How To Easily Collimate A Ritchey Chretien Telescope

[@Philip-KA4KOE]

First video I've seen starting with the focused ring. Makes sense.

[@rockchucksummit]

Great video as usual! Thumbs up for RC's. Their collimation isn't that difficult and doesn't deserve the drama people make it out to be!

[@michaellewis7768]

My next t-shirt - "Astrophotography... You're gonna spend more money!"

[@enteringintospace4685]

Lol....don't hate the player, hate the game🤣

[@Astrobloke]

Nicely covered Steve. I had an RC8 by Altair, i had filmed all the collimation steps with the intention of releasing a video and then I sold it as I bought an OOUK CT10. I thought you explained this really well without overcomplicating anything. Great job sir

[@enteringintospace4685]

Hey thanks so much! I've watched several of your videos and appreciate the "let's get right into it" format you bring as well. I was also interested in the oouk brand newtonians to possibly swap out my Quattro 200P but then this Ioptron was in stock so I pounced...lol Cheers and clear skies!

[@kantoskan4314]

I don't have an RC scope now but I'm just happy to see another Bucs fan. :)

[@jeffjastro]

Excellent video...great step by step structure and well presented (including humor) - thank you!

[@enteringintospace4685]

Thanks Jeff!

[@whereswa11y]

Very cool. Very simple. Very duh question… the collimating ring stays in place now yes? Ok off to spend more money

[@capturedbyhisdesign8656]

Hey great video and thanks for making it. I only have 4 rings in the primary mirror step not 5 like you have. They are evenly spaced/illuminated so not sure if that is ok or not?

[@bloodstone2000]

I got it! I can tell my significant other I'm going to spend more money to achieve Rockstar Stars! She might Just buy it! haha .. GREAT video as always my friend. I have been looking at an RC for a little bit and this one answered all my questions! Thanks man! 🤘🏻

[@enteringintospace4685]

Lol....we all in this together👊 Good luck mu friend😊

[@TheMje1963]

Don't forget you will have to get something just as nice for her or she will never let you live it down. LOL

[@bloodstone2000]

@@TheMje1963 😂 isn't that the truth huh! If I get new gear either Guitars or Astro? I ALWAYS have a Vegas trip planned for her first. Haha. Thats how I survived being married and touring. 😂

[@Dionaeatrap]

Great vid. Ive done a star test on my 8" carbonstar RC but never adjusted the primary or focuser. The cheshire tool I have seems a pain. May have to get a laser. I do not see a collimation ring available for my scope, but I do have a tilt adaotor on my cam, does that count?? I see no way to use tilt adaptor with laser tho.

[@brianastrodoc2886]

Excellent and informative as usual. I actually raised my hand but you didn’t pick me. I swear you must have an engineering background. Clear Skies

[@enteringintospace4685]

Practical engineering...lol. Thanks!

[@brianastrodoc2886]

@@enteringintospace4685 I checked my on axis collimation tonight with the out of focus star method and it looked perfect. I think my off axis stars can possibly be balanced out better, should I try to tweak the secondary mirror a little to improve it or will that effect the on axis star?

[@e.jaxs82]

I am learning so much. You need a Patreon account. Great video as always.

[@enteringintospace4685]

Thanks Sis!!❤😊

[@JB-kx9bx]

I finally got the collimation ring from Agena Astro after waiting more than a year for them to get in stock! I can’t wait for clear skies to test it out!

[@davidjennings2733]

I was looking to possibly getting an RC telescope however this additional expense of the collimation ring / collar and the Howie Glatter Laser Collimator which between both, they are almost as much as a scope. This is quite the deterrent. I think I may just stick to using refractors. Great video Steve and thank you for your expertise on this.

[@MemoBTL]

Awesome, thank you!! For your video i already have all the accesories! and now it´s super easy!

[@Tokyogeoff]

Thank you so much but I am stumped on seeing the concentric rings on the primary. It's a new scope and no dust so its just impossible to see. How do you do it? I've really been struggling with my GSO RC8 and actually see TWO laser spots on the secondary donut and have used two different Howie Glatters. Any ideas as to what causes that please? Sincerely. Geoff

[@enteringintospace4685]

Hey Geoff! Dimming the lights really helps and is what I do. If I'm out on the patio I try to do it at dusk so I can still see to fiddle with stuff. I've got a follow up video planned that will help fine tune collimation, hope to get it out soon!

