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Mike Harden
Vendor - ISTAR Optical
Reged: 05/11/11
Loc: Fort Myers, Florida
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8 inch Istar Scopes on Sale!
#5492174 - 10/27/12 07:51 PM Attachment (75 downloads)
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On Sale! Phoenix WFT 204-6 Comet Hunter Achromatic Doublet - $2994
On Sale! Perseus AT 204-9 Achromatic Doublet - $3244
Want to track down those DSOs? You need aperture. F6 or F9
Want to see great planetary detail? You need aperture. F9
The Rayleigh Limit for a telescope with a 6 inch aperture is approximately 0.9 arc seconds
The Rayleigh Limit for a telescope with a 8 inch aperture is approximately 0.7 arc seconds
An 8 inch scope gathers twice as much light as a 6 inch
An 8 inch scope has a limiting magnitude of at least 12.0
2 Element Achromatic Doublet designed by our own Master Optician Zdenek Rehor
210 mm Lens diameter with 204 mm (8 inch) clear aperture
1200 or 1800 mm Focal Length F5.9 and F8.8
Push-pull collimatable cell
Fully Multicoated lenses
Magnesium Alloy powder coated inside and out CNC machined tube
CNC machined, anodized and color scheme counter cell and back plate
New 3rd generation 2.5 inch fully rotatable, dual speed, draw tube brake,
CNC machined Crayford Style Istar focuser
Screw attached baffles.
Absolutely no plastic, glue, molded metal parts or thin walled aluminum
Scopes are hand assembled and individually star tested
F5.9 1220 mm tube length including dew shield
F8.8 1639 mm tube length including dew shield - 45 lbs.
All Scopes include free shipping anywhere in the continental US
8 inch scopes include an Istar US made newly designed 3rd generation focuser
5 year warranty on lenses and tubes
Available Pro style CNC machined powder coated tube rings
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galaxyman
Vendor - Have a Stellar Birthday
Reged: 04/04/05
Loc: Limerick, Pa
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Re: 8 inch Istar Scopes on Sale!
[Re: Mike Harden]
#5492521 - 10/28/12 12:40 AM
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Hi Mike
I just need to say I hope your 8" refractor can do better than 12th magnitude 
My 4" refractor can easily see stars past 12th magnitude and galaxies with high surface brightness of 12th magnitude.
My 8" refractor has seen galaxies down to 15th mag from excellent dark sites and nights.
Hope that is just a typo you got there, and not an issue with your 8" refractors 
Karl
E.O.H.
Chesmont Astronomical Society - www.chesmontastro.org
Galaxy Log - http://www.youtube.com/user/GalaxyLog4565?feature=mhee
Telekit (Swayze optics) 22" F/4.5 Dob
Homemade (Parks Optics) 12.5" F/4.8 Dob
TMB/APM 8" f/9 Refractor”The Beast”. One great DEEP SKY achro
ES 6" f/6.5 achro. Good one
Celestron Omni XLT 102 refractor.
Celestron 10x60mm Binos
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Astrojensen
Post Laureate
Reged: 10/05/08
Loc: Bornholm, Denmark
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Re: 8 inch Istar Scopes on Sale!
[Re: galaxyman]
#5492635 - 10/28/12 04:39 AM
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He's just being conservative, since there's a wide range of skill between observers. Some can go to mag 15 in an 8", others can't.
Clear skies!
Thomas, Denmark
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James Ling
sage
Reged: 09/18/10
Loc: Singapore
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Re: 8 inch Istar Scopes on Sale!
[Re: Astrojensen]
#5492646 - 10/28/12 05:07 AM Attachment (65 downloads)
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Having owned the 8" F8.8 for about two years, I would say this scope is really great for both planetary and DSO observation......
But one important aspect I want to mentioned here is the weight , at 45 LBs, is only the bare OTA, the whole OTA with all the accessories will exceed 60 Lbs, and mine even hit close to 70 lbs....
