Pixies

It's the rotation that is causing it to look tilted: You need to get the secondary appearing perfectly circular under the focuser first - before worrying about the reflection of the primary in it. That's one of the hardest parts when first learning how to collimate. Once that's done, it very rarely needs adjusting. When the secondary is aligned under the focuser correctly, then you can start finely adjusting the tilt to get the image of the primary centred. Get the secondary at the correct distance from the end of the tube and rotated so that the outer edge of the mirror surface appears as close as circular as possible in the focuser. Before you do this, have a check on any tilt that has been set up on the secondary assembly. It should start parallel with the vanes - i.e. all 3 adjuster screws should be at the same length. You might find that with your work so far, it isn't very level. Best start with it as close to straight as possible. In @Spile's guide, this part here: This gap really needs to be parallel when you start. It makes this stage a lot easier and with your open-tube design, it should be easy to see. You will be slightly adjusting the tilt later. Does that make sense? Everyone describes this process in slightly different ways, but it's the same thing really. Once you get your head around what you're doing, it all fits into place. There are different tools to help - from the most basic collimation cap, sight-tube/Cheshire,Concenter - all the way up to systems costing far more than the scope! You can do it roughly just looking down the focuser, though.

That's a new one, to me. I'll have to check it out next time it's clear up here.. Tomorrow's looking promising!

For those of you using Twitter, here's an interesting thread from the Senior Advisor for Science & Exploration at the European Space Agency, about the need for the sunshield: https://twitter.com/markmccaughrean/status/1477213435087761409

Cool. Are you able to see the comet naked-eye at all? If you have binoculars, they will be good for observing it in context. On a rare morning before it was too low from the UK, I managed to get a view of it in 10x50s and could just about see 1 degree of tail (in lightening skies). You should be able to see it much clearer!

Yes - the metallic pink one. Here was my initial review of it: Perhaps owners of the Astro Essential one can comment on it. I've never used one, I'm afraid.

I have the FLO one and it's pretty good. With the Astro Essentials one, I don't understand why it has that lip on the body: Is that as far as it goes in, or can you insert it further into the focuser? With the FLO one, I have it pretty much all the way in, which really helps when aligning the secondary. That is with a Bresser 8" dob.

Hi @DhamR, What sort of sight-tube are you using? If it a long one like the FLO Pro Cheshire, try inserting it a bit further, so the outer circle is much closer to the secondary. Also, from your picture, that outer circular edge doesn't look very circular. Not sure why - perhaps it's just a shadow of some kind? Anyway: To me, your secondary looks twisted. The top (in the picture) need to be slightly rotated towards you. It's also a little to far down the tube. Once that is sorted, you can adjust the tilt. The Yellow ellipse is how the outer edge of the secondary appears to me. It should be circular and aligned with the red reticles above. Having the open design of the Heritage makes it a lot easier to see what's going on!

I guess it will be at (or closely circling) the antisolar point. So due south on the meridian at midnight.

Mind you - you can ignore the collimation part in that video - for now. 06:00 - 09:00

Hi, Another Bresser newt owner here (200 dob). You are not the first to miss that adapter. I know someone who threw it out with the polystyrene packaging! Have a look at this video: (same type of scope). It covers basic usage including setting up the finder. I'd recommend the book Turn Left at Orion which is a very good guide on how to find stuff manually!

If you follow a guide like the Astro-baby one, they often suggest using coloured paper behind the secondary and down the tube, to help you determine the alignment of the secondary under the focuser. You then need to get it something like:

Ed Ting suggests the Vixen 80 and the Evostar 80 are the same scope: I'm sure owners will comment below.

Collimation won't have much affect on large fuzzy objects like galaxies. It will affect resolution of fine details on moon/planets as well as details of stars at high magnification. If the secondary is misaligned under the focuser or twisted, the laser won't be particularly effective. Also, depending on the quality and type of the laser, it might be out of collimation itself. If the laser bean does not leave the device perfectly centered and parallel, it will be of no use as a collimation tool. Put the laser into the focuser and rotate it - does the spot remain centered in the doughtnut marker on the primary? Also, as you tighten it in the focuser, does it always return to the same spot? Have a look at these for a useful guide on collimation with a cap: https://garyseronik.com/a-beginners-guide-to-collimation/ https://www.astro-baby.com/astrobaby/help/collimation-guide-newtonian-reflector/

I found a steel washer and milk-bottle plastic fixed the same problem I had with my Bresser. If you are taking the secondary assembly apart, you can use the opportunity to replace the 3 adjusting screws with some thumbscrews - it's makes adjustment so much easier.

Thanks Steve - added to the list.

How are things down-under? Have you managed to observe comet Leonard, yet?

Here's one from my dob a while back - using a phone camera down a collimation cap: The reticle is superimposed using the 'Mire de Collimation" application form this page (scroll to the bottom): http://sweiller.free.fr/collimation.html#:~:text=Also try to superimpose the image coming from the webcam with this freeware from Gilbert Grillot Note: this is for a Windows PC/laptop It's much easier using a long Cheshire / sight-tube. You can align the secondary much more easily when the reference circle is closer: and even closer! There is a very thin gap visible around the outside of the secondary:

Edinburgh - 55° North - but nowhere near that cold! Have hardly dipped below freezing this Winter, so far. I used to work next to a guy from Winnipeg. When some cold snowy weather was imminent and one of our colleagues was running around panicking about getting home, he turned his screen towards me to show his hometown weather forecast.... -44° C. Mind you, one of my neighbours here is Inuit. She's from Qikiqtaaluk Region. I had to look that up. 62° North.

There's a podcast called 'Actual Astronomy' - done by 2 chaps from Regina, Saskatchewan. Recently they've been doing a few episodes on cold-weather observing. Makes the local Edinburgh temperatures seem positively balmy!

Hi there. You have mentioned a camera a couple if times. If you intend to do any AP, you will need a mount that tracks the target. Away form the basic budget end, that means a GoTo mount, even if you only want it for the tracking facility. On your last question, with a full-sized dob, you are best seated. I'm a couple of inches shorter than you but have never had an issue using an old drum stool. The stool doesn't lower far enough if I'm looking at something VERY low near the horizon, but a proper observing chair will.

That's a great book. Probably my most used. Santa got me this. Which will help pass the cloudy evenings:

Thanks. Some good objects in there, some I have yet to see. Just need some clear nights! IC428 - do you mean IC418? The former is in Orion.

Why does the Catseye website look like it's 1995 again! Even the pictures download sooooo slowly, like I'm using a modem! The wifi Cheshire looks nice, though!

Every time I try and start the campervan!

Berlebach Castor II? There was one on AB&S recently, but it's gone now. Haven't used one, but it looks the thing. No slo-mo though.