[@malcolqwe2]

what if the secondary doesn't move in the direction you need it to move no matter how many times you try different combination of the three screws?

[@tacomaastro7462]

Great explanation. focuser adapter is on back-order (surprise) and I got tired of waiting so my first step was doing a primary mirror 'centering' alignment with the bright light on the wall and just looking down the tube. To my surprise, when I put the howie-gladder on it, it was damn near spot on. the rest was as you described here with a fine tune on the primary to finish up. Same Ioptron RC8 :)

[@enteringintospace4685]

Thanks! I was surprised at how well collimated the rc was out of the box. Even the focuser was really close. The secondary mirror holds its position extremely well. My newt on the other hand has to be collimated like every other night out.

[@tacomaastro7462]

@@enteringintospace4685 That's what I've heard on other videos about newts... sensitive little buggers :) I should note that my RC8 visually looked perfect but when doing DSO I was getting tails on the stars.

[@dawnpaulandelizabethromero3458]

Any chance you might do a video on cleaning the mirror?

[@enteringintospace4685]

Hey! I'm getting close to switching to wide field. When I do I will make a video on pulling and cleaning the mirror.

[@mcastrophotography76]

In the RC8 the fok is integral with the primary even if you put a collimation ring on it. The primary mirror should be "released" from the focuser, as in serious Trusses. For this reason, the best collimation method if one does Astrophotography is the DSI method: first the primary mirror is made on a very bright star and finally the secondary mirror is made by observing the small donuts on the sides. In this way, even small tilt errors that are always present in the cheap Chinese GSO RC8 are compensated. Furthermore, the collimation ring makes little sense to calibrate it without the optical train because the latter will certainly introduce a small deflection that must be corrected and the only system is precisely the DSI.

[@isaacmartinez4310]

FINALLY!!! Thank you! I have the 6in iOptron Ritchey Chretien.

[@enteringintospace4685]

Good deal!! How do you like it so far?

[@brettfadem2084]

Is there any danger to a person's eyes when they look at the single dot from the laser?

[@malcolqwe2]

and if you dont have a center dot on the secondary?

[@hael8680]

Good video! How well does the scope keep its collimation? Can you move it around from night to night without having to go thru this process every single time?

[@enteringintospace4685]

Thanks! I've been checking collimation once a month and making very minor adjustments. Nothing like nightly collimation of the newt.

[@davidcotten3727]

Hi Steve! Big Fan!!! I am interested in getting an RC scope, and collimation seems to be an issue for many people, but your video has changed my mind... Thanks for that!!! One question I have after watching this video has nothing to do with collimation, but of the ZWO EAF I see attached to your scope. The iOptron RC is what I have been looking at to purchase, but until now it seemed that it would only except the iEAF focuser. Did you have to do anything special to mount that to this scope?

[@enteringintospace4685]

Hey Thanks! I believe agena astro has a 3d printed mount for the eaf that fits the concave shape of the RC focuser. Im actually using one on my newtonian. The flat bracket the eaf comes with will crack the focuser if you tighten it too tight.

[@Astrolavista]

Excellent video, and the best guide to collimating an RC I've seen! (Assuming you star tested the scope after the 4 steps and the Fresnel rings were concentric?) I've owned an RC in the past and have been horrified by people taking their scope apart to try and collimate the things. I literally just made tiny adjustments whilst on a defocused star to do mine, although it was a compromise because I didn't have the camera tilt plate at the time. Good job on this, I think it will help disperse the fear surrounding RC's :)

[@enteringintospace4685]

Thanks! Yeah I debated a year before buying one because of how hard I thought us was to collimate. And yes defocused star test was spot on.

[@terrydoran8689]

I finally acquired all the tools here and ran into one problem. The concentric circles projected on my primary were no where bright enough to see. I found it much more easier to collimate the secondary by using the point beam to line up the reflection of the laser to it's point of origin.

[@scottlockwood2308]

I see mentioned in the comments a DSI scope which has the focuser as part of the secondary mirror assembly. Does this change anything shown in the video? I have this scope.

[@DavidHunt-pc4xi]

Steve. I have followed your guidelines, but in step 2 I don't see any laser rings inside on the primary mirror. How many extension rings are you using? I am only using the 2" extension.

[@enteringintospace4685]

Extension shouldn't affect how many rings your seeing reflected on to the primary. So you HG is in where the cam was and the concentric ring adapter is on it and your not seeing the laser rings on the primary?

