1 - quality of mount is a bigger factor than optical tube.

Point 3 - light grasp is important, but so is coma and flatness of field in a large SCT.

I can testify the C9.25 is great for an SCT in both these regards, as is I've heard the heavier LX200r

Point 4 - will you opt for a permanent set-up (e.g. a pier in your backyard) or will you tripod mount it in your place, or is it a grab and go scope?

It will take you maybe 30 minutes to set-up and polar align your scope each time (once you're very experienced)if you are going into the field and doing long duration astrophotography. For visual observing or very short duration photography - set-up will likely be under < 10 minutes from power on.

Hope this helps!

[want a be]

Thankyou for your quick responce. This will be a grab and go scope for my backyard. I have a celestron 80mm short tube refractor on a cheap eq mount and also a 80mm -900mm focial lenth meade goto refractor that got me interested in a bigger 8"-9.25" sct goto scope...I favor the fork mount because of the quick setup time vs. the eq mount. I know I can purchase a wedge in the future,but for now would like to get into some afocal photogragpy of the planets.

[[1ponders]]

You can still have a quick setup time with the eq mount for visual work.

As long as you don't change your azimuth and altitude settings, make sure your mount is level and place the feet of your tripod in the same position each time you set up, (place marks on the concrete where the legs are to go or sink a couple of bricks into the lawn at your leg positions) it should be no slower than using a fork mount. Modern gotos have a great ability to take into account slightly off alignment with their new pointing models and alignment setups.

I have had an LX200GPS 8" and Losmandy equatorial mounts using an Argo Navis and it was np either way. You do however have to spend time initially getting your eq mount setup right, but that is a one time only if you go back to the same position each time.

[matt]

Am very happy with my 9.25 and EQ6 set-up.

I leave the tripod permanently outside with the feet positioned according to marks on the concrete.

The OTA and mount take about 10 minutes to move separately from the house to outside and set up.

As Paul says, the V2.05a SynScan gives pretty good alignment even with approximate set-up. If I take the time to drift align... then I'm really nicely set up.

It really is a sweet rig.

[casstony]

A used 8" LX90 would not be a bad choice. They're light, easy to use, quick to set up and capable of some ccd work even in alt az mode. The biggest draw to this option is the price; used LX90's go for around half of new price (give or take). Just put a wanted ad on the forum and you'll get a few offers.

[ballaratdragons]

Hi 'Want to be' :welcome:

Firstly, thank you for asking us Aussies for assistance, considering that there must be a thousand Americans who could give you answers (all with different answers of course :lol: )

From what I have heard and seen at Astro Camps, the 9.25 is a winner. You can also piggy-back your 80mm short-tube onto it as a guidescope. That will also give you 2 imaging platforms simply by moving the camera from one to the other.

I would also recommend the EQ mount. No field rotation and breaks down into managable parts for transporting.

Good luck, and let us know your final decision.

[netwolf]

The CPC-925 or LX200R 10" are the two to compare. My mate bought the LX200R and is happy with it. He researched quiet a bit though the C9.25 was better priced (almost 1000$ less) the 200R optics get better reviews.

A suitable EQ mounts for th 9.25 or 10" OTA
1. Gm-8, Vixen Sphinx, AS-GT and HEQ5. These will do the job but will be at there or near there weight capacity. Well suited for 8" OTA's.

2. G-11, Vixen Atlux, CGE, and EQ6, better suited to the bigger OTA's.

Not sure if you have checked out Astromart yet, but If I was in USA I would start there and look for a 2nd hand scope.

Visit a store and try to see if the will let you play with a scope, pick it up etc. I recently saw my dream mount a G-11 and the beast GM-200 and I was shocked at the size of it.

I have met and spoken with (perhaps just a coincidence) far fewer people who are visual astronomers. I find the majority eventually are drawn into the imaging craze.

Regards
Fahim

[want a be]

Thankyou for everybodies advise. I went and bought the celestron 8" cpc goto fork mount scope with gps and xlt coatings. I lifted the 9.25 cpc @ 58 lbs. and then the 8" cpc @ 42 lbs. and as I have a bad shoulder I decided on the lighter of the two. I know aperture rules,but only if you can take the scope out when you want. I have to carry it up two fights of stairs to my backyard (outback). I don't think 1.25" of apertue will make that much difference. I will use it for more plantary viewing then anything else and lite photography and will eventully buy a wedge for it. I also bought a gto 2" sct diagonal with 1.25 adaptor, 31mm 2" eye piece and a AC adaptor. I already have a 21mm,12.5mm,10mm and a 8mm 1.25 celestron x-cel series eye pieces. I have a small digital camera I like to try a Orion SteadyPix Camera Mount to do some afocial photography. Anyone have suggestions on photography will a small digital camera?

[ballaratdragons]

You can go here and look at the last article on the 'Australian Astrophotography' page :thumbsup:

http://australian-astronomy.bravehost.com/

There is a link to Afocal Astrophotography right at the end.

