50 replies to this topic

[noisejammer]

Magical green paint ...

 

I've used five distinct Tak models .. FS-102, TOA130, TOA150, Epsilon E-160ED and a 300 Mewlon. All were excellent. Then I took the sick-green paint off my Epsilon, powder coated it like a E-180 and now it works far better.

[macdonjh]

Magical green paint ...

 

I've used five distinct Tak models .. FS-102, TOA130, TOA150, Epsilon E-160ED and a 300 Mewlon. All were excellent. Then I took the green paint off my Epsilon, powder coated it like a E-180 and now it works far better.

Ahhhhhhh!    That's like stripping the varnish off a Stradivarius because it's dull and scratched.

 

I considered a Mewlon 210 carefully.  But then I got my ATM classical Cassegrain with CFF mirrors working...  I'd love to have a complete CN-212 as well.

[Voyager 3]

BMW and TOA . 

[base16]

Here you can see me getting the TOA-150b onto the RST-300 for a visual setup in AltAz.

 

https://youtu.be/jXYrijCDxyE

 

This is my grab and go setup and leave the scope mounted for days at a time when I expect clear nights; the counterweights are only there to reduce mechanical stress on the pier extensions during this extended use. For a single night in-person use, the counterweights are not required.

Edited by base16, 22 August 2021 - 04:18 PM.

[teashea]

BMW and TOA . 

But a TOA is missing the new and very ugly BMW grille.

[Voyager 3]

https://encrypted-tb...q6yH5n6MJ8&s=10

 

But a TOA is missing the new and very ugly BMW grille.

[tcmclarney]

I happened to go looking for a fine little scope to use on my C-14 as a combo guider and wide-field imaging scope. I'd never looked through a fine refractor before.

 

After seeing what the FS-60CB showed, with a 6mm Delos, I sold the C-14 and bought a TSA-120. The SCT's are good for certain things, but putting up vibrant, contrasty views wasn't one. Some will say that I must have gotten a bad C-14, or didn't know how to collimate it - and, perhaps they're right. Maybe I got the best FS-60 ever, too. The TSA-120 was very sweet, but left me wanting more cowbell (cowbell = aperture). I stumbled across a Mewlon 250 at a price too good to refuse. Bingo! Mounted net to the TSA-120, I could not discern from the view which scope I was looking through.

 

Still hoping to make a go at Hyperstar imaging, I bought a C-11 Edge. Let's assume that the corrective elements work, and the view out to the edge is better while the on-axis views match what a standard Celestron SCT presents. I felt that the C11 Edge was showing me about the same view as the C14. On planets, it was like looking inside a month-old pizza box. Stale. Powerful? Sure! Vibrant and real-looking? Not so much. The Mewlon 250CRS showed me a view that was essentially equal to the view of the TSA. Several orders of magnitude more contrasty than the Celestron SCT's.

 

My understanding is that the TOA's are better in terms of color correction than equivalent A-P scopes, like the 155. Roland Christen said so, in a CN forum post comparing TOA-150's and the A-P 155. He said that the greater separation used by Takahashi in the TOA cells acts as an extra element in the color correction process. I've seen many complaints about TOA weight bloat, but I believe some of the bloat is due to the longer lens package that produces the edge in color correction performance.

 

I'm hoiping to hang onto my Mewlon 250, and to acquire a -300 at some point to see how the -300 performs. I would think that the 2,960mm focal length there would lend some advantage to the Mewlon, over the 1,100mm of the TOA-150.

 

One of the things that interests me, in this forum, are the comments about getting 100x per inch. With the TOA-150, you folks touting the 100x/inch are running with a roughly 2.2mm eyepiece. Exit pupil .30mm. All I can say is that it must be nice to be young, and to be able to operate in that realm. I've tried to work in sub-.5mm exit pupil territory, and with my old eyes all I get is muddy and muddier views as the exit pupil drops.

 

I try not to bite on the hype; but, I did buy two bottles of Tak green paint, just to be safe. Cheers to all!

[rockstarbill]

Though I feel that the F ratio of TOA-150b is better suited for visual use

Couldn't have made a more inaccurate statement than this. Speed isn't everything, and with it's 645 flattener it produces 1 micron spots on axis and 5 micron spots 30mm off axis. Good luck finding any refractor or reflector that can match that performance.

