1.20
#...
·
·
1
like
|
|---|
Jacob Heppell: I concur with the statement with the fast scope + reducer causing all sort of issues. I have been using the Starizona CC/Reducer, and while it speeds up my 6" orion, it also magnifies any collimation and tilt errors. I recently bought Sharpstar CC from Agena astro, which only reduces 0.95X, which is basically nothing, but my image no longer suffers from extreme tilt. I still have a tilt though and it's due to the compression ring connection. Unfortunately, getting a threaded tilt is like trying to find an albino crocodile at the North Pole. A futile attempt if you ask me. And I did look around and anything close to a good focuser with little to no information if it's even compatible with a 150mm (6") or a 203mm (8") is not totally clear with them. I tried messaging someone at Farpoint Astro, since their focusers look decent, but I can clearly see they are also compression ring style connectors. It seems like telescope companies still haven't caught up with math and physics or they just want to throw a fast scope together and call it an "astrograph", but the parts they use may pass for visual observing, but doesn't work with cameras which catches the smallest optical error such as tilt. Not to mention their weight capacity. I just can't use my mono camera setup on my 6" newtonian, that's for sure. I just recently purchased a supposedly heavier duty linear bearing focuser, but I'm almost feel like sending it back, because just plugging in the 12V cable made the focuser move in, while the tension screw is already at max. Same thing was going on with my RC 6" and its linear bearing Crayford. I replaced it with a rack and pinion focuser with threaded end (special order from Aliexpress) and all my tilt problems and poor focusing issues was gone immediately. I tried to find the same focuser for the Newtonian, but none available, even though it would be only a slight modification to make the focuser fit inside the focuser hole (trust me I already tried that with the RC focuser) and Voila! Rack and pinion focuser- definitely heavy duty - non slipping- threaded end. I just don't know when this extremely futuristic design /idea of mine ever reaches TPO/GSO/Orion/Skywatcher ! (insert heavy sarcasm). I know Sharpstar had an idea about this, since their rather expensive Newtonian that comes with its own flattener uses rack&pinion focuser and threaded connections. |
1.20
#...
·
|
|---|
Unfortunately, getting a threaded tilt is like trying to find an albino crocodile at the North Pole. A futile attempt if you ask me. And I did look around and anything close to a good focuser with little to no information if it's even compatible with a 150mm (6") or a 203mm (8") is not totally clear with them. Pretty much any focuser will go on any newt; you just need a base plate that matches the curvature of the OTA. When I bought my 3" feather touch, I bought a base plate that fits a 10" tube then installed it. Albeit I had to drill new holes in my OTA to install the baseplate as its hole pattern didn't match the stock base plate that came with the OTA. TS Optics have a good selection of focusers including from feathertouch. Might be worth just having a browse. I'd recommend rack and pinion with a threaded end cap. |
|
1.20
#...
·
|
|---|
It seems like telescope companies still haven't caught up with math and physics or they just want to throw a fast scope together and call it an "astrograph", but the parts they use may pass for visual observing, but doesn't work with cameras which catches the smallest optical error such as tilt. Well yes that was a problem when I bought my 10" Quattro. Wasn't up to scratch. I've modified the hell out of mine over the years to make it much more robust. Can hardly call it a skywatcher anymore. |
|
1.20
#...
·
|
|---|
Same thing was going on with my RC 6" and its linear bearing Crayford. I replaced it with a rack and pinion focuser with threaded end (special order from Aliexpress) and all my tilt problems and poor focusing issues was gone immediately. Same here. Just wish I bought the r/p threaded endcap focuser earlier. |
 #...
·
·
1
like
|
|---|
Jacob Heppell:Same thing was going on with my RC 6" and its linear bearing Crayford. I replaced it with a rack and pinion focuser with threaded end (special order from Aliexpress) and all my tilt problems and poor focusing issues was gone immediately. Jacob Heppell:Same thing was going on with my RC 6" and its linear bearing Crayford. I replaced it with a rack and pinion focuser with threaded end (special order from Aliexpress) and all my tilt problems and poor focusing issues was gone immediately. Interesting. I've had a little variance in my corners that I usually don't pay a lot of attention to. I assumed I just wasn't doing a fantastic job of collimating, but I'll try the screw on adapter again. Have you found a way to adjust the camera angle? I'd guess there is some sort of stopper ring that goes over the threads? |
11.91
#...
·
|
|---|
John Tucker: Anything simple or off the shelf that you use to allow for rotation will undo all the benefit of the threaded focuser. The best method, I think, is to just use a well built focuser with rotation capability designed from the get go like the Moonlite. |
|
1.20
#...
·
|
|---|
John Tucker:Jacob Heppell:Same thing was going on with my RC 6" and its linear bearing Crayford. I replaced it with a rack and pinion focuser with threaded end (special order from Aliexpress) and all my tilt problems and poor focusing issues was gone immediately. my focuser can manually rotate should I need to change the camera angle. |
#...
