Optic Nerve

21 hours ago, Sunshine said:

Self collimating telescopes, simply push a button and lasers instantly align mirrors to a degree even the human eye cannot.

Ooh yes please put me down for one of them.

I've found it a bit unreliable. It's sometimes accurate but other times I've been out in the garden with completely clear skies above while Clearoutside assures me there is 100% cloud cover. I prefer the Met Office cloud cover map (UK)

Hey so the clouds finally cleared and I got a good look at the moon tonight. I'd say the view I had was a bit better than before, but definitely no worse. Not sure if that is due to the attempted improvement of the collimation, or the fact the moon was higher in the sky when I looked tonight, I've read that objects do look better when higher up. But then I didnt give the telescope proper time to cool down to the outside temperature tonight whereas I did the other night so I was dreading worse views but ended up pleasantly surprised.

I do need to get the secondary mirror right at some point but I've decided to hold off on doing it until I'm more familiar with the scope. For now I just want to get more comfortable using it. Will looking through the cheshire and realigning the doughnut on top of the black dot every few sessions keep the collimation at roughly its current quality?

25 minutes ago, CraigT82 said:

How come? Did you run out of travel on the primary screws? 

No it just wouldn't sit nicely, it was sort of like I was chasing it around the dot.

21 minutes ago, CraigT82 said:

There are two main aspects to beginner collimation to get your head around, secondary and primary.

• Secondary is (as the name suggests) adjusting the position of the secondary mirror so that the entire primary mirror can be seen in the secondary mirror as you look through the cap. Secondary collimation isn't that important for a beginner to master, the consequences of getting it wrong is mainly uneven field illumination, it wont have much effect on the sharpness of the image.
• Primary collimation is adjusting the tilt of the primary mirror so that its optical axis is exactly aligned with your eye.  This is the important one to get right as the sharpness of the views can suffer if it's way off because of something called coma. Looking through a collimation cap or cheshire, you're trying to place the dot in the centre of the donut and this is done mainly by adjusting the three screws on the bottom of the scope behind the primary mirror,

In the last images you posted the dot and donut are quite far apart. which is bad... I've annotated it below.  Try to sort this out first and you can worry about your secondary later.

Couldn't quite get it bang on but https://imgur.com/a/DJDjZUq

23 minutes ago, bosun21 said:

If you stick with the hobby I’ll wager that in a years time you will look back and laugh at the predicament you are in at the moment, and wonder what all the fuss was about. The secondary mirror can be seen much better with a coloured sheet of paper between it and the primary mirror. A second sheet of white paper slid into the tube directly opposite the focuser will help you a great deal. If it’s all getting too much for you I second what @Mr Spock has advised and state where you are situated so that a member can possibly drop in on you and guide you through the procedure step by step. I wish you well.

Yeah probably, that seems to be the consensus in everything I've read about collimation. A massive headache to start with then it just clicks in your head and becomes straightforward. It hasn't put me off the hobby, although I've decided that if the view I have now ends up being about as good as what I had before, I'll just leave it at that for now. Spend time familiarizing myself with the scope and observing what I can, and then return to collimation after studying the guides until I'm more confident in what I'm doing.

I'm in the north of England

23 minutes ago, wulfrun said:

Yes...but there's always the difficulty of the angle the camera was or might have been at, so it could look better (or worse) than it is. Assuming the camera was central, it's better but not right.

If I were in your shoes, I'd just use it for a while and take the time to re-read and absorb the principles before any more fiddling. That's not being unkind, most of us have been there! Amazing what a break from a task can achieve.

Also remember that the difference between "close" and "perfect" is unlikely to be noticed in real-life usage on visual astronomy. When you do tackle it again, aim for "perfect" but accept "close", don't obsess.

Thats what I'm going to do. And yeah I'm not too bothered about getting it exactly right, I thought the views I had initially (with the secondary way off) were actually good.

By the way now that ive reangled the mirrors will my aim be off? I struggled to get my finder scope precisely aligned, the red dot had to be pointed to the moon and then about an inch to left. Will I maybe find its not in the right spot now, maybe instead its a bit to the right/down/up from the red dot?

42 minutes ago, wulfrun said:

Spot-on, yes much easier to do than describe in words. Once you get the idea behind it it does make sense. There's a multitude of adjustments on two mirrors, so it's not hard to get confused over what does what. Also easy to read too many guides & watch all the videos and make yourself more confused. Time for a pause if you've got there!

Do you think the image through the cheshire now is better than what it was?

11 minutes ago, wulfrun said:

No, it means you won't get the clarity and sharpness that you could have got. I bumped one of my newts, knocking the secondary quite a way out (it was not locked properly and I'd failed to realise). It didn’t make much difference, for most targets but for things like planetary detail it did degrade the view.

