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Stargazing with Maks/BV?

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#1 Prescott702

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Posted 22 February 2019 - 09:36 PM

Two things im aware

 

Maks focal lenght is not the best for low powers, rich fields. If you want to use binoviewers focal lenght gets even larger and to made things worst focal reducers seems to reduce aperture too and they are not “universal” plug and play, they need specific setting to keep f/l at minimun

 

But i found this 

 

https://www.cloudyni...k-063x-reducer/

 

First problem “solved” heres the second one, Maks are also not the best in image contrast ... my question is, do you give your two cents to binoviewer mak working at medium powers on stars? Its easy to find a shynta ota on the second hand market , if you already got the rest, it can worth it for stargazing? Compared with similar aperture binos this is way cheaper

 

Pd: i open the thread here instead another subforum because most of you do stargazing


Edited by Prescott702, 22 February 2019 - 09:39 PM.


#2 Prescott702

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Posted 22 February 2019 - 09:41 PM

And forget to say, im not talking as a substitute but as “complement” or optional tool.

 

However the tool need to work and be useful ... thats my doubt


Edited by Prescott702, 22 February 2019 - 09:43 PM.


#3 gezak22

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Posted 22 February 2019 - 10:01 PM

Well, I have an Edge 11 and a binoviewer which complements my 140 mm refractor + binoviewer. While I am no expert in either, I think both are nice and useful setups. The 140 mm is great on most nights, the 11" on nights when seeing is cooperating and I want higher powers.


Edited by gezak22, 22 February 2019 - 10:02 PM.


#4 GlennLeDrew

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Posted 24 February 2019 - 12:13 PM

This would be better addressed in the binoviewer forum.



#5 Erik Bakker

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Posted 24 February 2019 - 12:38 PM

Moved to the binoviewer forum for a better fit.



#6 Eddgie

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Posted 24 February 2019 - 01:18 PM

You can slap a binoviewer on just about anything, but with just about anything, there will be compromises.

 

The compromise you make with an MCT with moving mirror focus is that if you don't use some kind of Barlow or Glass Path Corrector, in most cases, you will experience aperture reduction and if you do use a Barlow or Glass Path Corrector to allow full aperture, you will reduce the corresponding loss low power and true field.  Without the Barlow or Glass Path, the focal length of the telescope is also greatly increased, which lowers the field size and raises the magnification. 

 

You can do it, but if the goal is to get a good all around experience with a Binoviewer, I recommend a minimum of an 8" Newtonian and a small MCT would not by a scope I would recommend.  Yes, you can do it, but the question is are you willing to accept the compromises.     

 

Let's do a comparison.   If you use the 6" f/12.5 MCT at native focal length and a 6" f/5 reflector with a 2x Barlow.     With the 6" MCT, the focal length of the scope when used with the BV without a Barlow or GPC will be over 2000mm even with great effort to keep the light path as short as possible (short visual back, Baader 1.25" Prism diagonal, BV connected directly diagonal). 

 

With the 6" f/5 reflector though, if you use a Barlow to reach focus with the binoviewer and you are working at 2.3x then the focal length will be  1725mm, so you wind up with a less expensive scope purchase that gives a wider true field and really does not weigh much more so will be comfortable on a mount of about the same size.

 

Again, you can binoview anything but one has to look at the compromises, and binoviewing an MCT without a Barlow is probably going to reduce some of the aperture and increase the focal length.  The aperture reduction also means that the secondary obstruction size grows even larger as a percentage of aperture.

 

My advice then is to use a Binoviewer in a small scope, a small Newtonian is a better choice.  Not only do you get a wider field when binoviewing, you get a huge increase in true field when you are not binoviewing.    A 6" f/5 Newtonian is just not that much bigger and heavier than a 6" MCT to make a difference in handling or mounting.

 

I would only recommend binoviewing smaller refractors if the scope can work at native focal length with the BV, or it it will only be used for planet.  In these small scopes, the dimming is a much bigger penalty than in a bigger scope like an 8" Newtonian. Yes, there is the same amount of dimming in the bigger scope, but the brighter starting image (for the same power) means you get a more enjoyable view.

 

If you choose to go with a BV in a small MCT though, I recommend the configuration I mentioned above.


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#7 Eddgie

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Posted 24 February 2019 - 01:26 PM

I should also mention this.  There was only one configuration that I used that would let my C5 work at full aperture.

 

This configuration was a Baader SCT 10mm to T2 adapter:

 

https://www.telescop...scopes Products

 

Attached to a Baader T2 Prism Diagonal Baader Part # T2-01C:

https://agenaastro.c...1c-2456005.html

 

And a pair of Maxbright Binoviewers (which are T2 compatible, so can mount directly to the top of the above prism with no need for an eyepiece holder). You can buy T2 adapters for BVs like the William Optics units that allow direct mount to T2 Prism.

 

This was the only configuration I used with my C5 that worked at full aperture.  No other configuration resulted in full aperture performance.   I don't have any figures for MCTs, but most SCTs will not work at full aperture with BV unless you use a very short light path configuration, and my guess is that most MCTs would have even more trouble.


Edited by Eddgie, 24 February 2019 - 01:27 PM.

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#8 Hesiod

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Posted 24 February 2019 - 03:36 PM

Well, may give a look at this http://shop.tecnosky...=TObinR&Score=1

 

prisms are small, but this may be somewhat offset by the fact that focal amplifiers are not require to reach focus

 

I saw the binoviewer 2 years ago at a fair, build was better than my Maxbright, but can not speak about its performances




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