First Astro shot with 350D

[Striker (Tony)]

Look forward to catching up with you Tony.....keep working on Imagesplus will you.

I am getting the hang of things going through all the video tutorials.....only problem their is so many I forget them the next day...

As Trevor said David..you can not use the LCD to focus on the 350D...only camera capable of doing this is the 20DA.

[Striker (Tony)]

Originally Posted by Itchy

On an earlier question, you do have to convert your RAWs to another format (Tifs or fits, NOT Jpeg) before processing them further.

Thats the reply I have been asking for over a week now Tony....thanks.

I converted some old raws with the same process through linear conversion on ImagesPlus and found the tiffs easy to work with.

I was under the impression you work on the raws before converting to tiff which I was having difficulty doing....do you convert to 16 or 8 bit tiff...does it matter.

Thanks Tony.....that has made things a lot more workable and whole lot easier.

[westsky]

Thanks Itchy, that makes things a bit clearer for me as well. I used Rawshooter to convert to Tiffs then I stacked 4 of the images with Registax then did some processing in Photoshop CS It's interesting to see how much detail there is in very short exposures taken in very light polluted sky.

David

[Itchy]

Originally Posted by Striker

Thats the reply I have been asking for over a week now Tony....thanks.

No Worries, my pleasure.

I was under the impression you work on the raws before converting to tiff which I was having difficulty doing....do you convert to 16 or 8 bit tiff...does it matter.

Thanks Tony.....that has made things a lot more workable and whole lot easier.

I use 16 bit until processing is complete. The bit depth determines how many levels of each colour (R, G or B) you can store. 8 bit gives you 256 levels where 16 bit gives you 65536 levels. When you stretch you brightness levels, 16 bit allows for smoother colour transitions. The trade off is file size. A 16 bit TIFF from a 300D is 38Mb. ImagesPlus gives you the option of using 16 lossless compressed FITS files which are about half the size. When I'm done in IP, I convert to 16 bit TIFF to use in Photoshop.

Cheers

[Itchy]

Originally Posted by westsky

Thanks Itchy, that makes things a bit clearer for me as well. I used Rawshooter to convert to Tiffs then I stacked 4 of the images with Registax then did some processing in Photoshop CS It's interesting to see how much detail there is in very short exposures taken in very light polluted sky.

David

Hi David,

That is a great improvement on your first post. Well Done. Image stacking is the secret to good astro images. You can easily see the difference between a single image and a stack of 4. The more you stack, the better the image will be. This is because the noise in the image is reduced by the square root of the number of images stacked. So 4 images = half the noise. 10 images the noise is reduced to around one third. 100 images gives you a 10 fold reduction in noise.


Cheers