first light of modded skywatcher 200 ota

[DaveGibbons]

Before reading this please take a look at my post in the DIY section regarding the mods I made to my secondhand Skywatcher 200 OTA .

I got the opportunity to try out the scope briefly last night and am pleased to report the difference in optical performance- in particular contrast- made it all worthwhile.

Double stacked barlow and 6mm ortho

(click to enlarge)

(click to enlarge)

The only problem I had was trying to make sure a rocket didn't hit me or the scope as all my neighbours seemed to be setting off enough ordinance for world war three!

When putting the scope back together I made sure the secondary was perfectly central in the ota by adjusting the spider vane screws. I then centred the secondary in the new focuser using a cheshire eyepiece.

Laser collimator used for optical axis alignment with the centre spotted primary and final primary collimation I use a simple reflective collimation cap .

I was able to test the optics on a number of close doubles in particular Delta Cygni and the much more difficult lambda cygni - a sub arc second double- . I was able to split lamda cygni using double stacked 2" apo barlow and tal 1,25 achro barlow with a 9mm eyepiece= x444. I obtained an even wider split same set up and 6mm ortho giving x666 over 80x per inch. This is a testament to the quality of the skywatcher mirrors along with(blowing my own trumpet) absolute perfect collimation. The magnification per inch is well and truly in excellent refractor territory and the extra contrast from total flocking allowed the dimmer binary members to be seen well even at the image dimming mags I used.

The general darkness of the sky is hugely improved at the eyepiece partly the tube and diagonal edge flocking- coupled with the Astrozap dew/ light shield fitted to the end of the ota- the secondary mirror is way too close to the end of the open tube and easily affected by stray light and dew , the dew shield solves both problems.

I had hoped to take the opportunity of taking some webcam images of Mars but unfortunately the mist and cloud moved in so that must wait for another day. It will also be interesting to see what kind of lunar images it is capable of.

In all honesty I never expected such performance from a cheap f5 newt and I doubt that my 10" intelliscope will be getting that much use this winter.

cheers

Dave

[beamish]

The pics look great and the write-up is enough to make me (almost). You ought to be well pleased yourself done a good job-and it's not really that cheap any more . You'll not be getting rid of that sometime soon.

Nice one !! Look fwd to some images from it too.

Karlo

[Whippy]

Dave, you got x666 out of it? That's the magnification of the beast!! (I'll get my coat...) Seriously though, I'm planning on doing the same to my C8N if it improves it like that . Where did you get the dew/lght shield from?

Tony..

[jonifive]

Two excellent and informative write ups for us SW 200 owners.....well done my friend. I enjoyed reading them and if I ever get more than one night a month out of my scope I will be following in your footsteps.

BTW it looks like there was a hell of a lot of dew in your garden, I'm glad the Astrozap did its job.

JV

[barkis]

Dave, I congratulate you on taking so much time and trouble effort, to tune up your telescope. It looks very classy, and I know it is classy. Your mods have improved it to the nth, and it's performance under Ideal conditions will be astounding.

There is no finer instrument on the planet that a well oiled Newt, and £ for £ they are unbeatable, and well tuned, will out perform more sophisticated instruments.

A very tidy piece of work.

Ron.

By the way, do you know you have toadstools in your garden.?

[Kaptain Klevtsov]

There is no finer instrument on the planet that a well oiled Newt, Ron.

Hear hear!

They were, after all, invented by the man who wrote the book on optiks. Price per inch there's nothing close, and when they're set up properly they're awesome, I really like my 200mm and use it more than the others that I own.

Kaptain klevtsov

[Andrew*]

I'm in refractor mode at the moment, but can't wait to get back to enjoying my newt. Maybe when I do it'll be nice and blacker inside

Very nice mods.

Andrew

[DaveGibbons]

Tony, the dewshield is an Astrozap made for a celestron c8 purchased from Steve at FLO. It is a perfect fit for the Skywatcher 200 tube. You guys are dead right about a good newt maybee not sexy but the best bang for your buck!

Ron,that's really a magic mushroom

Dave

[barkis]

Ron,that's really a magic mushroom

Dave

:D It's working too.

[SteelRat]

Good stuff Dave 8) Thanks for the update.

[philsail1]

Dedicated and professional bit of work there Dave. Encouraging for all Skywatcher Newtonian owners. I flocked the main tube on my 200mm Newt, and I'm definitely going to flock the edge of the secondary, and inside the focuser tube - and I'll double check that the secondary mirror is in the dead centre of the tube. All these "mods" must add up to a significant improvement in the scope's performance.

Many thanks for your write up.

Regards,

philsail1