·
·
1
like
|
|---|
Arun H:John Tucker: Jacob Heppell:John Tucker: I'll probably just continue to crop as needed. As long as the corrector is fully inserted into the focuser tube its not that much of a problem for me. Its funny, I used to worry a lot more about getting things perfect. But I took about a year off from the hobby due to some life events, and then I looked at my old pictures and thought "these are actually very nice". I'm doing the 80/20 thing these days. |
#...
·
·
1
like
|
|---|
|
Interesting to note the improvement in the corners here with the corrector screwed to the focuser. As usual, some trouble with blue light punching through the L-Extreme filter and giving halos. Tried to fix this manually in Lightroom. I use the Televue 2.4 inch extension tubes to attach the corrector to the focuer. I guess I'll pick up some of those little spacer rings and see if I can use those to rotate the camera/corrector assembly while keeping the corrector screwed on tight. Does anyone know how many turns per mm the thread is? I see 1 mm and 2 mm Televue spacer rings but I wonder if there are smaller ones that would work to give intermediate rotation.  |
|
1.20
#...
·
|
|---|
John Tucker: Glad you could see a good improvement in the stars upon using a threaded connection. You don't have to use the televue spacers specifically. Any spacer ring that matches the size of the thread is fine. |
#...
·
·
1
like
|
|---|
| @Jacob Heppell This was quite interesting to me. Several years ago I bought a TS Optics "Power Newt", a carbon fiber F/4 Newt bundled with a TS Optics 0.7x reducer/corrector to give an effective F/2.8 Newt. I also purchased a non-reducing "Superflat" corrector. The reducer corrector gave me fits and I sold it without getting any pictures that were satisfactory and after many many hours of trying to correct tilt issues. It now seems apparent from the results above, that each time I removed the camera assembly from the focuser in order to be able to access the adjustment screws on the tilt corrector, I changed the angle of the corrector in the focuser tube. So the bizarre and unpredictable results I got trying to adjust the tilt corrector now make sense. The Superflat corrector has an extra long thread on the camera side. I screw an adapter on there followed by the camera, and the other side of the adapater screws onto the focuser. Even if I had kept the reducer/corrector, it had no such extended thread on the camera side. I don't know how I would screw it onto the focuser, but this sounds like it might have solved a lot of problems. F2.8 would be a blast if it worked. How do you screw your corrector to your focuser? Is there a similar long thread and adapter? I'm not seeing these long threads in most of the correctors I look at online. Picture of the Superflat corrector with the adapter screwed on below  |
|
1.20
#...
·
·
1
like
|
|---|
John Tucker: Yes makes perfect sense to me why you would have struggled with F2.8 without the security and reproducible positioning of a threaded connection. The paracorr II coma corrector has a female thread (65mm I think) that I connect to this adapter, which gives me an M68 female thread to connect to the focuser and an M48 male thread to connect to the camera/FW/OAG assembly. |
|
1.20
#...
·
|
|---|
Jacob Heppell:Unfortunately, getting a threaded tilt is like trying to find an albino crocodile at the North Pole. A futile attempt if you ask me. And I did look around and anything close to a good focuser with little to no information if it's even compatible with a 150mm (6") or a 203mm (8") is not totally clear with them. Are there any reasons we don't get similar products in the USA? I know about the Feathertouch and the Moonlite focusers, but browsing the TS Optics site (and some other ones from UK), it seems there are a lot more quality scope + scope accessories available, while in US it's either a special order or "never heard of it" options. Interestingly the EU stuff is also made in China and Taiwan, just like the stuff in USA. |
|
1.20
#...
·
|
|---|
Are there any reasons we don't get similar products in the USA? I know about the Feathertouch and the Moonlite focusers, but browsing the TS Optics site (and some other ones from UK), it seems there are a lot more quality scope + scope accessories available, while in US it's either a special order or "never heard of it" options. Interestingly the EU stuff is also made in China and Taiwan, just like the stuff in USA. Well, like you say, the manufacturing is largely done in China/Taiwan so not really local to either the US or EU. Feathertouch and Moonlite are very well reputed US brands that have done astro a great service over the years. So if they were your only options, you're in good hands. |
#...
·
·
1
like
|
|---|
Jacob Heppell:Are there any reasons we don't get similar products in the USA? I know about the Feathertouch and the Moonlite focusers, but browsing the TS Optics site (and some other ones from UK), it seems there are a lot more quality scope + scope accessories available, while in US it's either a special order or "never heard of it" options. Interestingly the EU stuff is also made in China and Taiwan, just like the stuff in USA. I guess what I'm not following is how you put this together. I have a threaded focuser (God knows what the thread size is, I bought the adapter recommended by TS Optics), and an adapter that fits onto the focuser and a thread on the corrector (which thread is immediately adjacent to the one for the camera and a little larger than M48, looks like about M52). I briefly played with the idea of reinvestigating the 0.7x corrector (F2.9) with the corrector threaded on this time. But was not able to identify any reducing corrector that has a thread analogous to the one on the TS Optics Superflat corrector that I use now and which is pictured above. Surely you don't use the filter thread to connect to the focuser? I wouldn't expect those to support the weight. |
|
1.20
#...
·
|
|---|
John Tucker: Sounds like you've got it together! |
