Collimating Epsilon 180 (Secondary mirror ONLY)
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- เผยแพร่เมื่อ 24 มิ.ย. 2024
- Takahashi Epsilon 180 is my first Newtonian telescope. Before that I have used a Schmitt Cassegrain and a Refractor, and I can tell you big aperture Newtonian telescope is the most challenging when talking about collimation and tilt adjustments. I'll explain how to do the collimation for Epsilon 180 in this video.
For a scope with a price such as this one, it s nothing short of an insult to the customer to not make a decent guide and decent collimation tools. Thankfully I have never felt a desire for their products. Thanks for the informative content!
Thanks for the info. Very informative! Don’t think I want to mess with that. Think I’ll steer in the direction of a refractor.👍
thank you so much! first time its ever been properly explained!
Thanks for your encouraging comment!!
Excellent Ben...thanks for share
Good idea !!!! Saludos desde Chile!!!👋👍📸🔭
The secondary mirror is the hardest part of the fast Newtonian collimation. Once it is properly done, the primary mirror collimation is a piece of cake. The secondary mirror is pretty close to perfect out of the box according to my experience. It seldom requires collimation except it disassembled for cleaning.
epsilon collimation separates the men from the boys
Good man!
Sorry about my English, I live in Spain and I don't speak the language well. Congratulations on the tutorial, I have learned a lot.
Could you do another tutorial explaining how to collimate the primary?
Thank you so much. With examples like this, it is wonderful to learn.
Perdón por mi inglés, vivo en España y no hablo bién el idioma. Muchas Felicidades por el tutorial, he aprendido mucho.
¿Podría hacer otro tutorial explicando cómo colimar el primario?
Muchas Gracias. Con ejemplos como este, es maravilloso aprender.
Such a great demonstration! What is the purpose of the nylon-threaded piece? It doesn’t seem to need to be centered? Your collimation looked outstanding at the end.
Good question Michael! I didn't use it because it was hard to be tightened and not exact in the center. But 2 months later, I realized it will actually help with tilting the focuser and making sure the camera is pointing at the right center of the imaging circle. So, it is useful and it should be centered as well, but it's more about tilting than collimation.
Thanks Ben anything video on the primary collimating
Hi Jaspal, I'm not sure about the primary collimation, it sounds super difficult from Taki American guys, I won't move that unless absolutely necessary...
Hi Ben, thanks for you very informative contributions. I however do have a question.
You are saying that you collimated the scope 10 times. Seems a bit much considering it had first light +- 4 months ago.
What is you opinion about the ability for this telescope to holds it collimation. Does it need collimation on each trip by car?
Hi, thanks for the comment! Oh, this scope holds the collimation very well, very very solid. The reasons for me doing that is:
1. I was not sure about the whole process, didn't do it right in the first couple tries.
2. I actually had a tilt problem on my optical train, and I only found out after another couple tries.
3. The combination of collimation and tilt adjustment is a super tricky one, it took me 4-5 more tries to get a good process for that.
I'm glad you raised this question, this could become a huge misunderstanding about this scope... Thank you!!
Yes, I will probably make another video about the tilt adjustment.
Hello Ben. Good video. Thank you for sharing.
After doing collimation, did you check the result with another tool (laser, concenter, Chesier, etc.)? After the collimation shown, would you be able to post a video of what the collimation looks like with the other tools? Do you also plan to show the collimation of the main mirror? I have a Concenter eyepiece. Shouldn't the secondary mirror be exactly in the center of the Concenter okular after collimation? Thank you in advance for answering my many questions. Clear sky.
Hi Stephan,
Thanks for the message. At least for my E-180, collimation scope is the best tool to do the job, I do have a laser chesier collimator, but I use that to check/adjust the tilt on focuser. When collimation scope says it's good, it's good. As for the main mirror, I don't have the courage to mess with it. From what I learnt, if that part need collimation, the best option is to send it back to Houston... Also for E-180, the secondary mirror is not concentric to the main mirror at all. That's why I can't use that as a clue for collimation on E180. I know this is probably the case for other newtonians, but unfortunately, this is not for E180. Hope this answers your question, clear skies!
@@bensastrophotography5915 Thanks for your quick reply. The adjustment of the main mirror is easier than that of the secondary mirror. You just have to understand how the special screws work. Then it's not a problem. Adjusting the secondary mirror is also easy with the Takahashi description. The prerequisite for this is that the marking on the secondary mirror is exact. After setting the secondary mirror like in the video, do you have round stars all over the field? It's true with the Epsilon everything looks shifted because of the offset. But if I understand everything correctly, the secondary mirror must always be set in the center and circular to the focuser. This works excellently with the Concenter eyepiece. If you have a Facebook account then I could show you pictures I made.
