Thank you. That is very rewarding to hear. 👍

Get oneeee!!!😊

Same

I don't have one either.... But I do have a gambling problem 🫤

I have a small refractor for beginners but not a newtonian

I just got AWB 130p and IM IN LOVE WITH ASTRONOMY NOW

mate much appreciated . you are an inspiration 👍

@@Astrobiscuit Dude! that means a lot coming from you mate :)

thx for that good point. Fyi I didn't think that the focuser not pointing at the optical axis merited being in the basic video as most scopes have oversized secondarys which partly compensate for the error. However of course its better to have it squared off so i do run through it in the advanced video and I found a poorly aligned focuser can cause the sensor to be tilted with respect to the mirror and this can potentially make star collimation very difficult. Plenty of free videos about squaring off the focuser out there. feel free to highlight one if you wish. and thx.

oh mate thanks. Really appreciate it.

awesome. job done. 😁

😂im always thinking about what im saying...

ah thx bud

Yeh im sure fyi the advanced video takes you thru how to get it back into collimation.... but of course that is only available to patrons for £3 a month which judging by some of the comments makes me the prince of darkness😂

@@AstrobiscuitAll hail the prince of darkness! Does that make you a digestive with plain chocolate on it?

yes very true

😂

that means your laser collimator needs collimating... see the rig i use in the video. The focuser may be fine... there is a different check for that.

im afraid thats in the advanced section. just look up using a laser collimator to check your focuser us pointing straight.

true... Ive actually caught the laser. I wonder if they're designed to be not TOO dangerous. Hope so.

wow... that is suprising. i feel you must be a true nerd at heart. 🤣

yup, people really shouldn't be touching something stronger than a Class II imho unless they really need the power or are laser enthusiasts.

@@xander1052 I was somewhat shocked when I noticed mine has class 3.....

baader diamond steeltrack seems v good. Its hard to find any for small 6inch newts tho

an old np101 with a bit if fungus on the lens😭

Thank you😁

hi

yes its good...

well im glad i now know how to pay my morgage.😂😂😂😂😂 but seriously youve got 16 mins of well explained newtonian collimation advice for free why are you complaining?

@@Astrobiscuit well i'm not complaining honestly, just gaving you some advice for free!

yep refractor is what you need.

😂

That’s a good idea. I’m looking at replacing mine with knurled head screws so I can just use my fingers.

my laser has stayed collimated for about a year now.... good luck building the newt with no secondary. I have thought aboht it.

I've thought about this too and ive not seen any available commercially

The Hershillian reflector is perhaps the most obvious type. The most common way we see this is with a typical household satellite dish. Optically it’s very hard to do and get anywhere near the consistency needed across a small mirror let alone a mirror of the size for a telescope. Those off axis mirrors are available but in smaller sizes and become very expensive beyond a couple of inches. However some segmented designs of reflectors have all their mirrors except for the centre one as off axis mirrors. Main example is the James Webb. Unfortunately each single mirror wasn’t exactly affordable. I did ask someone who is a very well known guru on figuring mirrors on the chances of of this being feasible for an amateur telescope. The answer was preceded with some drawing of breath and wincing.

well not just you... its something ive been strugglong with for years and niw i feel like i have a good understanding i thought I'd make the video.

I dont agree with everything you say. I think you need to check you fully understand secondary mirror offset. I must admit ive no idea why folks barlow their laser. Perhaps you could enlighten me. I see no advantage over a well collimated regular laser...

@@Astrobiscuit I do understand secondary offset, it offsets the secondary holder toward the primary and away from the focuser, intercepting the entire light cone of the primary allowing even field illumination. Anyways those 3 screws have nothing to do with offset, they are meant to center the secondary under the focuser, opticians know what the do, they haven’t installed the 3 screws to annoy us… The barlowed laser simply magnifies the laser spot on the target so it’s easier to read any miscollimation

im afraid i don't think centering the secondary is a great thing to do in a fast newt. Fine for f5 ot six but i think an f4 newt the secondary should be pushed slightly forward towards the primary mirror by the secondary diameter / (4xfocal ratio) This is quite advanced though so i don't cover it in this basic tutorial.

​@@AstrobiscuitAgreed 👍, however there's no standard placement for the secondary offset in fast newtonians. The offset is entirely dependent on the manufacturers design which should be easily confirmed.

if your star test is fine then leave it and be happy👍

@@Astrobiscuit that is good news for me. It means I will be checking this video later someday :)

Look up vignette this can cause what you describe. BBC sky at night web site has a piece on it. ‘What is vignetting?’ was my search term. Hope you get it sorted.

optically flat windows cost more than the scope itself but they are quite good i think and help with thermals as well as diffraction spikes....

@@Astrobiscuit Thank you, I appreciate your reply and time.

There are Schmidt-Newtonian scopes, but looks like they aren't in production any more:(

sorry i uploaded the video to patreon so there is no easy way but if lots of folks request the same thing then I'll try and sort something out...

Alright, I will sign up then , don’t bother

most visual scopes are f6 or 8 so yes a collimation cap is fine... and a quick check with an out if focus star would get you very good collimation but if your scope is f5 or less then maybe you want more. Ultimately star collimatiin is thr best and collimation is very important for planetary observation.

@@Astrobiscuit Great! Thanks for the reply. I'm going to build a 6-inch f8 scope soon and collimation is a bit scary. I'll definitely come back to this video

well then you have to hope its pointing straight... and if it is you're ok.

yes it's possible. People have even done it before.

Technically? Yes. But you'd be introducing more elements into the light path. Depending on what type of camera you use, you'll block more of the incoming light. Especially with a DSLR, which due to its shape will also block the light in an irregular pattern. So you'd have to use a smaller circular camera such as a dedicated astro camera. Also, you can't use filter wheels with your camera, since the filter wheel assembly would also sit in your light path, so there's that limitation as well. Still, let's say you go with the bare astro camera. Now you have the cable coming off the camera that will asymmetrically block the incoming light. Why is this a problem? Well, on a standard Newtonian, the secondary mirror is held by spider vanes that are as thin as possible, in order to distort as little as possible. Yet we still see their effect on the stars. The crosses around stars that you see in astrophotos are diffraction spikes caused by the vanes; look up "spider vane diffraction spikes" for an explanation. So now imagine what an extra USB cable, which is a lot thicker than your typical spider vane, will do to your view. Now, there is a telescope design that keeps everything in-line, but solves the problem differently. The various catadioptric designs like the Schmidt-Cassegrain, Maksutov-Cassegrain etc. have a glass disc in front through which the light enters. It then hits the primary mirror in the back, which focuses the light and sends it forwards. There it hits a secondary mirror that's stuck to the inside of the glass (or a mirrored section in the center of the glass), which throws the light back again towards the back of the telescope. Finally it goes through a center hole in the primary mirror, and exits out the rear of the telescope, where the focuser sits. You can use whatever camera you want, since it sits behind the telescope, and does not block the incoming light. There are no diffracion spikes because there are no spider vanes holding the secondary in place. Finally, compared to refractor (with lenses) or Newtonian telescopes, these designs are shorter for the same focal length (magnification), which makes them more compact and reduces their weight. This makes them easier to transport to a remote dark site.

yes... and if you're camera is small its a good idea but you'll need a longer tube.

It's called a hyperstar.

well i personally dont centre my secondary in the focuser tube but for thosee who do they are fine if a little pricey.

@@Astrobiscuitthanks. I've always had problems with secondary mirror.

star collimation is still best as it'll account for things like camera sensor tilt.

me too😂