Another scope? MN190?

[garymck (Gary)]

Hi,

as someone who is only a year or so away from retirement, I'm endeavouring to get all the bits and pieces I need to keep myself busy when it happens. As part of this, I am thinking about buying one more OTA, and looking for some suggestions.

At the moment in my little observatory there is the following:
Losmandy G11 G1, Takahashi TSA120+reducer corrector, side by side ZWO guidescope and QHY5L 11 guider.
An alternate OTA is a superb C11 + Starizona reducer corrector (for planetary and long focal length imaging)

As a portable mount, I have an Orion branded version of the AZEQ6.

My ccd is a QHY9S with 7 pos. filter wheel and full set of Baader filters.

I am going to be going to a dark sky site on a monthly basis, and don't want to have to demount everything each time I go.

I am thinking about buying a Skywatcher MN190 and mounting that permanently in the Obs and using the Tak for portable to the dark sky site. (Fortunate to have a little bonus from work coming my way)

I have no personal experience of Mak Newts, so was wondering if anyone can enlighten me as to how well they work photographically? This appeals because I would have the TSA for wide field, the MN at medium FL and the C11 at long FL.

The other option is a newt plus paracor, but I'd rather avoid having to use correctors if possible. Are there any other suggestions?
advice welcome...

cheers
Gary

[LewisM]

I owned the Orion imaging version (made by SW). I liked it, but in the end, it was NOT for me since I do not have a permanent observing site or observatory. The limiting factor to me was weight - it is 11kg "dry" OTA, and rather awkward to move around as it is decidedly front heavy with that THICK corrector.

Pros:

• Decent aperture
• reasonably well made
• solid

Neutral:

• optical quality - not perfect, not mushy either. Slightly above average perhaps. I would never call the image pinpoint on velvet, but it was acceptable

Cons:

• heavy and cumbersome, and requires a good mount to swing it
• collimation proves to be annoying, but doable. For imaging, you will want Cats eyes or similar, as a laser is not precise enough for good imaging with these
• cool down is long. The fan helps a lot. I found the image was not stabilised enough for imaging after waiting 3 hours. Visual, fine enough, not imaging
• Dew - you will need a dew shield extension and a heater (the combo one will work best). These dew up evilly like an SCT
• Focuser needs replacement - Moonlite makes a flange and focuser that is ideal for it, as does FT I believe.

The claim is it is effectively a 7" refractor - no, it isn't. factor in the central obstruction, and you are down to a 5" refractor, with optics on par with say a SW 120ED. And NOT being ELISTIST, the image will NOT be as good as your TSA 120. Several interferometric testing reports have shown it falls short of the TSA120.

If you were to consider the Intes version (which SW copied almost EXACTLY), which is decidedly more expensive unfortunately, you will get a MN with superior optics to the SW/Orion, and a better stock focuser.

I liked the Orion MN190, but in my experience the cons outweighed the pros. Your circumstances are different, so many of my cons won't be a consideration. The killer in the end for me was the cooldown (though Glend says his cooldown is less - maybe he is talking visual only?) and the optical quality, which in my exact case was inferior to the Vixen FL102S I had.

[glend (Glen)]

Gary the MN190 is a wonderful scope and I highly recommend it. It has no trouble handling my rather heavy cold finger modified DSLR and produces great images with no diffraction spikes typical of newts (because the secondary is mounted directly onto the back of the corrector. With it's small secondary it provides good contrast while still able to illuminate my APS-C camera sensor. Unlike some scopes I have bought over the years it did not require any tuning other than a collimation check and it holds collimation very well. I take mine to my dark site now and then and it travels well if required. They are heavy for their size due to the front corrector (as are all Mak-Newt), but well balanced compared to a typical rear heavy Newt and easily handled by my NEQ6 so your mount should have no problem. Being an F5.3 the sub exposure times can be kept shorter than many of the F8 imaging scopes around. In a side by side comparison with my GSO RC08 the MN190 is much easier to use and keep collimated, and I believe produces a better image.
Visually it is as good as a larger APO refractor and the colours are all true renditions as its a mirror based scope. to me it is the equivalent of a 6+" APO for one third the price, thus a real bargain for what you get.

Here are two sample single sub images taken through my MN190 with my cooled Canon DSLR:

http://www.astrobin.com/full/202362/0/

http://www.astrobin.com/full/185615/0/

Hope that helps.

