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Best Illuminated Reticle Eyepiece For GoTo

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#1 Jeff55

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Posted 05 August 2009 - 10:06 AM

There are a number of eyepieces available and I could use some advise as to which is best to buy and why. Thanks!

#2 Bowmoreman

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Posted 05 August 2009 - 12:02 PM

By definition, the highest power one you can successfully use with your various scopes will yield the most precise alignment.

I have been using the Orion 5mm IR EP (with my 800mm Vixen - now gone, and my 1200mm XT10i). But, now with a C11 (2800mm) about to join the stable, I think I won't be able to successfully use a 5mm IR... and so may now have to get something more like 12-13mm so as to not be TOO high power.

HTH

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#3 Jeff55

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Posted 05 August 2009 - 12:20 PM

David;
Is there a particular eyepiece you might recommend such as the 12.5mm from Orion...is there an advantage to pay for the best optics (Ultrascopc) or average such as a Plossl. Most of the newer versions seem to be in the 20mm to 25mm category.

#4 gnowellsct

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Posted 05 August 2009 - 02:18 PM

If all you are doing is using the illuminated reticle for computer alignment then you don't need anything particularly special. You're just trying to reduce the error factor in the mount model by reducing your error in estimating the center of the field of view.

I actually don't recommendn Bowmerman's advice of highest possible magnification, because when you're hunting for a star it's helpful to have some field, and these cross hair eyepieces are narrow to begin with. So I would think something in the ten to 13 mm category would be fine. The crosshairs will give you a center.

One trick that I use is to throw the star out of focus. With SCTs and Newtonians the center of the star will have a secondary shadow (black dot in the out of focus star). Put the black dot in the center of the crosshairs and you're ready for the next alignment.

regards
Greg N

#5 Bowmoreman

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Posted 05 August 2009 - 08:41 PM

well... i have used the 5mm Orion with great success... obviously, the 12.5mm will work better in my soon to arrive C11...

but if you use low mag, your error potential IS much higher... keep in mind, you really should be using a wider angle "finder" type EP before you insert your IR first anyways...

I have ONLY experience with the 5mm Orion (which was NOT cheap)... I see no reason that any J-random cheap 12mm or so wouldn't work fine...

Again though, I strongly recommend highest power possible - for accuracy; clearly NOT for FINDING in the first place...

clear enough skies

#6 CounterWeight

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Posted 05 August 2009 - 09:53 PM

I'll own up to using the Orion 12.5 illum plossel on all my scopes :) Worked fine in my 12, 11, 8" SCT's and my 160, 130, and 128mm refractors of late... never had any problems or much resulting error in 'goto' using the 12.5 in any of them.

#7 Chris Rowland

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Posted 06 August 2009 - 08:04 AM

My reticle EP is a 25mm Plossl with hairs glued across the field stop.

It's "illuminated" by the light of the unfocused star. With a SCT there's a tiny bright dot in the centre of the doughnut formed by the shadow of the secondary.

I think this gets me to better than an arc minute in accuracy. It isn't good enough for autoguiding but fine for aligning.

Chris

#8 Alph

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Posted 06 August 2009 - 01:38 PM

Your question is moot. You have no choice. All illuminated reticle EPs, that I have seen, have pretty much same FL around 12mm. Please show a 25mm illuminated EP. I will be grateful to you.

#9 Bowmoreman

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Posted 06 August 2009 - 01:44 PM

Your question is moot. You have no choice. All illuminated reticle EPs, that I have seen, have pretty much same FL around 12mm. Please show a 25mm illuminated EP. I will be grateful to you.


Most decidedly NOT true! Orion still sells to this day a 5mm IR EP. It is not cheap, but it works well (for me).

I make no claims, either way, for anything LONGER than around 12-13mm however.

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#10 jim molinari

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Posted 06 August 2009 - 02:38 PM

"Your question is moot. You have no choice. All illuminated reticle EPs, that I have seen, have pretty much same FL around 12mm. Please show a 25mm illuminated EP. I will be grateful to you."

It's not a 25mmm, but, Orion offers a 20mm illuminated centering eyepiece with a 70 degree apparent field of view.

#11 Alph

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Posted 06 August 2009 - 03:06 PM

It's not a 25mmm, but, Orion offers a 20mm illuminated centering eyepiece with a 70 degree apparent field of view.


Awesome! That's the best centering EP on the market.

#12 Harold925

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Posted 06 August 2009 - 05:43 PM

I ordered a new Orion 20mm illuminated centering eyepiece on 7/29/2009 with another item, and the 20mm is to ship on or about 8/16/2009. I have another week and a half or two before I can pair it with my 9x50 illuminated crosshair finder for the perfect alignment on my SCT.

#13 Jeff55

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Posted 07 August 2009 - 06:58 AM

Harold;
I to just ordered the Orion 20MM from OptCorp...I think the extra wide field will make it easier to locate objects. I'm hopeful the eyepiece will be that good compromise and provide just enough power to be fully functional.

