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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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#1 GaryShaw

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Posted 16 September 2019 - 09:17 AM

Hi All

I’m considering purchasing one of the above scopes for EAA and visual observing. Both are available as either F4 or F5. I’ve been impressed by what I see in the specs (see links below) for these scopes and the tech support on my questions has been prompt and helpful so far. I am preparing a final few questions for TS and would include any questions that arise from this post as well. I’m passing on a similar 8” fast newtonian by Vixen (R200SS), which had a great review in ‘The Sky at Night’, due to the surprising lack of information that Vixen provides.

 

My concerns on the scopes relate mainly to the collimation process and how sensitive these scopes are to needing frequent collimation. I’ve read, in other CN topics, of real horror stories trying to collimate fast newtonians which, I understand, can involve ‘offsets’ in the location and orientation of the secondary mirror which seem to be quite difficult to achieve and maintain. The reason for considering the F5 is I’ve heard that the F5 scopes need less frequent collimation - I don’t really know if they’re that much more forgiving or not. I’ve never made adjustments to the primary mirror on my current F3.6 scope since secondary adjustments keep the laser centered in the primary and return the beam to drawtube center.

 

Anyway, I hope some of you will have some experience with the TS products and also some input on F4 versus F5 and the collimation process. Am I making a bigger deal of it than I should perhaps?

 

Thanks very much for any insights you can provide!

Gary

 

TS UNC F4(F5 similar):

https://www.teleskop...arbon-Tube.html

 

TS PHOTON F4(F5 similar):

https://www.teleskop...arbon-Tube.html

 

 

 



#2 ICit2

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Posted 16 September 2019 - 11:27 AM

If it's collimation you're concerned about then consider this:

 

https://www.teleskop...-Objective.html

 

I have the Starwave version and had the Explore Scientific N208CF Newtonian which is very similar to the ones you're looking at on TS.

I sold the ES Newt which I got for night vision and kept the Starwave 152.  The Starwave produces higher contrast and better resolution.  It's fast which means it's great for NV.  And no collimation needed each time you set up, and after you back out the secondary obstruction, it's really just as bright as the 8". 

 

On another topic... I just recently dealt with TS on a purchase of a 102ED and they, and the scope, were fantastic.  I'd buy from them again, no problem.

 

Happy trails.



#3 Mazerski

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Posted 16 September 2019 - 12:29 PM

I have the 8" Boren-Simon from TS (purchased thru Markus at APM). Scope is f/2.8 or f/4 (comes with corrector) and I use it with night vision intensifier devices - best scope ever.

 

I added the Berlebach handle and Losmandy plate.

 

Highly recommended.

 

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

 

 

 

 

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#4 SeattleScott

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Posted 16 September 2019 - 03:50 PM

If you don’t like messing with collimation you should get the Vixen R200. I had to collimate mine once, after it fell of my mount onto the pavement. (I have since switched out the dovetail bar for one that fits better). But generally Vixen states that collimation is set at the factory, and shouldn’t need further attention. Being a push-pull system it took a little time to figure out but it holds collimation extremely well.

I bought mine used from someone who used it with a Mallincam. He started out with a cheaper Chinese model but found it didn’t work well for him, vignetting and so forth. He was much happier with the Vixen. I suspect he eventually upgraded to something better, maybe an Apo or whatever, but he was happy with the Vixen for years.

I’m sure the TS scopes are great too, and probably cheaper. Diffraction spikes are an issue with the Vixen. Some like them, some don’t, doesn’t seem like a big deal for EAA. But the spider vanes on the Vixen are on the large side. Probably part of how it holds collimation so well.

Scott

Edited by SeattleScott, 16 September 2019 - 03:52 PM.


#5 GaryShaw

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Posted 16 September 2019 - 04:05 PM

If it's collimation you're concerned about then consider this:

 

https://www.teleskop...-Objective.html

 

I have the Starwave version and had the Explore Scientific N208CF Newtonian which is very similar to the ones you're looking at on TS.

