cweinhei
sage
Reged: 01/14/06
Posts: 222
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I purchased Meade SN8 about three years ago and have been using it for astrophotography ever since then with some great results. I'm now longing to do a little visual work. All I have in my collection is a 20 mm Plossl and it's probably not very good.
Any recommendations on a wide field 2" eyepiece that has a relatively flat field, good eye relief, and doesn't cost more than my scope? I know there are price/performance trade offs as with all telescope accessories.
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Orion Atlas EQ-G w/ EQMOD
8" F/4 LXD75 Schmit-Newt (Flocked)
JMI NGF-55D Focusor
Hutech Canon Rebel 350 XT (Clear filter)
DSI Pro (for guiding)
Shoestring USB Shutter Control
Shoestring Focusor Control
HNSky,PHD,DSLRFocus,WCS,Iris
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KWB
Postmaster
Reged: 09/30/06
Posts: 7635
Loc: Westminster,Co Elev.1646Meters
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At F/4 your going to need a real good widefield eyepiece if your definition of good is anything like mine. Do you need to wear eyeglasses to correct for astigmatism? Any idea as to what focal length your contemplating using?
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Kenny
"When dealing with a mystery,choose the most unlikely of the likely possibilities"-Sherlock Holmes
Edited by KWB (09/16/08 01:00 AM)
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cweinhei
sage
Reged: 01/14/06
Posts: 222
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No. My eyes are fine.
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Orion Atlas EQ-G w/ EQMOD
8" F/4 LXD75 Schmit-Newt (Flocked)
JMI NGF-55D Focusor
Hutech Canon Rebel 350 XT (Clear filter)
DSI Pro (for guiding)
Shoestring USB Shutter Control
Shoestring Focusor Control
HNSky,PHD,DSLRFocus,WCS,Iris
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cweinhei
sage
Reged: 01/14/06
Posts: 222
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I don't think I've ever really looked through a great eyepiece. All my experience is with Plossls and probably not very good ones at that.
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Orion Atlas EQ-G w/ EQMOD
8" F/4 LXD75 Schmit-Newt (Flocked)
JMI NGF-55D Focusor
Hutech Canon Rebel 350 XT (Clear filter)
DSI Pro (for guiding)
Shoestring USB Shutter Control
Shoestring Focusor Control
HNSky,PHD,DSLRFocus,WCS,Iris
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KWB
Postmaster
Reged: 09/30/06
Posts: 7635
Loc: Westminster,Co Elev.1646Meters
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How much are you bothered by eyepiece off axis astigmatism,as in cheaper widefield eyepieces being less well corrected for it? My tolerance for it is low so my budget for an eyepiece may have to be higher than yours.
Here is an example of an eyepiece that works about as well at that fast focal ratio as can be expected. 22T4 Nagler It works real well at F/4.7.
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Kenny
"When dealing with a mystery,choose the most unlikely of the likely possibilities"-Sherlock Holmes
Edited by KWB (09/16/08 01:10 AM)
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cweinhei
sage
Reged: 01/14/06
Posts: 222
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What can I get for $150 dollars, versus $300, versus $600.... Am I looking for a longer FL eyepiece like a 40 mm or bigger?
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Orion Atlas EQ-G w/ EQMOD
8" F/4 LXD75 Schmit-Newt (Flocked)
JMI NGF-55D Focusor
Hutech Canon Rebel 350 XT (Clear filter)
DSI Pro (for guiding)
Shoestring USB Shutter Control
Shoestring Focusor Control
HNSky,PHD,DSLRFocus,WCS,Iris
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KWB
Postmaster
Reged: 09/30/06
Posts: 7635
Loc: Westminster,Co Elev.1646Meters
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I'd think long and hard about using a 40mm eyepiece in an 800mm focal length scope. Unless you have the darkest skies known to mankind and have the eyes of an owl,the exit pupil of such an eyepiece/scope combo will come in around 10mm. I think you should decide on what focal length eyepiece might best suit your purposes before commiting to any specific price range/brand. Read this primer
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Kenny
"When dealing with a mystery,choose the most unlikely of the likely possibilities"-Sherlock Holmes
Edited by KWB (09/16/08 01:30 AM)
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cweinhei
sage
Reged: 01/14/06
Posts: 222
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I don't really know what I want. For general purpose use, what focal length would you recommend for that scope for low, medium, and high power? I think right now I want to keep to the less expensive eye pieces, since I haven't done visual ovbserving in a while? Moderate light pollution is a factor as well.