[@jaredroberts6409]

i literally was just doing this and also can't see the rings. if i hid my eyes behind secondary i could sorta see them. I ended up using single point method of doing best to reflect dot on itself. My theory is the lazer not out far enough.

[@enteringintospace4685]

@jaredroberts6409 how was the room you were in. If it's bright where your at you probably won't see them.

[@DavidHunt-pc4xi]

@@enteringintospace4685 Yeah, I'll try racking the HG farther out. Thanks

[@DavidHunt-pc4xi]

@@jaredroberts6409 Yeah, I could kind of see rings on the black barrel of the telescope. I'll rack the HG farther out. Thanks

[@hael8680]

Do you use any dew protection with this type of telescope? Dew straps? Dew shield?

[@enteringintospace4685]

I didn't at first but I'm finding I need to figure out how to Dew protect the secondary mirror. Might just have to make a shield

[@davidjennings2733]

Hey Steve, Just curious, do you still have your IOptron RC scope and if so, do you use it much or are you now using The BEAST Orion Newt? I am still on the fence about getting an RC scope, perhaps the 10 inch but have not bit the bullet as of yet. So just curious if you still have yours, if so are you still happy with the results it produces and so on., Thanks again and Clear skies. DJ

[@enteringintospace4685]

Hey DJ! No I sold it probably a year ago. It did ok, lots of soft spongy images. I think if BX was out when I had it I might have kept it. I never could get it reduced so I was always shooting at the native f8. With my skies I need speed. I've kicked around getting and edge hd, but I would probably have the same issues. So for now the newt rules. If your heart is dead set on owning one I would look at the sharp star v2 series. It's a 10" at f5, like 1400mm I think. Pricey but a really cool RC. Good luck!

[@davidjennings2733]

@@enteringintospace4685 Thanks for the update Steve and yeah, not really dead set on getting one, it's a toss up between a Newt, 8 to 10 or CAT-RC but I am really leaning towards the NEWT as it's faster with the same diameter scope. Ugh, decisions, decisions.. Thanks again for the response, I appreciate that. CS, DJ

[@Philip-KA4KOE]

I've had an 8" rc for awhile. Maybe now I can collimate it.

[@werner7156]

You haven't lost a word about the distance between the hyperbolic mirrors, so this is more than relevant. I had completely disassembled my RC and then had to do a complete basic setting. I noticed how important the distance between the mirrors and me is Despite everything, I adjusted everything cleanly and it was a very bad image. Only resetting the second mirror by 2 1/2 turns of the pressure screws gave me the result I needed. Expensive adjustment means are not necessary. I worked with PinHole and Cam.

[@twinturbostang]

How do you know if the distance between the mirrors is correct? I have collimated my GSO RC 6" scope but the images are still not great. I suspect the distance between mirrors needs to be changed.

[@werner7156]

@@twinturbostang That's exactly the point I wanted to make, I also dismantled my entire scope to clean it and have to do a complete readjustment, unfortunately I've only now realized how important the distance between the two hyperbolic mirrors is, you have to I'll take it slowly with all caution, my scope is not to far from perfect but still needs Adjustments. I test my scope mainly on Betelgeuse and repeat all collimations steps after adjusting a littel the distance between mirrors - that's a must do. My last result isn't even that bad, here's a video after focusing, I had previously put on the Bahtinov mask. kzbin.info/www/bejne/b5u3iHWVl9KqgMk You should also test how much play there is between the mirror hole and the holding tube. In my case there was a whole 0.8 mm of space to move back and forth, I applied tape to stop it.

[@twinturbostang]

@@werner7156 Changing the distance between the mirrors is easy (I think) using the center screw on the secondary. But my question is.. how do you know when the distance is CORRECT? Is there a way you can easily measure this? Without taking the scope apart hopefully? Sorry, I'm a beginner when it comes to RC scopes. But I thought I saw someone talk about uploading an image (of stars I think) to a website and it can calculate the effective focal length. If you know what it should be, then that can tell you if the mirrors are too close or too far apart. But I don't remember any details how to do this.

