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Advice on what binoview to get for my dobson telescope

Dob Observing Reflector Equipment
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#1 BabyShoes

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Posted 27 February 2021 - 03:34 AM

Hi everyone, im currently struggling with a question I can't seem to find an answer to and I hope you guys can help me with this.

Right now I'm looking to get myself a binoviewer, but I don't know which one to get. If I get one, I'll want to use it with my 12" f4.9 dobson telescope both for planetary and dso observations.

I'm currently looking at:
- TS-Optics standard BV - $200
- TS-Optics big BV - $400
- Baader Maxbright 2 - $500
- TS-Optics 0 path length BV - $400

My problem is that I can't see the use of a big and expensive bino for my setup with a large diameter clear path. If I won't be able to avoid using a GPC with my dobson, which will increase the focal length of my telescope to a point that my 24 Panos will effectively operate at 12-14mm, then why bother with a big binoviewer?
A less expensive standard bino from TS with a clear path of 21mm is plenty for the Panos in this configuration.

Using a conventional binoviewer with a dobson telescope for dso observations is in this regard also a bit of stretch because I won't have a high enough focal length left in my eyepieces for a wider FOV.

The TS-Optics 0 path length binoviewer is an interesting choice because it will allow me to use my eyepieces without an extra magnification from a GPC. The clear path on that binoviewer, however is only 22mm so I can't use the 24 Panos without experiencing vignetting, which is also bad.

I feel that there isn't a good choice for a binoviewer, if it's intended for a dobson telescope and that my best bet is to go with the standard binoviewer from TS-Optics.

Am I missing something? Any feedback is welcomed.

Thanks, Bogdan

Edited by BabyShoes, 27 February 2021 - 03:37 AM.


#2 Spartinix

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Posted 27 February 2021 - 03:45 AM

You can consider a Siebert 1.3x amplifier :).



#3 David I

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Posted 27 February 2021 - 11:47 AM

I can comment on the TS-Optics 0 path length BV , the field stop is 17.4

With the Delos 17.3mm  (72deg AFOV) the  field stop is 21.2, so there is :

"degraded imagery at the left/right edges, but perfectly fine over the rest"

as described in ORION LINEAR BINOVIOEWER - mini-review  

https://www.cloudyni...eview/?hl= mini

 

 

For planets you can get away with a 10mm Delos also described in this "mini-review".

Our member "Lentini" described that on his 12inch dob he had good views with this linear bino and 10mm eyepieces 

which gave him 160X. 

https://www.cloudyni.../#entry10914981

 

David



#4 BabyShoes

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Posted 28 February 2021 - 02:31 AM

Thank you for your feedback and for the links to the mini review of the TS-Optics 0 path length BV. It was an interesting read.

David, as I understand this bv is overall a decent choice for a reflector and that's great to see.
Do you happen to know how it performs in situation with high magnifications e.g. 250x - 500x? I couldn't find any information about this in the review.
Would a traditional BV be better for high power observations?

Thanks, Bogdan

#5 Jeff B

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Posted 28 February 2021 - 12:32 PM

This:

 

https://astromart.co...viewers-package

 

Then sell the Denk 21 eyepieces for $350.

 

But you had better act quickly.

 

Also, get a weight to put down towards the mirror to counter balance the weight of the viewer.

 

Jeff


Edited by Jeff B, 28 February 2021 - 12:36 PM.


#6 David I

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Posted 28 February 2021 - 12:52 PM

Bogdan, 

        Tom's mini-review says the 5mm eyepiece is hard to view with the linear binos . The 10mm Delos works well but  I'm hoping someone will now test the linear bino with 9mm to 6mm eyepieces . 

 

       In the previous review by Lentini the 10mm eyepiece gives good views at 160X with the 12inch Dob, so then by adding a 2.5X Powermate would give you 400X . This is supposed to work but I have not seen any reports yet.

 

David



#7 Lentini

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Posted 28 February 2021 - 03:21 PM

(Actually the 10mm are 182.2X with the SIPS installed.) I should have some testing with a pair of 6.7mm ES 82 degrees at 270.3X soon. I did view one eyed with a Delos 6mm and TMB 8mm Planetary II and they were very nice, but I couldn’t check a merged view, obviously. The only higher power I might try would be with 4.5mm Morpheus... But I only have one now. That would be 402.4X.  I’ll report any updates I can... darn this weather.


Edited by Lentini, 28 February 2021 - 03:22 PM.


#8 BabyShoes

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Posted 01 March 2021 - 08:26 AM

Ok, I think I get it now. The shorter the focal length of the EP, the harder it is on the BV. However, this can be mitigated by using medium focal length EPs in combination with a barlow lens.

This is actually great because I already have a TV delite 9mm and a TV 2x barlow. I could just get another 9mm delite and reach a 333x magnification with the linear BV.

 

@Lentini: an update on high power views with the linear BV when you get the chance would be much appreciated.

 

Thank you all, Bogdan



#9 BabyShoes

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Posted 01 March 2021 - 08:33 AM

This:

 

https://astromart.co...viewers-package

 

Then sell the Denk 21 eyepieces for $350.

 

But you had better act quickly.

 

Also, get a weight to put down towards the mirror to counter balance the weight of the viewer.

 

Jeff

Thanks Jeff for the link, but I live in Germany and would it be too much of a hassle to get on that deal. I'll have to find something on the European market.



#10 Jeff B

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Posted 01 March 2021 - 10:29 AM

Well shoot! 

 

Maybe you can find something like it on your side of the pond.

 

Good luck!



#11 Doug Culbertson

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Posted 01 March 2021 - 03:03 PM

Thanks Jeff for the link, but I live in Germany and would it be too much of a hassle to get on that deal. I'll have to find something on the European market.

That one is sold anyway; I was #2 in line for it. The other Denk II on Astromart is, IMO, priced about $400 too high. I've seen Binotron 27s go for less than $925. 



#12 Spartinix

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Posted 01 March 2021 - 03:08 PM

There was a Binotron set sold in Sweden, not long ago, for €800.

It was one of the rather rare occasions one is seen in the classifieds in the EU though.



#13 faackanders2

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Posted 01 March 2021 - 11:11 PM

I would get Denks or Earthwin with powerswitches to save on eyepiece swapping pairs.




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