25 replies to this topic

[John Berger]

Do the Quattros have a main mirror aperture ring? The TS UNCs and ONTCs? The Orion astrographs?

 

I'm trying to figure out if it's worth it to get a better quality astrograph, rather than use my Celestron reflector (non-astrograph) for astrophotography.

 

I'm looking for something with:

 

a two speed focuser with stiff focuser tube (my cheap focuser has a bad focusing gear ratio, and has sharp focus knobs, which look like they're 3d printed, and those knobs are held in place by a thin aluminum shaft),

 

large secondary mirror (my secondary does not cover the entire view in my focuser),

 

blackened internal surfaces (my OTA's tube's paint is okay, but my focuser tube is definitely not okay; it's painted inside and out in a silvery metallic color, almost like it was done on purpose; what's the cost difference between silver paint and black? Why couldn't they just paint black? Painting it silver is not even beneficial for visual users),

 

and aperture ring already installed (my newt had not aperture ring mask, but that's understandable since it's not an astrograph).

 

And also has more than 8 inches of aperture.

Edited by John Berger, 25 February 2024 - 06:16 PM.

[Ethanwyh]

Do the Quattros have a main mirror aperture ring? The TS UNCs and ONTCs? The Orion astrographs?

 

I'm trying to figure out if it's worth it to get a better quality astrograph, rather than use my Celestron reflector (non-astrograph) for astrophotography.

 

I'm looking for something with:

 

a two speed focuser with stiff focuser tube (my cheap focuser has a bad focusing gear ratio, and has sharp focus knobs, which look like they're 3d printed, and those knobs are held in place by a thin aluminum shaft),

 

large secondary mirror (my secondary does not cover the entire view in my focuser),

 

blackened internal surfaces (my OTA's tube's paint is okay, but my focuser tube is definitely not okay; it's painted inside and out in a silvery metallic color, almost like it was done on purpose; what's the cost difference between silver paint and black? Why couldn't they just paint black? Painting it silver is not even beneficial for visual users),

 

and aperture ring already installed (my newt had not aperture ring mask, but that's understandable since it's not an astrograph).

 

And also has more than 8 inches of aperture.

I can only say for the Quattro 8. SW does not ever include aperture rings, you have to 3D print them yourself (or your local astronomy retailer may carry 3rd party options). The internals of all Quattros have blackend baffles. The focuser on the quattro is okay: it is a two speed crayford style focuser, but if you want threaded connections, it's almost impossible unless you swap out the focuser with offerings from TS optics. 

At that price point, i think getting a UNC + V-powered focuser will be a better choice (imo) if you are planning on using it for the long term. 

[Garyth64]

I have a TPO 8" f/4 astrograph.  It has a 203mm primary, dual-speed (10:1) 2" focuser, finder, tube rings with dovetail, and a cooling fan.

It does not have an aperture ring.

[Devonshire]

Why does an aperture ring have to be preinstalled?  Easy enough to DIY install. 

 

I made mine and installed it, but if you prefer an aftermarket ring that's not 3D printed, Backyard Universe has rings for Skywatcher Newts, etc. (Site link below). 

Probably the easiest way to order is from First Light Optics, as international shipping from them is fairly painless.   I haven't seen any sign of BU having representation on this side of the pond.

 

https://www.backyard-universe.de/en/

 

(Example ring)

https://www.firstlig...telescopes.html

[Alex McConahay]

I kinda know what an aperture ring, or at least I thought I did. 

 

Why are you interested in an aperture ring? What does it do for you?

 

I ask because I always thought of them as a way to correct an error in mirror figuring. Is there some other reason to be using it?

 

Alex

[John Berger]

I kinda know what an aperture ring, or at least I thought I did. 

 

Why are you interested in an aperture ring? What does it do for you?

 

I ask because I always thought of them as a way to correct an error in mirror figuring. Is there some other reason to be using it?

 

Alex

It does this: https://i.imgur.com/cLa2r1u.jpeg So I thought it was very important because of the big difference it makes (at least to me, it makes a big difference in image cleanliness).

