Some reflections on my Meade SN-6 6" F/5 Schmidt-Newton, after just over a year of use.

[michael.h.f.wilkinson]

A little over a year ago, on the day I turned 58, I saw that a scope I had been watching on the Dutch te-les-koop.nl website had dropped in price to a mere EUR 165. I decided to treat myself to an extra OTA, because having just one Cat (the venerable C8, of 25 years of age) didn't feel right . The black  cat needed company. More seriously, a 6" F/5 scope, with its 762 mm focal length, relatively fast optics, and little coma would sit nicely between the 8" F/10 C8 at 2030mm focal length, and the APM 80 mm F/6 triplet at 480mm (or 384 mm with 0.8x reducer). The C8 is my best planetary imaging scope, and the little APM 80mm is great for larger DSOs, but the SN6 might be a good bet for smaller DSOs like galaxies. It would also be a very good visual scope for larger DSOs, with a maximum true FOV of 3.34 deg at 24.6x magnification with the Nagler 31T5 "Panzerfaust". At this price (plus the petrol for an hour's total drive to and from Harlingen, which is also in the north of the Netherlands), I felt I could not go wrong. I also had mount capable of moving the scope around with ease: a Vixen GP-DX mount, so I contacted the seller, hopped in the car, and got myself a lovely white Cat to go with the black.

As you can see, the two cats get along well .

The scope came with an upgraded focuser, Bahtinov mask, and dew shield, and better flocking. It is shown here with the original finder which I have since replaced with a 9x50 RACI. I already had laser collimator, so was good to go. The OTA is quite light: just 5.8 kg, which is only a little bit heavier than the C8, which means the GP mount (rather than the GP-DX) is able to carry it as well.

Collimation is fairly easy, and whenever I set it up I check collimation and it is never far off. It is not nearly as rock solid as the collimation of the C8, but I rarely spend more than a few minutes to get collimation right.

Visually, the scope is really impressive. The vieuws of targets like the Pleiades, M31, M33, and M42 at low magnification with either the Nagler 31T5 or 22T4 are superb. The absence of diffraction spikes, the very well controlled coma (much better apparently than the bigger F/4 Schmidt-Newtons), and total absence of chromatic aberrations makes for very enjoyable views, especially given the big 6"aperture. Sure, there are no doubt 6" apochromatic triplets in the words that will beat this optical quality, but they would tend to cost several orders of magnitude more than the EUR 165 I paid. Views of the moon and planets are good as well, but the C8 shows more detail (predictably). It has also been quite the comet catcher, bagging me 4 comets visually.

So is it a good imaging scope? Well, I have tried it, and I am quite pleased with the results, combined with an un-cooled ASI183MC. To date it has all been without guiding, just tracking because I haven't got my computer to talk RS-232 with my mount (will give it a go later this year). Here are some of my favourite results.

5 hours on the Leo Triplet (still must reduce some gradients in the background)

4 hours on M101

13 hours on M27 with L-eNhance filter

1 h 38.5 m on M13

3 h 37.5 m on M1, with L-eNhance filter

Not bad, especially from Bortle 4-5 skies, and such a cheap scope. The brighter stars show slight diffraction spikes, which might be due to the focuser intruding into the optical path. The only suitable extension tube I have is a bit too long, so the focuser is racked inwards too far, must get a new extension tube. All images need more data, and I still haven't found a denoising method I really like (developing one myself at the moment).

In conclusion, I think this scope has been a wonderful buy, with big potential as imaging instrument for an astounding price. The nearest equivalent now on the market if the ES 6" F/4.8 Mak-Newt, which I suppose will have better correction. If ever I decide to replace this little scope, the Mak-Newts will be high on the list. For the moment, I will stick to this one (and get guiding sorted once Windows allows APT to use the RS-232 port of the GP-DX).

 

Bottom line: should you ever find a Meade SN-6 OTA for sale for silly money: grab it!

 

 

[Merlin66]

I still have one of the original Meade 6” f3.6 Comet Seekers, a very nice SN.

I can appreciate your comments, the SN can punch well above its weight.

 

[michael.h.f.wilkinson]

11 minutes ago, Merlin66 said:

I still have one of the original Meade 6” f3.6 Comet Seekers, a very nice SN.

I can appreciate your comments, the SN can punch well above its weight.

 

I spotted one of those too recently. Interesting scope. I also spotted an SN-10, but that is rather a beast, requiring a considerably sturdier mount. 

[Stu]

Wonderful results Michael. Great to see the GP-DX performing so well, even without guiding 👍

[JeremyS]

Super results 👍🏻

[michael.h.f.wilkinson]

8 hours ago, Stu said:

Wonderful results Michael. Great to see the GP-DX performing so well, even without guiding 👍

Your old mount is doing sterling work here. I just need to find the permission settings in W10 to allow APT access to the RS232 port. Then I can start guiding and using longer subs. 

