Collimation with Concenter eyepiece

[Corpze]

Hi, I know that there has been a couple of threads on how to collimate a newtonian, more specific, how to center the secondary mirror under the focuser.
I bought mine "Concenter eyepiece" for almost a year ago and can't praise it enough - it makes centering the secondary a breeze.

Have anyone else tried this? What is your opinion?

I have also read that some have questions of how accurate it is? - I might not know the answer to this question, but what I do know is that after I have been centering the secondary with the Concenter eyepiece, I finish of the collimation with the Catseye XLKP and Blackcat. The small adjustments I have to make of the secondary after adjusting it with the Concenter eyepiece tells me it is very accurate. It is just the absolute finest adjustments i have to make afterwards.

I have made a video of how it works and how it looks like when I am collimating my scope. (10" f3,4 astrograph)

Best regards, Daniel
 

 

Edited December 8, 2020 by Corpze

[johninderby]

I’ve been using and recommending the Concenter for a while. Have recently changed to the Concenter Visus which has a couple of advantages over the original.

I consider it an essential in setting up a Newtonian as nothing else is as accurate in setting up the secondary which in turn makes the rest of collimation much easier as you are not comoensating for a misadjusted secondary when adjusting the primary.

I finish off collimation with a Hotech laser.

Edited December 8, 2020 by johninderby

[Corpze]

This looks like a nice step forward, the only remark I have on the "original" concenter eyepiece is exactly that this new version might solve - It is a bit difficult to hold the eye in the correct position so that the circles is exactly in the middle of the visual center.

[johninderby]

They made the Visus as long as they could to make it easier to focus on the rings and the rubber eyecup helps. They also added a luminos ring inside to illuminate the rings if exposed to a bright light for a while. Also has a small port in the side to shine a light into to illuminate the rings. The idea is to make it usable at night but not sure if that is needed. 

[Corpze]

On 08/12/2020 at 13:04, johninderby said:

They made the Visus as long as they could to make it easier to focus on the rings and the rubber eyecup helps. They also added a luminos ring inside to illuminate the rings if exposed to a bright light for a while. Also has a small port in the side to shine a light into to illuminate the rings. The idea is to make it usable at night but not sure if that is needed. 

I am satisfied with my eyepiece, but as you describes the Visus, i am eager to try that one out myself
I have also seen that my version is available with a luminous ring also.

[Craig a]

My concenter arrived last week and got straight onto collimating my Quattro 10 inch, have to say it’s a great bit of kit I don’t think my seconary has ever been looking so good it’s perfectly centred under the focuser and is perfectly round aswell, it’s expensive but so what we spend 100s if not 1000s on our scopes so what’s 70 quid to get probably the best collimation ive ever seen in my scope 

Edited December 16, 2020 by Craig a

[johninderby]

Another convert.

Simple tool..........simply works perfectly.

[Corpze]

I totally agree with what u guys are saying, easy to use and perfect results

[johninderby]

I hope FLO is taking notice of the increasing popularity of the Concenter and perhaps could think about stocking them.

[johninderby]

Re: the Concenter Visus have experimented with shinning a light through the little port in the side but have found a much easier method.

Just use one of those little keyring lights to shine into the end and the ring inside for a minite or two and it will glow long enough to check secondary collimation in the dark.

[Corpze]

That looks really useful when out in the field! (and cool)

/Daniel

[Tiago Ferreira]

Great video Daniel, it helped me to find and understand this wonderful effective and simple tool. Not many people using it i suspect because it's manufactured and invented in Europe and we unfortunately have loads of obstacles to buy from US and them from buying to us.

Well, i created my own method which boost the potential of the concenter.

Sooner or later people realize that lasers aren't good to collimate (even if they are collimated). Just have to align all and then mess with the focuser screws or move around the laser to see all messed up again.

Fortunately i quickly realized that and since then i just use my own system that i can assure you that works like a charm and i just check collimation before observations and have it almost all the time collimated or moved 1 or 2 mm that i adjust quickly. And guess what? I also use my crap laser to collimate, yes. If you have a crap laser please check my video before throw it to the bin. You will need a concenter and any laser. A concenter is a wonderful european tool that you can buy easily on Europe and super efficient and easy to use.

This is not a regular method that use a concenter then use a laser like 2 independent tools. This is a method that use a concenter secundary collimation and then you MANUALLY ADJUST a laser dot at the primary mirror TO THE CONCENTER JOB in order to obtain the full collimation as a hole. It's a concenter and laser INTERACTION that allow a cheap laser to be used with an accuracy it doesn't have by itself alone because it relies on the concenter accuracy.

 

[Ricochet]

Have you tried the barlowed laser method for your primary? Concenter for the secondary and then barlowed laser for the primary should give you a very accurate result, without the need to try to manhandle the laser into pointing at the centre of the doughnut. 

[CraigT82]

53 minutes ago, Ricochet said:

Have you tried the barlowed laser method for your primary? Concenter for the secondary and then barlowed laser for the primary should give you a very accurate result, without the need to try to manhandle the laser into pointing at the centre of the doughnut. 