Try this guide, it's one of the simplest I have found:

https://garyseronik.com/a-beginners-guide-to-collimation/

I also suggest you pause for a bit and don't worry too much. You can follow the guide above methodically but I think the best part of it is that he explains, in simple terms, the "whys" and "hows".

Its clear skies tonight so I'm going to have another look at the moon and see what difference my tinkering has made, hopefully I wont have made it any worse, I'd take that as a win at this stage.

I try to read through these guides but they are really confusing. I get the feeling collimation is a bit like tying your shoes or learning to ride a bike, difficult to actually talk someone through it but straightforward once you understand. My only worry there is I fell on my bike loads when learning!

If the views I have tonight are similar ish to what I had before I'll be ok with that and then leave a proper collimation until ive gone over the guides again and again and it clicks. Its a bit of a frustrating start to the hobby, but it hasnt dampened my interests in looking up to space, its just a bit of a blow to my ego that I am basically being outsmarted by a mirror

14 minutes ago, ollypenrice said:

This link https://fedastro.org.uk/fas/members/members-location-by-county/  will take you to a comprehensive list of UK astronomical societies. (I'm not certain that you are in the UK but you write without an accent. ) I'm sure that, if you went along there, someone would sort out your Newt in no time and show you how to do it.

Olly

Yes in UK.

Does what I have now look better or worse than what I had before? Waiting for tonight when theres clear skies to see for myself. At this stage I'm just hoping for something like what I had before. I think everything looks a bit closer to what it should be but I've a bad feeling I missed something, if the secondary is rotated/tilted I guess that means any object I look at will appear tilted too?

36 minutes ago, bosun21 said:

I’ve already posted how to position your secondary mirror. Your secondary is oval shaped and needs rotated.

This is way to complicated for me. Sorry if that sounds stupid and I appreciate that people have put in the time to reply and try and help, but when it comes to altering the secondary mirror I mucked it up before and struggled to get things back to, I couldn't see either of the mirrors at one stage. I'm worried sick that tinkering with it much more and I'll end up mucking it up completely. I was ok with the views I had before, so at this stage I'll happily settle for an alignment that's about as good as that. Is it possible to look at what I had before, and what I had now, and say if I've at least made some progress in the right direction?

First two images are what it was before, through the Cheshire and also through the focuser with no eyepieces attached. This gave a view of the moon that I thought was quite good.

https://imgur.com/a/YvShjOV

https://imgur.com/a/H0joaLO 

The second two images are what I have now.

https://imgur.com/a/uDitdAO

https://imgur.com/a/lEm1CZj

That's with a sheet of A4 covering the primary mirror, as well as a look down the focuser when there's no eye piece or cheshire in it.

https://imgur.com/a/lEm1CZj

Am I going in the right or wrong direction from what it was initially? Part of me is concerned I may have totally mucked it up.

2 minutes ago, happy-kat said:

That looks better. I'd go outside and enjoy your telescope and come back to this another cloudy day to improve it. If you are adjusting your secondary then it's safer to protect your primary mirror from anything falling on it.

I wasn't sure, it did seem to look more aligned than the first couple of pics and certainly that last one where the mirrors are totally out of view.  The couple of things that concern me is that I can't see the three clips for the primary mirror although I do seem able to see the mirror itself completely in the frame now. And also, that picture was taken with the cheshire put into the viewer and screwed into place. But it's not firmly in place, the cheshire can move a bit if pressure is applied which makes it look a bit less aligned than that.

15 minutes ago, wulfrun said:

First couple of times is when you get your brains tangled up. Read the guides until it sticks in your head and you can look and know what you're seeing. Once you "get it" it becomes a simple and quick job, so stick with it! Ask any Newt owner, they'll likely tell you much the same. First time I did one of mine, I was faffing for hours. Now takes a few minutes, worst case, when I've bumped it (which happens).

Does this look any better https://imgur.com/a/uDitdAO I can't see the three mirror clips for the primary mirror though.

Sorry about the image spam by the way. I know this should be simple enough and I dare say it will be eventually, after enough attempts it will just "click" and become second nature but it's a bit confusing right now.

https://imgur.com/a/QzvYuXi

Tried fixing the secondary mirror but just made it a lot worse

The mirror was loose at one point and I accidentally moved it so its probably off-kilter now. Maybe I should have gone with a refractor, this is frustrating

8 minutes ago, happy-kat said:

It's a bit better.

In your fiddling have you only touched the primary mirror?

Yes. There's 3 knobs at the base of the scope to move it, I can reach them while still looking through the Cheshire so I've been doing that in trial and error trying to centre it.

