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MN61 first light

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#1 bierbelly

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Posted 19 October 2005 - 09:37 AM

Well, my brother finally got his mount (ASGT) for his recently acquired MN61. Aside from the mount not even powering up, we had a good observing session. I will say that even in bad seeing, the MN61 provides quite amazing views. Pinpoint stars. An awesome scope. These small MakNewts have to be the best value in telescopes available today.

Oh yeah, the factory focuser is terrible.

#2 jrcrilly

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Posted 19 October 2005 - 10:02 AM

Well, my brother finally got his mount (ASGT) for his recently acquired MN61. Aside from the mount not even powering up, we had a good observing session. I will say that even in bad seeing, the MN61 provides quite amazing views. Pinpoint stars. An awesome scope. These small MakNewts have to be the best value in telescopes available today.

Oh yeah, the factory focuser is terrible.


I had first light with my recently-acquired MN61 the other night also. It looks like a typical Chinese Newt until you pick it up (over 20 pounds!). It did give nice tight star images and is certainly less expensive and lighter than a 6" APO. I was surprised at the focuser myself - it's way too fast. Not enough drag for me, though I imagine I can adjust it tighter. I guess an upgrade is in order at some point.

I was unable to focus the 300D with the shortest T adaptor I had handy. It's 1.25" and I didn't have a short 2"-1.25" focuser adaptor I could find in the dark. I have hopes that something here will do the job; either a short 2" T adaptor or a shorter 1.25" focuser adaptor. A Barlow cell in the T adaptor did permit focus but of course the FOV was reduced.

#3 Doggie

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Posted 19 October 2005 - 12:34 PM

I just received a MN56. It is about 2 years old. All the remarks about "refractor-like" views are certainly correct. It has the "improved" crayford focuser which is indeed nasty. After only one night I decided to spring for the Moonlight CR2. I suspect that this scope will be a keeper.

Anyone have eyepiece favorites for this scope? I will mainly be using it for the Moon, planets, and very bright objects due to my light poluted skies.

Best,

Paul

#4 rodrake

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Posted 19 October 2005 - 01:00 PM

I've gotten good views with UO Orthos and Konigs. I use a 16mm Konig as my primary low power eyepiece and also have a 12mm Konig. My favorite is the 3-6 Nagler Zoom though. It covers the high power range from 127x to 254x. Views are comparable to the orthos + Klee barlow with a larger FOV. Highly recommended.

#5 Bob A (SD)

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Posted 19 October 2005 - 06:08 PM

Paul,

Like Rich, I've found Abbe Orthos and Konigs are great in my MN56. That said I've parked my 5, 7, and 9mm UO Abbe Orthos in favor of a Speers-Waler 5-8mm ep which also works great with a PowerMate 2.5X for silly high powers when conditions permit. I prefer the wide FOVs and decent eye relief here that the Abbes don't give. In the Konigs those from Gary Russell are bargains. I particularly favor my 2" 13mm. The other ep that sees a lot of use is an old Speers-Waler 24.7mm. Mine is one of the better of this breed.

Posted Image

Trust this is of some help :)

#6 Doggie

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Posted 19 October 2005 - 06:59 PM

Thanks to Bob and Rich for the replies. I have a TV 3-6 that I am hoping will fill the bill. If I was starting over I probably would have gone for the SW zoom.

Bob. Your post about the Moonlight got me motivated to remove my crayford. I am hoping to get the focuser from the Big Brown Truck tomorrow. Any trick to removing the old focuser?

Bierbelly. Sorry for the thread hijacking :bow:

Best,

Paul

#7 Bob A (SD)

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Posted 19 October 2005 - 07:55 PM

Bob. Your post about the Moonlight got me motivated to remove my crayford. I am hoping to get the focuser from the Big Brown Truck tomorrow. Any trick to removing the old focuser?

Paul


Paul,

Not sure which type you have (e.g. screw on, small or big hole drop in) but I've handled both the drop in and of course mine was a screw in. So that we don't change the focus here, please PM me and let me know what style adapter you're getting with your Moonlite and I'll give you a description of what to expect in making the swap :)

#8 bierbelly

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Posted 19 October 2005 - 07:57 PM

Not to worry, I've been reading with interest and have directed my brother to the Moonlight website.

