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Old 25-12-2020, 10:34 PM
yoda776 (Matt)
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Join Date: Oct 2014
Location: Adelaide, South Australia
Posts: 277
Quote:
Originally Posted by astro744 View Post
I couldn’t agree more, Allan. A Newtonian with a first class custom mirror makes for an excellent planetary and deep sky telescope. My 10.1” f6.4 Suchting mirror gives me exquisite views when seeing permits. The only time I have seen better on Saturn and Jupiter was through a friends 16” f5 Suchting mirror.

However I think the OP has his heart and mind set on a Mewlon for sentimental reasons and that is reason enough to keep it as the discussion point. I’m not sure how much difference a 210 will be over an 8” SCT. It should be noticeable but whether it is cost effective I’m not sure. If sentiment is involved then I guess it really doesn’t matter.
I appreciate the feedback and view points and as with all things scope related there are differing view points for what is best. What is best can be defined for an individual based on circumstance, experience, certainly partly an experience leading towards sentiment, knowledge amongst other factors. Yes I would appreciate keeping to the topic as I have been spending a bit of time on this to determine some answers specific to Mewlons.

There are a few factors guiding my decision on this and would also mean it replaces several of my scopes (part of the deal with the boss).

I will digress and say I do agree dobs (good ones) punch above their weight and no matter what people say the Orion XX16g scope has been good as a goto dob and the views I have been happy with (people have been surprised when I have taken it to previous member's nights for the astronomy club). The weight of the components is an issue especially the base board with the motor. In referring to Suchting mirrors I am guessing you are referring to SDM scopes? I can imagine the Orion does not compare but have enjoyed it and looked after it as I do all my scopes.

For me I keep going back to the SCT / Mewlon design and just something I go back to and have given some thought to. The mirrors on the Takahashi gear in Japan when I viewed through the 16" scope were amazing (mind you the observatory 1.04m scope was nice ... so would be the price tag!). We saved for a very long time so enjoyed the only trip overseas we have had and likely to in the foreseeable future. I have good optics in my eyepieces and diagonals so do appreciate good optics in the whole system and certainly understand differing view points. I have found with refractors, SCTs and Dobs there are pros and cons for all (and by no means claiming to be a genius on it all, nor am I devoid of experience or knowledge).

Getting back to the Mewlon I am interested in Mewlon 210 users and experiences. What works and what does not and what accessories are best. The M250 just costs too much and I cannot justify that to the boss anyway, even after considering its weight where you also add tube rings and plates as well which comes back to the weight issue. Be great to view through them to make decisions easier but given today's environment and lack of star party's due to the same issue I would need to rely on experience from others. I am aware of cool down issues mind you I have that with the Intes scope and others. The primary mirror focusing and image shift give some concern but can be negated in some way.

I would be looking at:
* Mewlon 210
* A mount (looked at Takahashi EM200 Temma-2M and 2z, although I have an AZEQ6 which is likely to work also)
* An external focuser to help negate image shift and likely a Moonlite given forums answers and research - a Feather Touch again is pricey. The R&P focuser on the Mewlon you still need to add the 2 speed focusing knob as an extra cost and not sure this is actually better than the Moonlite / Feather Touch (current commentary I can find suggests this is the case, although may sacrifice more back focus - any comments helpful on this).
* A focal reducer / flattener which a forum answer on this topic has provided me the answer so will look towards this
* Changing the finder scope with one with illumination (I like a dimly lit finder to get the precise alignment)
* While a Tak TOE eyepiece would be nice I am not sure I would spring the $400+ for one - I have Zeiss, Leica, Nikon NAV HW, Docter 12.5, Meade 3000 series, Circle Vs, University Optics, Brandon, Televue Plossls, Naglers and Ethos etc to draw from (probably too many and may have to reconcile that too). Would wait to see what they yield before deciding on anything there.
* I have a Baader BBHS 2" diagonal I could use so would not get the Takahashi diagonal - I am not convinced it would be better without comparison unless there was a convincing factual argument to suggest otherwise.
* Are there other accessories / parts that are really crucial to the enjoyment of using this scope?

Regarding the mount and looking at the Takahashi Em200 Temma-2M / 2z mount
* I was a bit concerned about the polar scope time limit mentioned in this thread and how to get around it given the goto relies on this and not a 1 or 2 star alignment like other mounts do?
* Concerned about getting a polar alignment in a site that is not a dark sky site (best SQM rating is a little over 20 at 20.12) - it does not rely on one star, two star or three star alignment like other mounts and does appear more manual. Learning curve perhaps?
* Query about guiding with a mount like this (although understand SkyFi and Sky Safari on an iPad would work) - not sure if I need SkyFi on a Temma-2z if it has Wifi - finding it difficult to confirm this?
* Auto guiding when there is not really facility to place a guiding scope with the Mewlon - guessing either tube rings or a bar mount of some sort to mount side by side?

Any answers to these queries would be most helpful.
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