Edited by John Berger, 25 February 2024 - 08:49 PM.

[John Berger]

Why does an aperture ring have to be preinstalled?  Easy enough to DIY install. 

 

I made mine and installed it, but if you prefer an aftermarket ring that's not 3D printed, Backyard Universe has rings for Skywatcher Newts, etc. (Site link below). 

Probably the easiest way to order is from First Light Optics, as international shipping from them is fairly painless.   I haven't seen any sign of BU having representation on this side of the pond.

 

https://www.backyard-universe.de/en/

 

(Example ring)

https://www.firstlig...telescopes.html

Can the 8 inch backyard universe aperture ring fit on an 8 inch Celestron reflector, or just a Skywatcher newt?.

[astrodrawn]

Do the Quattros have a main mirror aperture ring? The TS UNCs and ONTCs? The Orion astrographs?

I'm trying to figure out if it's worth it to get a better quality astrograph, rather than use my Celestron reflector (non-astrograph) for astrophotography.

I'm looking for something with:

a two speed focuser with stiff focuser tube (my cheap focuser has a bad focusing gear ratio, and has sharp focus knobs, which look like they're 3d printed, and those knobs are held in place by a thin aluminum shaft),

large secondary mirror (my secondary does not cover the entire view in my focuser),

blackened internal surfaces (my OTA's tube's paint is okay, but my focuser tube is definitely not okay; it's painted inside and out in a silvery metallic color, almost like it was done on purpose; what's the cost difference between silver paint and black? Why couldn't they just paint black? Painting it silver is not even beneficial for visual users),

and aperture ring already installed (my newt had not aperture ring mask, but that's understandable since it's not an astrograph).

And also has more than 8 inches of aperture.

If you have no budget, then go with astroworx. They have internal cooling,carbon fibre exterior, black internal, dew heaters on the secondary and primary mirror and best of all you can customise the focal length, mirror size, if you want an automatic aperture cover, anodize detail colour, extra mounting brackets and one thing you're after, focuser of choice. These telescopes come to a big price though (10" closed carbon new=$10,000 AUD).

[Devonshire]

Can the 8 inch backyard universe aperture ring fit on an 8 inch Celestron reflector, or just a Skywatcher newt?.

No idea, John - I'd email the vendor and ask.  

[John Berger]

If you have no budget, then go with astroworx. They have internal cooling,carbon fibre exterior, black internal, dew heaters on the secondary and primary mirror and best of all you can customise the focal length, mirror size, if you want an automatic aperture cover, anodize detail colour, extra mounting brackets and one thing you're after, focuser of choice. These telescopes come to a big price though (10" closed carbon new=$10,000 AUD).

Hmmm, nahhh... My budget is like $400-$500 anyways, and If I had no budget, I would get one of the ASA scopes, not one of these teeny tiny newts.

[John Berger]

No idea, John - I'd email the vendor and ask.  

I will do that right now

[Alex McConahay]

It does this: https://i.imgur.com/cLa2r1u.jpeg So I thought it was very important because of the big difference it makes (at least to me, it makes a big difference in image cleanliness).

The aperture ring in that case does something for THAT mirror, and in particular the way THAT mirror is mounted. 

 

Another mirror mounted a different way may be just as clean as the one you like because it does not have defects at the edge (turned down edge---common in mirror making) and particularly those three black protrusions (mounting clamps).

 

In other words, it is not the presence of an aperture mask that you look for, but the overall quality of the image produced by the mirror. And many mirror makers can achieve that quality without resorting to an aperture mask. Some mirror makers make the mirror as well as they can and then use an aperture mask to hide the deficiencies in their less than perfect mirrors. (It is perfectly legitimate----nobody is trying to cheat. It is a common practice among mirror makers.)

 

Note that an aperture mask, by definition, takes away some of the light. How much depends on how much smaller the mask is compared to the mirror. 