They don't exist.

[base16]

Couldn't have made a more inaccurate statement than this. Speed isn't everything, and with it's 645 flattener it produces 1 micron spots on axis and 5 micron spots 30mm off axis. Good luck finding any refractor or reflector that can match that performance.

They don't exist.

Missed this response. Bill, there is nothing inaccurate about that statement. I (or anyone doing DSO imaging) would have liked for a faster scope than f/7.3 especially for AP.. that doesn't mean I don't appreciate the other aspects of this scope. For instance, see my previous & next sentence to what you have quoted.

[rockstarbill]

Missed this response. Bill, there is nothing inaccurate about that statement. I (or anyone doing DSO imaging) would have liked for a faster scope than f/7.3 especially for AP.. that doesn't mean I don't appreciate the other aspects of this scope. For instance, see my previous & next sentence to what you have quoted.

You won't find a refractor at the moment that has spot sizes I mentioned. Fact. Looking at the f ratio alone is not all there is about a telescope when it comes to imaging performance. Not at all. Spot size is far more important these days with small pixel CMOS cameras dominating the market.

Edited by rockstarbill, 02 November 2021 - 03:36 PM.

[base16]

You won't find a refractor at the moment that has spot sizes I mentioned. Fact. Looking at the f ratio alone is not all there is about a telescope when it comes to imaging performance. Not at all. Spot size is far more important these days with small pixel CMOS cameras dominating the market.

 

 

I initially ordered this scope for visual only - after considering other high-quality larger refractors that are available on the market to purchase new. I had very little to no intentions of imaging with it when I placed the order. But in the last few months I've had this scope (correlation, not causation), I've gradually developed an interest in the imaging side of our hobby so I am certain that in a few months I would have converted this scope into an imaging setup.

 

 

 

Over all, I am not disagreeing with what you are saying -- they're built with enough precision & consistency to take great pictures. Unlike an Epsilon-160 f/3.3, or the DeltaRho 350 f/3 which are built primarily for taking images, scopes like the TOA also make good visual scopes given their f ratio and are not LIMITED to imaging.

 

The fact that the TOA takes great images was not my criteria when I purchased it, but is something I would leverage now that I am moving into imaging. f-ratio is not the main criteria for image performance, ofcourse, but is the fundamental variable that controls how much time you want to spend in acquisition; beyond a certain f-ratio it becomes pointless no matter how good the scope is. but, like I said, the toa-150 f-ratio makes it usable for both visual & imaging.

[rockstarbill]

I initially ordered this scope for visual only - after considering other high-quality larger refractors that are available on the market to purchase new. I had very little to no intentions of imaging with it when I placed the order. But in the last few months I've had this scope (correlation, not causation), I've gradually developed an interest in the imaging side of our hobby so I am certain that in a few months I would have converted this scope into an imaging setup.



Over all, I am not disagreeing with what you are saying -- they're built with enough precision & consistency to take great pictures. Unlike an Epsilon-160 f/3.3, or the DeltaRho 350 f/3 which are built primarily for taking images, scopes like the TOA also make good visual scopes given their f ratio and are not LIMITED to imaging.

The fact that the TOA takes great images was not my criteria when I purchased it, but is something I would leverage now that I am moving into imaging. f-ratio is not the main criteria for image performance, ofcourse, but is the fundamental variable that controls how much time you want to spend in acquisition; beyond a certain f-ratio it becomes pointless no matter how good the scope is. but, like I said, the toa-150 f-ratio makes it usable for both visual & imaging.

People image with f10 SCTs hosted in expensive sites like Chile. The point I was making is that focal ratio is not the only useful metric when looking at a scope for imaging.

A 14" CDK is f7.2. Based on what you said earlier, this would not be a scope ideal for imaging because of it's focal ratio, which is obviously false as the scope is designed for imaging. It does have 3.1-6 micron spot sizes though across a 70mm fully corrected field.

The TOA telescopes have always been imaging beasts. With their new flattener aimed at small pixel cameras up to a 60mm corrected field with 1-5 micron spots they are now the most desired for those so inclined.

