Peterson Eyeopener II

[sharpiel]

Recently I came across some online conversations regarding possible vignetting using 2" eyepieces due to the 1 1/2" obstruction in the focuser attachment on the visual back of my LX200 Classic Meade SCT. I measured it myself (pic attached) to be a 1.5" maximum opening for the light cone throuput.

I subsequently went online and found the Peterson EyeOpener II (link is here) which replaces this obstruction with a true 2" opening on the visual back. Peterson advertise this as a way of gaining the most from 2" eyepieces and binoviewers...which does make sense without sitting down and calculating the exiting light cone and how it's reacts with the field lens of 2" eyepieces etc etc.

Prior to buying I thought I'd ask the community who had used the Peterson, or a similar expansion of the maximum visual back obstruction, what the benefits are for visual and AP use and what alternatives may be available.

Your thoughts?

[wayne anderson (Wayne)]

Hi Les, I have the Petersons eyeopener on my 12inch LX200 and have noticed that the only advantage is if you use wide field 2 inch eyepieces with a large field stop. My 41mm Panoptic and 26mm Nagler with the eyeopener show better views to the edge of field with no vignetting however the 17mm ethos shows no change in views over the standard visual back.

[sharpiel]

Originally Posted by wayne anderson

Hi Les, I have the Petersons eyeopener on my 12inch LX200 and have noticed that the only advantage is if you use wide field 2 inch eyepieces with a large field stop. My 41mm Panoptic and 26mm Nagler with the eyeopener show better views to the edge of field with no vignetting however the 17mm ethos shows no change in views over the standard visual back.

Thanks Wayne.

What focuser have you attached to the eyeopener? I was planning on a Moonlite.

[wayne anderson (Wayne)]

Hi Les, I use the Meade zero image-shift focuser attached directly to the Petersons eyeopener.

[sharpiel]

Anybody else out there had experiences? Any thoughts on negatives or positives? Different focusers attached?

[BlackWidow (Mardy)]

No Negs on these.. Great item to have and really well made... I have no idea why Meade don't do this as standard (Price I guess).. I have one on my LX200 and so do two other of my Nerd Friends (sorry Guys.. I have left you nameless) If you get into astrophotography you really need this item... Time to make a Purchase Les

[sharpiel]

Originally Posted by BlackWidow

No Negs on these.. Great item to have and really well made... I have no idea why Meade don't do this as standard (Price I guess).. I have one on my LX200 and so do two other of my Nerd Friends (sorry Guys.. I have left you nameless) If you get into astrophotography you really need this item... Time to make a Purchase Les

Thanks Mardy. Great news. As mentioned I'm hoping to attach a Moonlite to the eyeopener. Are you aware of any issues there?

[AndrewJ]

Gday Les

I dont use the Peterson unit, i bought the AstroPhysics unit, as it allows me to use 2"barrel connections, instead of being tied to the meade microfocusser.
That said, you need to check what the dia of your baffles are.
Most Meade LX200s have a 2" baffle all the way,
but ( IIRC ) some early 14" units only had a 1-1/2" baffle, and hence the eyeopener gave no benefits ( vignetting wise )

Andrew

[sharpiel]

Originally Posted by AndrewJ

Gday Les

I dont use the Peterson unit, i bought the AstroPhysics unit, as it allows me to use 2"barrel connections, instead of being tied to the meade microfocusser.
That said, you need to check what the dia of your baffles are.
Most Meade LX200s have a 2" baffle all the way,
but ( IIRC ) some early 14" units only had a 1-1/2" baffle, and hence the eyeopener gave no benefits ( vignetting wise )

Andrew

Thanks Andrew. Are you saying the only focuser I can use on the eyeopener is the Meade micro?

[redbeard (Damien)]

Hi Les,

I was using an Eye opener on my 10" Meade LX200GPS and loved it.

Currently though, I have a Moonlite focuser and it came with its own threaded flange which threads onto the back of the Meade's thread which is an exceptional piece of work. The main focuser then attaches to that and can easily be rotated etc. On the one I ordered, (there are a few types), it is designed to have a 6.3 focal reducer inserted into it at just the right place and out of the way. Great idea and the camera goes straight into the focuser. The hole is big and not restricted. You order whatever flange to suit.

I would recommend getting the flange from Moonlite as the cost may be similar, (no idea really without checking). Email Ron at Moonlite if you have questions and/or info on selecting the best flange and draw tube. Their web site is pretty good on info.

Best add on I've done on the Meade.

Cheers,

Damien.

[sharpiel]

Originally Posted by redbeard

Hi Les,

I was using an Eye opener on my 10" Meade LX200GPS and loved it.

Currently though, I have a Moonlite focuser and it came with its own threaded flange which threads onto the back of the Meade's thread which is an exceptional piece of work. The main focuser then attaches to that and can easily be rotated etc. On the one I ordered, (there are a few types), it is designed to have a 6.3 focal reducer inserted into it at just the right place and out of the way. Great idea and the camera goes straight into the focuser. The hole is big and not restricted. You order whatever flange to suit.

I would recommend getting the flange from Moonlite as the cost may be similar, (no idea really without checking). Email Ron at Moonlite if you have questions and/or info on selecting the best flange and draw tube. Their web site is pretty good on info.

Best add on I've done on the Meade.

Cheers,

Damien.

Thanks Damien.

Sounds like what I'm looking for. My intention was to add a Moonlite to the visual back of my Meade 12" so if they also supply a flange without a limiting baffle which replaces the 1.5" baffle in the Meade visual back then that's perfect.

[AndrewJ]

Gdau Les

Are you saying the only focuser I can use on the eyeopener is the Meade micro?

Yep, unless the manufacturer of the focusser has an adapter that specifically mates to the EyeOpener, or you buy Petersons visual back adapter
http://www.petersonengineering.com/sky/2-in_adapter.htm
that converts the unit into a std 2" visual back
( and that's effectively what i bought as a 1 piece adapter )
http://www.astro-physics.com/product...ap.htm#adasctl
look for the ADASCTLM

Andrew

[sharpiel]

Originally Posted by AndrewJ

Gdau Les


Yep, unless the manufacturer of the focusser has an adapter that specifically mates to the EyeOpener, or you buy Petersons visual back adapter
http://www.petersonengineering.com/sky/2-in_adapter.htm
that converts the unit into a std 2" visual back
( and that's effectively what i bought as a 1 piece adapter )
http://www.astro-physics.com/product...ap.htm#adasctl
look for the ADASCTLM

Andrew

Brilliant stuff Andrew.

Thank you.

[redbeard (Damien)]

Originally Posted by sharpiel

Thanks Damien.

Sounds like what I'm looking for. My intention was to add a Moonlite to the visual back of my Meade 12" so if they also supply a flange without a limiting baffle which replaces the 1.5" baffle in the Meade visual back then that's perfect.

Yep you got it!
The focuser threads onto the Meade 3 1/4" flange that is part of the scope. I'm guessing that the LX200 has the same size thread.

If you click on the (MoonLite CS Model SCT Focusers) page, there is some good info there. I've added pics of my setup.

Cheers,

Damien.

[sharpiel]

Originally Posted by redbeard

Yep you got it!
The focuser threads onto the Meade 3 1/4" flange that is part of the scope. I'm guessing that the LX200 has the same size thread.

If you click on the (MoonLite CS Model SCT Focusers) page, there is some good info there. I've added pics of my setup.

Cheers,

Damien.

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That's just brilliant mate. Thanks everyone who took the time to reply. Legends