 

Alex

[Devonshire]

Alex,

 

The aperture mask doesn't just cover a bad edge, it also covers clips, if you have them.  Depending on your specific issue, might help clean up the stars.. 

 

Here's an example: 

https://www.cloudyni...n/#entry7839342

 

 

[John Berger]

The companies replied back:

 

Backyard Universe:

 

"Hi John,

Celestron should be identical to Skywatcher, but I am not sure. Best would be to measure the primary mirror cell (distance between the screws in a clamp and between the screws of different clamps)

Best wishes,
Michael"

 

First Light Optics:

 

"Hi Thomas," (another one of my aliases  )

 

"Thank you for getting in touch,

Although marketed towards Sky-Watchers, there is a good chance it will also fit Celestron Newtonians as they are off the same production line in China.

I can't think of a reason why it wouldn't work for your needs, but you are covered by our 30-day returns policy if you encounter any problems at all,

Best wishes

Chris"

 

"Off the same production line in China"  got my attention; I don't know exactly what that means, but it sounds good... 

 

If I do buy, it will be from FLO because of the returns policy.

Edited by John Berger, 26 February 2024 - 03:39 PM.

[Oort Cloud]

Hmmm, nahhh... My budget is like $400-$500 anyways, and If I had no budget, I would get one of the ASA scopes, not one of these teeny tiny newts.

400-500 isn't enough for what you're looking for (astrograph newt over 8" of aperture). Even the 10" quattro is $1,200, and that's without the coma corrector.

[John Berger]

400-500 isn't enough for what you're looking for (astrograph newt over 8" of aperture). Even the 10" quattro is $1,200, and that's without the coma corrector.

Yeah I realized that. And I also realized modifying my newt to be good for imaging would cost a lot, so I'm unsure whether I should continue with the newt...

 

Let me just compile a list of costs to show what I mean:

 

1. Aperture mask - $70 for the piece of aluminum (is there no other way to hide the clips?

2. Baader Diamond Steeltrack focuser - $374

3. TS GPU coma corrector - $357

4. ZWO OAG - $115

5. M42 Filter drawer - $80

6. Astronomik L2 filter - $125

 

Total is $1121

Is it worth it to insist with my newt?  And what if, after all this, my images turn out crappy?

[Alex McConahay]

>>>>>>>And what if, after all this, my images turn out crappy?

 

You will be among friends. 

 

Alex

[Alex McConahay]

>>>>>>>>>"Off the same production line in China"  got my attention; I don't know exactly what that means, but it sounds good...grin.gif lol.gif

 

Yes, that always sounds good. But what does it mean?

 

If it is true, it means it came "off the same production line in China."

 

You know, a given production line can produce various products...........Swap in this accessory (focuser/mirror cell/ secondary holder) versus that one. All on the same production line. Maybe different runs of that line. 

 

Or, send each of the mirrors in for testing. If they pass the most stringent of tests, they go in this pile, and are put into this brand of telescope. If they meet minimum acceptable, they go in that pile for the next production run on this line, and become that brand telescope. 

 

The production line could be fulfilling orders from the marketer. The marketers may have different specs. 

 

"Same production line" does not mean identical products. 

 

Alex

[Oort Cloud]

Yeah I realized that. And I also realized modifying my newt to be good for imaging would cost a lot, so I'm unsure whether I should continue with the newt...

 

Let me just compile a list of costs to show what I mean:

 

1. Aperture mask - $70 for the piece of aluminum (is there no other way to hide the clips?

2. Baader Diamond Steeltrack focuser - $374

3. TS GPU coma corrector - $357

4. ZWO OAG - $115

5. M42 Filter drawer - $80

6. Astronomik L2 filter - $125

 

Total is $1121

Is it worth it to insist with my newt?  And what if, after all this, my images turn out crappy?