This is my exact method pretty much. I use a concenter to get the secondary in the right place then use a glatter tublug with a cheap seben laser to align the primary... Laser always agrees with the cheshire this way. Tublug is costly but much better than DIYing a barlowed laser.  

[Skyline]

I have been using the concenter for a good few years before my spine operation.

[Tiago Ferreira]

19 hours ago, Ricochet said:

Have you tried the barlowed laser method for your primary? Concenter for the secondary and then barlowed laser for the primary should give you a very accurate result, without the need to try to manhandle the laser into pointing at the centre of the doughnut. 

I had already a cheap laser and a concenter which (only) with this method gives me an excellent result.

When a team is a winning team we don't change it. This applies to all of course, i show my new method to help people that struggle, the ones that don't have problems just stick with their own method (also a winning team).

Also i realized there is plenty of people using cheap lasers, convinced that they have the scope collimated and it is not for obvious reasons, so my video also expose that issue for those to check it and find the facts. Also i give a solution for that without the need for extra and expensive tools (well, except the concenter which is a must have).

For last, i really prefer my method because depends only in the concenter (not the concenter + another tool) and as long as one knows how to use it it's perfect. And we save those poor crap and cheap lasers from unemployment eheheh

cheers.

Edited February 2, 2021 by astrocanito

[Jiggy 67]

On 01/02/2021 at 17:36, astrocanito said:

 

Sooner or later people realize that lasers aren't good to collimate (even if they are collimated). Just have to align all and then mess with the focuser screws or move around the laser to see all messed up again.

Might be true of cheap lasers (as it’s true of all things that are cheap) but not true of the better more expensive versions 

[Tiago Ferreira]

9 minutes ago, Jiggy 67 said:

Might be true of cheap lasers (as it’s true of all things that are cheap) but not true of the better more expensive versions 

yes, i believe you. but i may never test an expensive laser, they are, well...too expensive to achieve the same results i have now.

And there was a time i was prepared to buy those expensive ones and put mine in the trash. Almost did it. Until while looking for them i found this concenter and "cooked" this powerful "fusion" with my cheap laser. My message is: you can have perfect collimation with a cheap laser and a concenter.

Someone that already has a concenter and a cheap laser in a box, just try my method.

[Tiago Ferreira]

question: alone with the barlowed laser can you collimate turning the knobs at once and finish the process? without having to stand up and down, up and down, until see that the dougnut fits the barlow paper?

[Ricochet]

6 minutes ago, astrocanito said:

question: alone with the barlowed laser can you collimate turning the knobs at once and finish the process? without having to stand up and down, up and down, until see that the dougnut fits the barlow paper?

Yes. So long as the laser has an angled face then you can turn the face so that it faces the rear of the tube and watch the result as you adjust the primary. You may find that certain barlows work better for this than others as the different focal length will change how big the doughnut shadow is. 

[Tiago Ferreira]

6 minutes ago, Ricochet said:

Yes. So long as the laser has an angled face then you can turn the face so that it faces the rear of the tube and watch the result as you adjust the primary. You may find that certain barlows work better for this than others as the different focal length will change how big the doughnut shadow is. 

oh, of course. thanks

[Corpze]

Nice work with your method Nebula! 

I do how ever have noticed on three different laser (cheap "china" laser, hotech and Howie Glatter) that it is a HUGE difference in how reliable they are.

The hotech beeing the worst of theese three according to me, and the howie glatter with the tublug is very well made and Solid as a rock.

/Daniel

[Tiago Ferreira]

On 05/02/2021 at 08:51, Corpze said:

Nice work with your method Nebula! 

I do how ever have noticed on three different laser (cheap "china" laser, hotech and Howie Glatter) that it is a HUGE difference in how reliable they are.

The hotech beeing the worst of theese three according to me, and the howie glatter with the tublug is very well made and Solid as a rock.

/Daniel

Thanks. Nebula is the forum rating lol Nickname is Astrocanito.

Please note i don't compare other effective options and the premium lasers accuracy because in my method doesn't matter to have a premium laser.

My goal was to have a balance between the purpose (achieve accurate collimation), budget, effectiveness and simplicity of use.

That i achieved with this, using a crap laser that was going to trash and made it useful when connected to the concenter.

So, cheap laser + concenter = budget solution, very accurate, very effective and super simple to use. The concentric circles help really a lot with the secondary adjustments and allow quickly detection of the lack of adjustment.

This is not intended to depreciate other nice methods mechanics, this is the method that suits better on my needs to achieve accurate collimation.

Edited February 21, 2021 by astrocanito

[Spile]

 

18 hours ago, astrocanito said:

So, cheap laser + concenter = budget solution, very accurate, very effective and super simple to use. The concentric circles help really a lot with the secondary adjustments and allow quickly detection of the lack of adjustment.

My budget solution is cap + washer

This and Gary Seronak's guide is what I follow:

http://uncle-rods.blogspot.com/2009/07/zen-and-art-of-telescope-collimation.html?m=1