[Stu]

18 minutes ago, michael.h.f.wilkinson said:

Your old mount is doing sterling work here. I just need to find the permission settings in W10 to allow APT access to the RS232 port. Then I can start guiding and using longer subs. 

Good to hear. I often miss it, but know that it would not be getting regular use. It’s little brother GP does get used a lot for solar and lunar observing just with dual axis tracking. Lovely mounts both.

[Roy Challen]

Great images, Michael. Reading the title, I thought some optical fault had developed after a year of use...glad to hear that's not the case.

[EntropyTango]

Very nicely done in the Dutch weather and overall light pollution

[michael.h.f.wilkinson]

42 minutes ago, Stu said:

Good to hear. I often miss it, but know that it would not be getting regular use. It’s little brother GP does get used a lot for solar and lunar observing just with dual axis tracking. Lovely mounts both.

I also have the little brother, and just love that mount. It's been going for 25 years, with one replacement of the worm gear and a replacement of the motors (now with a Synscan Goto system). Hope to get guiging to work on that mount shortly as well

[ollypenrice]

Really great pictures, all of which could be developed with more exp. time. I'd call this purchase a success!

Nice to see a solution which doesn't involve pelting the problem with money...

Olly

[Alkaid]

Great images Michael.   I like the M13 one, can you tell me what is the galaxy shown at 8 o'clock in the image?  I've seen many pics of M13, but only on yours did I spot that little galaxy!

Nice!

[Stu]

10 minutes ago, Alkaid said:

Great images Michael.   I like the M13 one, can you tell me what is the galaxy shown at 8 o'clock in the image?  I've seen many pics of M13, but only on yours did I spot that little galaxy!

Nice!

Looks like NGC6207

[michael.h.f.wilkinson]

It is 6207. Closer in, there is IC 4617 as well (tiny little smudge)

[michael.h.f.wilkinson]

17 hours ago, ollypenrice said:

Really great pictures, all of which could be developed with more exp. time. I'd call this purchase a success!

Nice to see a solution which doesn't involve pelting the problem with money...

Olly

Cheers! I plan to add more data to all of them.

[philtodd]

Wow - great images! 

[Robindonne]

Great result. And again a prove we’re all being a little bit voluntary fooled by the fency pency shiny expensive astro stuff😅.   Im really curious if a well experienced astrophotographer could tell what scope is used when seeing a random picture.  I mean is it really justified to spent K’s?

We are probably the only one in the world to justify again a €2000+ purchase because we really need that item😭. We talk a bit about all the price increases lately but in the end we really need that one adapter part thats gone up from 400,- to 575,- and get sucked into the endless astro blackhole where no valuta will survive.

in short: nice pictures with an underrated telescope😉

Edited March 18, 2021 by Robindonne

[Peter Drew]

An interesting design, the Schmidt-Newtonian, a bit of a "Cinderella" instrument.  I made, possibly the earliest SN in the early 1970's,  I had been making some 8" F20 Schmidt-Cassegrains with optics by James Muirden and Jim thought it worth trying a Schmidt-Newtonian.  We made a 4.25" F4 and gave/sold (?) it to noted UK amateur Colin Henshaw who used it mainly overseas.  I seem to remember an 8" and 12" version.    🙂

[michael.h.f.wilkinson]

1 hour ago, Peter Drew said:

An interesting design, the Schmidt-Newtonian, a bit of a "Cinderella" instrument.  I made, possibly the earliest SN in the early 1970's,  I had been making some 8" F20 Schmidt-Cassegrains with optics by James Muirden and Jim thought it worth trying a Schmidt-Newtonian.  We made a 4.25" F4 and gave/sold (?) it to noted UK amateur Colin Henshaw who used it mainly overseas.  I seem to remember an 8" and 12" version.    🙂

Interesting to hear that. I actually read that people often bought the SN6 with an LXD-55 mount, because that was the cheapest way to get an LXD-55, they often ditched the OTA. Later it was said the OTA was actually the best part of the deal, given all the problems with the electronics of the LXD-55. Meade certainly made an SN-8 and SN-10 (both F/4), but I have never seen a 12".

[Peter Drew]

40 minutes ago, michael.h.f.wilkinson said:

Interesting to hear that. I actually read that people often bought the SN6 with an LXD-55 mount, because that was the cheapest way to get an LXD-55, they often ditched the OTA. Later it was said the OTA was actually the best part of the deal, given all the problems with the electronics of the LXD-55. Meade certainly made an SN-8 and SN-10 (both F/4), but I have never seen a 12".

I was referring to a 8" and 12" that I made.      🙂

[michael.h.f.wilkinson]

Just now, Peter Drew said:

I was referring to a 8" and 12" that I made.      🙂

Would have loved to see those