Hard to say.  I have found that in this hobby, that it is often advantageous to use things for the purpose which they were built.  Often newts are designed as visual scopes; one prime example would be that a number of them can't come to focus with a camera unless the sensor is placed inside the focuser like a mini camera (eyepiece style, very small sensor, most often used only for guiding), or by moving the primary closer to the secondary to push the focal plane out of the focuser.  Also newts made for imaging often have a larger secondary to provide a more reasonably sized image circle.  On one hand, the parts you've mentioned add up to the cost of a 10" quattro, but on the other hand, a new newtonian would also need a fair amount of those (like a coma corrector).  Either way, both are out of your budget, so I would focus on getting a good coma corrector; you'll need that either way.  A better focuser could always transfer to a new OTA if you get one down the road, but it sounds like that would have to wait anyway, since the coma corrector and focuser alone is already more than your budget.  I guess really I should have started by asking the burning question: Can you bring a camera to focus with your current newtonian?  If not, this is a lot more complicated: the question then becomes, do I modify my OTA to bring the primary up in the tube or do I buy a new OTA.  In which case, I say buy the new OTA.

 

That said, I don't own any newtonians, so I am no expert here; just regurgitating what I've heard from others with more experience than myself.  I do hope to eventually buy one, but my interest is solely imaging, so I will be sure to purchase an newtonian that has been designed for imaging (larger secondary, more robust focuser, focal plane outside the focuser, etc).

 

>>>>>>>And what if, after all this, my images turn out crappy?

 

You will be among friends. 

 

Alex

LoL. Yup.

[John Berger]

Hard to say.  I have found that in this hobby, that it is often advantageous to use things for the purpose which they were built.  Often newts are designed as visual scopes; one prime example would be that a number of them can't come to focus with a camera unless the sensor is placed inside the focuser like a mini camera (eyepiece style, very small sensor, most often used only for guiding), or by moving the primary closer to the secondary to push the focal plane out of the focuser.  Also newts made for imaging often have a larger secondary to provide a more reasonably sized image circle.  On one hand, the parts you've mentioned add up to the cost of a 10" quattro, but on the other hand, a new newtonian would also need a fair amount of those (like a coma corrector).  Either way, both are out of your budget, so I would focus on getting a good coma corrector; you'll need that either way.  A better focuser could always transfer to a new OTA if you get one down the road, but it sounds like that would have to wait anyway, since the coma corrector and focuser alone is already more than your budget.  I guess really I should have started by asking the burning question: Can you bring a camera to focus with your current newtonian?  If not, this is a lot more complicated: the question then becomes, do I modify my OTA to bring the primary up in the tube or do I buy a new OTA.  In which case, I say buy the new OTA.

 

That said, I don't own any newtonians, so I am no expert here; just regurgitating what I've heard from others with more experience than myself.  I do hope to eventually buy one, but my interest is solely imaging, so I will be sure to purchase an newtonian that has been designed for imaging (larger secondary, more robust focuser, focal plane outside the focuser, etc).

 

LoL. Yup.

I remember I was able to focus on the stars, but I got no image that I can show of this; I got this moon and jupiter image with my newt a while ago though, and I wasn't too satisfied with the result: https://www.astrobin...ction&nce=26108

 

I have a question:

I have noticed that when I try putting my guide camera, an ASI120 Mini, in my focuser, and the image doesn't come into focus when pointed at some clouds (in the daytime), but when I try focusing with my full frame Canon camera, it comes into focus; note that this is just the terrain, not the stars; I haven't tried focusing on the stars with the guide cam through the Newt. Can you explain this phenomenon? Is this abnormal?

 

Here is an image of the clouds with my full frame Canon camera:

[calypsob]

Why does an aperture ring have to be preinstalled?  Easy enough to DIY install. 

 

I made mine and installed it, but if you prefer an aftermarket ring that's not 3D printed, Backyard Universe has rings for Skywatcher Newts, etc. (Site link below). 

Probably the easiest way to order is from First Light Optics, as international shipping from them is fairly painless.   I haven't seen any sign of BU having representation on this side of the pond.

 

https://www.backyard-universe.de/en/

 

(Example ring)

https://www.firstlig...telescopes.html

the purpose of this is to hide TDE, it does act as a aperture stop but it was designed to hide TDE. 

