22 replies to this topic

[Celestro21]

Hi guys, so laying in my bed this morning looking through a few scopes on website for fun, I stumbled across a 14 inch Apertura RC truss style scope. Looks cool and eye catching especially for those public star parties I participate in. As I laid there looking at it, I remember that RC scopes aren't good for visual observation do to their fast F ratio and having a larger secondary mirror. However the question came, is this the same for night vision. I do all my visual observation through NV. Anyone with this sort of set and experience please share. I have an 11 inch SCT but maybe I just get jelly over the views in my friends 25 Obsessed. So even though ita not close, a 14 inch will have more light collecting power then an 11

Thanks

[sixela]

RC scopes aren't good for visual observation do to their fast F ratio

Uhm? They're usually f/9 or slower (possibly with reducers that make them f/6). That's not what I personally would call "fast"; it's in the realm of what is typical for most SCTs (and indeed the Meade ACX and Celestron Edge HD have an optical formula that is not dissimilar, although they use a subaperture corrector for it rather than the RC formula). As for "not good for visual observation", that's not my experience. Yes, some of them have large secondaries to illuminate humongous fields because they're astrographs, but so what? If you're not going to use them at extremely high powers or humongous exit pupils that's not an issue.

Edited by sixela, 15 November 2023 - 10:49 AM.

[mpsteidle]

RC's generally are not "fast" telescopes, usually being around F/8.  They do well for deep sky observations, but the contrast of planetary views can suffer a bit from the large secondary.

Collimation of RC telescopes is also impossibly finicky.  You'd be much better off with a 14" SCT and a reducer.

[Joko]

Hi guys, so laying in my bed this morning looking through a few scopes on website for fun, I stumbled across a 14 inch Apertura RC truss style scope. Looks cool and eye catching especially for those public star parties I participate in. As I laid there looking at it, I remember that RC scopes aren't good for visual observation do to their fast F ratio and having a larger secondary mirror. However the question came, is this the same for night vision. I do all my visual observation through NV. Anyone with this sort of set and experience please share. I have an 11 inch SCT but maybe I just get jelly over the views in my friends 25 Obsessed. So even though ita not close, a 14 inch will have more light collecting power then an 11

Thanks

There's no official statement, but I consider a fast telescope to be F/4 or less.

 

I would recommend 2 types of telescopes for NV :

1. a telescope of at least 16" or larger and F/4 or faster. This would be to observe most of the targets like galaxies, globulars, planetary nebulae, planets...
2. a telescope of 6" or 8" still F/4 or faster to observe large targets (mainly nebulae) at low magnifications and wide FOV.

Please note any telescope will work with NV including a 14 inch Apertura RC truss though I wouldn't recommend it.

You suggested an Obsession 25" and I know many NV users who also own an Obsession Telescope. 

So, if you can afford it, it would be an excellent choice. 

[Phil Cowell]

My 16” RC is F8.

 

Uhm? They're usually f/9 or slower (possibly with reducers that make them f/6). That's not what I personally would call "fast"; it's in the realm of what is typical for most SCTs (and indeed the Meade ACX and Celestron Edge HD have an optical formula that is not dissimilar, although they use a subaperture corrector for it rather than the RC formula). As for "not good for visual observation", that's not my experience. Yes, some of them have large secondaries to illuminate humongous fields because they're astrographs, but so what? If you're not going to use them at extremely high powers or humongous exit pupils that's not an issue.

[sixela]

Also not particularly fast.

[Celestro21]

Okay I completely forgot about this post...wow. Anyway, I do have my eye on a 10 inch RC and a skywater cq350 pro mount. Waiting for my credit cards to be paid off...almost there. Once they are I'll be buying this set up

[Deadlake]

Hi guys, so laying in my bed this morning looking through a few scopes on website for fun, I stumbled across a 14 inch Apertura RC truss style scope. Looks cool and eye catching especially for those public star parties I participate in. As I laid there looking at it, I remember that RC scopes aren't good for visual observation do to their fast F ratio and having a larger secondary mirror. However the question came, is this the same for night vision. I do all my visual observation through NV. Anyone with this sort of set and experience please share. I have an 11 inch SCT but maybe I just get jelly over the views in my friends 25 Obsessed. So even though ita not close, a 14 inch will have more light collecting power then an 11

Thanks

A 11” SCT presume this is a C11. A good place to start if you add a 0.75 AP reducer and Televue 67 mm. You can search for more on using a C11 with NVD on this forum.

you would also want a WFOV, I’d look at an 8” F4 newt as well.