Tinkered a bit with the primary mirror screws at the bottom of the scope not sure if I made it better or worse

https://imgur.com/a/XIpxJpL

17 hours ago, Spile said:

I prefer to make a judgment from an image taken through a cap. Can you do that?

Cheshire arrived today, taken a few pics

https://imgur.com/a/YvShjOV

This may be a stupid question but is collimation an incremental process where a small improvement to the alignment results in a corresponding small improvement in the view, all the way up to a perfect alignment resulting in the best view you can get from that scope? Is there some margin for error for example if I get it from being “way off” to “a little bit off” will I still benefit from a much better view?

12 minutes ago, Spile said:

I prefer to make a judgment from an image taken through a cap. Can you do that?

I've ordered one of these https://www.firstlightoptics.com/other-collimation-tools/astro-essentials-cheshire-collimating-eyepiece.html will post an image through that.

1 minute ago, Mr Spock said:

Indeed. It's not comparing like with like but with my 12" I've just been looking at Mars at x380 and seeing a lot of detail. A poorly collimated scope would be blurred with little or no detail and certainly wouldn't be able to hold high magnification in good seeing conditions. No scope on Earth will see fine detail in poor seeing conditions though!

Are there any "before and after" photos showing how objects like the moon look with poor collimation versus properly collimated?

10 minutes ago, Carbon Brush said:

Hello and welcome to SGL.
Collimation is still way off.
The key word from @Mr Spock is 'concentric'
All of the circles in your views must be concentric.
Once you get the cheshire, it will be easy.

Did you buy from an astro retailer?
Any astro retailer will be happy to show you collimation if you take the scope back into the shop.
We can offer advice, or pointers to videos. But 5 minutes hands on is (in my opinion anyway) much better.

Bought it online.

That's a shame it's off, I have to say I'm not looking forward to tweaking the secondary mirror. Primary seems straightforward enough when I get my cheshire.

I've actually been quite impressed with the views I've got so far, of the moon. Once I've got the mirrors properly aligned will I see things even sharper?

1 hour ago, Mr Spock said:

If that's a view down your scope then the collimation is way off! 

When you look in the secondary, you should see all of the primary and it should be concentric. That's the first thing to correct.

Then when you adjust the primary, the little doughnut should be right in the centre. Your Cheshire will help you do this.

Does it make a difference? Yes, when a scope is properly collimated the image will be much sharper.

Here's a couple with the viewing cap taken off.

https://imgur.com/a/H0joaLO

I can see the primary mirror and the three mirror clips but should all of it be further "up" on the secondary mirror? There's a lot of empty space up there

Hey everyone. Recently bought myself a Sky Watcher Heritage 130p flextube and have a few questions, as I understand that as a reflector telescope it will sometimes need to be collimated.

• How often is it likely to need collimated? I have heard everything from "I collimate it every time" to "Not collimated in months and it's been fine". I don't move it a lot, just take it out into the garden when its a clear night and then bring it back indoors when finished.

• When it first arrived I tried (perhaps foolishly) to try and "collimate by eyeball", training it on the moon and then turning the collimation knobs of the primary mirror in a trial and error fashion, checking the view to see if it got any better or worse. I stopped eventually as I wasn't seeing much change either way. I know that was probably a silly idea, at least until I'm more comfortable and know what I'm doing, but hopefully as there wasn't a noticeable change in quality of the view it's not a massive problem.

• At this stage, I'm only interested in observing fairly local objects, mainly the moon and Jupiter and Saturn. Does this make collimation more or less important than if I was observing nebulae/galaxies/further away objects? Or is it the same? I know the scope works by having the mirrors concentrate the light into a smaller area, so I wondered if the fact the moon is a lot closer than some random nebulae, there is more light available for the scope to pick up even if the alignment is not perfect?

• Will I need to align the secondary mirror often on this particular scope? The primary seems easy to adjust and I've read that's where 90% of collimation issues are,  but the secondary seems a bit more complex.

• Is poor collimation something that gets worse over time or does it just stay at that same "level" of poor until properly aligned?

• I've ordered a Cheshire collimation tube. Here's a picture of what I see when I look into the viewer at the moment https://imgur.com/a/MXkEvAV Does collimating the primary mirror basically consist of putting the cheshire in like I would normally put an eye piece in, then I'll see crosshairs on top of that view in the picture, and then I just need to move the collimation knobs on the bottom of the scope until the grey doughnut is in the middle of the crosshairs?

I'm very much a beginner at this, only had my scope for a week but I am really enjoying it so far. I can spend ages just looking around the various lunar mares. I live in an area with quite a bit of light pollution and don't drive, so very limited opportunity for truly "dark" sky viewing. But even so, I'm still quite impressed with the views I'm getting. If this is going to be a long term hobby I will need to get familiar with collimation at some point, even though it seems a bit daunting to me right now!