REgards
James Ling
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Paul C-I
super member
Reged: 03/23/08
Loc: United Kingdom
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Re: 8 inch Istar Scopes on Sale!
[Re: James Ling]
#5493219 - 10/28/12 03:07 PM
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Hi James,
Thats interesting to hear. Today I've just aquired a Losmandy G11 mainly for the purpose of handling my soon to be built (by me!)homemade Istar 8" 8.8 refractor. Just waiting for Mike to check the lens before it arrives in my workshop.
The pics of your 8" have inspired me to upgrade my mount from an EQ6 in preparation. Anyhow, I was pushing the limit of the EQ6 with my Vixen Atlux 6" F9 along with Baader Mkv and some large eps, not to mention a sliding scope counterweight (43lbs total!)
Have appreciated the updates you have posted over the last few months on your Istar. Beautiful looking scope!
Cheers
Paul
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galaxyman
Vendor - Have a Stellar Birthday
Reged: 04/04/05
Loc: Limerick, Pa
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Re: 8 inch Istar Scopes on Sale!
[Re: Astrojensen]
#5493485 - 10/28/12 06:20 PM
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Quote:
He's just being conservative, since there's a wide range of skill between observers. Some can go to mag 15 in an 8", others can't.
Clear skies!
Thomas, Denmark
Hi Thomas
Understand, but 12th magnitude only in any quality 8" scope (in particular a refractor) is much more than conservative 
Karl
E.O.H.
Chesmont Astronomical Society - www.chesmontastro.org
Galaxy Log - http://www.youtube.com/user/GalaxyLog4565?feature=mhee
Telekit (Swayze optics) 22" F/4.5 Dob
Homemade (Parks Optics) 12.5" F/4.8 Dob
TMB/APM 8" f/9 Refractor”The Beast”. One great DEEP SKY achro
ES 6" f/6.5 achro. Good one
Celestron Omni XLT 102 refractor.
Celestron 10x60mm Binos
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mikey cee
Postmaster
Reged: 01/18/07
Loc: bellevue ne.
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Re: 8 inch Istar Scopes on Sale!
[Re: galaxyman]
#5496613 - 10/30/12 06:10 PM
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The sky here in the Omaha area is roughly a mmagnitude 4.5-5. With my previous 8" Brandt I could glimpse the 13.0 mag companion star of M-57. I know without a doubt in the country the 8" could very easily reach 14+ mag.  Mike
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Starman1
Vendor (EyepiecesEtc.com)
Reged: 06/24/03
Loc: Los Angeles
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Re: 8 inch Istar Scopes on Sale!
[Re: mikey cee]
#5496643 - 10/30/12 06:29 PM
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It all depends on the darkness of the sky and what you mean by "seeing to X magnitude".
Under magnitude 21.5 skies (6.8NELM) my 8" SCT used to reach magnitude 15.1-15.3 with the star visible about 10-20% of the time with averted vision.
Under magnitude 22.0 skies (7+NELM), my 8" SCT reached 15.6 with the star visible 10-20% of the time with averted vision.
Beginners often interpret "sees to...." to mean 100% of the time with direct vision. And that can easily be a magnitude or more brighter than a limit observation.
Also, the limit of a scope depends on the altitude of the target, the spectrum of the target, your age and experience, your visual acuity at the selected exit pupil, and the magnification used.
Telling someone with an 8" that they will reach magnitude 12 is a sure thing. EVERYONE will reach that, even in a light-polluted city environment. It's when it starts getting fainter that people begin dropping off. Under ideal skies with an ideal 8" scope and an ideal observer under ideal conditions, it's possible to pass magnitude 16 with an 8" scope.
So the claims of "faintest magnitude visible" are, I believe, typically chosen so no one is disappointed in what his scope can do. It doesn't have much relationship with reality.