I'd give you the link directly, but then you'd miss out on seeing my site :lol:

[want a be]

Thankyou once again. I hope to get my new scope out this wk.end...

[netwolf]

Congrats on the CPC-800. Your a wise man to select the scope you will use most. That is the key in this game, unless you have a permanent observatory, then you can have what every you can afford. You should be able to piggy back your 80mm on the CPC as a guide scope or for widefield imaging later on down the track.

There is also a wealth of information on this scope over on Cloudynights.com forums. I am not sure if you know the site already or not.

Regards

[want a be]

Thanks for the site netwolf,I will check it out. How long have you been into astronomy if you don't mine me asking....

[netwolf]

I am a relative newbie to the actual use of a telescope, about 2 years. But I have been interested since i first looked up at the stars as a little kid and discovered magnets. In year four we moved to Australia and until then I really did not want to be at school. Thats until i found the library, and books about magnets and stars.......... If there was one thing that truly impressed/inspired me was the invisible magnetic force. Its only when you asked me now that I gave it some thought, but that was the turning point in my life. That and a strong faith gave more depth and meaning to the world around me. How odd.

After getting married my wife and two colleagues at work encouraged me to get my first telescope, a dob and now I have a LX90 8". And I hope a long road ahead...

Regards
Fahim

[want a be]

I have been interested since that first time I saw Saturn though my dime store scope when I was a boy. I always had a cheap scope, as I got older
I got a Meade 80mm x 900mm refactor. I learned a little tracking the planets and learning a few constelations. Then I got the 80mm short tube and learned a little more. Got to take out my 8" CPC tonite and take a GoTo tour. It was a clear, cold nite (32 F). I looked at Saturn at low to higher power. Thougt I'd see more detail then I did, but it was also a full moon and I live in the suberbs about 15-20 miles from the lites of Baltimore City,Maryland on the central east coast in the US. Took me twice to get the GoTo aliened right. Once aliened it tracked well at 203x even after a tour of the sky it came right back to Saturn center on the eye piece at high powers. Maybe I was exspecting to much with this new scope. I also thought the planet would look alot bigger then my other scopes. Maybe darker skies and better seeing is the answer.....I try again tomorrow...Clear Skies

[netwolf]

Well I was out there again tonight with the LX90 and I had a crowd who wanted a look. Gave a short talk on how I know and was sure that was Saturn in the EP. How the planets/stars move, constellations etc. They were amazed that I even had this interest, or found the time to pursue it. Well I gave them a look at Saturn at about F50 ~300x through a recently acquried TV 32mm Plosl. There was not much detail to see apart from the globe, the rings and some moons. But it blew them away. I allso let the younguns look at it with a GSO 15mm Plosl at F50 ~600x and while image scale was good the moon obstructed any detail, and turbulence could be seen due to hot air rising from nearby roof tops. Seems like from opposite ends of the earth we are being affected by similar symptoms and both are perhaps demanding more of the 8" than is possible.

Regards

[want a be]

What do you mean by F50~ 300x? I know 300x is the power of the eyepiece,but what is the F50? I thought our 8" scopes were F10. Also how did you get 300x from a 32mm,if my math is correct 32mm into a 2032mm (8" scope) gives me 63.5x and a 15mm 135x. What am I missing, remember I'am still learning. As far as detail I just want to see detail like I see in some of those pics I see people taking from their 8" & 10" scope. What are we doing wrong. Thanks for taking the time to respond to my questions.

[netwolf]

Your missing a 5x Powermate, which i forgot to mention. F50 means my F10 with a 5x barlow. A barlow is a lens that increases your focal length by a specific magnitude. And hence a barlow increases your magnification by the same magnitude. A Focal Reducer has the reverse effect of a barlow, ir reudces the focal length by a magnitude. A 0.5x focal reducer will make your F10 into a F5. The most popular focal reducer is sold as a 6.3 this is actually a ~1.5x but the label it 6.3 because it will reduce a F10 to F6.3.
Thats Barlow's 101 for you. So my 32mm EP in a F10 scope is 63.5x in a F50 scope its 5x that, which is 312.5x.

This is not a freebie though there are penalties in magnification. The focal ratio is an indication of the speed of the Optics, A F10 takes twice as much time to gather the same light as a F5. And 1/5th of the time to gather the same light as an F50. So you get magnification, but the penalty is you need to track the object longer to capture detail (photons of light).

I am not expert so some please jump in and make any corrections.

Regards

[netwolf]

The general visual magnification rule is that you will get about 40x-50x for every inch of aperture. So a 8" telescope has a max visual magnification of 320x-400x. This is further limited by the seeing conditions, limited by atmospheric conditions etc.

[guru_meditation]

Fahim/Netwolf,

You own the 8 inch LX90, after having used it for a while, would you have thought that the 10 inch would be more suitable? I am just wondering what limitations you find the LX90-8 has.

If you were to purchase the Lx90 10 inch, what accessories would you buy with it?

