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Anyone familiar with TS Optics’ 8” Photon or UNC Reflectors?

CMOS collimation EAA equipment imaging optics reflector
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#26 GaryShaw

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Posted 20 September 2019 - 10:23 PM

I should add that I think some of these TS Newtonians are specifically optimized for photography, not visual.  I'm pretty sure the ONTC goes either way.  But best to ask. 

 

And I'd probably worry a little bit about buying a fast Newtonian that wasn't carbon.  I think the rigidity is important to maintaining collimation 

That’s a good point on rigidity which has not come up until now. My focus is on EAA, not photography so getting to the fastest scope is not my priority. F4 will be fine. With my F3.6 I capture most of what I go after without more than 4-8 sec stacked images. 

Thanks

Gary



#27 GaryShaw

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Posted 20 September 2019 - 10:39 PM

I’m not sure who’s saying what but, the TS web page states the following:

 

https://www.teleskop...Astrograph.html

 

 

TS-Optics Boren-Simon 8" f/2,8 PowerNewton Astrograph

So, although I started this topic with my interest in the TS Photon and Unc F4 or 5, all this talk about the Boren Simon scope has been interesting. I just skimmed the link you provided and it’s not clear what the native F ratio is for this scope. It appears that at 2.8 it requires and corrector / reducer and going to F 4 requires and coma corrector.....so it sounds like an F4 that ships with the corrector/ reducer so it functions at 2.8 out of the box. If you want to use it for higher resolution imaging, take out the corrector/ reducer and put in the coma corrector.  A good marketing strategy to sell reducer/ correctors and coma corrector accessories....you guys know more than me, am I misunderstanding this?

 

Next question, they mention several times that this mates well with DLSR with aps-c sensors. Not sure what that is but I use ZWO 178 and 294 sensors so I’m guessing the scopes optics and my cameras might not be a heavenly match. If I decide to pursue this scope, I’d certainly ask Simon that question.

 

thanks for the great discussion on all this. 

Gary



#28 John Tucker

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Posted 21 September 2019 - 05:10 AM

Thank you John. I’m headed towards the 8”TS F4 Photon or UNC scopes but it’s reassuring to read what you say about collimation not being the nightmare I’ve heard it can be.

 

I recently was recommended to use a FarPoint Chesire and collimation cap and that the laser collimators didn’t work well unless the drawtube was very well made and no slop existed that could allow the laser to tilt and give bogus results. I’ll check out the Farpoint Chesire and collimation cap and also see what they say about the laser version. I already have an Orion laser collimator so it may be just the Chesire and cap for me. 

 

Thank you you for your help!

Gary

The final step in the collimation process is or at least can be to point at a moderately bright star, defocus, and tweak until the out of focus star is symmetrical.  So the laser doesn't have to be absolutely perfect, though it is easier if it is. 

 

I think a lot of the scary commentary about collimation comes from astrophotographers, and a lot of those on this site are extreme perfectionists.

 

I think giving the Orion collimator a try before speniding a lot of money on a high end collimator is a good iidea.  I was just worried that collimation was going to be diffficult and so bought the expensive stuff.  It really wasn't.


Edited by John Tucker, 21 September 2019 - 05:12 AM.

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#29 John Tucker

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Posted 21 September 2019 - 05:22 AM

So, although I started this topic with my interest in the TS Photon and Unc F4 or 5, all this talk about the Boren Simon scope has been interesting. I just skimmed the link you provided and it’s not clear what the native F ratio is for this scope. It appears that at 2.8 it requires and corrector / reducer and going to F 4 requires and coma corrector.....so it sounds like an F4 that ships with the corrector/ reducer so it functions at 2.8 out of the box. If you want to use it for higher resolution imaging, take out the corrector/ reducer and put in the coma corrector.  A good marketing strategy to sell reducer/ correctors and coma corrector accessories....you guys know more than me, am I misunderstanding this?