Here is a magnitude limit chart you can use right now at the scope to see how faint you can reach. Remember, a "limit" observation is ONLY visible with averted vision about 10% of the time, and never visible with direct vision.
http://www.flickr.com/photos/edhiker/5954756749/
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BillP
Postmaster
Reged: 11/26/06
Loc: Vienna, VA
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Re: 8 inch Istar Scopes on Sale!
[Re: Starman1]
#5497598 - 10/31/12 11:14 AM
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Great chart Don. Thanks!
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aa6ww
sage
Reged: 10/23/11
Loc: Sacramento, Calif.
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Re: 8 inch Istar Scopes on Sale!
[Re: James Ling]
#5593852 - 12/29/12 07:04 AM
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Having owned the 8" F8.8 for about two years, I would say this scope is really great for both planetary and DSO observation......
But one important aspect I want to mentioned here is the weight , at 45 LBs, is only the bare OTA, the whole OTA with all the accessories will exceed 60 Lbs, and mine even hit close to 70 lbs....
REgards
James Ling
For Visual work, the G11 has no problem handling 70 pounds if you really balance out everything. I put my C14 with an Orion 120ST on top of it and its rocking right in the 65 pound to 70 pound range, and it seems to have no issues handling the load even during high power focusing.
I'm not using an extension pier though, and I don't have the long moment arm the big 8" Istar has, but I've seen your video of you slewing around on the moon with the big Istar and it looks fine for stability.
I do love the big glass. I wonder what a 9" F/6 will weight?
...Ralph
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aa6ww
sage
Reged: 10/23/11
Loc: Sacramento, Calif.
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Re: 8 inch Istar Scopes on Sale!
[Re: Mike Harden]
#5593856 - 12/29/12 07:13 AM
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On Sale! Phoenix WFT 204-6 Comet Hunter Achromatic Doublet - $2994
On Sale! Perseus AT 204-9 Achromatic Doublet - $3244
Want to track down those DSOs? You need aperture. F6 or F9
Want to see great planetary detail? You need aperture. F9
The Rayleigh Limit for a telescope with a 6 inch aperture is approximately 0.9 arc seconds
The Rayleigh Limit for a telescope with a 8 inch aperture is approximately 0.7 arc seconds
An 8 inch scope gathers twice as much light as a 6 inch
An 8 inch scope has a limiting magnitude of at least 12.0
2 Element Achromatic Doublet designed by our own Master Optician Zdenek Rehor
210 mm Lens diameter with 204 mm (8 inch) clear aperture
1200 or 1800 mm Focal Length F5.9 and F8.8
Push-pull collimatable cell
Fully Multicoated lenses
Magnesium Alloy powder coated inside and out CNC machined tube
CNC machined, anodized and color scheme counter cell and back plate
New 3rd generation 2.5 inch fully rotatable, dual speed, draw tube brake,
CNC machined Crayford Style Istar focuser
Screw attached baffles.
Absolutely no plastic, glue, molded metal parts or thin walled aluminum
Scopes are hand assembled and individually star tested
F5.9 1220 mm tube length including dew shield
F8.8 1639 mm tube length including dew shield - 45 lbs.
All Scopes include free shipping anywhere in the continental US
8 inch scopes include an Istar US made newly designed 3rd generation focuser
5 year warranty on lenses and tubes
Available Pro style CNC machined powder coated tube rings
Hi Mike,
On the Phoenix WFT 204-6 Comet Hunter Achromatic Doublet, is the front element positioned at the very front of this scope like the Perseus AT 204-9, or is it more of a conventional refractor where the dew shield extend out in front of the front objective? I haven't seen any photos of the front of this particular model to tell me one way or the other?
...Ralph in Sacramento
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mikey cee
Postmaster
Reged: 01/18/07
Loc: bellevue ne.
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Re: 8 inch Istar Scopes on Sale!
[Re: Starman1]
#5596211 - 12/30/12 01:54 PM
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Don thanks for that link. That has got to be the coolest 7 scope set up I've ever seen on one mounting. I had to chucke in a way.  Mike
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