#9 Bob A (SD)

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Posted 19 October 2005 - 08:13 PM

Okay :) Paul and Bierbelly:

Removing the screw in helical in the older MNs is easy as it just screws off leaving the factory mounting plate attached to the OTA. The adapter screws in and the Moonlite is attached to the adapter by 4 hex bolts. There is enough tension so that the adapter can be positioned where you want the focuser's controls to be even though the adapter is not fully screwed down "tight."

The newer Intes-Micro Mak-Newts use two small set screws to hold the factory crayford to the stock OTA focuser plate. (There's some good photos now on the Moonlite web site). Simply back those twin set screws out until the drop in factory focuser can be lifted out. Insert the adapter plate and retighten those same twin set screws. Then the Moonlite focuser bolts to the adapter plate with the 4 hex bolts. Loosening the factory set screws allows you to position the combined adapter plate-Moonlite focuser where you want the controls at. Retighten the factory set screws.

Both may require you to align the focuser so that the secondary is squarely centered under the drawtube (a sight tube is helpful here). Do so by loosening either the 2 or 4 screws holding the factory mounting plate to the OTA and shift things accordingly, then retighten.

That's it :)

#10 Bob A (SD)

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Posted 19 October 2005 - 08:31 PM

John,

The Intes-Micro Mak-Newts will work with a CCD but not a 35mm camera without shifting the optics. What you'll probably need is a very low profile focuser and a short draw tube like a Moonlite CR series with the 1.5" primary drawtube along with the short couplers you mentioned.

Try taking out you ep and place a piece of glass or saranwrap over it and with a magnifying glass (old eyes here) adjust the focuser until you achieve focus on something like the moon. That height plus the distance in your DSLR camera to the CCD chip is what you'll need to maintain to do astrophotography. Most digicams and DSLRs have a significantly shorter distance from lens to sensor than a 35mm camera has to the film plane. That said there are some that may not work... hence the sanity check routine. This "trick" was suggested to me by Gary Beal from New Zealand when we exchanged e-mails about my needs to pursue video-astrophotography. BTW that's why I have the EQ-6 SynScan ordered :) My CR2 is equipped with their shortest primary drawtube (1.5") and an extender for the 1.25" ep adapter. I'm looking to acquire a MallinCam Pro Ultra.

#11 Doggie

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Posted 19 October 2005 - 08:46 PM

Okay :) Paul and Bierbelly:

The newer Intes-Micro Mak-Newts use two small set screws to hold the factory crayford to the stock OTA focuser plate. (There's some good photos now on the Moonlite web site). Simply back those twin set screws out until the drop in factory focuser can be lifted out. Insert the adapter plate and retighten those same twin set screws. Then the Moonlite focuser bolts to the adapter plate with the 4 hex bolts. Loosening the factory set screws allows you to position the combined adapter plate-Moonlite focuser where you want the controls at. Retighten the factory set screws.

Both may require you to align the focuser so that the secondary is squarely centered under the drawtube. Do so by loosening either the 2 or 4 screws holding the factory mounting plate to the OTA and shift things accordingly, then retighten.

That's it :)


Great! Thanks alot Bob. Mine is the second one you described with the two very small screws. Can the new focuser be centered pretty well by eye if it is off?

Based upon my first nights viewing of the moon the collimation looks very good. That was a relief. It was a terrible night for viewing since the moon was full, but I was chomping at the bit. Full moon or rain, I guess you get a choice for first light ;)

Best,

Paul

#12 Bob A (SD)

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Posted 19 October 2005 - 08:50 PM

Paul,

I tried a cardboard tube after not trusting a plain old fashioned bare eyeball approach. Ulimately I bought a cheshire / sight tube (from dbaAstronomy) to absolutely ensure I was dialed in here as if you're off a hair collimation of the rest of the optical train will be slightly skewed as well. These scopes have such great optics and ability to handle high magnifications that it would be a shame not to ensure precise alignment (which holds quite well once set too).