I sold the ES Newt which I got for night vision and kept the Starwave 152.  The Starwave produces higher contrast and better resolution.  It's fast which means it's great for NV.  And no collimation needed each time you set up, and after you back out the secondary obstruction, it's really just as bright as the 8". 

 

On another topic... I just recently dealt with TS on a purchase of a 102ED and they, and the scope, were fantastic.  I'd buy from them again, no problem.

 

Happy trails.

Hi, and thanks for your note.

I've never used a refractor so its hard for me to imagine a 152mm F5.9 being faster or brighter than a 208mm F4 but I get that you preferred it over the ES208 - which I had been considering.

 

Can you explain what you mean by your sentence '...back out the secondary obstruction'.

Thank you!

Gary



#6 GaryShaw

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Posted 16 September 2019 - 04:17 PM

I have the 8" Boren-Simon from TS (purchased thru Markus at APM). Scope is f/2.8 or f/4 (comes with corrector) and I use it with night vision intensifier devices - best scope ever.

 

I added the Berlebach handle and Losmandy plate.

 

Highly recommended.

 

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

Hi, that looks just like the TS scopes. Does it have the CF tube made in Germany?

 

At F2.8, how is your collimation process working out. TS makes a version of the UNC I'm likely to get that allows a change from F5 to F3.6. It works by moving the focuser location and adding a corrector/reducer. I wasn't planning on going that route since my working assumption is that the lower the F number, the more of a pain the collimation will be. Still hoping to hear folks address that.

 

What mount am I seeing in the pic? Looks pretty interesting, is it motorized with goto?

Gary



#7 GaryShaw

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Posted 16 September 2019 - 04:23 PM

If you don’t like messing with collimation you should get the Vixen R200. I had to collimate mine once, after it fell of my mount onto the pavement. (I have since switched out the dovetail bar for one that fits better). But generally Vixen states that collimation is set at the factory, and shouldn’t need further attention. Being a push-pull system it took a little time to figure out but it holds collimation extremely well.

I bought mine used from someone who used it with a Mallincam. He started out with a cheaper Chinese model but found it didn’t work well for him, vignetting and so forth. He was much happier with the Vixen. I suspect he eventually upgraded to something better, maybe an Apo or whatever, but he was happy with the Vixen for years.

I’m sure the TS scopes are great too, and probably cheaper. Diffraction spikes are an issue with the Vixen. Some like them, some don’t, doesn’t seem like a big deal for EAA. But the spider vanes on the Vixen are on the large side. Probably part of how it holds collimation so well.

Scott

That's great information Scott - thank you.

 

I dropped the Vixen option since they refuse to part with any specs on the mirrors and in general included very little information at all on a fairly pricey scope. I initially preferred it since it was from Japan and the review in 'The Sky at Night' was very positive - including a comment on holding collimation well. Ummm, I guess its worth another thought.

Cheers

Gary



#8 Mazerski

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Posted 16 September 2019 - 05:13 PM

Gary,

 

Yes, the Boren Scope is CF and since TS sells it (and APM) I assume it’s German made. If you need a photo of Made In Germany, just say.

 

The 8” as shown with added 8x50 Finder, filter wheel and night vision device (PVS7 or Mod 3) weighs in at about 21 pounds. The handle makes all the difference in moving / mounting it.

 

No AP - all visual. I use the 2” laser device: 

https://www.astrosystems.biz/laser.htm

 

This is my first reflector and what seems to be the case is that no matter what collimation device is used, there is slight tolerance in focuser so the collimation device can never be in the exact same position. I can’t speak to your comment on high or low f/# and easy or difficult to collimate. 

 

I periodically check with device shown in web link and the alignment holds and visually,  globular clusters, Ha emission Nebula, stars and galaxies look really nice.

 

At f/2.8 (using corrector) the stars are sharp to edge.

