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How do you know if you can image something?

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#1 Desertanimal

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Posted 07 March 2021 - 05:02 PM

So let's say I'm looking at a chart app and I see some random DSO on the chart up where I can currently view it. How do I know if I can get any kind of image if I point my camera that way?

 

I imagine size, and magnitude are the answers but what numbers would tell me it is a good object to try to shoot based on the equipment I have?

 

There seems to be charts and algorithms to figure out everything in the astronomy/AP world so I'm sure the information is out there.

 

Thanks!!



#2 happylimpet

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Posted 07 March 2021 - 05:07 PM

Easiest way is by comparison with other objects youve previously imaged. IN terms of magnitude mainly for point sources. Galaxies all have similar surface brightness so if you can image one you can image them all.



#3 Dynan

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Posted 07 March 2021 - 05:10 PM

https://telescopius.com/ can generate a great target list that can be sorted by a number of parameters, including brightness.


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#4 Desertanimal

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Posted 07 March 2021 - 05:24 PM

Awesome guys!

Thanks! I will look into that site.

#5 RogerM

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Posted 07 March 2021 - 07:42 PM

From what I've learned by just imaging and experimenting, image scale and FOV are the primary considerations.  Object brightness (magnitude) can be accommodated by total integration time.  That said, a handy phone app, Skysafari for one, has a feature that I regularly use -- 'Observe-Scope Display' in which you create/plug in your equipment specifics (focal length, pixel size, sensor size, etc. and the app generates a FOV and places it on the viewing map.  You then select an object from the database and can immediately see if the target will be sufficiently sized within your specific equipment's FOV. You can then rotate this indicator to 'compose' the target and apply that rotation to your camera/scopes orientation to match.

 

For magnitude, after awhile you will learn what general settings/sub lengths work to produce useable images.  For example, with my general terrestrial gear anything above mag 8 ish and I can start with around 1-2 hours total integration time.  I wish all objects were around Mag +4!  For mag 10 that may go up to double the total integration time.  Most of my targets despite their birght magnitudes takes me months to image properly due to my location's seeing conditions, L.P. notwithstanding, so I just head out, re-target and acquire more data.

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#6 Desertanimal

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Posted 07 March 2021 - 08:27 PM

I appreciate depth if your explanation!

Thank you!

#7 whwang

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Posted 07 March 2021 - 09:52 PM

Just do a search at Astrobin to see how others image this object.  Then you should have a good idea about whether you can also do it.



#8 Andynator

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Posted 08 March 2021 - 08:53 AM

https://astronomy.to.../field_of_view/
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#9 boxcorner

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Posted 08 March 2021 - 02:33 PM

https://telescopius.com/ can generate a great target list that can be sorted by a number of parameters, including brightness.

Thank you for sharing that link.



#10 boxcorner

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Posted 08 March 2021 - 02:33 PM

Thank you for sharing that link.


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