Astrophotography

Discuss the technical side of photography
Peter Connan
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Re: What gear do you have...

Post by Peter Connan »

Thanks BluTuna and PRWin

BluTuna, remember that this is full frame, and I am actually seeing a little bit of trailing in the corners already (I don't think it's Coma, because the direction is just what one would expect for trailing). What I am saying is that these "rules" are not accurate for high-resolution sensors. They are probably fine for a 12-14Mpix camera, but for our 24's, you can't use them unless you only want to share on the web or similar.

And this of course puts big strain on your camera's high-ISO performance. There is a method where the guys take 5-20 photos, then stack them in Photoshop using photomerge (in two seperate steps, one for the foreground and one for the stars, with the unwanted areas painted out), and then using a median filter for noise reduction.

There is a tutorial here:

http://www.lonelyspeck.com/stacking-noise-reduction/

And also some inspiration and other ideas here:
https://luminous-landscape.com/introduc ... otography/

But for me at the moment these techniques are too advanced. I use Lightroom exclusively, so can't stack. Not sure for how long this will continue though. But my feeling is that if you are not prepared to use these types of techniques, you need a full-frame camera or you will only frustrate yourself.

So just pack me in as well when you go! =O:

PRWin, f4.5? That's at least a whole stop darker than these, which are all at f2.8 and either ISO5000 or ISO8000?


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PRWIN
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Re: What gear do you have...

Post by PRWIN »

Peter I agree , but ISO 5000 at 2.8 and ISO 6400 at 4.5 are about the same, had a look at the video, You can do the same from one photo as well in layers lol lol lol with Photoshop \O


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BluTuna
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Re: What gear do you have...

Post by BluTuna »

I heard about the 600 rule many years ago from astrophotographers I knew at the Astronomical Society.

some instructions I found for some stacking photography said to take 50 shots of the sky then take 50 more of the same duration with the lens cap on. The software will stack the images and use the second 50 shots to remove the noise.

Here's the link : http://www.instructables.com/id/Astroph ... /?ALLSTEPS


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ExFmem
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Re: What gear do you have...

Post by ExFmem »

Truly impressive photos! ^Q^


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PRWIN
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Re: What gear do you have...

Post by PRWIN »

Maybe we should start a thread on star photography where we can say what we did and how we did it -O- -O-

Peter, BT using some of the method http://www.lonelyspeck.com/stacking-noise-reduction/ below (NO1)


This one done normally (NO2)



NO1- was done taking a single photo and making 6 layers, Taking 6 black layers and then following the link above,
It then HDR, saturation and the normal added, big difference compared to no 2 which was a single frame as well , noise reduction added and HDR

Settings ISO 6400 at 30s 28mm at F4.5
Last edited by PRWIN on Tue Nov 10, 2020 7:13 am, edited 1 time in total.


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BluTuna
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Re: What gear do you have...

Post by BluTuna »

PRWIN wrote:Maybe we should start a thread on star photography where we can say what we did and how we did it -O- -O-
My thoughts exactly, I'll ask a Mod to move the last few posts to a new Astrophotography topic.


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Peter Connan
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Re: What gear do you have...

Post by Peter Connan »

PRWIN wrote:Maybe we should start a thread on star photography where we can say what we did and how we did it -O- -O-

Peter, BT using some of the method http://www.lonelyspeck.com/stacking-noise-reduction/ below (NO1)

Image

This one done normally (NO2)

Image


NO1- was done taking a single photo and making 6 layers, Taking 6 black layers and then following the link above,
It then HDR, saturation and the normal added, big difference compared to no 2 which was a single frame as well , noise reduction added and HDR

Settings ISO 6400 at 30s 28mm at F4.5
This is beautiful PR!

Unfortunately this format is too small for any difference to be visible.

Looks like I need to get Photoshop sometime...


Peter Connan
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Re: Astrophotography

Post by Peter Connan »

Some in-camera techniques:

Image
This is done by starting the exposure carefully focused on the stars, leaving it for about ten seconds, then slowly de-focusing for the remainder of the exposure.

Image
And this is done in a similar way, but rotating the zoom-ring instead of the focus ring.


ExFmem
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Re: Astrophotography

Post by ExFmem »

Exquisite!

Do any of you (currently or in the past) use the custom function noise reduction setting in the camera? Is it worth the extra time it takes for the camera to take the second exposure in order to subtract/reduce noise, or is it just as easy to do it during post processing? :-? Thanks.


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nan
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Re: Astrophotography

Post by nan »

very interesting thread... and beautiful pictures.... have to try... but how... with what I have to start 0*\


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