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Orion Atlas EQ-G w/ EQMOD
8" F/4 LXD75 Schmit-Newt (Flocked)
JMI NGF-55D Focusor
Hutech Canon Rebel 350 XT (Clear filter)
DSI Pro (for guiding)
Shoestring USB Shutter Control
Shoestring Focusor Control
HNSky,PHD,DSLRFocus,WCS,Iris
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KWB
Postmaster
Reged: 09/30/06
Posts: 7635
Loc: Westminster,Co Elev.1646Meters
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Reread my previous post as I have added a link to a valuable repository on knowledge,as in Al Nagler. Whether you choose his eyepieces or not,heed his wisdom.
I'd say an eyepiece anywhere from 20 to 26mm in focal would be as low as I would go with your telescope used in light polluted skies. 22mm would work for me as a low power sky sweeper as my eyes are older. Medium and high power would be up to you through trial and error. Buy the lowest power eyepiece first and it will act as a gauge as to what you'll need/want later.
Wait for what other opinions/posters have to say. Good luck.
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Kenny
"When dealing with a mystery,choose the most unlikely of the likely possibilities"-Sherlock Holmes
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cweinhei
sage
Reged: 01/14/06
Posts: 222
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Thanks for your advice. I'll probably start with a 25mm or less eyepiece to see where that gets me. I'll wait for the other readers to comment on best choices in the various price ranges.
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Orion Atlas EQ-G w/ EQMOD
8" F/4 LXD75 Schmit-Newt (Flocked)
JMI NGF-55D Focusor
Hutech Canon Rebel 350 XT (Clear filter)
DSI Pro (for guiding)
Shoestring USB Shutter Control
Shoestring Focusor Control
HNSky,PHD,DSLRFocus,WCS,Iris
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RogerRZ
Whatta you lookin' at?
Reged: 01/09/06
Posts: 2165
Loc: West Collette, NB, Canada
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Any eyepiece longer than 28mm will effectively limit the aperture of your scope, due to an exit pupil greater than 7mm.
Wide field, long focal length eyepieces can get expensive in a hurry, especially if you're fussy with regard to edge of field performance.
I own, and am very happy with, a Meade series 5000 18mm UWA, which I bought used for 165$. This eyepiece would yield 44x in your scope, with a true field of 1.9 degrees. I never tried it in an F/4 scope, but I suspect it would be good to very good.
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-Roger Pitre-
1 X 7 binocular
Meade 2080 LX10
5" Celestron SCT
Skywatcher Equinox 66
Starblast OTA
EQ6 Pro mount (spiffed up with ADM stuff)
8X42 Bushnell binos (pretty decent for 25$)
Canon Rebel XT (AKA 350D)
Starshoot autoguider
Tolerant Spousal Unit (AKA The Lovely Mrs. RogerRZ)
----------AJP Observatory----------
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sixela
Postmaster
Reged: 12/23/04
Posts: 9499
Loc: Boechout, Belgium
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Pan 24 would be one of the cheaper options (but good luck finding a used one!).
If you want to go used, there's sometimes the odd Nagler 20mm T2 on Astromart. Very good, but HEAVY and LARGE (and I usually don't like using all caps in a post!).
Another eyepiece which isn't too shabby at f/5 is the 23mm Axiom LX; I have no direct experience of how these behave in an eyepiece torture bench like an f/4 scope, but the answer (from the fact it's hard to find anything cheaper that behaves what I'd call really well in an f/5 scope) is very probably "better than anything at that price".
Whether that's good enough for you is another matter. An f/4 scope is (apart from the f/3.66 Überdob) the most difficult scope to get good widefields for, and for low magnification you *want* a wide field to prevent the exit pupil from becoming too large.
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400mm f/4.46 David Lukehurst truss Dobsonian on Tom Osypowski equatorial platform
Orion Starblast (114mm f/4 reflector, Alt/Az)
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deSitter
scholastic sledgehammer
Reged: 12/09/04
Posts: 779
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I've had excellent results with Meade UWAs (5k series) and now, with a Paracorr. The 14mm is ideally suited to this scope. The shorter ones all give excellent views with very little edge aberration. The 24mm has some pincushion and will show a lot of coma, if uncorrected. I had excellent results with my SN10 on Saturday with a Paracorr and the 24mm, the entire Pleiades cluster being in the field with stars sharp and coma-free to the edge. Mind you the combination is a beast, 7 inches tall and almost 2 lbs. You'll need to remove the top screw that holds the rack to the drawtube - this may require taking out the natural spring in the rack by gentle bending. Otherwise the Paracorr will bump against the nut and will not fully insert, requiring you to leave part of the bottom of the drawtube in the light path. The one bottom screw and nut are sufficient to hold the rack in place. A replacement focuser is a better option.
-drl
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doctordub
scholastic sledgehammer
Reged: 01/11/06
Posts: 908
Loc: New Rochelle, New York
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I use a 27mm Panoptic with my SN10 F/4, and it gives very sharp and well corrected views. The 26mm Nagler has a wider FOV but it is heavier and more expensive.
