It’s 3 years later, but I want to say thank you! Perfect tutorial!

@martinsastrophotography

2 күн бұрын

Always appreciated, no matter how long after I make a video. Clear skies!

The best tutorial on KZread. Watched a dozen other vids on this topic but they just kind of discussed the process, not really tutorials. Great job!

@martinsastrophotography

8 ай бұрын

Thank you!!!

You made it sound and look easy. Thanks 👏🏻 I'm binging on your tutorials 🤣

@martinsastrophotography

Ай бұрын

Thank you!! Enjoy.

Thank you very much for this video! A klutz like me especially appreciates the reminder that this procedure should be done with the tube in horizontal to avoid dropping tools on the promary mirror.

As always, a great video, easy to follow and very informative!

@martinsastrophotography

2 жыл бұрын

Thanks Andy. Glad you liked it. Clear Skies.

Thanks for the video. I like your style, straight to the point and easy to follow. Good camera work to actually see what you are doing. I have the same scope and will be 'correcting' my previous attempts to collimate after seeing your video. thanks !

@martinsastrophotography

3 жыл бұрын

Thanks Bruce. Glad you liked it!

Thank you Martin for a very pleasant and easy demonstration on how to collimate a Newtonian Telescope. I will follow this video step by step when I come to collimate my Skywatcher 200p.

@martinsastrophotography

3 жыл бұрын

Glad you liked it Paul, and thanks for subscribing!

That was so helpful thanks!

Thank you, it was very helpful. :)

This vid helped me very much. Thankyou

@martinsastrophotography

Жыл бұрын

I’m pleased to hear that. Thank you. Clear skies!!

Your graph not just help me understand the collimation, but also how Newtonian telescopes works! Thanks you so much 🎉!, btw, what is fan for at the back of your telescope? Help for cooling?

@martinsastrophotography

2 ай бұрын

It prevents the ‘boundary layer’ problem by creating air flow across the primary mirror.

Very good video.

@martinsastrophotography

2 жыл бұрын

Thanks Monty.

Excellent video. 🤗

@martinsastrophotography

3 жыл бұрын

Thanks Edward. Clear Skies!

@astrovert.ed2321

3 жыл бұрын

@@martinsastrophotography Edward 😝

Thank you for the great instructions. I have the same OTA and I noticed that you are using an autofocuser. Which are you using?

@martinsastrophotography

3 жыл бұрын

Thanks for the positive comments. It’s a Hitecastro DC Focus controller connected to a Skywatcher Auto Focuser motor, with a home made adapter arrangement to make it fit the scope focuser. Took a while to get right but works great. I will never focus manually again!!! :-)

@LyngJohn205

3 жыл бұрын

I tried using your technique. I have the same telescope, but I was not able to loosen the 3 screws on the secondary mirror, and I was reluctant to force it. Do you need to unlock it first?

@martinsastrophotography

3 жыл бұрын

@@LyngJohn205 I am not aware of a lock, but there is a central screw that could be loosened slightly which might help. However the three small screws should loosen without needing to do this. You must use the correct size Allen key.

Do you find that the adjustments you make with the laser are enough? On RC lasers get you close but a fine tune on a star field is usually needed. Is this true with newts as well?

@martinsastrophotography

2 жыл бұрын

Hi there. I find they are enough for me. I get nice round stars and clean diffraction spikes apart from a small extra spike that I believe is caused by the focus tube rather than a collimation error.

Can I ask you, how do you find the Quattro on the HEQ5? I have considered getting one but I thought it may be too heavy for my HEQ5.

@martinsastrophotography

3 жыл бұрын

Clive Roberts Hi Clive. It’s fine. I have many good data sets with this combination, and I have the coma corrector, ZWO OAG, ZWO EFW8 and ASI1600MM Pro on board as well, plus a Telrad. Needs both counterweights about 60% of the way down the counterweight bar. I wouldn’t add any more payload than this, but the HEQ5 handles it. Note my Quattro is the CF version which is a bit lighter than the Aluminium one.

