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Anonymous
Unregistered
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Can you use a focal reducer with the ETX 90, and what sort of results could I expect?
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John Hoare
I is who I is
Reged: 04/25/04
Posts: 10761
Loc: Foggy Bottom, Kildare, Ireland
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Hi Ceejay,
I've been looking at these things recently and everything I've seen suggests not; however here is an alternative: Field Doubler for ETX 90/105/125 and NexStar 4. Note that it's only for photography, not a visual tool. For visual use a focal reducer is equivalent to multiplying the focal length of your eyepiece by a factor x such that x>1. In many cases buying an eyepiece with a longer focal length (say 40mm if you have a 25mm) can be just as effective for visual purposes, and an eyepiece is something you can carry forward to future scopes without any compatibility issues.
--------------------
John
Traditionally qualified Scealaí.
IFAS
O....oøoo
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Anonymous
Unregistered
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I have been looking for some way to get a wider field in my ETX and I found this little item reviewed on Weasner’s
http://www.weasner.com/etx/shutan.html#wfa
You will need a visual back to use it as intended – but this guy also did some innovative work w/o one.
I just bought an Apogee Wide Field Adapter on eBay myself.
A bit strange thou that Weasner did not test it with a longer f/l ep than 26 mm. I’ll be eager to test how it works with a 32 mm plossl. Used with a 26 mm it is supposed to provide a 64% wider TFOV.
Apogee only sell them through Shutan.
http://www.shutan.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=1&Product_Code=595-6370&Category_Code=b
Disclaimer: I have no affiliation with either Shutan or Apogee other than that I soon hope to be a happy user of this product.
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Hiram
sage
Reged: 01/06/04
Posts: 213
Loc: Cd. Delicias, Chihuahua, Mexic...
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Yes, you can, I have a celestron focal reducer/corrector for SCT model #94175 Actually I have two of them, even I can stack them using my webcam to get a wider field of view but they show a litle deformation on the image as a vertical reduction when use both
I made my own visual back.
It is great, works wonderful with my 24.5 meade SWA.
A lot field of view and brightnes.}
One more thing, as more distance you can put through the eyepiece and the Focal reducer, using an extensor, you will notice a higer reduction efect, the focus range it is the limit. I been reach 655 f.l. stacking two reducer, but I had to remove the diagonal to rech focus 
hiram
an image axample the red circle it is with the two reducer, the blue circule it is with out the reducer and the single reducer field it is between them
Edited by Hiram (06/16/04 12:46 PM)
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