At f/4 I see a little distortion at edge but it doesn’t bother me.

 

The mount is the AYO Digi II — it can hold 2 scopes and the photo shows the ADM counterweight system - seems more like center of gravity vs. a typical counterweight.  Mount is Alt-Az and is Push To. I use the Nexus DSC and it is easy to setup and use. The tripod you don’t see is a Berlebach Planet.


Edited by Mazerski, 16 September 2019 - 05:14 PM.

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#9 GaryShaw

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Posted 17 September 2019 - 09:31 AM

Gary,

 

Yes, the Boren Scope is CF and since TS sells it (and APM) I assume it’s German made. If you need a photo of Made In Germany, just say.

 

The 8” as shown with added 8x50 Finder, filter wheel and night vision device (PVS7 or Mod 3) weighs in at about 21 pounds. The handle makes all the difference in moving / mounting it.

 

No AP - all visual. I use the 2” laser device: 

https://www.astrosystems.biz/laser.htm

 

This is my first reflector and what seems to be the case is that no matter what collimation device is used, there is slight tolerance in focuser so the collimation device can never be in the exact same position. I can’t speak to your comment on high or low f/# and easy or difficult to collimate. 

 

I periodically check with device shown in web link and the alignment holds and visually,  globular clusters, Ha emission Nebula, stars and galaxies look really nice.

 

At f/2.8 (using corrector) the stars are sharp to edge.

At f/4 I see a little distortion at edge but it doesn’t bother me.

 

The mount is the AYO Digi II — it can hold 2 scopes and the photo shows the ADM counterweight system - seems more like center of gravity vs. a typical counterweight.  Mount is Alt-Az and is Push To. I use the Nexus DSC and it is easy to setup and use. The tripod you don’t see is a Berlebach Planet.

All very interesting and a big help. I will look further into the Boren scope. A few questions if you have a minute:

 

1.  What is involved in going from F2.8 to F4? They indicate it’s a quick change but they don’t mention what you have to do to make the change. 

 

2.  When you’re at F4, could you use a coma corrector? I take it that you don’t use one now. 

 

3.  TS product info says the change to a ‘ high resolution’ F4 is quick. That seems to imply that at F2.8 the resolution may not be so good. Do you see higher resolution images at F4?

 

4. Can you tell me how long the tube is? TS doesn’t include that info.

 

Thank you very much for the information Mazerski!

Gary


Edited by GaryShaw, 17 September 2019 - 12:01 PM.


#10 B 26354

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Posted 17 September 2019 - 10:02 AM

Regarding question #1:

 

My understanding is that this scope is an f/4 Newtonian. It comes with a "4-Element ED Reducer and corrector", which converts it to a fully field-corrected f/2.8 Newtonian. The reducer/corrector is the black-tubed device shown in the fifth photo on the webpage, and is used by inserting it into the scope's draw-tube, like any other corrector.

 

Regarding question #2:

 

You'd probably want to have TS recommend a specific non-reducing corrector for this scope... if there even is one.

 

Regarding question #3:

 

He answered that question in post #8 -- which you quoted.

 

"At f/2.8 (using corrector) the stars are sharp to edge.
At f/4 I see a little distortion at edge but it doesn’t bother me."

 

Regarding question #4:

 

Again, on the TS webpage...

 

"Total length of only 790 mm, weight of 7.6 kg"

 

waytogo.gif



#11 GaryShaw

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Posted 17 September 2019 - 11:59 AM

Regarding question #1:

 

My understanding is that this scope is an f/4 Newtonian. It comes with a "4-Element ED Reducer and corrector", which converts it to a fully field-corrected f/2.8 Newtonian. The reducer/corrector is the black-tubed device shown in the fifth photo on the webpage, and is used by inserting it into the scope's draw-tube, like any other corrector.

 

Regarding question #2:

 

You'd probably want to have TS recommend a specific non-reducing corrector for this scope... if there even is one.

