Ultimate Planetary Scope

[Solar B]

This is it ... and was confirmed to me some time ago ( approx 14 yrs) and again recently 

It will out preform any refractor regardless of strehl around this aperture

I'm saying this and I am genuinely a refractor only guy & abhor mirrors 

https://www.astrobuysell.com/uk/propview.php?view=162025

Brian 

 

[Craney]

Indeed. 

I saw that ad ... looked at my car for a fleeting moment and thought....what if.. .........no...stop it !!!

Regardless of the impressive optical specs....... only weighs 9.5 kilos !!!

[Solar B]

27 minutes ago, Craney said:

Indeed. 

I saw that ad ... looked at my car for a fleeting moment and thought....what if.. .........no...stop it !!!

Regardless of the impressive optical specs....... only weighs 9.5 kilos !!!

Mate if the planet's were my thing then this would be it 

It's actually good value in comparison to the highest end refractor's 

I'm thinking the 140 is worth a look at again and is also carbon 👍

Brian 

 

 

 

 

 

 

 

 

 

 

 

[Craney]

I've got a 140...

and it's as sharp as a pin.

 

Edited June 1, 2020 by Craney

[Solar B]

Velly nice and perhaps somewhat (or a lot) underrated me thinks 👍

Brian 

[Gina]

I'd like it but haven't got three and a half grand!!

[Solar B]

On 02/06/2020 at 16:54, Gina said:

I'd like it but haven't got three and a half grand!!

There was that other Intes Mak thingme but this ! .... well that 🔴 planet.

 

 

[John]

I reckon this might beat it (just about)

https://www.astrobuysell.com/uk/propview.php?view=162161

I used to have the 6 inch version - it was a brilliant planetary scope.

 

[markse68]

Hi John, what makes a mak newt like that a better planetary scope than a regular newt? It’s quite a “fast” scope which isn’t normally associated with being a planet killer? I understand that mak newts have lower (possibly zero?) coma- an advantage in a faster scope and it seems to have a smaller secondary so better contrast (why can it have a smaller secondary?) And no spider so no diffraction spikes- is that an advantage for the planets? Or is it just that it’s easier to make a more perfect spherical primary? But then the lens has to be good too. Just wondering

[John]

- Very small secondary and no secondary supports so very low diffraction.

- 30% the coma that a normal newtonian has.

- A "niche" design so expensive and made to high quality.

Despite all that, I don't have one now. I went for a refractor instead

 

[markse68]

8 minutes ago, John said:

- Very small secondary and no secondary supports so very low diffraction.

- 30% the coma that a normal newtonian has.

- A "niche" design so expensive and made to high quality.

Despite all that, I don't have one now. I went for a refractor instead

 

How does it get away with the smaller secondary John? Is it because of the lens?

[John]

6 minutes ago, markse68 said:

How does it get away with the smaller secondary John? Is it because of the lens?

http://www.ianmorison.com/the-maksutov-newtonian-telescope-discussion-survey-and-an-image-of-the-10-day-old-moon/

Like everything in astronomy, compromises.

 

[markse68]

16 minutes ago, John said:

http://www.ianmorison.com/the-maksutov-newtonian-telescope-discussion-survey-and-an-image-of-the-10-day-old-moon/

Like everything in astronomy, compromises.

 

Thanks John- that’s a good article that explains a lot.  An f6 with only 14% central obstruction sounds like it’s pretty dedicated to planetary indeed! I thought I was pushing the boundaries a bit with 18% with my f8

[Mike JW]

Hi folks, I have followed your discussions with interest. I owned an OMC 200 (1/8 wave, secondhand) for a few years - simply put they are seriously good on planets, moon and doubles. I can still remember those rare transparent, very steady nights and I would cruise the lunar surface at x400 with ease - awesome. The contrast is apo like without a doubt. On double stars again is was so good and made splitting doubles a pleasure.  The big disadvantage was the narrow fov so if I was hunting out doubles then the GOTO mount needed to be aligned very well. The narrow field of view was also frustrating with lunar observing - I was unable to see all the moon. So I bought a second hand Meade 127 Apo (triplet). It was a pleasure to see all the moon but at 5" aperture it was no match to the OMC for brightness of view/detail for lunar or planets. Aperture does win out. Before the OMC I had a chance to use a Mewlon 180 - beautiful scope but OMC still beat it because of the extra aperture.

Earlier on in my telescope journey I owned a Intes Micro MN56 (secondhand) - lovely contrasty views (apo like) but 5" aperture gave dimmer views. So when I had the chance to buy a secondhand MN 76 (1/8wave) I went for it. This scope was impressive. I remember putting it alongside a quality 15" Dob on a rare exceptional night and it held its own against the Dob but the Dob did win out because of the brightness of the view. However on most nights 15" of aperture would be too much.