Regards

Simon

[netwolf]

Simon,

I have only had the LX90 for about 1.5 Weeks, and have used it 3 times. Its very nice telescope and easy for me to move around and setup quickly for observing. While it has not got the light gathering power of my 10" dob, it makes up for it in ease of use.

My friend has a 10" LX200R that I saw at the Bintel Store, I do not think I could easily lift and move that setup on the Tripod. Mine stays in the hall so I can lift and take it out in one step. Recommend you goto a store and look at the two. Also you could go to a Star Party or a armature club night, find out and look through similar scopes to see the difference.

Join the LX90 groups on yahoo and check out the file,photos and link sections. Also look at the MAPUG website. Both resources will help you see what mods and accesories people have added.

The 8" comes with one limitation, the hole for the visual back is only 1.5" in diameter, this limits your EP size to 1.25" 30-32mm EP's. The visual back provided is only 1.25" so your limited to 1.25" diagonal. You can purchase 2" Diagonals with adapters to fit and use the 1.5" hole, this does (frome reports on LX90 group) some what improve views with 1.25" EP's and will let you use 2" EP's. But you will see vigneting on the 2"ers and hence your paying for glass you will not use.
The larger versions have a bigger hole and hence permit the use of third party visual back adapters to use 2" diagonals and EP's.

There is a post on the LX90 group reccomending ideal budget EP's a 32mm Wide angle with FOV of 70-80degrees, a 18-15mm with half the FOV of the 32mm, and a 9mm for high power planetery work. A 2x barlow to start off with, and work yourself up would be a good idea. A focal reducer if your considering wide field Photography. Note there is a particular Budget 32mm EP that was reccomended on the groups known as the 1rpd (made in china) there is a better one now for about the same price but better performance. These clone EP's are sold under many names. I was fortuante that my mate wanted to upgrade his 32mm TV to a panoptic so I bought it from him. The FOV is less than what I wanted to get, but its a TV and its sharp to the edge . Watch for good deals on used TV EP's on Astromart and other places. Else check out the amazing deals from Frontier optics on EP's. You max visual magnification is about 320-400x in good seeing conditions so dont bother with EP's less than 8mm. You can always barlow the 8-9mm to give you a 4-4.5mm EP.

There are some very good modifications from Peteresons engineering that can improve your LX90 or LX200 performance. The EZ DEC upgrade is a good one, mine came with this. Also the Eyeopener (allows 2" visual back).

Research an effect known as Rubberbanding, it is known to occur in Autostar LX telescopes. Essentially when your manually slewing in DEC, and release the button it keeps slewing. The original owner of my Telescope had it taken into Bintel to fix this and he also had his Autostar hand controller replaced twice before the effect went away.

There is a wealth of knowledge out there, but I think i have suggested enough Accessories to get you started, you can gather more as you progress.

Regards
Fahim

[netwolf]

This is the article you should read.
http://f1.grp.yahoofs.com/v1/sIfrRUQBLNmRuzEcgR5JeSig0EwKkokyqr-rVzba_R21Wtj7xR0bu8DPGjm76m962iAtAT E_xFOCkdZ-z9DLFYhZlRY0OSwKf6c/An%20eyepiece%20selection%20guideli ne%20for%20the%20LX90.txt
Also do a search in the group for people feedback on using the reccomended EP's. Note the one I mentioned before as a replacement to the 1rpd is 2" 30mm UW fro Clearvue. Do us this on a 8" you will need to get a 2" diagonal and you will get some vigneting, but for the price (same as the 1rpd) apparently the area you do see is far better than the 1rpd.

Regards

[MarkN]

I second the thoughts on the 10" LX90. Only another couple of inches but whooeee! What a difference they make to the moveability. Getting to the grunt & heave stage for many of us; certainly not grab & go.

Could be wrong here but I think the point at which vignetting occurs has more to do with the EP field stop vs scope visual back diameter rather than the barrel size. There are some 2" EPs that have a field stop smaller than the visual back of the 8" LX90.

Definitely forget about the 31 mm Nagler or the 41 mm Pano.

Mark.

[guru_meditation]

Hi Netwolf & Mark,

Yes, it appears to be the case with the 10 inch. In my case it is just 'Aperture Greed', and I am reluctant to step down from the 10 inch Newt. Hence my question on the essential difference between the 10 and 8, besides the weight.

For Netwolf, cheers for the comprehensive reply on the LX90, and for mod details also.

I am leaning towards the 10 inch LX90, knowing that I will probably have issues with size. However, with a purchase of this dollar amount, I can't see much point in getting a scope I wont be happy with in terms of aperture and viewing quality.

Rgds

Simon :)

[netwolf]

Simon the decision was tough for me to step down from a 10", but there is no point having a scope if you are not using it. That being said, you need to look at the area you observer in and come up with a way to make the telescope more portable for you.
See here under "Scope/ Tripod Transport Device Designs:"
http://www.mapug-astronomy.net/pages/memberprod.html

I really like this design.
http://www.mapug-astronomy.net/AstroDesigns/TrpdSled/portable_scope_stand/Portable_Telescope_Stand.html

Regards