As to the issues raised by Lewis, I should point out that the Orion version is no longer produced, only the Skywatcher is available. The Orion had a larger secondary than the Skywatcher. The MN190 central obstruction is 26%. The MN190 has a fan portal behind the rear mirror and I use a fan on mine occasionally but find it cools down quickly anyway (and yes this is for imaging). If you have a pull through fan mounted on the back portal and remove the focuser plug you can get good ventilation, however if your going to have it mounted in your obs then this may rarely be required as it will always be at ambient. I have never had to run the fan for more than 30 minutes. I agree that a dew heater and dew shield are a good idea, I run a 8" dew heater wrapped around the corrector ring and that's all it needs as far as heating is concerned (this will also heat the secondary). I have a simple dew shield made out of a camp mat and it works great, I have run most of the night in winter out at Bretti with no fogging problems using that setup.
Forget changing the focuser would be my advice, at least until the suppliers can come up with a better adjustable tube flange adaptor. The focuser on the MN190 (like all Mak-Newts) is mounted close to the front of the tube and needs to be correctly aligned to the corrector mounted secondary, the issue for replacement focusers by Starlight and Moonlight is the lack of an adequate tube adaptor to allow their focuser to be precisely placed over the centre spot on the secondary. There is an adaptor for the Intes Mak-Newts but it does not fit the MN190. In any case I have had no problems with the factory 10:1 focuser on mine and it holds my camera well. Over on the Stargazer forum there is a long thread about MN190 focuser replacement and the issues that people have had trying to do it - suggest you read that.

Plenty of reviews published online, this is one, from Steve at the Astroshop in Brisbane:
http://www.myastroshop.com.au/guides/swdm190.asp

[garymck (Gary)]

Hi Lewis and Glen,

thanks for taking the time to make such comprehensive replies.

I guess most of the issues that you relate Lewis are for portable use - since in my case this will be a fixed scope I won't have to worry about weight or cool down too much, and I already have dew control for my TSA and SCT so no worries there. I'm a bit more concerned about the optics not being excellent though. Your experience is a bit different to what I have read - couldn't find any critical comments. I would be really interested in links (Pm if you like) that I can review.

Glen, your experience is more like what I have read and there may be a few questions I may have before committing to purchase - mind if I PM you when buying time gets a bit closer - perhaps a phone call as well. Don't want to waste your time until I'm ready to go though....

cheers guys, and thanks for the help.

Gary

[glend (Glen)]

Sure Gary, PM if needed or you want to talk on the phone.

[LewisM]

Originally Posted by garymck

Hi Lewis and Glen,

thanks for taking the time to make such comprehensive replies.

I guess most of the issues that you relate Lewis are for portable use - since in my case this will be a fixed scope I won't have to worry about weight or cool down too much, and I already have dew control for my TSA and SCT so no worries there. I'm a bit more concerned about the optics not being excellent though. Your experience is a bit different to what I have read - couldn't find any critical comments. I would be really interested in links (Pm if you like) that I can review.

Glen, your experience is more like what I have read and there may be a few questions I may have before committing to purchase - mind if I PM you when buying time gets a bit closer - perhaps a phone call as well. Don't want to waste your time until I'm ready to go though....

cheers guys, and thanks for the help.

Gary

Gary, considering I was the second owner, and the same scope has changed hands a further 3 times since to the best of my knowledge, it may well have been not a great sample.

I will TRY to find images I took with it, if I can remember what they were, but in those days I was not overly systematic with my file naming convention.

[Ken]

Hi Gary I have had a early model Orion 190 since they were released with the single speed focuser, I have replaced this with a jmi unit I had lying around. I think the optics are very good for average seeing conditions that I have @ 1.0 m focal length covering most deep sky objects. I use a qhy9 with 7 position wheel, thin oag, loadstar guider on a eg6 mount in a observatory. After using Newtonians with correctors I prefer the Mak Newt.
Clear skies Ken.

[garymck (Gary)]

Thanks Ken,
I like the idea of no correctors as well - my camera is the same as yours as well. Will mount it on a G11G1 and use my Tak as a portable.... Unfortunatly Andrews won't have any until Xmas

cheers
Gary

[Capricorn1(Tom)]

Gary...appears Steve from "My Astro Shop" has one in stock listed on his web site. Tom

[glend (Glen)]

Originally Posted by Capricorn1(Tom)

Gary...appears Steve from "My Astro Shop" has one in stock listed on his web site. Tom

The AstroShop webpages says it is a 'Special Order Item', and their listed price is (14%) higher than Andrews. As these are not 'volume sellers' it is no surprise that it would be a special order item for the Astroshop who (I believe) does not actually hold stock direclty but arranges 'drop shipments' (nothing wrong with that business model BTW).