#14 skybsd

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Posted 07 August 2009 - 05:00 PM

Hi,

It's not a 25mmm, but, Orion offers a 20mm illuminated centering eyepiece with a 70 degree apparent field of view.


Had a look at this EP at OPT.., looks remarkably just like the Antares Illuminated crosshair eyepiece in Europe :smirk:

Will check with Markus to see if he's got stock..,

Regards,

skybsd

#15 Harold925

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Posted 07 August 2009 - 05:23 PM

Hey Jeff,

I ordered from Orion, I hope that you receive your order faster. "All Good Things Come To Those Who Wait, And Are Patient"! I checked OPTcorp and I see that the unit is backordered there too. :foreheadslap:

Take care,

#16 mchaser

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Posted 07 August 2009 - 06:05 PM

I've been using the Orion 20mm for a month or so. I used to use a 12.5mm Meade. I like the Orion for its wider field of view. Also, the crosshairs stay centered, unlike the Meade (at night my fat fingers tended to accidentely turn the reticle adjustment knobs.

The Orion crosshairs are a bit bright, even dimmed fully. The Meade has a double crosshair, which can make position changes slightly more apparent when drift aligning. I feel the Orion's wide field of view (to help finding alignment stars) trumps the other concerns.

HTH

#17 Harold925

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Posted 07 August 2009 - 07:34 PM

It sounds to be a very welcome and valuable accessory. Low power to switch from the finder, with illuminated crosshairs to center and align! Next, Boom, the mount places the target dead center in your scope. No more estimating. Sounds Great.

#18 gnowellsct

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Posted 07 August 2009 - 08:19 PM

Well, no, I use my 12mm in both my c14 and my refractors. I used to put a barlow into the f/6.5 4" refractor because of the radically shorter fl, but then I discovered that the error incorporated into the model is fairly minimal, and more to the point, a four inch refractor can stand more error in the pointing model than a c14. So the problem is self-limiting, as it were.

But the way I do it, I get the finder scope tight enough that I can bring the star right into the reticle which is 326x on a c14 or maybe 1/7th of a degree, I guess 8 arc minutes and change. So I don't swap eyepieces.

It is true that the box at the center has noticeably more "travel time" for a star that you're centering with the f/6.5 four inch refractor than does the c14, but as I say, I have found this to be of no practical significance for a pointing model.

And a 12mm reticle can be barlowed down to a 6mm reticle much more easily than the reverse.

Anyhow there's many ways to skin a cat, I get by fine with 12mm in a wide variety of conditions, there are other ways to do it.

regards
Greg N

#19 CounterWeight

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Posted 07 August 2009 - 10:15 PM

Not trying to go off topic but am curious.

I know many use red dot finders, rigels, telrads and etc, and I never use them, I use the traditional optical 8*50 or whatever. When my finder is aligned (and here I cannot say enough good about the TEC style finder mount) I never miss getting the star in the align ep FOV.... never. Currently using a Baader 8*50 illuminated on the TEC style finder mount. Same was true with my Tak (illum)finders. None of these finders was the amazingly useful and wonderful new tech stuff. All are the old optical style with crosshairs.

My C11 using the supplied Celestron (non illum) quick release finder (6*50?? cant remember) was a problem but it is a terrible and cheap design. No way did it hold from use to use. Had to set it up every time from scratch (usually meant 'tube' sighting a bright star and dialing in). Sure the C11 had a narrower FOV than my refractors or smaller SCT's - but the same essentially holds true, once the optical finder was set up, then align ep FOV wasn't a factor.

Is wanting a wider FOV lower power illuminated reticle eyepiece needed because of all the slop in the fancy newer style finders folks are using? Just curious. I dont see any need for either.

To me the only important thing in an illuminated reticle eyepiece is if the crosshairs are calibrated to the center, and though I like the illumination, have used when batteries are dead with good results. I had used the Meade a ways back and think I sold it with the scope - but I've had no problems setting up for goto with the 12.5 - provided the finder was set up as well. I guess I should add that a well made finder with accurate crosshairs is also very important.

I did a few tests of using a 26mm and up and down plossel sizes to center for align and found that even just eyeball centering gave pretty decent results for visual... maybe that is more to do with the Celestron pointing model and it's search/offset when locating stars - but for visual it worked fine. Moving to the 12.5 illuminated took out all the guesswork of apparent introduced error.

Anyway getting back - once the finder 'scope' is set up I dont need to worry about FOV of the crosshair reticle ep as it is always in there somewhere. Long live quality optical finder scopes and their mounts.

:penny: :penny:

#20 Alph

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Posted 07 August 2009 - 10:42 PM

Had a look at this EP at OPT.., looks remarkably just like the Antares Illuminated crosshair eyepiece in Europe



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