 

Regarding question #3:

 

He answered that question in post #8 -- which you quoted.

 

"At f/2.8 (using corrector) the stars are sharp to edge.
At f/4 I see a little distortion at edge but it doesn’t bother me."

 

Regarding question #4:

 

Again, on the TS webpage...

 

"Total length of only 790 mm, weight of 7.6 kg"

 

waytogo.gif

Hi and thanks for chiming in regarding the questions I’m hoping Mazerski will get back to me on. See below regarding your responses:

 

1. On this question, I’m asking him, as the user, what the F2.8 - F4 change process is like. I’ve never used corrector or reducer. I will likely use the scope for EAA and might change F ratios during an observing session - so, I’m curious about the change-over process.

2. Here I asking him to confirm that he didn’t use any corrector at F4 and am asking if he knew, from his interactions with the seller, if one could be used. 

3. He did not yet answer the question I posed in the quoted text. I am asking him about image resolution in F4 mode versus F2.8 mode and whether he notices a difference. I did incorrectly say ‘F4’ in my second sentence where I should have said ‘F2.8’. 

4. I had looked for the tube length on the TS ‘technical data’ page where I usually find that info. Thanks for pointing it out in the ‘details’ page. 



#12 B 26354

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Posted 17 September 2019 - 05:51 PM

Hi Gary,

 

I'm completely confused.

 

As I've stated, my assumption here is that the 8" Boren-Simon is an f/4 Newtonian (not an f/2.8 one)... that comes with a corrector/reducer which turns it into an f/2.8.

 

Theoretical proof of this is given in their "Technical Data" section, which states:

 

"Focal length: 568 mm with reducer/corrector"

 

Confoundingly, however... in the "Details" section, they state:

 

"Change the telescope from superfast f/2.8 to high resolution f/4 within minutes:

 

With the optional TSGPU Aplanatic 4-element Coma Corrector you can change the Boren-Simon F2.8 superfast Newtonian astrograph into a high resolution F4 astrograph with a very good illumination and 800 mm focal length."

 

These two statements are completely contradictory... so my strong advice would be to e-mail TS directly, and request clarification as to whether the scope's native focal ratio is f/2.8 or f/4... and whether the included "corrector" is a "reducer/corrector", or a focal-extender/corrector.

 

Whenever I've e-mailed them with questions, they have been extremely responsive and helpful.

 

That advice also applies to your question 2, about using a non-reducing corrector with the scope. This will, of course, depend upon whether or not the scope's native format is, in fact, f/4. If it is... TS "should" be able to recommend a suitable non-reducing corrector... if indeed, one does exist.

 

In any case... I'm looking forward to whatever info you're able to gather!  grin.gif



#13 Mazerski

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Posted 17 September 2019 - 06:00 PM

Let's see if I can answer your Qs (6 photos attached):

 

== I use with night vision which includes a filter wheel. I have tried with glass EP and it provides sharp views of moon, planets and stars - I have a 50mm tube extension and it is required for glass EP. ==

 

1) Scope length = 29.25" (+ 12" Astrozap flex dewshield) -- the Reflectix is a test over summer / winter to see if fog. dew. haze is minimized. So far so good.

 

2) The TS2Korrr is the included corrector for f/2.8 - TS calls it an ASA corrector / reducer. Nice sharp views

 

3) The Baader or Astro-Physics AP16T nosepiece is what I screw in back of filter wheel for f/4. To change between f/2.8 and f/4, I simple change the piece on back side of filter wheel - takes a minute or less.

 https://cloudbreakop...nosepiece-ap16t

 

4) Are you asking if you can use a Paracorr at f/4? I don't know and have never seen one in the flesh.

 

5) The views (visual image) I see thru scope are amazing... the Veil, Horsehead, M13, M82... with night vision, astronomy (visual) has forever changed for the better. I would say the image scale is different from f2.8 to f/4. At f/2.8, the Leo Triplet are all within FOV and at f/4, they may still be within FOV but they look better at f/2.8.