 

Next question, they mention several times that this mates well with DLSR with aps-c sensors. Not sure what that is but I use ZWO 178 and 294 sensors so I’m guessing the scopes optics and my cameras might not be a heavenly match. If I decide to pursue this scope, I’d certainly ask Simon that question.

 

thanks for the great discussion on all this. 

Gary

I think we know the native focal length is about f4 because its a 0.75 reducer and you end up at 2.8. 

 

APS-C refers to the size of the sensor, which is 22 x 17 mm.  This is a very common sensor size for DSLRs.  Most telescopes create an imaging circle that is a little too small for such a large sensor and you get vingetting.  So being able to fully illuminate a DSLR sensor is a good thing if you are an APer and use a DSLR.  

 

A smaller sensor won't give you as large of a field of view as a larger one.  It looks like the ZWO 294 sensor is 19 x 13 mm, which is pretty nearly the same as an APS-C.  Seems like a reasonable match to me. 

 

Two pictures I took with the PowerNewt my very first night out are here. 

 

https://www.cloudyni...inch-powernewt/

 

Neither is a great picture, as both are underexposed and my unmodified DSLR took a lot of the color out of the nebula. But you can see that even my first night out the stars in the middle are pretty round.  Those on the edge are oval because the spacing between the sensor and the corrector was way off.  

 

Not showing this to indicate what the telescope is capable of, but just what I was able to get on my first night out without having optimized the spacing. 


Edited by John Tucker, 21 September 2019 - 05:38 AM.

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#30 GaryShaw

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Posted 21 September 2019 - 10:28 AM

John - these seem like great pics to me. Totally excellent!

 

It happens I was live-imaging M31 Thursday night and was pleased to get a far lower quality and less detailed image. Ah, but that’s the difference between EAA and AP...... if only I had the patience and talent for AP. It is great fun sitting under the stars with some music playing and watching the image build and the detail fill in. 

 

Anyway, it speaks well for your scope. 

Thank you

Gary



#31 John Tucker

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Posted 21 September 2019 - 10:51 AM

John - these seem like great pics to me. Totally excellent!

 

It happens I was live-imaging M31 Thursday night and was pleased to get a far lower quality and less detailed image. Ah, but that’s the difference between EAA and AP...... if only I had the patience and talent for AP. It is great fun sitting under the stars with some music playing and watching the image build and the detail fill in. 

 

Anyway, it speaks well for your scope. 

Thank you

Gary

I see the appeal of what you are trying to do.  Even when I'm just observing, I slap the old DSLR on the end of the scope and use the LCD screen as sort of a digital eyepiece.  If I just want to see what something looks like, 30 seconds exposure time is like viewing through an eyepiece of a telescope with a 10x bigger mirror. 

 

Depending on your budget, there are a lot of ways to go here.  It sounds like F4 is a reasonable fit with your goals and tolerance for hassle and that a carbon tube would be a good idea to minimize hassle too.  The issue of course is that with a fast telescope you either give up focal length for speed or you buy a more expensive telescope that has a bigger mirror.  



#32 Mazerski

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Posted 21 September 2019 - 01:13 PM

Gary,

 

Me: visual user with night vision (NV) devices - I just want to look. While AP is tempting, I seem to have no desire to deal with the steep learning curve + processing time.

 

The Omega, Veil and M82 are NOT my photos... but with NV devices, I can see these objects close to these photos (I see the Veil smaller) with various Ha CCD and IR filters.

I see objects in B&W as the NV devices are white phosphor. (some have a bluish hue: Cat's Eye and Saturn nebula) 

 

The Dumbbell is me holding an iPhone (no tracking) -- very difficult to keep hand still.

 

For my purpose, the BS8" is a great scope.

 

 

Attached Thumbnails

  • Omega.JPG
  • Veil.JPG
  • M82.JPG
  • NV_4.JPG
  • Dumbbell.JPG

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