[@werner7156]

@@twinturbostang The only way I know of would be to use a Ronchi eyepiece when setting the mirror distance, where the stitches on a real star must be absolutely straight when viewed in the correct setting. An eyepiece like this costs around €60 here in Germany, I don't own one myself but I started making one myself out of 0.1mm wires. I am just trying to find the best Point / image for myself. Since I can't give you a link here because otherwise my post will be deleted, please use the keywords to search on Google so that you can understand and what the illustrations say / mean. ( Appearance of Cassegrain Ronchi Patterns insinde Focus )

[@werner7156]

@@twinturbostang KZbin tries to prevent information from me in various ways, so I'm giving up providing detailed information. Please deal with the topic of Ronchi Okulat and become active yourself. I've really tried everything to give you information but my postings keep getting deleted. Also search for the term (( Appearance of Cassegrain Ronchi Patterns inside Focus )) so you can understand what is going on based on the illustration. I can't offer you anything else otherwise the post will be deleted again !!

[@Psychlist1972]

Every one of these videos uses the Howie Glatter Laser. Unfortunately, he passed 4-5 years ago and these have not been available for a while. It doesn't appear that anyone has picked up their production. I've been looking for a bit. Has anyone found a substitute? It's frustrating trying to collimate when everyone is showing how much easier and more accurate it is with this tool :P

[@I_Spaced_Out]

I found a real easy budget hack for seeing the super bright laser in the middle of that centering ring of the Secondary Mirror: DO this step in daylight. Seriously - the ambient light knocks down all the glare and the laser dot is pin point small. Centering is trivial then ;)

[@enteringintospace4685]

Lol...why didn't I think of that🤣 Makes since....its a back and forth thing because steps 2 and 3 need darkness. Thanks!

[@hael8680]

What about the collimation ring? Do you keep it on for imaging?

[@enteringintospace4685]

Yes it becomes a part of the image train

[@enteringintospace4685]

@Socom3988 so the rc 8's focal point from the back of the ota is just over 9 1/2". You've got 4 " of focuser travel. It's simply about getting your sensor at that point with enough focus travel on either side of focus. When I wasn't using the collimation ring I needed all 3 extension rings that came with the scope. I removed 1 1" ring and replaced it with the collimation ring.

[@ele4853]

Great job! I'm still waiting for my adapter rings to be able to attach my badder mirror box, camera and eyepiece. I'm hoping mine is not out of collimation too bad, or will have to spend more money! What? Spend more money! You told me that was your last purchase! No more soup for you! 😂 😂

[@enteringintospace4685]

Lol...soup nazi was the best episode! Mine was actually very well collimated out of the box. I shot like 5 projects before I decided to install the collimation ring. You should be able to do the same. Good luck!!

[@Jmw845]

Hi Steve thanks for the video. Did the eaf go on ok or did you have to MavGyver it?

[@enteringintospace4685]

Little of both...lol. only place to attach the plate was the tension screw so I had to find a screw that held it on securely but still provide enough tension for the focuser to work

[@Jmw845]

@@enteringintospace4685 ok seems straight forward enough. Maybe a trip to the hardware store, if the scope ever gets here. Thanks!

[@TheMje1963]

Dam dude, I wish you had this video a year ago when I purchased my GSO RC 10" I have a Carbon Fiber Truss type. I didn't have to worry about the focus alignment ring, This one it was built in at the base. I did change out the focuser and all but tossed it in the round file cabinet. Anyway for some crazy reason and I don't know why, seems like there is a step or 2 missing. I'm most likely wrong. Like you I have watched so many darn video on collimation that it all runs together and makes your head spin in 5 directions at once. Now if you can do one on collimating an SCT or EdgeHD

[@enteringintospace4685]

Dang it! Well I'm sure you'll cross paths with one in the future! I too watched so many videos I wasted a year going back and forth.. Its a great scope that severs a specific purpose and does have some down sides. But I have 3 other scope to fill those gaps. Just need 3 other mounts and cameras...lol

[@davidschaeffer5322]

Hey Steve, great video as usual. I just did my iOptron 8" just like you did. First step showed focusserr out of alignment. After that everything else looked good. I noticed your scope showed 5 concentric circles on the wall where mine only shows 4. They were all solid and lined up. I was getting some funny color aberrations in my stars. Could just the focus tilt be the only cause. Probably won't see clear skies for a while but thought I'd ask. Thanks!!

[@enteringintospace4685]

Hey David! Quick response is your focuser was probably at different position than mine was so the the HG being closer would only reveil 4 circles. I'll be doing a follow up collimation video where knowing this will help you fine tune your collimation. The aberrations could have come from the primary mirror not being at Ambient temp?

[@alexanderwagner9524]

I'd like to see a collimation video with tools that are not more expensive than the whole telescope. I am looking into DIY solutions because I don't want to buy a laserpointer for 600€. Thats so far from reasonable, that I will never even think about it.