Be aware that new stock coming in is likely to be subject to the recent exchange rate changes so I would not be surprised if all new stock is more costly to us in AUD.

You could consider the ebay seller "Adventure Products Universal" who appears to be a Tasco ebay retailer used to dispose of factory seconds, retailer display stock returned, and write-offs on ebay. They share the same address with Tasco in Brookvale, NSW. If you really want an MN190 and are willing to take a risk on the history of the stock item your buying, then have a look here (cheapest price you will find):

http://www.ebay.com.au/itm/Mak-Newto...-/251930734386

I make no recommendation concerning Tasco's (Universal Adventure Products) as I have had to return a scope to them before (not a MN190).
Note I bought my MN190 from Andrews.

[glend (Glen)]

Lewis your last post here just disappeared - I assume you (or someone with moderator powers) took exception to something that you published

Regardless, I am very glad to hear what you briefly said Lewis, and I stand corrected thank you, and have removed the paragraph from my previous post that caused you to write what you did. It actually raises my opinion of Andrews further and I don't have a problem with them cutting out the middle-man, and this is consistent with their GSO import arrangement as well.

[Clancy Lane (Phil)]

Courtesy of Tom at Tasco, my newish MN190 arrived this morning....yes it is the one advertised on Ebay with the dual speed controls and is in almost new condition, with collimation nearly spot on.

My friend Dennis checked out the scope on Wed morning, giving it a good going over and Tom posted it the same day.

Tom knocked a fair bit off the price due to some scuff marks on the tube that I think will easily polish out.

This is now my third 190 MN and I am looking forward to more great images being taken at Leyburn in the coming months.

cheers,

Phil

[LewisM]

Originally Posted by glend

Lewis your last post here just disappeared - I assume you (or someone with moderator powers) took exception to something that you published

Regardless, I am very glad to hear what you briefly said Lewis, and I stand corrected thank you, and have removed the paragraph from my previous post that caused you to write what you did. It actually raises my opinion of Andrews further and I don't have a problem with them cutting out the middle-man, and this is consistent with their GSO import arrangement as well.

Nah, nuttin' sinister - in fact, I found out today that Andrews is now a Tasco dealer - perhaps that is why their prices are higher than they have previously been on SW products?

[LewisM]

Originally Posted by Clancy Lane

Courtesy of Tom at Tasco, my newish MN190 arrived this morning....yes it is the one advertised on Ebay with the dual speed controls and is in almost new condition, with collimation nearly spot on.

My friend Dennis checked out the scope on Wed morning, giving it a good going over and Tom posted it the same day.

Tom knocked a fair bit off the price due to some scuff marks on the tube that I think will easily polish out.

This is now my third 190 MN and I am looking forward to more great images being taken at Leyburn in the coming months.

cheers,

Phil

You are getting too old to carry it - heck, the thing is taller than you Phil

[glend (Glen)]

Originally Posted by Clancy Lane

Courtesy of Tom at Tasco, my newish MN190 arrived this morning....yes it is the one advertised on Ebay with the dual speed controls and is in almost new condition, with collimation nearly spot on.

My friend Dennis checked out the scope on Wed morning, giving it a good going over and Tom posted it the same day.

Tom knocked a fair bit off the price due to some scuff marks on the tube that I think will easily polish out.

This is now my third 190 MN and I am looking forward to more great images being taken at Leyburn in the coming months.

cheers,

Phil

That's great news Phil, they are wonderful scopes. If it's your third you would know that of course.
Looking forward to your images.

[Clancy Lane (Phil)]

Thanks Lewis!

I am moving back out to dark skies soon, having sold the house at Morayfield, so the scope can be permanently mounted on the pier at Leyburn.

The TSA 120 will be used in the obs at my new acreage at, probably, Blackbutt.

By the way, I need to organise with you to adjust that Teflon pad on the TSA for me if we can arrange a time that I can bring up the gear to your place!

Ta!

Phil

[LewisM]

Phil, Will let you know, but next week should be fine. I may need to drive down to collect something out of Customs if you are still at Morayfield a while longer? otherwise I go out to Kingaroy regularly so could meet in Blackbutt