Author Topic: Best Way to Composite Venus Transit in PI  (Read 4533 times)

Offline kerrywaz1

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Best Way to Composite Venus Transit in PI
« on: 2012 June 07 09:02:40 »
I took a lot of images of the transit of Venus as it made its way across the face of the sun. What is the best way to create a composite image using PI that will clearly show the planet's position througout the transit?

Thanks
Deep Sky Instruments RC14C
FLI PL16803 w/MOAG + StarlightXpress Ultrastar
Pyxis 3"
Astro Physics AP1200
Tak FSQ-106EDXII
Apogee Alta F16M
Hap Griffin modified Canon EOS 5D Mark II
PixInsight, MaxIm DL, PhotoShop CS5

Offline vicent_peris

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Re: Best Way to Composite Venus Transit in PI
« Reply #1 on: 2012 June 07 14:49:38 »
If your images are aligned, this would be a simple PixelMath expression:

Min( Img1, Img2, Img3, ... ImgN )


Regards,
Vicent.
« Last Edit: 2012 June 08 05:47:12 by vicent_peris »

Offline jdonald

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Re: Best Way to Composite Venus Transit in PI
« Reply #2 on: 2012 June 08 04:27:43 »
Simple he say ;)

I often wondered how to do this in pixinsight.  What does that string do, in plain English?

Offline naavis

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Re: Best Way to Composite Venus Transit in PI
« Reply #3 on: 2012 June 08 04:50:26 »
Simple he say ;)

I often wondered how to do this in pixinsight.  What does that string do, in plain English?

For each pixel in the stack, it takes the minimum value. So if you have several images of Venus at different positions on the sun's disk, the pixels containing Venus will be chosen for the final image (since they usually are darker than the sun).
Samuli Vuorinen

Offline vicent_peris

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Re: Best Way to Composite Venus Transit in PI
« Reply #4 on: 2012 June 08 05:47:51 »
Simple he say ;)

I often wondered how to do this in pixinsight.  What does that string do, in plain English?

For each pixel in the stack, it takes the minimum value. So if you have several images of Venus at different positions on the sun's disk, the pixels containing Venus will be chosen for the final image (since they usually are darker than the sun).


Exactly.

Another requirement for this is to have the Sun disk perfectly aligned in all the image set.


V.

Offline kerrywaz1

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Re: Best Way to Composite Venus Transit in PI
« Reply #5 on: 2012 June 08 09:31:49 »
I have over 100 images in the set. Is there a way to do this with an Image Container?
Deep Sky Instruments RC14C
FLI PL16803 w/MOAG + StarlightXpress Ultrastar
Pyxis 3"
Astro Physics AP1200
Tak FSQ-106EDXII
Apogee Alta F16M
Hap Griffin modified Canon EOS 5D Mark II
PixInsight, MaxIm DL, PhotoShop CS5

Offline Carlos Milovic

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Re: Best Way to Composite Venus Transit in PI
« Reply #6 on: 2012 June 08 09:35:51 »
You may use ImageIntegration. Just select Minimum as the Combination method.
Regards,

Carlos Milovic F.
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Offline vicent_peris

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Re: Best Way to Composite Venus Transit in PI
« Reply #7 on: 2012 June 08 10:30:19 »
With 100 images I would go with ImageIntegration. Integrate them as a normal light set but instead of calculating the average value, calculate the minimum one. Also don't select any rejection method, as this would reject Venus.  :D


V.

Offline kerrywaz1

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Re: Best Way to Composite Venus Transit in PI
« Reply #8 on: 2012 June 08 22:33:19 »
Thanks guys. Here is the result.
Deep Sky Instruments RC14C
FLI PL16803 w/MOAG + StarlightXpress Ultrastar
Pyxis 3"
Astro Physics AP1200
Tak FSQ-106EDXII
Apogee Alta F16M
Hap Griffin modified Canon EOS 5D Mark II
PixInsight, MaxIm DL, PhotoShop CS5

Offline Giorgio

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Re: Best Way to Composite Venus Transit in PI
« Reply #9 on: 2012 June 08 23:12:00 »
Hello
good result, I really like.
Can you tell me what kind of tools did you use the resumption of the transit.
Thanks
Giorgio.

Offline kerrywaz1

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Re: Best Way to Composite Venus Transit in PI
« Reply #10 on: 2012 June 09 01:22:32 »
Thanks. This was as much as I could get of the transit before sunset. :sad:

I used a Takahashi FSQ106EDXIII with a Baader AstroSolar Safety Film homemade filter over the objective, AP1200 mount, QSI 683wsg CCD camera.

The focus in the images were 'soft' because of a high wind that kicked up during the transit.
Deep Sky Instruments RC14C
FLI PL16803 w/MOAG + StarlightXpress Ultrastar
Pyxis 3"
Astro Physics AP1200
Tak FSQ-106EDXII
Apogee Alta F16M
Hap Griffin modified Canon EOS 5D Mark II
PixInsight, MaxIm DL, PhotoShop CS5