The focal ratio is not as important as your original comment states. That's just incorrect.

[base16]

My comment was, just to recap, the F speed of 7.3 makes it more usable for visual than imaging. But I agree for imaging the other aspects of this scope make up for the F speed shortcomings in a big way. Over time I hope the scope manufacturers improve their design to allow for faster scopes for imaging purposes without sacrificing the optical quality -- it's not going to be easy or overnight, but I think the market will drive that innovation as more people shift to imaging. Based on specs, user reports, and pictures on Astrobin, I agree with you that this is one of the best scopes on the market right now for imaging in spite of it being f/7.3. I like the fact the top-notch quality is obtained straight out of the box without requiring the customer to spend days/weeks trying to perfect it.

 

But in any case... the TOA is still in "Visual attire" for now .. but in the coming days when the skies clear up in the bay area, I plan to test it out with the RST-300 for a guided imaging session using a QSI683. The mount makes it easy for me, to setup and tear down each time without making it a hassle. Will soon find out how good the tracking performance is for CCD (not-so-short exposures) imaging with the TOA-150b.

 

 

 

 

[rockstarbill]

While we agree to disagree that f7.3 is bad for imaging (it isn't) there is a 0.7x focal reducer that works really well to about APSC for the small pixel cameras. That gets you to f5.1.

Hopefully they release a new TOA Reducer 645 with spots more suitable to smaller pixels and with field coverage for larger chips.

Edited by rockstarbill, 07 November 2021 - 04:34 PM.

[Howard Gao]

My comment was, just to recap, the F speed of 7.3 makes it more usable for visual than imaging. But I agree for imaging the other aspects of this scope make up for the F speed shortcomings in a big way. Over time I hope the scope manufacturers improve their design to allow for faster scopes for imaging purposes without sacrificing the optical quality -- it's not going to be easy or overnight, but I think the market will drive that innovation as more people shift to imaging. Based on specs, user reports, and pictures on Astrobin, I agree with you that this is one of the best scopes on the market right now for imaging in spite of it being f/7.3. I like the fact the top-notch quality is obtained straight out of the box without requiring the customer to spend days/weeks trying to perfect it.

 

But in any case... the TOA is still in "Visual attire" for now .. but in the coming days when the skies clear up in the bay area, I plan to test it out with the RST-300 for a guided imaging session using a QSI683. The mount makes it easy for me, to setup and tear down each time without making it a hassle. Will soon find out how good the tracking performance is for CCD (not-so-short exposures) imaging with the TOA-150b.

 

 

IMG_1410.jpeg

2 counter weights seems unnecessary for TOA and the tripod?

[rockstarbill]

2 counter weights seems unnecessary for TOA and the tripod?

I do not use the 10lb cw for imaging. For visual use it's probably useful. The front of the toa150 is significantly heavy.

[base16]

While we agree to disagree that f7.3 is bad for imaging (it isn't) there is a 0.7x focal reducer that works really well to about APSC for the small pixel cameras. That gets you to f5.1.

Hopefully they release a new TOA Reducer 645 with spots more suitable to smaller pixels and with field coverage for larger chips.

Agree, I looked into the TOA-35RD but I am going to wait for an updated reducer that covers a larger chip as well.

[base16]

2 counter weights seems unnecessary for TOA and the tripod?

You're asking a very valid question :-)

 

I like to use counterweights with the RST-300 even with the 130GTX out of abundance of caution even though its not necessary; the mount can easily handle the 130GTX and track it perfectly well. I keep the weights just to ensure there are no accidents in case of power loss or cable snag. These are hard to replace scopes, so these counterweights are used to help the RA brakes so it doesn't get overwhelmed and give up when the OTA is pointing at an unusual angle (usually near zenith).

 

For visual, with the TOA-150b when I'm standing right next to it there is no need for counterweights -- we can save the situation by holding the gear even if the power goes out. But for imaging I will most certainly use counterweights to help the RA brakes because I most likely won't be standing right next to it during the session. I don't need to balance the weights in any particular way though so I leave them there just to reduce the amount of imbalance when the need for RA brake kicks in.

 

 

I do not use the 10lb cw for imaging. For visual use it's probably useful. The front of the toa150 is significantly heavy.