The disadvantage of the Mak Newt was as with all Newtonians is the constant need to adjust the scopes position to have the eyepiece in a comfortable position. It was built like a tank and thus was quite heavy. I am told the Intes Micro MN88 is a seriously good planetary scope not only because of the extra aperture but the small secondary. However it is heavy.

I have found a happy compromise scope (secondhand) - it is the STF Mirage 7" Mak Cas. Just enough aperture (in my view) but compact, light and with its quality optics delivers very good views (not as good as the OMC) and a reasonable fov as it is the f10 version. In combination with my iOptron MIni Tower Pro (v2) is is a very good grab and go set up.

As I final thought. MakCas scopes give so much better views than SCTs. My C11 gives such soft views that it a relief to use the small STF where black is black and white is white and to see sharp stars.

So my ideal planetary/lunar/doubles scope would be a quality (1/8 or 1/10 wave), 8"aperture and f10 - does such a scope exist? Also I prefer to sit comfortably and that was not always possible with the Mak Newts and refractors need to be mounted somewhat higher.

Finally re the advert for the MN86 (APM version) - overpriced? Also I have heard that this APM version of the Intes Micro has a different mirror cell arrangement which may not be to everyone's liking. It would be interesting to put it alongside the OMC 200. I doubt there would be much in it but the OMC would be so much easier to handle

All the best

Mike

Edited June 7, 2020 by Mike JW
factual mistake

[dweller25]

8 minutes ago, Mike JW said:

So my ideal planetary/lunar/doubles scope would be a quality (1/8 or 1/10 wave), 8"aperture and f10 - does such a scope exist?

@Mike JW

Mewlon 210 would be close ?

Edited June 7, 2020 by dweller25

[Mike JW]

Yes it would but a good friend who is a Mewlon owner still reckons the OMC beats the 210. The Dall Kirkham design suffers from coma, unless corrected, which if I remember correctly the 10 and 12" Mewlons are corrected but not the 8 or 7".

Mike

[dweller25]

I had a Mewlon 210 and a carbon fibre OMC200 Deluxe with 1/10th wave optics, did not keep either as they were rather slow to cool down.

Now have an Intes Micro 715 Mak with built in cooling fan that pulls air from the front of the OTA across the primary getting rid of the boundary layer - works very well and gives super sharp views.

[andrew s]

I had the first carbon tube OMC 200 new from OO to use in France but sold it on as it was not getting much use as we did not spend as much time there as originally planned.

However, I was clearing out my files today and came across the receipt just a tad over £2k !

Regards Andrew 

[Solar B]

Ah that's a point I hadn't pondered the above ad does not state if it's the deluxe 

model or not so it may not be ... as I'm aware the original OTAs were plain white 

and can recall seeing one of those up for sale at £800 but the carbon OTAs look

just magnificent don't they.

Brian

 

[Stu]

I had a white aluminium version some years back. It was a fickle beast, on its day it could deliver outstanding planetary views, but was a devil to cool and dewed up quite easily; running the fans to cool it often caused it to fog up internally too!

I’ve had three OMC140s as well! Glutton for punishment really. The last one was probably the best. I think if the planets were higher I might be tempted back to one in future, who knows!

[Mike JW]

My OMC was an early one and yes cool down could be a problem but I would always start the cool down process well in advance (2hrs ahead). I was able to keep the scope in an outside store close to ambient temperature in the first place. Noway would I run a fan that pulled air through the scope, despite the filter system - dust and grot are best kept out of the tube. Also as commented above, there is the danger of dewing up inside.  I checked the scope collimation on purchase and never needed to adjust it. 

Intes Micro 715 Mak - agree - lovely scopes.

Mike

[Peter Drew]

I'm currently going through similar considerations to find out which telescope in my possession will give the best results on Mars later this year.

 

• The line-up so far is 5" F15 triplet APO,  OMC 140, 7" F15Meade Mak-Cass, 8" F8 (1/20th wave) OOUK Newtonian, 8.5" F12.5 achromat, 12" F20 Dall-Kirkham with David Hinds "A" quality optics.  Despite these options, to date the best views of Mars I've had have been with my 16" Meade SCT and the 8" Celestron that I keep in Tenerife.         🙂    

Edited June 7, 2020 by Peter Drew

[Rusted]

I have a 10" f/8 1/30th wave mirror from a famous US mirror maker.
Even when it was badly colimated it could show Plato craterlets without even trying.
I tried to be clever in an OTA duplex beam design, but it never worked successfully.
Torsion resistance was very poor on an equatorial. Just reaching the eyepiece needed a ladder.

The mirror has never found its way into a "proper" tube to prove its true abilities.
I made a cardboard tube and it weighed a ton and sagged. Dowels in rings were even worse!
I used big saucepans for the cells. The "prop" is just a measuring stick.
The 'tiny' mounting underneath is a Fullerscopes MkIV.