Illuminated Reticule EP

[moondog]

Last night I tried out an illuminated reticule eyepiece. Bought it to try to improve tracking on the HEQ5 Go-To, but not initially for drift aligning.

I have been using a 40mm Plossl with a TAL (came with scope) screw in non illuminated reticle to centre the alignment stars when setting up the HEQ5. This TAL has a plain cross reticule, quite chunky - makes it difficult to position over star. Thought new reticule EP with central alignment area would make it more accurate.

So... put old reticule EP in to start alignment process. This 40mm EP gives just under 30x mag. in my scope. Scope went to first alignment star. Not in view of 40mm EP (as usual). Centred it on finder scope, looked through 40mm EP and centred star in TAL reticule. Swapped for illuminated reticule which is a 10mm EP, giving about 110x mag. Not a surprise but it showed the star some way off centre. Centred star and went to second (and final) alignment star. This was in 10mm EP's field of view, centred star in reticule and finished alignment.

Looked at star in East at about 45 deg altitude, framed it in reticule and timed drift.

Normally when the mount is set up it's good for no more than 2 minutes tracking. Using the new EP seemed to improve this to just less than 3 minutes.

I'm happy with the result, it tells me that properly centring the alignment stars does make a difference. I'll have to have a go at drift aligning next, I understand that this may get me up to 5 mins tracking. That is if I can get the seeing through the carp skies !

MD

[centroid]

Wouldn't be without my 12mm Illum Rect eyepiece.

When used in conjunction with a Barlow, for drift alignment, any small amount of drift, shows up very quickly.

Dave

[MartinB]

MD a good alignment wont improve equatorial tracking. The mount will just be moving along at sidereal rate and whether the target moves or not is only related to periodic error (which shouln't be anywhere near large enough to move anything out of the EP), and drift from non perfect polar alignment. The drift from inaccurate polar alignment varies depending on where the scope is pointed - max along the celestial equator, and, obviously, how well the scope is polar aligned.

You will enjoy doing the drift aligning though MD. You can always find lots of other set up jobs to be doing whilst it is going on and even a short time spent - 30 mins makes a big difference.

[Vega]

I implemented a great idea from Captain Chaos for drift alignment. Use the trusty Phillips Toucam and the Riticule display in K3CCD Tools... genious! Up the frame rate/brightness on the webcam, rotate it in the ep holder to get the on screen crosshairs in the right orientation and your off. It works a treat and saved me a packet not spending out on an illumintaed EP.

Matt

[moondog]

Martin

I'm going to try drift aligning tonight as, at the moment, it looks as if it might be OK. Providing I can see stars in the right places I can have a practice without the sky being too clear. I'm going to have a go at improving my initial polar alignment any way, using the free piece of software Polar Finder.

Vega

For me an illuminated reticule EP is far cheaper than buying a webcam and a laptop - about £450 cheaper I reckon!. It's a good idea if you've got them though.

8)

MD

[MartinB]

Good luck with the drift alignment MD. I always forget which way I'm supposed to move things so always take out my own laminated idiots guide!

[lunator]

Good luck with the drift alignment MD. I always forget which way I'm supposed to move things so always take out my own laminated idiots guide!

Martin

I know the feeling. Most drift alignment explanations are based around CAT type scopes and have the line

'For Newtonians the directions are reversed'. So I end up trying to work out how to apply this counter intuitive process in reverse. :? :?

Cheers

Ian

[moondog]

Didn't manage to get out last night to try drift aligning. Will try tonight if OK.

Good idea Martin - I've put the intructions an a post card with a marker pen.

When I've done all this I'm going to have a bash at PEC training as the HEQ5 Go-To allows this.

Might as well do this while waiting for the skies to improve a bit !

MD