CS
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Jonathan
TeleVue TV102 on Vixen SXW mount
Meade LXD 55 SN10/UHTC Modified
Jason 60mm F11
Canon 15x50 IS
Olympus E-510, 14-42, 40-150 Zuiko
Meade DSI, LPI
TeleVue:
Binovue & 2X Cor.
3x barlow, 2x 5mm, 2x7mm,
12mm, 17mm & 2-4mm Zoom Naglers,
2x24mm, & 27mm panoptics,
55mm Plossl & 3mm Radian
2" OIII & Nebustar filters
Siebert Power Mag wheel
Lumicon Filter selecter &
2" focal reducer
Celestron: 7 1.25" color filters
7.5mm, 26mm eps & 2X ultima barlow
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dvb
Carpal Tunnel
Reged: 06/18/05
Posts: 1924
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Remember, too, that with Newtonian-type scope you are limited in how low you can go before you start seeing the black circle of the secondary in the middle of your view.
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Skywatcher 10" f/4.7 Newt on Matilda
Skywatcher 10" f/4.7 Collapsible Dob
Meade 8" SN f/4
Celestron C8 SCT
Celestron C6 SCT
Skywatcher ED100
Skywatcher ED80
EQ6 Pro "Matilda"
AT Voyager
Skymaster 15x70
Mallincam HyperColor Plus
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cweinhei
sage
Reged: 01/14/06
Posts: 222
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Thanks guys. That is the type of advice I'm looking for.
--------------------
Orion Atlas EQ-G w/ EQMOD
8" F/4 LXD75 Schmit-Newt (Flocked)
JMI NGF-55D Focusor
Hutech Canon Rebel 350 XT (Clear filter)
DSI Pro (for guiding)
Shoestring USB Shutter Control
Shoestring Focusor Control
HNSky,PHD,DSLRFocus,WCS,Iris
|
cweinhei
sage
Reged: 01/14/06
Posts: 222
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What is the difference between say a 20mm Pentax XW with a 2X powermate vs. a 10mm Pentax XW?
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Orion Atlas EQ-G w/ EQMOD
8" F/4 LXD75 Schmit-Newt (Flocked)
JMI NGF-55D Focusor
Hutech Canon Rebel 350 XT (Clear filter)
DSI Pro (for guiding)
Shoestring USB Shutter Control
Shoestring Focusor Control
HNSky,PHD,DSLRFocus,WCS,Iris
|
RogerRZ
Whatta you lookin' at?
Reged: 01/09/06
Posts: 2165
Loc: West Collette, NB, Canada
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The weight and price...
--------------------
-Roger Pitre-
1 X 7 binocular
Meade 2080 LX10
5" Celestron SCT
Skywatcher Equinox 66
Starblast OTA
EQ6 Pro mount (spiffed up with ADM stuff)
8X42 Bushnell binos (pretty decent for 25$)
Canon Rebel XT (AKA 350D)
Starshoot autoguider
Tolerant Spousal Unit (AKA The Lovely Mrs. RogerRZ)
----------AJP Observatory----------
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Bowmoreman
Carpal Tunnel
Reged: 09/11/06
Posts: 2992
Loc: Bolton, MA
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Quote:
Reread my previous post as I have added a link to a valuable repository on knowledge,as in Al Nagler. Whether you choose his eyepieces or not,heed his wisdom.
I'd say an eyepiece anywhere from 20 to 26mm in focal would be as low as I would go with your telescope used in light polluted skies. 22mm would work for me as a low power sky sweeper as my eyes are older. Medium and high power would be up to you through trial and error. Buy the lowest power eyepiece first and it will act as a gauge as to what you'll need/want later.
Wait for what other opinions/posters have to say. Good luck.
I'm with Kenny on this. While I'm selling my SN8 (to be replaced in a day or so by a R200SS/CF, which is also f4 200mm) I've had great luck with my 22T4 as my low power...
Sometimes I put in my 31T5 for giggles, but, the EP is a bit big and its not THAT much wider that its worth it.
I will also state that unless you get a very well corrected wide-field EP, you are going to be disappointed with the sharpness of the outer part of your FOV...
The SN8 is well corrected and very widefield; it deserves better EPs...
Maybe find a good used UWAN somewhere in the 20-26mm range? (if they exist)... or find a good deal on a used 20T5 or 22T4...
HTH
clear enough skies
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Dave
Ustream
YLive
XT10i, RTP, CGE, R200CF, TMB80SS
31T5, 22T4, 13Ethos, 8Ethos, TV 3-6 Zoom; Paracorr
MallincamColorHyperPlus,SBIG STV&237A;CanonRebel Xti
WilderSkiesObservatory(BYO #90)
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