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Eclipse Mak 150 comments and questions

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#1 Guest_**DONOTDELETE**_*

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Posted 28 August 2005 - 10:30 PM

I hope this is posted to the right group. I have finally gotten to a point in life to pursue some of those adventures that get put off until the kids are out of college. Over the years I had accumulated a couple telescopes . . a Celestron 102 widefield and a "ebay special" newtonian. Both did a reasonable job for what they were designed for but . . not to what the expectations were becoming. . . . So recently I traded around and came up with a Eclipse Mak 150 (D=152 F=1900 f12.5) from a shop near my place up north (northern Michigan fly fishing escape). The scope is what I see as the overall balance of my interests - the big look at nature and the better look of the sky - with interest on planets being the current trend. So far I have WOWed a couple times :jump:.
So for the last few clear skys and then daytime corrections I have been sorting out the telescope and my inadequate knowledge of such things. Today I think I got most of the issues worked out but I am looking to get more input.
I have tried for over a week to get to the importers website for any information that they might have and it is still . . .unavailable. The dealer has been great in his help but this was the only scope he has gotten from them (he claims slow delivery issues) so. It has been alot of reading from such places as here.
The biggest issue is that the scope was out of collmination. The mirror adjustments are easily accessible from the outside via rubber popouts. There are three sets of push-pull allen head cap screws and once I played it became real easy to bring the mirror ontrack. Earlier I was getting a washout streak in the view . .after collmination I was reading the numbers off a electrical transformer on a pole 3/4 of a mile from me.
But . . .It appears as if the front element is set against a rubber cushion with screws that could be tightened to fine adjust on it as well. However I have found nothing online to indicate if this is doable or how to determine if it is needed.
Other questions come to mind because of my eyesight . . Old fart . .agstigmatism (wear glasses). Currently I am using the supplied 1.25" back on the telescope and am investigating what benefits changing this to a 2" and using a bigger diagonal and eyepiece . . but I am reading that at the powers(125 - 225) I am using there appears to be no real gain due to the optical angles and that the eyepieces only yield about the same eye relief that I already have (in the 20mm range).
Then lastly I get what seems like light flares around the space viewed stars and such and have read with interest about how some folks have lined their optical lead in tubes with flocked paper and such. So I am pondering doing this and perhaps checking to see if the mirror edge is blackened.
I sense the scope is a great unit . .I see my experience as the fine tuning to maximize its benefits . . . Any and all comments would be greatly appreciated

#2 wilash


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Posted 28 August 2005 - 11:32 PM

The front corrector is usually fixed and cannot be collimated. Do you have any reason you think this is out of alignment?

The only advantage with 2" eyepieces is lower powers. You need to check the scope's specifications if it is able to use 2" accessories. Many Chinese Mak (I assume it is Chinese) are designed for 1.25" accessories only, but some people have gotten away with using 2" EPs.

Flocking the tube should reduce flare. Do you use a dew cap? That will also help. Blackening the edge of a mirror does not really do anything.

#3 Guest_**DONOTDELETE**_*

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Posted 29 August 2005 - 04:59 AM

I have a question for you Rod. How does the FOV of the instrument seem to you? Many who have Mak-Cass instruments report a narrower FOV compared to other designs which takes away from DS viewing.

#4 Guest_**DONOTDELETE**_*

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Posted 29 August 2005 - 09:30 AM

Rod, does the obstruction, the secondary mirror in your Mak, cause any noticeable image degradation compared to an achromatic refractor?

#5 Guest_**DONOTDELETE**_*

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Posted 30 August 2005 - 10:02 PM

Well - as I suspected most of my issues were in learning the . .care and feeding of the telescope. I was out the night before last on this beautiful night and I was Wowed at the difference Between this scope and the one's I previously used.
It appears that the collmination of the mirror was a big factor. I suspect that the scope may have taken a few bounces in shipping or something to misalign it.
one of the other issues is the eyesight and I am learning to adjust for that. I am reasonably accustom to being out in the dark and know how the eye need time to adjust - and to use red light so that I don't lose . .night vision. and I have now got a chair and the height adjustment so I am not trying to stand and gaze wobblingly into the eyepiece.
I had already made a dew shield out of Armaflex (the black 3/4" rubber insulation). And I am looking at finding some flocked adhesive papaer to line the infeed tube with.
I have never been able to get to the importer website sucessfully - but the scope looks like one seen at hioptic - so I am assuming it is of chinese origins.
as it most imports the grease they use on the tripod for lubrication is just horrid. So another I disassembled the mount and cleaned all the crud of grease out and then lubricated the surfaces with a good teflon grease. This made a night and day difference on how well the movement glided.
I had some great views of Mars and of several other interesting objects the other night. See I am too used to mis using what i had before and the poor image that doing so yielded. With the 102 wide field I couldn't get past 120 power and the CA was a major issue for me. we see it at the edges of the object but it effects all the details in the same manner. And the ebay reflector was - seemingly unfocusable - there is a long thread elsewhere in the forum about that.
I have not been around too many really good scopes before so I may be easily impressed. But the views I am now getting are crisp clean images . . and no . .there is not any vision lost because of tube interferrence.
I am not familiar enought to know what star I should see and how they should appear but. .I had a good enough "seeing" so that I brought Mars in at 275 power and I could easily see detail of the planet. I don't have a motor drive on the mount yet so I did the slow twist to track the planet and with the time spent lubricating it followed well enough so there wasn't bounce at that magnification. I did howerever have to readjust the DEC every so often so I may not have the polar setting down right or there may be a glitch. So more discoveries to be made.
You know how those frustrations seem to drift away when things finally go right - the other night was like that - that start of seeing the things I have always wanted - neat stuff . . . :jump:

#6 Patrick


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Posted 31 August 2005 - 04:48 AM

Hi Rod and Welcome to CN!

Great report on your new adventures!

Regarding your astigmatism, eyeglasses, and subsequent desire for 2" eyepieces, I believe Wilash is corrected in the difficulty involved in converting the scope to a 2" format. However, I learned something of interest recently during a visit to my local eye doctor. I learned that astigmatism can be corrected with contact lenses. Prior to that, I thought the only way to correct it was with eyeglasses. I've tried the contact (I only use one) on my left eye, and it really helps. (I'm 53 years old by the way and have never worn contacts before). Now, there's no need to wear glasses at the eyepiece and I have full access to the entire field of view.

If contacts aren't your thing, Televue now sells astigmatism correctors for a wide range of their eyepieces.



#7 tolmac


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Posted 31 August 2005 - 10:19 PM

I tried the Eclipe Mac 6 after I was told it was slightly better than the Orion. Well since I own a 127 and I'm very fond of it, I took the plunge.
The Eclipse arrived in a multi-tape layered box looking like it's been around the block a few times. The interior of the OTA was dirty and the primary had at least a dozen hair line scatches of different lengths. It was also way out of collimation. The finder's eye cap was missing and the diag had none. I was told..."Oh! they are coming in that way".
On collimation, the star test showed the classic turned edge and bad defraction rings inside vs outside. The ronchi test proved the pronounced turned egde and a massive central zone with text book gitar shaped lines thru the center surrounding the obstruction. In contrast, the Orion Mak shows almost perfect ronchi lines with maybe 1/6 to 1/8 wave undercorrection and I easily get 400x out it.
All I can say is that if you can't first physically try out the Eclipse, I would be hard pressed to try it again. Hopefully, I'm the only one who has experienced such a lemon and the other Eclipses are fine but for now I'll stick with Orion.

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