Great video. One question. How do you ensure your secondary mirror is correct orientation to the eye piece. I bought a second hand one and had to strip it down to clean the mirrors. Hope to hear from you Cheers

@martinsastrophotography

3 жыл бұрын

Neil Tonks Hi Neil. The mirror is attached to the tube with four spider veins. There are therefore four possible orientations when you re-fit it to the tube (or 8 I suppose if you turned it upside down!). You must fit it so that the flat secondary mirror’s surface is reflecting the light from the primary out into the Focuser. Any other orientation and you will see nothing through the telescope! Does that answer your question?

@neiltonks

3 жыл бұрын

@@martinsastrophotography sort of, I just wondered if the was a way to be precise.

@martinsastrophotography

3 жыл бұрын

Neil Tonks I’m a bit confused by your question. The purpose of collimation is the make the orientation of the mirrors precise, and that’s exactly what this video shows you how to do. When you adjust the three small screws on the secondary you are fine tuning its orientation.

@getawaydance

3 жыл бұрын

@@martinsastrophotography I was interested in this as well. As how do you correct for rotation of the secondary mirror. A laser pointer will not correct for this. You can have the secondary mirror rotated and the laser dot can still be made to hit the center donut.

@martinsastrophotography

3 жыл бұрын

@@getawaydance Are you talking about the in-plane rotation of the secondary mirror?

What about the screws that take in place the spikes (the cross ones which hold the secondary mirror of course). I'm a newbie and in the newtonian arrived the 4 screws weren't tight at all. But if I thight them I surely apply some torsion to the crossed spikes aaand... so?

@martinsastrophotography

Жыл бұрын

Take up the slack, tighten gently, but do not over-tighten. Use a ruler to make sure the secondary is central in the tube. I hope this helps.

I have the same laser collimated as you use in this tutorial and would like to mention that mine is itself not collimated. I noticed this when collimating my Newtonian first with an old fashioned "Cheshire" and then doing it right afterward with the laser. The laser suggested the initial Cheshire collimation was off. At first I believed the laser -- it seems much more high tech after all. But then I did some quick checks and realised the laser beam does not come out parallel with the axis defined by the tube that goes into the eyepiece holder. In mine, it was in fact way off. I did some research and discovered that this is not an uncommon error. It was also basically impossible to fix since it is determined by how the laser diode chip is attached on the inside and there was no way to adjust it from the outside. I came to the conclusion that the Cheshire, despite being very old school, is more accurate and reliable -- there is little to go wrong. Also, you can effectively use the Cheshire to get the secondary mirror in proper position (since it comes with a built in "collimation cap"). Moreover, the Cheshire is much cheaper and has no battery that inevitably runs out because you forgot to turn off the laser completely (mine has 7 different "on" positions). I found some references that support my negative opinion on laser collimators. For example, see garyseronik.com/collimation-tools-what-you-need-what-you-dont/ : Option #3: Cheshire Eyepiece. This “all-in-one” collimation tool is excellent. Indeed, if you have one of these, you need nothing else. Option #4: Laser Collimator. Laser collimators have been around for many years now and seem to be especially attractive to those who equate lasers with precision. Unfortunately, it’s been my experience that beginners all too often end up de-collimating their scopes when using one of these. See also, www.astro-baby.com/astrobaby/help/collimation-guide-newtonian-reflector/ : I have not covered collimation with a laser because my own experience has been lasers seem to create more problems than they solve as they also require collimation which isn’t always possible with some low cost lasers. Another one, www.catseyecollimation.com/pensack.pdf : 2. Laser collimator: not useful unless perfectly collimated itself, possessed of a small beam diameter, and not accurate enough for primary mirror collimation unless used with a Barlow lens, but quite useful in the dark. Finally, www.nightskyimages.co.uk/sct_collimation.htm : The key to obtaining good results from a laser collimator is ensuring that the collimator itself is accurately collimated! You cannot assume that a laser collimator is correctly calibrated when it arrives from the manufacturer, you MUST carry out this calibration yourself.

