GRIPE - why are there no 2" illuminated reticle eyepieces?

[h0ughy (David)]

Life is not fair!

First your expected to slave away at work for 37.5 hours a week for some hard earned reddies! Then when you really, really, are after some astronomical goodies you really want to have and have been seeking for the past 20 years, no mug out there has built one yet. yes i am referring to the 2" illuminated reticle eyepiece!!!!

Meade, celestron/synta, Mr Nagler et al....... please please listen, there is a market for one of these creations, a 9mm illuminated 2" eyepiece.

Is there a god??? (rhetorical question peoples don't go for that one, i know there is!) Why can't one of the manufacturers Mod one of their eyepieces to suit, just for me???

[RB (Andrew)]

Don't know Houghy......

What would be the advantage in that though I wonder.
It would add extra weight on the end of the scope won't it?

[h0ughy (David)]

Originally Posted by Rocket Boy

Don't know Houghy......

What would be the advantage in that though I wonder.
It would add extra weight on the end of the scope won't it?

more comfortable viewing and guiding, larger area to view, easier to pick up all the light, bragging rights (well maybe not but it sure would be a good talking point), but the main thing is that I have all 2" Ep's, so why not a 2" reticle EP?

yes it would be heavier, but if i balance the scope then when i put the 2" EP in there wont be that much of a change in weight

[h0ughy (David)]

woohoo someone else voted with me!!

[Roger Davis]

Dave,

Please consider:
1. The illuminated reticle, even a red one, would lower the contrast of the image. Red LED's have quite a high blue component. ie field wash out
2. The illuminated reticle was designed to guide on a star whilst a photograph was taken. You don't need a large apparant field to do this.
3. The other use of the illuminated reticle was for the finderscope. Most of these have an aperture of 50 - 80mm and are ~f/4. That's a cone of light 200-320mm long. The size of the field lens of a 9mm eyepiece is not necessarily 2" across, more likely in the order of 10mm. This does not require a 2" barrel size.
4. Depending upon where the focal plane is also determines the position of the reticle. In some designs this is not always accessible. Usually it falls immediately on the field side of the aspheric first surface. If you can design a reticle that will curve and be equally illuminated without flooding the field lens with background red light, good luck.
5. Having said that, I have in the past made an eyepiece that had a 60° apparant field of view with dual crosshairs. Quite easy to make really. The field lens in this case was a doublet with the first surface virtually flat. Couldn't make it illuminated though as the focal plane fell inside the chrome 1.25" barrel and I couldn't access the reticle with a light source.

BTW what are you wanting it for?

[h0ughy (David)]

Wow, thanks for the detailed response Roger. Well I like 2" EPs and cannot see why there are not any 2" reticle EPs on the market. I have a 12mm illuminated one at the moment and a 25mm one on the st4. i would prefer the 12 be larger in eye relief for me to see into.

Apart from that, aesthetics, and the want for one. If they are that rare and someone hasn't done it before then there could be a market????? I'll be buying one if they ever make one.

The issues you raised seem very logical, and I can understand some reasoning's with the evidence presented. Thanks for your valued comment BTW Roger.