The great thing about these new Moonlite CR series adapters is that there really shouldn't be any need to shift the position of the screws holding your factory mounting plate if they were properly set to begin with. I also use a Helix holographic laser to collimate things. I've had it for 5 years and it has been great :)

Again trust this is of help.

Oh BTW there are two sizes of the drop in style factory crayford focusers with one having a larger OTA hole than the other. Ron at Moonlite can help folks determine which they have if they're in doubt.

#13 jrcrilly

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Posted 19 October 2005 - 09:07 PM

Try taking out you ep and place a piece of glass or saranwrap over it and with a magnifying glass (old eyes here) adjust the focuser until you achieve focus on something like the moon. That height plus the distance in your DSLR camera to the CCD chip is what you'll need to maintain to do astrophotography.


Hi, Bob.

We used to use that trick (but with Scotch tape) to find a preliminary focus setup for the old CCD imagers where there was no finder. I have no idea what the distance is from the T ring to the image plane in the DSLR so I'll just remove the 2" to 1.25" adaptor and shove the 1.25" adaptor into the hole and find the focus point in the finder. Then I'll know how much I'll have to fiddle. With that tiny secondary, I figure a 1.25" T adaptor will give me everything there is, so if necessary I can use an inset 2" to 1.25" adaptor to drop the camera quite a bit; that might buy me enough. Because the telescope is already 900mm long I won't want to use the Barlow cell more than occasionally.

The webcam, with its shallower depth, did reach focus just fine but of course I want to use the other Mak for planets.

I just came in from the observatory (had to get something) and I looked at the focuser in the light. I couldn't set enough drag to please me without the drive shaft slipping so unless I just get it focused once and lock it down it may get a focuser transplant sooner than I had planned. I have to say that I like the optical tube; it does deserve a premium focuser.

#14 Bob A (SD)

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Posted 19 October 2005 - 09:34 PM

John,

You're right... I searched and couldn't find the specs on the sensor depth from the lens mount. I know Paul Hyndman has a MN86 that he uses a Canon 10D with (sometimes coupled to TeleVue Powermates with a special adapter) very successfully. He's always been very helpful to me in the past. You might want to drop him a quick e-mail about setting up your MN61 with your 300D. Paul's web site: http://www.astro-nut.com/

Of course what you're describing will get you there too. Now that you've added a Mak-Newt to your battery of scopes, you'll find that the Mak-Newt gang is great about sharing tech tips (Gary and Paul being just two sterling examples).


#15 bierbelly

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Posted 19 October 2005 - 09:56 PM

What length draw tube should my brother get with the CR1/CR2 for visual observing with his MN61? Wish I could retrofit my Vega with one.

#16 jrcrilly

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Posted 19 October 2005 - 10:03 PM

I know Paul Hyndman has a MN86 that he uses a Canon 10D with (sometimes coupled to TeleVue Powermates with a special adapter) very successfully. He's always been very helpful to me in the past. You might want to drop him a quick e-mail about setting up your MN61 with your 300D. Paul's web site: http://www.astro-nut.com/


Hmmm. I see that he uses a Denkmeier 2" OCS with pretty good results except at the very edges. I have one of those lying around here I don't use - that might work on my Intes and get me on the air until I find a more rigorous solution - thanks!

#17 Bob A (SD)

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Posted 19 October 2005 - 10:05 PM

Bierbelly,

The standard drawtube length is 2" which should serve him well. Options include a compression ring vice thumbscrew to secure the eyepieces. The extended adapter for the 1.25" eps may or may not be something he needs. He should measure the length from the OTA to the top of the stock focuser for each of his eps in focus to ensure he gets the right drawtube and support for 1.25" eps.

There's also a new neat CR2 tri-knob option which gives you both rates on one side with coarse on the other.

#18 Bob A (SD)

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Posted 19 October 2005 - 10:11 PM

Hmmm. I see that he uses a Denkmeier 2" OCS with pretty good results except at the very edges. I have one of those lying around here I don't use - that might work on my Intes and get me on the air until I find a more rigorous solution - thanks!


