WANTED ~ Meade Astrometric 12mm

[ving (David)]

Hi guys, I dont suppose anyone had a meade astrometric 12mm EP they dont want? I'd settle for anything similary of course.
thanks for looking.
DH

[Rodstar (Rod)]

Not many people use those, Ving, so I imagine there aren't many on the market.

I have been eyeing the same type of equipment. I am keen to start measuring double separations and secondary position angles. Is that what you have in mind as well?

It might be worth your while emailing Richard Jaworski, who heads up the double star committee of the NSW Astro Soc. He might know which one is best to get, and maybe even know of or have an old one to sell to you????

I know Bintel have the item you have mentioned, new. It is pretty pricey though.

Celestron also have one, which Ausastronomer says is better. I am not sure why.

Let me know how you get on.

[ving (David)]

yup thats why i want one
how doi get in touch with this richard character?
I saw the bintel one and yes its a bit $$$. I'd be interested to know why the celestron one is better too.

I thought this would be the next step: PAs and separations

[Merlin66 (Ken)]

I've used these eyepiece, as well as Iceland spar slivers for some years, but recently came across a great program called Reduc (freeware) and well supported by it's French author. It's used to measure separations/ PA from webcam/ CCD images. For guys with CCD capablities , well worth looking at.
Much more accurate than the old filar micrometer for stars in the +2 sec sep range.

ps The better Celestron one I have has two neat micro screws, adujustable centring of the scale, very good illuminator and a clean set of grids/ scales, its marked " Celestron Or 6mm G-E". The other is the 12.5mm Micro-guide version, just basically a set of grids.

[ausastronomer (John Bambury)]

Originally Posted by Rodstar

Celestron also have one, which Ausastronomer says is better. I am not sure why.

Rod/David

The 12.5mm Celestron Illuminated Microguide Eyepiece is a 12.5mm Made in Japan Orthoscopic Eyepiece.

The 12mm Meade Illuminated Astrometric Eyepiece uses a 3 Element Modified Achromat design.

The Celestron Eyepiece being of orthoscopic design is inherently a high quality eyepiece that will perform well in fast F-Ratio scopes. The Meade uses a Modified Achromat design. The Modified Achromat eyepiece design is very similar to the Kellner design, excepting the field lens in the Kellner is "Bi-Convex" and in the Modified Achromat it is "Plano Convex". GOOD QUALITY Modifed Achromats can be very good planetary and double star eyepieces (particularly in a slow F-Ratio refractor) due to their high light throughput, but eye-relief is relatively short and they work best in telescopes having a focal ratio slower than F6; and the slower the scope the better they work.

Having regard to the scopes you guys own I don't know that any visible difference would be major. I just think the Celestron Microguide uses a better grade eyepiece as its starting point, which is why it costs more money. Like most things in life, you get about what you pay for

CS-John B

[ving (David)]

thanks for the info merlin and john, i'll look into it