Polar scope illumination.

[Stargazer33]

Hi, I was hoping someone could answer a quick question for me?

I read in the thread about the Asda cam, that someone had converted theirs into a polar cam and it was suggested that they would require a red light to see the reticle properly.

Could you just drill a hole in the nose piece of the web cam and put a red LED in there or would you need a half mirrored diagonal to shine the light up the polar scope?

Or am I completely wide of the mark and the red light has to be placed at the object end of the polar scope?

Thanks in advance.

Bryan

[JamesF]

You really want to light the polar scope from the other end. I made an illuminator for my EQ3-2 recently. I'll find the thread in a moment.

James

[JamesF]

Here you go:

http://stargazerslounge.com/showthread.php?t=175561

I was planning to make a polar scope cam, but to be honest having the illuminator makes things so quick that I didn't bother in the end. I think it would only really be an advantage if I were imaging and had the tripod legs fully collapsed.

James

[Scott]

Here you go:

http://stargazerslounge.com/showthread.php?t=175561

I was planning to make a polar scope cam, but to be honest having the illuminator makes things so quick that I didn't bother in the end. I think it would only really be an advantage if I were imaging and had the tripod legs fully collapsed.

James

Nice mod James, I might try something like that next time we get some cloudy weather and I can't get the scope out.....Oh wait:(

[Stargazer33]

Thanks James, that's great!

It was really hard the other night holding my red light at the objective end of the polar scope and trying to look into the other end AND align everything up at the same time!

Good job I'm 6' 4" and ape positive (arm reach is bigger than height)!

Down to the local DIY shed for some waste pipe. If I don't end up using it for a polar scope illuminator, I can use it to get rid of some of this damn rain! Wettest drought I've ever seen!

Bryan

[glowjet]

Love the pipework James, a brilliant idea, If it is of any interest to those about to manufacture such an illuminator if you are already using a 12V supply for other purposes there is a 12V LED with a built in resistor, a CJ66W 3mm is standard brightness and a CJ70M 3mm high brightness, both available from Maplins. I used the CJ70M in line with a 470Kohm variable resistor to give me bright to almost unsee-able in my own unit, tested in the pitch dark of my workshop.

John.

[JamesF]

Good point about the resistor, John. I planned to put one in mine, but when I tested it with the PSU discovered it was pretty close to perfect, so never bothered

James

[Stargazer33]

Nice idea about the variable pot!

We've got some at work and I'm sure I've got an old one knocking about in my serviceable box somewhere.

looks like my lunchtime is booked for tomorrow.

Bryan