Edited by Deadlake, 19 July 2024 - 06:17 PM.

[Celestro21]

A 11” SCT presume this is a C11. A good place to start if you add a 0.75 AP reducer and Televue 67 mm. You can search for more on using a C11 with NVD on this forum.
you would also want a WFOV, I’d look at an 8} F4 newt as well.

Oh I don't want another newtonian. I have a F4 astrograph and it's just a pain in the butt. I am aiming for the public for when we do out reach programs and not everyone can bend down or reach over for a newt. I no longer want another newt in my life. The set up that I have in mind is what I will be going for once I cab

[sixela]

That pain-in-the-buttness is, I think, related more to the mount than the Newt itself. I'm using a 6" f/4 Newt (f/3.45 with its corrector) on an Alt-Az mount and it's quite comfortable, and nothing like the exercise for contorsionists that it becomes when put on an equatorial mount.

Unfortunately most really fast setups with an observer out of the light path tend to be Newtonian in nature. Unless you pick a short refractor with a reducer (that's what I'd pick given your allergy to Newts).

Edited by sixela, 19 July 2024 - 07:02 PM.

[Mazerski]

I agree with sixela on using a Newtonian is easy and works well. The photo shows the TS 8" astrograph which is mounted on the AYO Digi II and the Planet tripod. Easy to use and works great and the views at f/4 and f/2.8 are very nice. The scope does have a 14" Losmandy plate and the Berlebach handle as I don't trust myself.

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[Celestro21]

I agree with sixela on using a Newtonian is easy and works well. The photo shows the TS 8" astrograph which is mounted on the AYO Digi II and the Planet tripod. Easy to use and works great and the views at f/4 and f/2.8 are very nice. The scope does have a 14" Losmandy plate and the Berlebach handle as I don't trust myself.

I really don't want another newtonian. I have my f3.9. I guess I just want something completely different to add to my family. I have my eyes on the gso 10 cassegrain truss tube scope.

[Celestro21]

That pain-in-the-buttness is, I think, related more to the mount than the Newt itself. I'm using a 6" f/4 Newt (f/3.45 with its corrector) on an Alt-Az mount and it's quite comfortable, and nothing like the exercise for contorsionists that it becomes when put on an equatorial mount.

Unfortunately most really fast setups with an observer out of the light path tend to be Newtonian in nature. Unless you pick a short refractor with a reducer (that's what I'd pick given your allergy to Newts).

I am sorta looking at the skywatcher eq350 mount and they also have a eq/AZ combo. Maybe just go with that so I can show people the night sky during outreach programs and do my own things with the eq part of it when on my own

[Deadlake]

A 11” SCT presume this is a C11. A good place to start if you add a 0.75 AP reducer and Televue 67 mm. You can search for more on using a C11 with NVD on this forum.

you would also want a WFOV, I’d look at an 8” F4 newt as well.

Ok, I use the same reducer in an 130 mm F6 APO. Used with a TV67 mm it will give an effective speed for the NVD of F2.

The downside of this approach is the scope costs more then the NVD, although it’s easier to mount it’s an expensive trade off.

 

I agree an EQ mount is a pain to use with a Newt, 

 

As far as a RC scope, it’s just too slow and I do not know of a reducer you can use with enough back focus to use with a diagonal.

 

The AP reducer I use has a back focus of 150 mm making visual applications possible.

 

Here is a picture of a 105 mm I also use, 

 

 

There is quite a lot of weight of the focuser end, in the end I ended up using a Y axis adapter that allows the scope to be balanced.

Edited by Deadlake, 20 July 2024 - 02:21 AM.

[Celestro21]

Ok, I use the same reducer in an 130 mm F6 APO. Used with a TV67 mm it will give an effective speed for the NVD of F2.
The downside of this approach is the scope costs more then the NVD, although it’s easier to mount it’s an expensive trade off.

I agree an EQ mount is a pain to use with a Newt,

As far as a RC scope, it’s just too slow and I do not know of a reducer you can use with enough back focus to use with a diagonal.

The AP reducer I use has a back focus of 150 mm making visual applications possible.

Here is a picture of a 105 mm I also use,



There is quite a lot of weight of the focuser end, in the end I ended up using a Y axis adapter that allows the scope to be balanced.

