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M20 Trifid Nebula in LRGBHa

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Posts Made By: Gary Davis

October 1, 2003 03:17 AM Forum: Equipment Talk

Planetary ghosting

Posted By Gary Davis
Marc,

Have you noticed this every time you view or just within the last few days ?

If its just in the last few days, I would wait a few more and make sure the atmosphere is not the cause. Any time the scope just suddenly seems out of whack, check the atmosphere first.

An example, for three nights I thought I could see a ghost super-emposed (I could) on Mars while viewing. Then on the fourth night, it was gone. And its happened before. If you defocus slightly you may be able to see the underlying cause. Look for air rushing and distorting the image. Even on excellent nights slow movement of the air may be detected.

If its been every time you view then it may be something else. But, I have a feeling its not the scope. Could even be the EP you use or the angle at which you view.

October 26, 2003 03:13 AM Forum: Equipment Talk

DSC's with a Laptop

Posted By Gary Davis
If you have or can get the encoders and a cable "serial or most recently USB" to connect to your laptop it will work. There is no mystery, magic or special math required to build an astronomical computer, in fact all the algorithms and perimeters are already known. Why DSC units cost so much is anybodys guess. The encoders would be much more difficult to produce than the computer. 300$ for a DSC computer is shall we say, outrageous !

December 11, 2003 01:58 AM Forum: Deep Sky Observing

Favorite Open Clusters?

Posted By Gary Davis
Ivan,

In Canis Major, you might want to check out the star tau. This star "very bright" is surrounded by about 25 stars, I found it by accident while scanning the area. I could not find an NGC or HIP number for the cluster. If your to far north this may be out of reach. It's do-able even with a 60mm. Very nice cluster. I have often wondered how many of the cluster are a system. Nearby is NGC-2477 with at least 300 members and very large.

January 27, 2004 06:01 AM Forum: Equipment Talk

Reading Collimation Pattern

Posted By Gary Davis
Timothy,

Although I can't answer your question, I seem to have the same 3 circles that you see. This is a Meade DS 90 f/11, very similar to your Meade 390 f/11. I too, cannot get the circles to line up either. Same exact position "10, centered and at 4 o'clock" Is their anyone that can help us with this ? In most refractor doublets I see only two donuts not three. But I do get some very nice detailed views of jupiter with it. Hardly any false color, I use it alot.....

July 8, 2005 03:22 AM Forum: Maksutovs

The views !

Posted By Gary Davis
Sad to say but Roland is right. It has a turned down edge. It must be pretty bad too. I made a mask and attached it to the very front of the scope. All gone now ! And I'm left with about 80mm of aperture. Thats not all, in the star test it was observed that the first defraction ring was far placed from the airy disk but with the mask in place its no longer there "at least as far as I can tell." Ok, so now what ? Fixable or lost cause ? My luck, and one would think I would learn to stop buying problems from others huh ? K+ to you Roland.....And all who had good ideas, thanks..

July 8, 2005 03:26 AM Forum: Reflectors

My Mak and your thoughts...

Posted By Gary Davis
For the conclusion of this thread please see the post in Maksotuvs named "the views".

September 4, 2005 01:55 AM Forum: Equipment Talk

Orion Shorty Barlow not too good...

Posted By Gary Davis
Jim,

I'm not to sure I can help but I'll give it a go. One problem is, the more you magnify the dimmer the image becomes, no matter how you achieve it. I suspect the barlow works just as it should. As long as it introduces no false color or other abberations then it is working correctly. This particular barlow is an apocromatic lensed type, one of Orion's better optics. I'm not sure about your scope but most mirrors start to dim quickly above 25X per inch and some need lower numbers than that. You may need a larger primary if the image is to dim with resonable magnification. Exceptional nights only happen every so often in most locations and even a larger scope may not help.

July 6, 2006 05:18 AM Forum: After Dark

Re: Track the Space Shuttle

Posted By Gary Davis
The link below will take you directly to a page that will show the current visible passes of the ISS and Shuttle for your city. It will calculate for most cities world wide. I've used it for the last couple of weeks and it's accurate.

http://www.sciencedaily.com/releases/2006/07/060705171218.htm

June 22, 2007 07:36 PM Forum: Solar System Observing

ISS and Shuttle.

Posted By Gary Davis
According to the NASA website here, http://spaceflight.nasa.gov/realdata/sightings/SSapplications/Post/JavaSSOP/JavaSSOP.html The shuttle was behind and following the ISS, unless I misinterpreted the readout. Nonetheless, it was quite a site to see.

For those who like to watch the ISS and shuttle, the site I listed above has everything you need. It's super accurate....

August 23, 2009 01:36 AM Forum: Birding Optics and Photos

Mourning Dove w/White in Tail

Posted By Gary Davis
I have an idea that this dove has mated with a domesticated ringneck dove. I see huge populations of these birds here in Fresno. It may be a bad thing, as some species and their offspring become sterile when matings take place like this. I'm not sure why the states that have these doves haven't tightend the regulations regarding escaped and imported birds. Time will tell, but the morning doves pureness will surely suffer.

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