Illuminated centering eyepiece recommendations?

[JeremyS]

Any suggestions for a decent one to use when aligning a GOTO mount?

I'd like a wider field than most of the 12.5 mm 40deg FOV eyepieces. I see Orion has a 20 mm but also read about some problems with them.

Any views?

[wookie1965]

I give up with mine I use a zoom lens now quicker and since I have been really accurate.

[laudropb]

I was looking for the same a couple of months ago, but eventually just had to get the sky watcher 12 mm. Sometimes I have to find the alignment Star in 20 mm wa eyepiece first and then swap over to the reticile. Bit of a flaff but it does improve the alignment and subsequent go to quite a bit.

 

 

 

 

[johninderby]

This wide angle 2” one would work, but at a price.

https://www.teleskop-express.de/shop/product_info.php/info/p966_TS-Optics-Reticle-Eyepiece-32-mm-70----2--barrel-size---illuminable.html

[Ronclarke]

What we need is a cross-hair, 1.25 mm similar to a screw in filter. Then you can just screw it into whichever EP you use?

Does anybody make one??

 

Ron

[banjaxed]

4 minutes ago, Ronclarke said:

What we need is a cross-hair, 1.25 mm similar to a screw in filter. Then you can just screw it into whichever EP you use?

Does anybody make one??

 

Ron

That is a great idea, If nobody makes them then they should.

[johninderby]

Tal made one. sometimes one will turn up second hand.  Fits most 25mm eyepieces. Screws into the filter thread on the nosepiece. I have tested it on a few eyepieces and most 23mm to 26mm plossl types will work.

http://ensoptical.co.uk/tal-screw-in-cross-hair-eyepiece

Edited November 2, 2019 by johninderby

[Ruud]

The cross hairs should in the focal plane of the eyepiece. That is the same place where the field stop is (at least, where it should be: if the field stop is not sharp if it is not in the focal plane of the eyepiece).

Plössl eyepieces have an accessible field stop, Kellner, König and Erfle too. You can glue the hairs  to the field stop.

There are more. See here: Lord-Eyepiece-Evolution-Tree.PDF

Also see here: Google Books Search

 

 

Edited November 2, 2019 by Ruud

[Louis D]

9 hours ago, JeremyS said:

I'd like a wider field than most of the 12.5 mm 40deg FOV eyepieces. I see Orion has a 20 mm but also read about some problems with them.

Any views?

I have the 70 degree, 20mm Orion Centering eyepiece.  It's fine in the center but highly aberrated by astigmatism in the outer 50%.

I also have both the 40 degree, 12.5mm Celestron Ortho Microguide and 46 degree, 12mm Meade MA Astrometric eyepieces.  The Meade is wider but very astigmatic in the outer field.  The Celestron is pretty much sharp to the edge.

Below is a comparison image that includes the 20mm Orion and another that includes the two astrometrics.

[Oldfort]

On 02/11/2019 at 13:53, JeremyS said:

I'd like a wider field than most of the 12.5 mm 40deg FOV eyepieces. I see Orion has a 20 mm but also read about some problems with them.

APM carries a number of reticle eyepieces of varying FOV and focal length.

https://www.apm-telescopes.de/en/eyepieces/reticle--astrometric-eyepieces.html