@martinsastrophotography

3 жыл бұрын

Hi Douglas. Thank you for your message. I have come across a number of conflicting information sources just as mentioned in the article you referenced. It does seem that a Cheshire is the better choice. I don’t have one but will look into getting one to see what difference it can make. That said, my laser collimator has served me well so far. When I defocus a bright star I get a circular concentric disc. This star test suggests that I am close to perfect collimation at least. The Astro Baby article is very detailed and hopefully reasonably easy to follow. If I get a Cheshire I will try to follow the steps it describes. Clear Skies.

@MountainFisher

2 жыл бұрын

My laser is easily collimated, has three screws.

@petset77

Жыл бұрын

@@MountainFisher, yes, some are adjustable.

Great video - might be worth masking sure you cover Secondary rotation/ tilt as it's probably the most import part of collimation.

@martinsastrophotography

3 жыл бұрын

Thanks for your comment. Apologies, I do not follow. Secondary mirror adjustment is included in this video.

@astrotube3967

3 жыл бұрын

@@martinsastrophotography you didn't seem to cover secondary rotation unless I missed it

@martinsastrophotography

3 жыл бұрын

@@astrotube3967 That’s correct, but I cover tilt. Since the three tilt adjustment screws on the secondary are 120 degrees apart they can be used to correct for any rotation error. The result is the successful minimisation of coma. The shape of the field may be slightly different than if the rotation error had first been corrected via the large rotation bolt axis, but not the focus, which is what matters the most.

@astrotube3967

3 жыл бұрын

@@martinsastrophotography sorry but you are completely wrong. Tilt has nothing to do with rotation and tilt adjustments cannot correct rotation errors.

@martinsastrophotography

3 жыл бұрын

@@astrotube3967 I was quoting from a reference I read which made a lot of sense: www.cloudynights.com/topic/443288-about-secondary-mirror-rotation-and-tilt/ A key point made in this reference is that the three tilt screws must enable a component of correction of the rotation. I agree with this observation. If the mirror is parallel with a mirror that is perfectly aligned in both rotation and tilt then the field flatness and coma must be identical. I agree with this observation. If you do not, please explain your reasoning, as I would be interested to hear your view of it.

Thanks Martin for a great video. I've collimated my scope many different ways now and still can't get clear focus. I appear to be getting double images, my mirrors are clean with no scratches or blemishes. Any advice would be greatly appreciated. 👍

@martinsastrophotography

3 жыл бұрын

Darren Laws Thanks. That must be frustrating! What make and model is your telescope? Also, are you using a coma corrector or focal reducer of any kind? Finally, are you visual observing or taking photos?

@darrenlaws7989

3 жыл бұрын

@@martinsastrophotography Im using a Skywatcher 150/1200mm Newtonian with no coma corrector or reducer, I'm using for photography and have done so with great results after collimation yet for some reason after cleaning and recollimating I'm only getting double/blury images and visuals.. I'm new to telescopes yet have had no problems with collimation in the past.

@martinsastrophotography

3 жыл бұрын

Darren Laws It sounds to me like something went wrong during your last collimation. Did you use a laser collimator? I am wondering if it was incorrectly seated in the focus tube that particular time, which could cause the sort of trouble you are describing.

@darrenlaws7989

3 жыл бұрын

@@martinsastrophotography No laser as I always do it by eye, secondary first followed by the primary and had great results. I must have been over the whole scope several times and with the same end result. I've even tried collimating on a bright star while out of focus and with the same result.

@martinsastrophotography

3 жыл бұрын

Darren Laws How tightly do you do up the screws / retaining brackets that hold the primary mirror? Too much torque on these can cause double images even if collimation is perfect.

nice job, is that a 10 inch or 8 inch ?

