22 replies to this topic

[morticiaskeeper]

Being a newbie to astro processing, I wondered how you guys and girls would process this shot.

This is the JPEG


And here is the RAW
Dropbox - Error - Simplify your life

Those who know their way around the star will probably see the target, M31 Andromeda Galaxy.

[Warrick]

Ill load the raw file up tonight on my computer, Just a quick question as i cant see the raw data as of yet did you use a real high iso setting on the image as the jpeg looks a bit cluttered?

 

As mentioned ill load it up and have a look for ya

[morticiaskeeper]

I think the ISO was 1600

[Adam]

The color noise should be easy to get rid of, but the image itself looks like it's affected by motion blur, which you can't really fix up very much.  Still, a nice capture!

[Stas]

It is interesting) Will try tonight.

[morticiaskeeper]

ISO 1600 70mm. F4 15 seconds.

The ideal exposure would be 4.76 seconds, according to the 500 rule.

But... It's the first shot I've taken where M31 is clearly visible, dropping the shutter to 5 seconds at ISO 3200 might be a better trade off, or pull the lens back to 18mm F3.5.

I'm going to have a go at putting a red dot finder onto the hotshoe to aid aiming. Or maybe put the camera onto a motorised eq mount.

[Adamwesleyo]

I was just looking up eq mounts. There's a way to make your own for cheap but adding a motor changes the price a bit. If you have some cash to blow though there's this.

http://www.amazon.co...s=star tracker 

[morticiaskeeper]

I've got an eq mount on my scope, putting the 450mm lens on that is very easy, putting anything smaller on would mean I can't use the camera viewfinder. Ax the scoot tube obstructs it.

I'm wondering about making a bracket that will replace the tube rings with a tripod screw. But I'll play about with the red dot finder mount first!

[Stas]

Here is what I made.

Attached Thumbnails

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[morticiaskeeper]

Well that's better than my efforts!

Care to share what you did?

[Stas]

In Lightroom 5

I decreased "black" to make background really black.

I increased "white".

Worked a little with contrast.

Also I tryed to decrease noize but I'm not good in it so there still some problems with noize on photo.

Also you have some red, orange and yellow spots on your photo, so I had to decrease meanings of saturation of those colors. I think that's all whay I have done. 

[morticiaskeeper]

Thanks, it's good to see how someone else approaches it.

I think subtracting a dark image would help with noise. Stacking multiple exposures has got to be the way, it's just learning how to do it!

I made a bracket today to put a red dot finder onto a hot shoe.

It will need calibrating every use, but that will be easy enough with a known bright star.

Thinking about it, if an android phone could be clipped to the hotshoe, SKeye can be set as a goto whereby you point it at three known stars, the it can direct you around the sky. If the phone was connected to the camera via TriggerTrap, you would also have an intervalometer shutter control.

Think I'd better make another bracket :-)

[Stas]

You welcome) And what is this thing? What can it do?

[morticiaskeeper]

When you look through a telescope, you see a lot more stars than you can with the naked eye. Trying to align a scope on an eq mount, when the view through the scope shows a lot more stars, but a much narrower field of view, is pretty difficult.

The red dot finder puts a red dot onto a glass screen, like a rifle sight. When it is calibrated to the scope (or camera), you move the scope until the dot is on the object you want to see, then you look through the scope.

When looking at stars with a DSLR, you tend to see less through the eyepiece than with the naked eye, because the lens doesn't gather as much light. With the naked eye, on a good night, I can see M31. There's no hope of finding it through a camera, or even a scope. Use the RDF to point to your objective, then take lots of exposures, stack them & things will appear. With a scope, keep looking, things will appear.

[nbanjogal]

Today I just happened to find this article on removing noise from non-dark framed long exposures from one the photographers I follow on Facebook--his work is amazing! At first glance, the article looks understandable and helpful. 

 

JMG-Galleries – Landscape, Nature & Travel Photography » Removing Noise from Non-Dark Framed Long Exposures

[morticiaskeeper]

Thanks, just had a quick breakfast read, will look again tonight.

If only we could have some clear nights :-(

[kandidmoments]

Love the red dot finder idea... which do you think it's better for processing astro shoots? Lightroom or Photoshop... I have a bunch of shoots that I want to stack of m31....

[nbanjogal]

kandidmoments, I don't know if either is "better" because both can do a fabulous job--I think it would be a matter of what you're most comfortable with...though I guess stacking shots is a PS thing (I wouldn't know because I don't stack shots). For night sky processing I use Lightroom--I found some free (donations appreciated) Lightroom presets from David Kingham that work wonderfully. He is a wonderful artist, very generous to share his presets. He is a skilled, well-known night sky photographer, and he uses Lightroom. Royce Bair (another night sky master photographer), on the other hand, uses Adobe Camera Raw and Photoshop. So again, it's probably just a matter of what you're already accustomed to using and what you want to accomplish. 

[Gordo]

OK - gave it a shot.  Hopefully I can figure this image/ attachment thing out...

 

[Stas]

I like it. What programm did you use? And what exactly did you  do?