 

 

Another CN user - Eddgie, he has the 6" version and I got the 8" due to his writeup of the 6". If you still have specific Qs I can't answer, he is more knowledgeable and may be able to help you.

 

I see another user B26354 added info... he is correct in that the supplied corrector is what gives you f/2.8 and in my case, adding the AP16T to back of filter wheel = f/4. Or if moon and  planet looking, use a tube extension for f/4.

 

Ask if you have more Qs on photos

 

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#14 B 26354

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Posted 17 September 2019 - 06:16 PM

@Mazerski....

 

Thank you! Clarifying that the 8" Boren-Simon is an f/4 Newtonian, and not an f/2.8 one, is extremely helpful.

 

@GaryShaw....

 

I would still strongly recommend contacting TS by e-mail, regarding the non-reducing coma-corrector issue. On that web-page, at the very bottom, under "Adapters", they show a "TSGPU" 1.0x TS-Optics Newtonian Coma Corrector:

 

https://www.teleskop...connection.html

 

Which "may" be suitable for use with the 8" Boren-Simon.

 

grin.gif


Edited by B 26354, 17 September 2019 - 06:17 PM.


#15 Mazerski

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Posted 17 September 2019 - 06:42 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



#16 B 26354

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Posted 18 September 2019 - 10:08 AM

Exactly.

 

Which is, of course, the problem... since it's not a native f/2.8. It's an f/4, with an included reducer/corrector that converts it to an f/2.8.



#17 Mazerski

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Posted 18 September 2019 - 10:26 AM

B,

 

Ok, but I have to ask, why is it a problem that a corrector is needed for f/2.8 ?



#18 B 26354

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Posted 18 September 2019 - 10:42 AM

It's not.

 

My "problem" is with the completely ambiguous descriptions. On that web-page -- as you've pointed out -- the scope is described as a "TS-Optics Boren-Simon 8" f/2,8 PowerNewton Astrograph"... when in fact, it's a "TS-Optics Boren-Simon 8" f/4 PowerNewton Astrograph".



#19 Mazerski

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Posted 18 September 2019 - 11:27 AM

OK - now I got it. Sorry for being dense. I think for me the redeeming factor is they include the corrector / reducer.

 

The best news is with night vision at either f ratio the scope is a great performer.



#20 SeattleScott

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Posted 18 September 2019 - 11:44 AM

The Vixens have excellent optics. However I’m not sure how much that matters for NV. The coma corrector is great because it is built into focuser and custom to the scope, so you never have to think about changing settings or spacing for different eyepieces. Just install it and forget about it. Except for when you want to use a long barlow...

That being said, yes they are pricey, and the premium may not be worth it for NV. Personally I got mine on a local CN deal for a fraction of retail, so it made sense for me.

Scott

#21 SeattleScott

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Posted 18 September 2019 - 11:48 AM

Hi, and thanks for your note.
I've never used a refractor so its hard for me to imagine a 152mm F5.9 being faster or brighter than a 208mm F4 but I get that you preferred it over the ES208 - which I had been considering.

Can you explain what you mean by your sentence '...back out the secondary obstruction'.
Thank you!
Gary

I think he is talking about refractors being more efficient systems, so a 6” refractor is typically about as bright as an 8” reflector. Which is my experience too. I would say my R200 is probably slightly brighter than my 6” F8 refractor, but it isn’t an obvious difference. So it can really come down to personal preference, collimation, cooling, weight, mounting requirements, etc.

Scott

#22 GaryShaw

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Posted 18 September 2019 - 04:55 PM

I think he is talking about refractors being more efficient systems, so a 6” refractor is typically about as bright as an 8” reflector. Which is my experience too. I would say my R200 is probably slightly brighter than my 6” F8 refractor, but it isn’t an obvious difference. So it can really come down to personal preference, collimation, cooling, weight, mounting requirements, etc.