The one RC I'm looking at is a ioptron 12 f/8. I don't think it's super slowe compared to GSO's 10 cassegrain truss telescope at f/12 and a focal length at 3000. The ioptron had a focal length close to 2034

[Deadlake]

The one RC I'm looking at is a ioptron 12 f/8. I don't think it's super slowe compared to GSO's 10 cassegrain truss telescope at f/12 and a focal length at 3000. The ioptron had a focal length close to 2034

What reducer would you put in it, one with enough back focuser for a diagonal to work?

I suspect you will not find one, which is why the C11 + AP reducer is best option.

[Celestro21]

What reducer would you put in it, one with enough back focuser for a diagonal to work?

I suspect you will not find one, which is why the C11 + AP reducer is best option.

I decided to just save money, use my 8 inch f/4 astrograph. But I need another tripod. Looking at the skywatcher AltAZ/ Eq pro. Just looking to see if there are sales or anyone is selling it. 

[Joko]

Hi guys, so laying in my bed this morning looking through a few scopes on website for fun, I stumbled across a 14 inch Apertura RC truss style scope. Looks cool and eye catching especially for those public star parties I participate in. As I laid there looking at it, I remember that RC scopes aren't good for visual observation do to their fast F ratio and having a larger secondary mirror. However the question came, is this the same for night vision. I do all my visual observation through NV. Anyone with this sort of set and experience please share. I have an 11 inch SCT but maybe I just get jelly over the views in my friends 25 Obsessed. So even though ita not close, a 14 inch will have more light collecting power then an 11

Thanks

11 inch SCT is a good telescope for high magnification with your Night Vision device.

There is no issue to observe at slow F ratio, you can see some of my NV posts in the Cloudynights vendor forum.

Some of our customers use slow F ratio telescopes with their NVD. F/10 or F/15 telescopes are great too with NVD.

Edited by Joko, 21 July 2024 - 01:33 PM.

[Celestro21]

11 inch SCT is a good telescope for high magnification with your Night Vision device.
There is no issue to observe at slow F ratio, you can see some of my NV posts in the Cloudynights vendor forum.
Some of our customers use slow F ratio telescopes with their NVD. F/10 or F/15 telescopes are great too with NVD.

I think now the curiosity of using a rc with night vision is eating me more. Theu are such cool looking scopes. I wish I had someone who owned one so I can pop my NV in lol

[chemisted]

I think now the curiosity of using a rc with night vision is eating me more. Theu are such cool looking scopes. I wish I had someone who owned one so I can pop my NV in lol

https://www.cloudyni...8-155114436555/

[Mazerski]

My opinion means nothing but I have used a Maksutov scope (f/15) and the view is way too dark. Inserted various focal reducers and view was still too dark. Nice Intes Micro scope but not suited for NV. I do live in a light polluted area and I know that plays a role in what scopes reveal and what filters to use.

 

With the f/4 Astrograph and f/4.5 NewMoon, I have inserted a 2X Powermate to achieve f8 and f/9 (at face value) and you know what, I prefer the faster f/ratio. Why? Wider FOV, nebulosity is brighter and stars look more jewel-like. Yes, zooming in on a galaxy or glob or even the core of M42 is ok but to me DSOs look better at f/4 than f8. And for the double cluster, f/2.8 provides a spectacular view.

[Celestro21]

My opinion means nothing but I have used a Maksutov scope (f/15) and the view is way too dark. Inserted various focal reducers and view was still too dark. Nice Intes Micro scope but not suited for NV. I do live in a light polluted area and I know that plays a role in what scopes reveal and what filters to use.

With the f/4 Astrograph and f/4.5 NewMoon, I have inserted a 2X Powermate to achieve f8 and f/9 (at face value) and you know what, I prefer the faster f/ratio. Why? Wider FOV, nebulosity is brighter and stars look more jewel-like. Yes, zooming in on a galaxy or glob or even the core of M42 is ok but to me DSOs look better at f/4 than f8. And for the double cluster, f/2.8 provides a spectacular view.

So I am definitely a nebula girl. I love scanning the milkyway with my NV in the c11. It is addicting and I also take pics with the night vision. I have no interest in planets, galaxies or any sort of cluster. But nebulas...man they are my candy. I do want to out my Newt 3.9 on a different mount and see how it goes.

[Mazerski]

21,

 

We all like photos, consider posting a few. Scanning the Milky Way… if your NV device is c-mount you can attach an adapter / filter / camera lens (80-135mm for 3x-5x) as the views are great with wide-field. 

I use a 642nm IR filter for scanning (hand-held mode) the MilkyWay as an Ha filter darkens the view too much to see MW clouds. Later this year you should treat yourself to a wide FOV of the Double Cluster.