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ArcticMyst Security by Avery

No, I didn't use a Telescope.

RB astro

RB astro

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Just wanted to share an image I took a while back using my DSLR and 135mm lens.

It's the Rho Ophiuchus Nebula Complex.
Just over 2 hours worth of exposure (16x8 min).

I hope you like it.

Andrew
:)


rho2.jpg
 





Grix

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How do you take photos with exposures that long? Doesn't the stars move during that time?
 
BowtieGuy

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That's a spectacular photo RB! Thanks for sharing. :)
 
RB astro

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Thank you so much everyone.
I'm glad you like it.

lazeristasUVISIR said:
What was a mount?
Click to expand...
The mount is my standard one I use for portability use, an EM200.

Grix said:
How do you take photos with exposures that long? Doesn't the stars move during that time?
Click to expand...

ped said:
^^ What he said.

I'm presuming you have some kind of tracking mount?

Ped
Click to expand...
Yes indeed the stars have a very quick 'apparent motion', of course as you know, it's the earth that's rotating instead so we need to counteract that by using a tracking mount.
If you extend an imaginary line up from the earth's axis you have a point in the sky that seems to be stationary (the north and south celestial poles).
By lining up the mount's axis to this point, all other points in the sky will be compensated for when you take a photo.
In the north you have the star Polaris as your 'guiding' star and this is the closest star to the north celestial pole.

polar.gif


In the south we're not so lucky so we need to find the south celestial pole using other methods.

Once we have things setup we can take long exposures and not worry about star trailing.

This was just to show that even with a DSLR and lens, astrophotography can yield satisfying results.

Andrew
 
ped

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Next time your fiddling around, get a shot of you're set up please?.

Something I want to get into. Fantastic photo.
 
RB astro

RB astro

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ped said:
Next time your fiddling around, get a shot of you're set up please?.

Something I want to get into. Fantastic photo.
Click to expand...
Here you are Ped, my setup.
Notice at the top of the small scope is my 20mw green astro laser that points to my objects.
Mind you this astro photo was not taken through this scope, the DSLR/135mm lens was just piggybacked on top of just the mount itself (an EM 200) similar (looks excacly like this mount) but just smaller and is my portable setup.
This setup is rigged for more serious imaging and is not as portable.

RB-TOA130_EM400.jpg


USAbro said:
:)Super super cool!
Click to expand...
Thank you, glad you liked it bro.

RB
 
USAbro

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What was the zoom of your camera? Will a point and shoot at 12x zoom over 1 hour capture anything similar?
 
RB astro

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USAbro said:
What was the zoom of your camera? Will a point and shoot at 12x zoom over 1 hour capture anything similar?
Click to expand...

No zoom, it was a DSLR and a prime lens, fixed focal lenth of 135mm.
To use a point and shoot is more difficult, no really suitable.

This is because the P&S has a small sensor and leaving it on for 1 hour, if possible, will generate too much heat and yield a noisy image.

If you need to use a P&S, use it zoomed out and high ISO using short exposures in M mode for longer than 30 sec but less than say 3 min. Not all P&S have this feature.
You will need a mount to counter-act the earth's rotation and you need to be away from city light pollution.
You will get some MilkyWay Galaxy (ours) shots this way.
Best to learn the basics and then progress.

:)
 
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