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SH2-157_Seestar_S30_Pro

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Posts Made By: Bill Barrett

December 6, 2004 05:19 AM Forum: Refractors

Refractor collimation tolerances, at what point?

Posted By Bill Barrett
Gary;
Thanks for the response. For my current needs I believe the scope is indeed within tolerance. The views are very sharp up to the point when chromatic aberration becomes a factor.
I hear chromacors are extremely sensitive and unforgiving about collimation errors. I will look into being sure the focuser is exactly square to the optical path. thank you, Bill

January 4, 2005 03:55 PM Forum: Refractors

How to detect over or under correction?

Posted By Bill Barrett
The reason I ask this is because it has been difficult for me to tell with any accuracy if the diffraction rings are progressively brighter toward the outside/inside. However my scope definitely produces more defined diffraction rings intra focal...would that be any sort of indicator? thank you, Bill

March 16, 2005 01:39 AM Forum: After Dark

Neighbors lights wiping out contrast?

Posted By Bill Barrett
Thank you all for your input and great ideas. Last night shortly after posting, I moved the mount to the other side of the house away from the dreaded lights. Although I could only get a small piece of the eastern sky, Jupiter was there waiting for me. The contrast was indeed back...what a relief! I think its time to invite the neighbors over for a peek.

April 3, 2005 04:27 PM Forum: Refractors

Decided to get 4" APO...Should I sell the 4" F15?

Posted By Bill Barrett
Thank you for all of your feedback. This 50"+ relic from A. Jaegers (and my childhood) has always provided very detailed planetary views.
The only things I would look for from the APO would be portability and versatility.
It's not worth much money, and I would miss it. It would probably be smarter to let the Pronto go on the road to the APO. thank you, Bill



April 22, 2005 06:36 PM Forum: Refractors

What are typical mags used for planetary viewing?

Posted By Bill Barrett
I live in Seattle. The skies are frequently very turbulent and we do have significant light pollution. I have had many wonderful views of Saturn with Cassini's division distinct and some shading on the planet.
Jupiter has been more challenging: although image size increases,low contrast details fade as mags. get much over 200x. My goal with Jupiter is to resolve the GRS (when visible) & I'm not sure at what range of mag. that should occur.
thank you, Bill


April 24, 2005 07:00 PM Forum: Refractors

What are typical mags used for planetary viewing?

Posted By Bill Barrett
Thank you for all of your input. I must resign myself to the fact that I live in Seattle where the skies even on the best of nights, are no better than average. I do feel reassured that conditions are most likely the limiting factors than anything I am doing or wrong with my scopes.
I would love to take an observing trip out of this marine/metro environment into eastern Washington and see the difference. thanks again, Bill

May 25, 2005 12:38 AM Forum: Beginning Astronomy?

Understanding Magnification?

Posted By Bill Barrett
The 3" was a Televue Pronto (480mm) with a 6mm ortho for 80x. The 4" was an F15 Jaegers with a 17mm plossl for 88x.

I understand all things being equal, larger aperture = more light, which = more detail. However, would the same be true for image size or should 80x in a 3" scope produce the same size image as a 30" scope?

I've got to try this again.



May 25, 2005 06:19 AM Forum: Beginning Astronomy?

Understanding Magnification?

Posted By Bill Barrett
Thank you all for your input. This was definitely a case of pilot error. I should have paid closer attention to carefully matching the mags.

I went out tonight with a 6" F8 and the Pronto. It quickly became apparent that the same magnification would yield the same size image regardless of aperture.
P.S. I did catch the transit. Great stuff! thanks again, Bill

May 25, 2005 01:33 PM Forum: TeleVue

How to collimate a Pronto

Posted By Bill Barrett
I took the Pronto out the past few nights and as it turns out, the collimation is (& was) dead on.
I checked it again with a cheshire, and it was perfect. The star tests produced very sharp diffraction rings intra and extra focal. All is well. thank you, Bill

June 13, 2005 12:12 AM Forum: Beginning Astronomy?

Is there a recommended/definitive sky chart?

Posted By Bill Barrett
Thank you everyone! All of your input (as usual) has been very helpful. I think the Sky Atlas 2000 and the Orion Deepmap 600 will be good places to start. Thanks again, Bill

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