[calypsob]

Yeah I realized that. And I also realized modifying my newt to be good for imaging would cost a lot, so I'm unsure whether I should continue with the newt...

 

Let me just compile a list of costs to show what I mean:

 

1. Aperture mask - $70 for the piece of aluminum (is there no other way to hide the clips?

2. Baader Diamond Steeltrack focuser - $374

3. TS GPU coma corrector - $357

4. ZWO OAG - $115

5. M42 Filter drawer - $80

6. Astronomik L2 filter - $125

 

Total is $1121

Is it worth it to insist with my newt?  And what if, after all this, my images turn out crappy?

look at one of these over the baader https://www.ebay.com/itm/256199851986

 

GPU is a good CC, Paracorr is a great CC, Starizona nexus is a reducer that corrects well and converts your scope into a fast astrograph. 

 

reflectors are finniky, but you can rule out all of the errors with patience. 

Edited by calypsob, 26 February 2024 - 07:55 PM.

[Garyth64]

Yeah I realized that. And I also realized modifying my newt to be good for imaging would cost a lot, so I'm unsure whether I should continue with the newt...

 

Let me just compile a list of costs to show what I mean:

 

1. Aperture mask - $70 for the piece of aluminum (is there no other way to hide the clips?

2. Baader Diamond Steeltrack focuser - $374

3. TS GPU coma corrector - $357

4. ZWO OAG - $115

5. M42 Filter drawer - $80

6. Astronomik L2 filter - $125

 

Total is $1121

Is it worth it to insist with my newt?  And what if, after all this, my images turn out crappy?

Yes, but they could, as you are relying on how good the mirror is to begin with.  What about the mount?  Is the camera an expensive one?

 

And you forgot to add in a larger (Antares) secondary and holder,  that could cost about $175+.

You may even need a guide scope to help tracking.   

 

And, IMO, the aperture mask really isn't needed, I feel it's more of a gimmick.

 

Start on a lower scale, and see what images you can get with what you have.  Then start adding all the bling.

This astrophotography rabbit hole is not cheap.

Edited by Garyth64, 26 February 2024 - 09:04 PM.

[Alex McConahay]

>>>>>I have noticed that when I try putting my guide camera, an ASI120 Mini, in my focuser, and the image doesn't come into focus when pointed at some clouds (in the daytime), but when I try focusing with my full frame Canon camera, it comes into focus; note that this is just the terrain, not the stars; I haven't tried focusing on the stars with the guide cam through the Newt. Can you explain this phenomenon? Is this abnormal?

 

The point of focus is a given distance from the main optic.

 

You have to put the sensor at this precise distance from the main optic for it to be in focus. 

 

You will notice that the sensor on one camera is not in the same place as it is in another camera. That is, the sensor in your Canon may be 14 mm from the front of the camara. But the sensor for your guide camera may be only six. (I'm making these numbers up.)  If you are lucky, your focuser can move the camera this difference of 8 mm to position either camera where it needs to be. But if your focuser cannot do that, you may be able to get one in focus, and not the other.

 

Alex  

[John Berger]

Yes, but they could, as you are relying on how good the mirror is to begin with.  What about the mount?  Is the camera an expensive one?

 

And you forgot to add in a larger (Antares) secondary and holder,  that could cost about $175+.

You may even need a guide scope to help tracking.   

 

And, IMO, the aperture mask really isn't needed, I feel it's more of a gimmick.

 

Start on a lower scale, and see what images you can get with what you have.  Then start adding all the bling.

This astrophotography rabbit hole is not cheap.

AVX mount, ASI533MC Pro camera; I'm not going to use my Canon when I do the "real" DSO imaging, because up to this point, all my telescope images have been tests. My guidescope is also specified in my signature, but the focal length of the guidescope is too far from the focal length of the main scope, but I'll save the OAG for later and try the guide scope for now.

Edited by John Berger, 27 February 2024 - 04:07 PM.