[@StardustAstronomy]

You explained it very nicely. I have RC6 and I was struggling to collimate it. Now after watching your video I can also do this. Thanks for such an excellent video. I subscribed to your channel. Clear Skies!! Love from #stardustastronomy ❤

[@enteringintospace4685]

Very cool! Trying to get out a follow up fine tuning collimation video soon! Thanks!

[@kevannoble5550]

Great video Steven, as always. In a recent video you revealed you have moved on your RC 8”. Why was this? Is it because of the collimation maintenance, f8 or just bigger and better time had come. I bought my RC 8 because of you, and it has been challenging. Yeah Steven, feel bad! OK, your forgiven already 😂. However, I have in recent months decided to break that Steed in, and with a number of published methods and tools I’m starting to win. And then for the past couple of nights collimation terrible and then good. I think the extreme cold weather caused some shrinkage (no pun intended 😮) and caused some image train flop, or the known mirror flop. So hood up and see what’s going on …. Again. Clear skies, Kevan

[@enteringintospace4685]

Hey Kevan! Lol....yeah sorry about that. I like trying out different scopes without hoarding a bunch of OTA's. So when I find a new one I sell one. It was a great scope and the guy I sold it to is loving it. My skies aren't the best so I'm trying to find a better balance between focal length apeture and speed. Stay tuned for full rig set up for a new scope that I hope checks all 3 boxes. And yes....I sold my Quattro before buying it 😉

[@kevannoble5550]

@@enteringintospace4685 Thanks for your reply Steven 👍 I agree, f8 is hard work. Good luck with your next mystery scope and looking forward to the reveal video. CS

[@gregoryneufeld7566]

Hey, great vid. I recently bought an RC6 and have some difficulty with collimation. I have seen most of the vids and this for me is the best so congrats. Trouble is there seems like a worldwide shortage of all things astro. I have been waiting abt 4 months for the HG collimator and the collimation focuser ring is no where to be found. OPT is out and Agena may have by November :(. Were those images at the end taken on your RC? Thanks again for this and work you put into it, cheers from Manitoba, Canada.

[@enteringintospace4685]

Thanks!! Yeah I almost hated putting in the links because everything was back ordered. Yep...every image with taken with the RC 8! Did an eagle core image with it that got a top pic on astrobin....great scope!! Good luck and let me know when all you're gear comes in👊

[@AviationAstro]

I've been in the same boat with collimation. Did you ever receive your HG Laser? I finally broke down and ordered one today.

[@gregoryneufeld7566]

@@AviationAstro I’m still waiting. Now about 7 months.

[@AviationAstro]

@@gregoryneufeld7566 That's disappointing, but thanks.

[@AviationAstro]

@@gregoryneufeld7566 I emailed starlight instruments about my order. They replied that they are 3 - 5 months out on orders. I am considering cancelling and just selling my rc scope.

[@etx007blue2]

I spent $500 on the 6 inch RC, now I need to spend $500 more to get it collimated :( . How do I explain this to my wife?

[@taconley]

The good news is if you trade up to an 8 or 10 RC no new Collimation gear is needed.

[@etx007blue2]

@@taconley Guess what I did =-),, I have RC8 now to get ROI on my tools

[@carlostejeda6191]

Just found for my RC 6inc and other the following product - check this out -How to collimate a Newtonian Reflector - OCAL Collimator Review...

[@carlostejeda6191]

Good video, however if I have a RC 6 inch that cost me $500 and invest another $500 just for collimation? LoL

[@enteringintospace4685]

Thanks! You didn't get into this hobby thinking it was cheap did you??😉 The reason these scope are so inexpensive is the fact that some work and equipment comes along with great the images they produce.

[@Astronurd]

No need for the expensive Howie Glatter laser. All you need is a Cheshire and a pair of working eyeballs.

[@woody5109]

And this is why I would never own an RC scope, nope, not doing it, lol

[@Youtuber-ku4nk]

Be careful with all those lasers. It’s actually irresponsible to look at even the reflection of s laser. You are damaging the light sensors in your eyes.

[@red_star_rc2579]

Here is a correct way for RC collimation lambermont.dyndns.org/astro/rc/RC8-Collimating-Frustration-revision-1.4.pdf

[@sirchan9524]

Thanks for that. I read it. It's consistent with others using those tools. Personally I prefer the tools and method described here, understanding that I'm not done at step 4 and would run through each of the steps until no corrections were required. Cheers