Author Topic: Astrophotos with a new lens and ML  (Read 13824 times)

dmilligan

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Astrophotos with a new lens and ML
« on: January 07, 2014, 04:29:48 PM »
I recently aquired a Canon 200mm f/2.8L. I am rather pleased with it:





The first image is a stack of 24 x 300 second exposures (2 hrs), the second image is 12 x 300s (1 hr). Shot on a Canon 60Da at ISO800. Ambient temperature was about -5C.

Shot using the ML Intervalometer + Bulb Timer
Manual Focus using LV FPS override = 2fps, Low Light mode, 10x Zoom
Dark Red overlays to save my night vision

The camera and lens were mounted to my telescope's equatorial mount to allow the long exposure times. The images were processed using PixInsight and Photoshop CC.

Here's a wider angle star trails shot I did with my 28mm lens:


(Click on the thumbs for full size)

Phaenomena

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Re: Astrophotos with a new lens and ML
« Reply #1 on: January 08, 2014, 07:11:30 PM »
Great images! I dabble in astrophotography myself, so I can appreciate the effort put into capturing and processing images correctly x_x

spark802

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Re: Astrophotos with a new lens and ML
« Reply #2 on: January 12, 2014, 06:04:36 AM »
Excellent work!  I'm assuming from the details you provided that you weren't running your images through a laptop and imaging program. That's interesting. I have quoted you below. I may try  settings like these on my next session, if it ever warms up. Always happy to see work like this.


"Manual Focus using LV FPS override = 2fps, Low Light mode, 10x Zoom"


http://www.flickr.com/photos/49843779@N08/





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dmilligan

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Re: Astrophotos with a new lens and ML
« Reply #3 on: January 12, 2014, 08:10:37 PM »
Thanks!

I'm assuming from the details you provided that you weren't running your images through a laptop and imaging program. That's interesting.
Your assumption is correct, I don't use a laptop. I know this is kind of against the grain of what most APers do, but ML can automate everything I need to do, and the camera w/ battery grip can last all night, unlike my laptop. I image out in the middle of nowhere, so it's one less thing I have to have with me and set up. I also have two cameras and usually image with both of them at the same time -> I only have one laptop. Also, in the summer the screen attracts every insect in a 10 mile radius.


spark802

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Re: Astrophotos with a new lens and ML
« Reply #4 on: January 13, 2014, 02:47:45 AM »
Thanks!
Your assumption is correct, I don't use a laptop. I know this is kind of against the grain of what most APers do, but ML can automate everything I need to do, and the camera w/ battery grip can last all night, unlike my laptop.

This is good to know. Laptops eat lots of power too, and I have a battery grip.

Keep posting your nice images!
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Janke

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Re: Astrophotos with a new lens and ML
« Reply #5 on: January 20, 2014, 05:50:22 PM »
Thank you for the fantastic images! You know, this was the first time I've seen the Horsehead and the Orion Nebula in the same frame - and still great resolution!

I've only dabbled, but I have a nice lens in a 1960s Meyer Orestegor 135 mm f/2.8 - I'll have to do some more experimenting when the weather gets a little warmer - -15°C in Helsinki right now!

(Incidentally, I only have a cheap Meade with the Autostar alt-az computer control, but it has sufficed so far, tracking my EOS 550D, and it will certainly manage the new, much lighter EOS-M! I turned a camera holder to fit in the eyepiece tube, so it balances pretty well.)

What software do you use for stacking?

dmilligan

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Re: Astrophotos with a new lens and ML
« Reply #6 on: January 20, 2014, 06:17:31 PM »
135mm frames this area quite well too, you can get M78 in as well (it's just off bottom left of this frame).  -15C is perfect astro weather, way less thermal noise ;)

What software do you use for stacking?
PixInsight

Janke

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Re: Astrophotos with a new lens and ML
« Reply #7 on: January 20, 2014, 08:06:03 PM »
One more question: In the star trail 28mm photo, there are some white dots on some of the brighter trails. How come?

dmilligan

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Re: Astrophotos with a new lens and ML
« Reply #8 on: January 20, 2014, 08:43:05 PM »
airplanes

Janke

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Re: Astrophotos with a new lens and ML
« Reply #9 on: January 20, 2014, 08:51:33 PM »
No, I didn't mean the vertical flashing airplane trails, but the dots in the star trail arcs themselves. An artifact of combining images, perchance?

dmilligan

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Re: Astrophotos with a new lens and ML
« Reply #10 on: January 20, 2014, 09:10:58 PM »
well, there's a short amount of time between exposures, also the sensor sensitivity may change slightly over the course of each sub exposure

Janke

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Re: Astrophotos with a new lens and ML
« Reply #11 on: January 23, 2014, 08:57:15 AM »
I think it's an effect of overlaying exposures that basically have the star in the same position = it gets lighter in the combination.

Here's a shot with my T2i and the Meyer Orestegor 135/2.8 lens - just 3 x 30-second exposures combined in Photoshop, no special software.  The problem here in Southern Finland is the light pollution, I can never get a really black sky!


spark802

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Re: Astrophotos with a new lens and ML
« Reply #12 on: March 08, 2014, 01:57:51 AM »
I recently aquired a Canon 200mm f/2.8L. I am rather pleased with it:
Manual Focus using LV FPS override = 2fps, Low Light mode, 10x Zoom


I have a further question....why were you using fps override?  I thought that was for movie mode...or were you shooting in manual?
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dmilligan

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Re: Astrophotos with a new lens and ML
« Reply #13 on: March 08, 2014, 02:53:32 AM »
I was using it in LiveView with 10x zoom to focus. It allows for long enough exposure to use LV in almost complete darkness.