celestron 9.25 or meade 8" lx90 or lx200r

[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/sIfrRUQ...the%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/Astro...ope_Stand.html

Regards