Schmidt-Newtonian scopes... thoughts?

[chrisc]

Hi everyone,

Just wondering if anyone has experience with the Meade (does anyone else make them?) so-called Schmidt-Newtonian OTAs?

Curious as to how people feel about their pros and cons...

Cheers,
Chris

[adman]

No sorry I've never used or even seen one - but I am very curious to see what others say....

Adam

[pvelez]

I have a Meade SN - 8 inch variety. Its a good and fass OTA - f4. If you are looking for an entry level scope for astrophotography, this is a good choice, especially if your mount is so-so.

It suffers from coma so you will need a corrector - I use a Baader MPCC. The coma is not as pronounced as for a Newt but you do still need to correct for it.

Bear in mind that its a heavy beast - with an Orion short-tube 80mm guidescope and a heavy camera, it takes its toll on the EQ6 it sits on. Don't go near the Meade stock mount - its really not up to the heavy OTA.

Collimation is not too bad - I use an Orion laser and that yields satisfactory results.

Bear in mind its a modified Newt, so it can be a pain to balance.

The stock focuser isn't great - I changed to a JMI EV focuser which I have since motorised.

For quite a while I used a DSLR and it performed quite well. I've since moved on to a SBIG ST8300M. There is a reasonable amount of vignetting with this camera - I doubt there is much that can be done with it on that front - it does yield a v wide field of view so you can always crop out the dark corners or correct with flats.

Overally, I am happy with it. I've recently bought a Televue Powerview x2 and it works a treat with it (despite the temptation of the SCTs that keep cropping up in the For Sale section).

Hope that helps

Pete

[ausastronomer]

Hi Chris,

Do you plan to use the scope for visual or imaging ? Also what aperture are you looking at, 6",8" or 10" and what mount is it on, LXD 55 or LXD 75?

As a heads up I can tell you for visual work there are clearly better choices that will cost less money. I have seen a couple of these scopes that actually had serious optical issues. One 10" model I used was so astigmatic that I got to view the August, 2003 opposition of Mars in stereo, through it. 2 planets side by side through the 1 eyepiece :)

I would be wary, they aren't a great thing IMO with a large number of issues that I could go into more detail on, if you wished and had your heart set on one of these. You can be lucky and get a decent one, but there are a lot of these out there with problems. Trouble is, if you don't know what you're doing and what to look for, you might end up with a lemon. Be rest assured there are plenty of people out there using bad telescopes that don't know it's a bad telescope, because they have never used a good telescope under good conditions to appreciate the difference..

Cheers,
John B