Re: [ap-gto] [ap-ug] A start on the Arps


Oct 10, 2012

 


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#62082 Oct 10, 2012

I'm not sure if I'm just not discerning enough but I've never had much trouble with this tube. The mirror seems to mostly stay in place and focusing with a Bahtinov mask is pretty easy. If I shoot for 2 or 3 hours on any given night I might refocus once or twice but it's never that far off.



I've even had the focus hold after taking the tube into the house and back out again.



These things are always mysterious.



I have considered trying the AP 2 inch reducer on the camera since it seems like it would be a nice fit. But so far the 6.3 has worked well. I end up running at around F7, which is a nice focal length.



Pete

On Oct 10, 2012, at 9:22 PM, chris1011@... wrote:



>

> I have a 10" F10 Meade with the Advance Design optics. It produces a very nice coma-free field, and with our AP 2.7" telecompressor, it operates at F7.5 and produces a sharp flat field. It does have its drawbacks, basically it is almost impossible to focus with the internal moving mirror focuser. Also, it loses collimation just by going from East side to West side of the mount. I have tried locking the mirror down, but still does not help the collimation error. However, once you do get it focused, after much fiddling, it produces some nice results.

>

> Rolando

>

>

> -----Original Message-----

> From: Pete Su pete.su@...>

> To: ap-gto ap-gto@yahoogroups.com>

> Cc: Pete Su pete.su@...>

> Sent: Wed, Oct 10, 2012 8:13 pm

> Subject: Re: [ap-gto] [ap-ug] A start on the Arps

>

>

> I am using a Celestron 8, it's a tube off of an 8SE that I've attached to a

> Mach-1. The Mach-1 is just great. The camera is an ST-2000XM that I just bought

> used. It also works really well, especially with the guiding.

>

> Pete

>

>

> On Oct 10, 2012, at 9:05 PM, chris1011@... wrote:

>

>>

>> Nice shot. Thanks for the heads up, will try to shoot these later tonight. By

> the way, what scope you using?

>>

>> Right now I'm imaging in various parts of the sky with a 7"F9 refractor

> mounted on my 1600 observatory mount. I am imaging totally unmguided. The mount

> has encoders on both axes, so periodic error is essentially zero. Last Friday

> Howard did a short 26 point modeling run in APCC, the data from this run is now

> being used by the CP3 to adjust the tracking rates in both axes. We did a 35

> minute test after that run, and the mount tracked within 1 arc second for the 35

> minute time period. Subsequent 10 minute exposures produced perfectly round

> stars. So tonight I am imaging in H-a with no guiding required - as you know the

> SBIG-STL11 camera has the guide chip behind the filter, and it is always a

> problem to find a guide star when doing narrowband imaging. This setup with APCC

> will eliminate the problem.

>>

>> I will try your galaxies a bit later to see how well they record in my light

> polluted sky.

>>

>> Rolando

>>

>>

>> -----Original Message-----

>> From: Pete Su pete.su@...>

>> To: SBIG SBIG@yahoogroups.com>; ccd-newastro ccd-newastro@yahoogroups.com>;

> ap-ug ap-ug@yahoogroups.com>

>> Cc: Pete Su pete.su@...>

>> Sent: Wed, Oct 10, 2012 6:59 pm

>> Subject: [ap-ug] A start on the Arps

>>

>>

>> I've become interested in seeing how many of the Arp galaxies I can get a

> decent

>> picture of from my back yard. I realize that this isn't the best way to go

> about

>> this, but it's probably a constraint that I have to work with. I'm not after

>> APOD material here anyway.

>>

>> So here is last night's effort.This is 75min or so of monochrome on Arp 86,

>> which is a pair of connected galaxies in Pegasus. NGC7752 and NGC7753 (the big

>

>> one). This is a nice area of the sky for galaxies, apparently.

>>

>> www.flickr.com/photos/79904144@N00/8075412324/in/photostream

>>

>> Certainly another hour would make this cleaner. But I'm pretty happy with the

>> detail. And there are several smaller background galaxies scattered around,

>> which is always fun.

>>

>> Thanks for looking.

>> Pete

>>

>>

>>

>>

>>

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