Scott

Ok Scott, thank you. 



#23 John Tucker

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Posted 20 September 2019 - 09:49 PM

I recently purchased one of the TS Boren-Simon "PowerNewts".  Its very fast and is my first reflector, the first telescope I've ever collimated.

 

Other carbon fiber Newts sold by TS include the Photon series, the ONC series, and the ONTC series  The order of price/quality is Photon < ONC < ONTC.  I don't know all the differences, but the ONTC has extra holes drilled in the tube so that the front (secondary) mirror can be moved forward or backwards, which apparently provides an extra touch of optimization depending on whether you are doing photography or visual and whether you are using a reducing coma corrector or not. I believe the ONC comes with a standard focuser, whereas the ONTC price does not include the focuser and you pick from a list of several premium ones and add that to the price. 

 

The Boren-Simon "PowerNewt" appears to be essentially an F4 ONC that comes standard with a 0.75 ASA reducing corrector instead of a non-reducing one, making it effectively F2.8.  I bought this scope because I was tired of staying up all night with my F6 telescope doing astrophotography and finding I still had underexposed pics after 8 hours of data collection.  I don't have experience with a lot of telescopes, but so far I am happy with this one. 

 

I believe the 0.75 ASA corrector reducer is compatible with the ONTC Newtonians as well, so for example if you bought an F4 ONTC and the ASA corrector, you'd have sort of a high end "PowerNewt" at F2.8. It may also be possible to use the reducer-corrector with the F5 ONTC as well, so then if you had both the reducing corrector and a non-reducing one, you'd be able to choose between F5 and F3.75.  But I'd ask and not assume that. 

 

If you are a perfectionist, its probably important to note that the ASA 0.75x reducer-corrector does not correct all the way to the edges of an APS-C sensor (the size in a typical Canon DSLR)

 

As for collimation:  I have never collimated a telescope before and was very nervous about this myself.  I decided to buy a non-reducing coma corrector to complement the reducing one that comes with the scope because I was worried about collimation, especially at F2.8.  

 

So far, collimation has not been much of a problem.  I bought a nice FarPoint laser collimator and chesire, and followed the instructions that came with them.  It took all of about 10 minutes the first time I did it.  I check it when I go out to a dark site and sometimes spend 5 minutes giving it a quick tweek.  

 

The hard part is not collimation (which gets the stars in the middle of your field of view to be round), but getting the spacing between the camera sensor and the corrector right so that the stars in the corners of your picture are round too.  Once you figure out the right spacer, you're done for all time, but it does actually require you to go out and take pictures and repeatedly take the camera off and on the OTA while you iterate.  Mine has an otherwise imperceptible tilt of the focuser so that one corner always has a few stars that are just a bit oval. There are ways to fix this but so far I haven't bothered because its not noticeable unless I enlarge the picture specifically to look for that.

 

The spacing part is harder at F2.8 than it is at F4, and its probably easier yet at F5. Mostly I've been working at F4 so far. Its still new and I just haven't been able to get it out that many times to both take pictures and deal with the spacer issues on two different correctors. 

 

I think it depends on what you want.  I get out about 2 nights a month, and am thrilled to be able to get a pretty good picture in 2 hours at F4 and probably in an hour when I get the spacing correctly set for the reducing adapter.  But I'm not a pixel peeper and its not likely that I'm even going to worry about a few stars in the corners that appear oval when I enlarge the picture 10x.  

 

Some people hate the diffraction spikes that Newtonians produce.  Its kind of an individual thing.  I'm very happy. 


Edited by John Tucker, 20 September 2019 - 10:01 PM.

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#24 John Tucker

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Posted 20 September 2019 - 10:16 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 


Edited by John Tucker, 20 September 2019 - 10:17 PM.


#25 GaryShaw

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Posted 20 September 2019 - 10:18 PM

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


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