@martinsastrophotography

3 жыл бұрын

Thanks. It’s an 8 inch f/4 800mm Newtonian (Sky-Watcher Quattro 8CF)

First step should not be to set orientation of secondary mirror, it should be to position the secondary mirror. If you have tightened or loosened all 3 screws too much , the mirror will no longer be perpendicular to the tube, and you will need to compensate for that by introducing a misalign, which you will later compensate for again in the primary mirror. You will end up with a telescope that appears collimated because the laserdot is centered on the target, but in reality isn't. This is why a scope can fail the startest but pass the laser test.

@martinsastrophotography

Жыл бұрын

Thank you for this. I agree with what you say. Made this video quite a while ago…I guess it needs an update.

@mneste

Жыл бұрын

I do not understand the difference between orientation and position of the secondary mirror. Could you please explain what you mean and how to go about it? Thanks.

@martinsastrophotography

Жыл бұрын

@@mneste Ok, I will try to help you understand. Let’s talk about position first. Consider a point in the centre of the secondary mirror. This point needs to be on the axis of the telescope’s primary mirror, which is a line approximately down the middle of the cylindrical telescope tube. Now our point on the secondary mirror must also be on the axis of the focus tube, which ideally intersects the axis of the primary mirror, so that it will reflect light from the primary mirror down the focus tube. This is all, so far, about the position of the secondary mirror. We can now consider its orientation. You can rotate the secondary mirror around the axis of the primary mirror without the central point changing its position. It needs to be rotated so that the light from the primary is reflected into the focusing tube. Finally, consider rotating the secondary mirror in-plane of itself. There is one orientation in this rotation where the secondary will appear circular when viewed through the focus tube. This is the desired orientation. I have described position and orientation separately. I hope this helps your understanding.

@mneste

Жыл бұрын

@@martinsastrophotography Thank you kindly for that explanation. How would you know the difference if something is off, whether the position is incorrect or the orientation. Is there a tool for that? Like you mentioned in your initial comment, you may think that the collimation has been done and done correctly, but the position of the secondary might be off none the less. Perhaps you already explained this but I am just not putting it together. I just bought a Celestron 130SLT and I just want to ensure that I am getting the most out of it. Thanks

@martinsastrophotography

Жыл бұрын

I understand your concern. The best you can do is to take each of the steps I described and do it as accurately as you can, then do the laser collimation as per my video. There are other things that can degrade your image quality, such as the primary mirror clips, internal reflections, air currents, dirt on mirror surfaces etc… There are things you can do about all of these…it’s a question about how far you are prepared to go. I made a (flocked) ring to cover my primary mirror clips, added further flocking to reduce internal reflections, and made my own fan plate to push air across the primary mirror.

Which model is this, and can you comment on its weight vs the HEQ5 capacity?

@martinsastrophotography

3 жыл бұрын

Hi there. It’s the Skywatcher Quattro 8CF. With a coma corrector, camera and filter wheel added it works well on the HEQ5 which has a recommended maximum payload for imaging of 11kg but I think it is approaching the limit of what this mount can handle. I have not actually weighed it all together but can do so if you would like me to.

@aTillasSister

3 жыл бұрын

@@martinsastrophotography thanks. Considering reflector options for my HEQ5. Weight is a limiting factor but so is availability :-)

@martinsastrophotography

3 жыл бұрын

@@aTillasSister Availability seems to be a huge issue right now, especially on goods from China. Remember with Newtonians you will need a coma corrector for deep sky Astrophotography which increases cost and mass.

Why I couldn't see the donut on my telescope? Do i need to turn on the collimator?

@martinsastrophotography

8 ай бұрын

Not all Newtonian telescopes have a donut in the centre of the primary mirror. To check if yours has one, just shine a torch down the telescope from the front and take a look. Turning on the collimator will not help.

@yapgideon

8 ай бұрын

Thanks for the info and appreciated your replied

Insufficient. You need to check the position of the secondary first!

@martinsastrophotography

2 ай бұрын

I agree! We are always learning. Thank you for pointing that out.