[Leica] IMG: 6 inch reflector

Peter Dzwig pdzwig at summaventures.com
Mon Dec 21 10:50:32 PST 2020


My preference for detail is the narrow bandpass picture, because you can
see the filamentary structure.

However I prefer the contrast in the first stacked image. In the second
you can also make out the motion of the stars between frames. Funny
that, because you have more images stacked in the first than the second.
I assume that the narrow filter meant longer exposures per frame. Is
that right?

Peter

On 21/12/2020 15:05, Howard Ritter via LUG wrote:
> Hi, Peter—
> 
> The images are single exposures. Since posting them, I’ve learned how to stack multiple images of the same field to improve S/N and reduce color noise and granularity. It makes a huge difference!
> 
> I’ve just posted <http://gallery.leica-users.org/v/hlritter/Nikon+Astro/?g2_fromNavId=x98ac3343> a stacked version of the same Orion field as well as a stack of frames taken through a narrower emission-line filter. The latter I think is my preference.
> 
> http://gallery.leica-users.org/v/hlritter/Nikon+Astro/?g2_fromNavId=x98ac3343 <http://gallery.leica-users.org/v/hlritter/Nikon+Astro/?g2_fromNavId=x98ac3343>
> 
> —howard
> 
>> On Dec20, 2020, at 1250, Peter Dzwig <pdzwig at summaventures.com> wrote:
>>
>> Howard,
>>
>> are those single shots, or did you stack them? The one of the Orion
>> nebula is particularly fine.
>>
>> Peter
>>
>> On 19/12/2020 21:38, Howard Ritter via LUG wrote:
>>> Congratulations, Douglas. A first astronomical telescope is a memorable and possibly fateful thing, potentially a trap as dangerous as a first camera. With me it went the other way: At about age 10, my parents got me an Edmund Scientific 3” reflector, and this was enough to launch me on a lifelong hobby. I got my hands on a camera at about the same age. It’s a tossup which hobby has consumed more of my time as well as money! The apex was a 25” Dobsonian (I’ve downsized to a mere 20” now, plus a 6” refractor and a pair of 100mm astronomical binoculars.)
>>>
>>> The Dobsonian format is the ideal one for a neophyte, and a 6” aperture will show you wonders. I recommend getting a guide to the Messier objects, of which many look great in 6” of aperture, as I know firsthand. And you won’t need to be told to point your scope at the Moon! Dobson was a creative genius and the patron saint of amateur observers around the world, a tireless advocate of astronomy on the cheap for the masses.
>>>
>>> Good luck with the weather next Monday. Ours in Florida looks unfavorable. Because of that, I took the time to get a picture of the pair last night, when they were still 4 times as far apart as they will be on the 21st. After moonset, be sure to have a look at the Northern Hemisphere’s deep-sky (as opposed to Moon and planets) showpiece, the Orion Nebula. If you don’t have dark surroundings, take a dark cloth or hoodie to shut out all extraneous light as you look at the nebula and so you can keep both eyes open while you look. Start with an eyepiece that will give you about 50x.
>>>
>>> I put my images of Jupiter and Saturn, as well as the Orion Nebula, on the Gallery here <http://gallery.leica-users.org/v/hlritter/Nikon+Astro/>.
>>>
>>> http://gallery.leica-users.org/v/hlritter/Nikon+Astro/ <http://gallery.leica-users.org/v/hlritter/Nikon+Astro/>
>>>
>>> —howard
>>>
>>>> On Dec19, 2020, at 1326, Douglas Barry <imra at iol.ie> wrote:
>>>>
>>>> This is the telescope I got recently as a birthday present from my sons. It works extremely well, even in light polluted suburbia. I haven't taken it out to darker skies yet due to the pandemic.
>>>>
>>>> http://gallery.leica-users.org/v/DouglasBray/Sky+Quest+Dobsonian.jpg.html
>>>>
>>>> With the conjunction of Jupiter and Saturn coming up on Monday, I hope it won't be too cloudy so that I can use this. It's pretty good for a 6 inch, but with my back bothering me at the moment, I could with lightening the Dobsonian base a bit without sacrificing stability. Maturer years don't like heavy weights.
>>>>
>>>> By the way, if you would like some marvellously therapeutic viewing have a look at the great John Dobson making a reflector telescope by hand, including hand grinding and polishing the 16 inch mirror.
>>>> https://www.youtube.com/watch?v=snz7JJlSZvw
>>>>
>>>> Douglas
>>>>
>>>>
>>>>
>>>> _______________________________________________
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>>>
>>>
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>>>
>>
>> -- 
>>
>> Dr. Peter Dzwig
>>
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> 
> 
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> 

-- 

Dr. Peter Dzwig


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