 

That's right.. the scope is significantly front heavy for visual. But good to know you're using it without the CW ring -- I suppose you have a full imaging train already. I am very light on the imaging train right now though, so might need to use the CW ring until I add in my accessories over time. For now I don't even have an autofocuser (its going to be either of FLI Atlas / Nitecrawler). The QSI683 with its integrated FW & OAG that I currently have is super lightweight.

Edited by base16, 07 November 2021 - 09:59 PM.

[rockstarbill]

You're asking a very valid question :-)

I like to use counterweights with the RST-300 even with the 130GTX out of abundance of caution even though its not necessary; the mount can easily handle the 130GTX and track it would track it perfectly well. I keep the weights just to ensure there are no accidents in case of power loss or cable snag. These are hard to replace scopes, so these counterweights are used to help the RA brakes so it doesn't get overwhelmed and give up when the OTA is pointing at an unusual angle (usually near zenith).

For visual, with the TOA-150b when I'm standing right next to it there is no need for counterweights -- we can save the situation by holding the gear even if the power goes out. But for imaging I will most certainly use counterweights to help the RA brakes. I don't need to balance the weights in any particular way - they're there just to reduce the amount of imbalance when the need for RA brake kicks in.



That's right.. the scope is significantly front heavy for visual. But good to know you're using it without the CW ring -- I suppose you have a full imaging train already. I am very light on the imaging train right now though, so might need to use the CW ring until I add in my accessories over time. For now I don't even have an autofocuser (its going to be either of FLI Atlas / Nitecrawler). The QSI683 with its integrated FW & OAG that I plan to use right now is super lightweight.

I only had the qhy268m, filter wheel, and 645 flattener on the back of the stock focuser with a Sesto Senso 2 motor. It came to balance nicely and worked great. No need for the counterweight for imaging IMO.

Now if you used a DSLR then yeah you would probably need it.

[base16]

I only had the qhy268m, filter wheel, and 645 flattener on the back of the stock focuser with a Sesto Senso 2 motor. It came to balance nicely and worked great. No need for the counterweight for imaging IMO.

Now if you used a DSLR then yeah you would probably need it.

Good to know, thanks.. once I have it up in the next few days (next Fri looks to be a clear night) I'll check it out and see if the scope clears the tripod legs. 

 

The supermount CYG54G tripod has an adjustable pier, but I have ordered a fixed pier extension so I can get some clearance. That should also help remove the need for the CW ring.

[base16]

Thanks for the tip on the the CW ring. It's now been removed. I tested for rough balancing on a table -- if I can lift the right side (camera side) too easily, then the lens side is too heavy so I slide the lens closer to the rings. The RST-300 doesn't need (and doesn't allow) fine balancing, so I just perform a rough balance like this to ensure the OTA doesn't drift down on DEC axis on power loss; for RA there is a brake.

 

 

 

With random indoor slews the tripod legs have cleared so far. The 10lb reduction is a good compromise for now, atleast for imaging. I'll be adding some heavier equipment in the future so the balance should only get better (right now its still slightly front heavy).

 

 

The M72 to 2" that comes with the scope is only useful for visual, as you can see from the thumbscrews in the second picture; I have a threaded adapter on order so I can safely use the camera and also avoid any a potential reason for tilt.

[rockstarbill]

The dew shield is really long so if you need to move it in to help with balance you should be okay. I use the powerbox and a 8" Astrozap dew strap which is perfect for the scope.

[Raface]

​Hi,
Congratulations!
I use TOA-150B on RST-300, too, and the powerful torque of this harmonic drive mount makes it possible to remove the 5kg tube weight of TOA-150B. And I don't usually use the counterweight of the mount, but when it's windy, I attach it to bring the center of gravity of the entire system closer to the center of the tripod's grounding triangle to prevent it from tipping over.

[Raface]

I currently have two TOA 150s. I use him strictly for imaging. I’m about to get a visual train for one of them. I simply cannot believe that you don’t need any backspace spacer to reach focus visually?
Couldn’t really be this simple?
Bino viewers?
Any bones you can throw my way will be greatly appreciate it

[Scott in NC]

I currently have two TOA 150s.

 WOW!