Good deal! :)

I came here to get help and have. It's nice now to be able to help others even if it is simply to point to someone else who may engender some ideas.

#19 jrcrilly

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Posted 19 October 2005 - 10:17 PM

I came here to get help and have. It's nice now to be able to help others even if it is simply to point to someone else who may engender some ideas.


You'd be surprised at how many folks read this stuff. Every tip you share goes farther than you may think. That what makes the community so worthwhile.

#20 Doggie

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Posted 20 October 2005 - 09:18 PM

Paul,

Oh BTW there are two sizes of the drop in style factory crayford focusers with one having a larger OTA hole than the other. Ron at Moonlite can help folks determine which they have if they're in doubt.


This is a great thread. Thanks for the ongoing help Bob.

I got my CR2 this afternoon and of course could not restrain my enthusiasm. The first thing I found was that the crayford was in really tight to the OTA plate. I ended up marking its position and taking the whole thing off. It was not easy to separate the two pieces but I eventually did. The two set screws were certainly not needed. The next part made the first part seem easy. You say that there are two sizes of "L" adaptor plates. I wish that Ron at Moonlight had told me that! I just assumed that I had a poorly machined Intes base so I worked very hard indeed to get the new focuser adaptor into the hole. I eventually got it in but a little askew. After 15 more minutes of gentle "coaxing" I had it where I wanted it. If I ever decide that I want the focuser at a different angle I am just going to sell the scope. It is in there for good! The old focuser is truly nasty. It looks like it was made in a retooled tractor factory!

Now the good news. That focuser is a work of art. I got the standard red one and it is just plain beautiful. Wonderful craftsmanship and precision. The dual speed is a dream. Naturally it is cloudy tonight but I will report more later.

I think that I will order a Cheshire first and then work up my courage to collimate. Unfortunately my scope did not come with the user’s manual, although it does have the ITE report. Maybe I can get a copy from ITE.

Thanks to all for the help. :bow:

Paul

#21 Bob A (SD)

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Posted 21 October 2005 - 06:54 PM

Paul,

Actually the two sizes of "L" adapter plates are tied to whether your factory mounting plate is a 2 screw or 4 screw version. The opening into the OTA differs in size with these two flavors of factory mounting plate.

As for collimation, check this article written by the same Paul Hyndman I cited earlier for John:
http://www.cloudynig...php?item_id=396
It should give you a good primer on what needs to be done with your MN56 :)!

Best!

#22 bierbelly

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Posted 21 October 2005 - 07:20 PM

Oooooh! There's an Orion tagged version of the MN61 for sale on AM. I am having bad thoughts!

#23 jrcrilly

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Posted 21 October 2005 - 07:44 PM

Oooooh! There's an Orion tagged version of the MN61 for sale on AM. I am having bad thoughts!


Looks like a very attractive price, too.

#24 Nebhunter

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Posted 28 October 2005 - 01:59 PM

Great information here regarding focusers. Maybe you should start a second thread after you get more observing information regarding the scope - which is what I am really interested in. Leave the original thread to deal with the focuser.

#25 Doggie

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Posted 12 November 2005 - 10:12 PM

Hi,

I thought that I would do a follow up post on my experience with my new (used) MN56 and my new (new) Moonlight CR2 focuser.

As mentioned earlier the focuser is a dream but the mounting plate was an extremely tight fit into the stock Intes base. Basically I had to use force to place it into position. After a few days I decided to contact Ron at Moonlight about the tightness. He could not have been more helpful and positive. He had me send the two nearly permanently mated pieces back to him. He then re-machined my adaptor and returned it. It now works very well and allows me to rotate the focuser as intended. He said that he had originally used just one sample to tool up the adaptor but now has made adjustments to his existing stock based upon having another stock plate in hand.

Ron was really great to work with and I recommend the Moonlight to any MN owners out there. I am thinking about using the old stock focuser as a walnut cracker, a duty it is better suited for :lol:

....Now to tackle collimation!

Best,

Paul


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