Artifical Star

[FlashDrive]

I am considering purchasing an Artificial Star ...I've never used or owned one.

Am I wasting my money :question: .. or .. are they handy to have for collimation checking ... ??

Col...

[croweater]

Hi Col. I made my own using a torch covered with aluminium foil with pin holes in it. It works pretty good (I've also used a torch shining on a ball bearing). It'a lot easier(and less frustrating) collimating without having to track a star and not worried about seeing, weather etc.I have looked at buying the hubble artificial star torch (and probably will when have some spare cash) It gets pretty good reviews and I think is a bit cheaper than the one you're looking at. So ,yes either make or buy one as they are a good thing Col.
Cheers, Richard :)

[FlashDrive]

Thanks for your reply Richard ... I'll google and find this ' Hubble ' unit you talk of... check some reviews also.

EDIT ....The Hubble has been described as a ' cheap ' plastic torch with ' holes ' at the front..some people swear by them....some think it's a piece of junk.

I'll make up my own mind on this I guess.

:thanx: Col

[tempestwizz]

I made my own using a fibre optic patch cable. Needs to be glass fibre, not plastic. The light diameter through the fibre is 50 microns. Can illuminate with a torch or any light source at the far end.
May not look as ‘sexy’ as a store-bought version, but if you have some fibre patch cords laying around, simple to make.

[FlashDrive]

One review on why people think they can make one... ( up to the person I reckon .. if you can make one that works for you .. then good )

Is this just a flashlight with holes poked in it?

Over the years, a number of customers have commented that this is simply a cheap flashlight with holes poked in it, implying that this would be something easy to replicate at a much lower cost. While this is indeed a cheap flashlight, the value of this item is not in the flashlight but in the pinhole mask in which the precision pinholes are 0.05 - 0.25mm in diameter. You cannot simply take a pin and poke holes in a substrate to get anything remotely this small and accurate. We once had a US supplier provide us with a quote for the pinhole mask provided in this artificial star. Their quoted price was $80 for each single mask!

Maybe it would be better for me to purchase one and be done with it ...!!

https://www.ebay.com.au/itm/Hubble-Optics-5-Star-Artificial-Star-s-for-Collimating-and-Testing-Telescopes/193358798868?ssPageName=STRK%3AMEBI DX%3AIT

Col...

[multiweb]

Piece of aluminium foil and a small pin prick and you have one artificial star.

[AstroApprentice]

Hi Col,
I bought direct from Hubble Optics as it seems to be the cheapest:
http://hubbleoptics.com/artificial-stars.html#payment_section
The torch is cheap quality, but as you said, the precision drilled mask is the key and it works well for me - I slide the torch into mini-guidescope rings so I can mount on a tripod.

[FlashDrive]

Refer to Post #5 :lol:

[multiweb]

That's because you drink too much coffee. :P

[codemonkey]

I had (have?) the Hubble one... never used it. By the time I needed to use it I couldn't find it. I then DIY'd with a torch and some aluminium foil and it worked fine for my purposes.

[Aron]

Anyone has both, how's the homemade one compared to commercial ones?

I used the aluminum method, I think it's rather nice since you can make the hole as small as you want, but I wonder if it's better/worse than the commercial one.

[billdan]

If you are going to make one, use a pattern like this.

Then you can adjust for coma, tilt or field curvature. You would have to position it so the corner stars show up in your FOV.

[billdan]

The only thing wrong with this artificial star concept is, with Newtonians you shouldn't collimate when the scope is horizontal. Because collimation could shift when pointing vertical.
Its better to collimate at about 60 - 70 degrees elevation. You then minimise any collimation shift during an imaging session.

I suppose you could get a ladder and mount in a tree or somewhere high up with a remote on/off switch.

[sharpiel]

I didn’t know that. Thx for the tip.

[erick]

Yep I have the Hubble and have used it several times to check/tweak collimation when the physical conditions are right, that is I have a good distance available to place it in a visible location. But this is the concern - I'd rather collimate at a good elevation and it's difficult to get the Hubble a hundred or so metres away at elevation! I don't have a tall enough tripod :D