Thanks for the info Stephan, the guys from Takahashi America advised me to avoid touching primary unless absolutely necessary, I think I'll probably keep myself away from that. I almost have round stars across the filed on my ASI1600, except 1 corner, but on my 5D Mark2, the stars are round all across, so I guess my ASI1600 probably has some tilt problem.
Do you plan on making a video for collimating the primary mirror? The Primary system of the Epsilon 180ED really confuses me and this is something that would help me out a lot.
Hi Joshua, I've done an overall collimation for E-180 just about when you posted this question, that includes secondary, focuser tilt and primary. I'll probably do a brief intro video about that soon. Thanks for your comment!
Hello! Great Vid! What kind of a light source do you use and exactly where do you place it?
Hi, sorry for the much delayed reply. I used a light box in front of the OTA, facing right into the primary mirror when making these videos, but it's not a must. You can just use a well lighted white curtain, or anything with a well lighted surface.
Thanks for posting Epsilon 180ed relevant stuff, Ben! I have a 180ed myself and spent months getting the primary and secondary mirror properly collimated. Also, my model's stock focuser had flexing issues which were a pain in the rear to tackle. Still have some and will probably have to replace the stock focuser with a more sturdyone, but as the 180ed is totally unforgiving I still need to do some more research before I decide, as not to buy something that can't live up to the task. I have a couple of questions: I see you use an ASI1600MM Pro with your scope together with the EFW 31mm filter wheel. Are you getting a lot of vignetting? I'm thinking of getting this camera for my 180ed but after working with 31mm filters on a QSI for a number of years, I'm thinking of maybe going for 2" filters this time to have a little less abrupt vignetting to flatten out. Secondly: did you have problems finding the right spacer to get the correct distance between the Epsilon's corrector and the filter wheel/camera? This is something I spent several weeks getting right with the QSI. Ordered something from www.preciseparts.com, but I had the wrong measurements which of course didn't end well. Fixed it with 3d-printed washers, hehe. What about you? Was it easy getting the distance between the scope an camera/filter wheel right with the ASI1600?
Ginge
Hi Ginge, thanks for the comment! It's always a great pleasure to talk to someone using same telescope as mine:) First, you should not worry about 31mm filters on ASI1600, if you use their filter wheel. I have to say I was impressed by the design of EFW, the filter is very close to the cmos, so you don't need a much bigger filter. For sure there's some vignetting, but nothing cannot be corrected by flat frames.
To answer your second question, I bought TCD0165 and TCD0013 from Taki, which is very close to the ideal backfocus (you can try put the M42 plastic pads that comes with ASI1600 to see if longer backfocus can get you better results on the corners). I also ordered a 1 piece adapter from PreciseParts, I took into consideration of 2mm thick filters while calculating the backfocus, so I think it works better than the Taki adapters (not very obvious though). I recently switched to ASI6200mm, so if you're interested, I can sell either of them:)
Oh, one more thing about the focuser. I haven't used my stock focuser for even 1 night, so no comments on that. And the 2.5" newtonian focuser customized for E180 from MoonLite did a decent job for me so far. But if you want a rotator, I see Optec's GEMINI is a great choise -- with a great price too. Just FYI.
Heheheh, the Optec Gemini looks perfect! I’ll just sell a kidney or two ;-). I might be interested in a spacer, though. Do you have an Astrobin account? If so, I can PM you there...
@@Gnifse Sure, my ID in Astrobin is: tbcgeorge
Thank you , what is the name of the adapter for televue phone mat, please ?
Hi Cedric, it's Televue's DIOPTRX adapter for Nagler type-6 eyepieces (DNA-6000 Adapter), I was lucky to have it just fit into the collimation EP from Takahashi.
Shouldn't everything also be centered on the crosshairs? Maybe it's the phone view, but it doesn't appear that way at 9:17. I thought that was part of the goal, not just getting everything concentric.
You're right, I realized later that these's one more thing to be aligned: tilt of the focuser, and that will take care of the central spot on my secondary.
Excellent video... Chinese counterparts cannot be collimated to that level... thanks for share
Do not touch the middle screw - just work one of the three outer screws one at a time. If you mess up with the middle you are losing the secondary mirror position...
Thanks Lachezar! But in my case, I changed the stock focuser right away, which means the secondary position has to be moved. After this video, I have been struggling with the collimation till last month, 2 more things I found that affects collimation: 1. focuser's perpendicularity, 2. primary mirror collimation. -- Yes, I finally moved 1 set of screws of the primary, and guess what? I have the best image according to CCD Inspector! I'll try to release a video on that too, let's see...
@@bensastrophotography5915 I am glad to hear that - it is a nice scope.
@@bensastrophotography5915 How do you set focuser's perpendicularity?
もっと要点を捉えて説明した方がいい。