combining exposures

[little col]

i am interested in how you combine exposures , as an example when imaging m42 at a long and high iso it will enevatably get a core burn out , i have seen that most people take a few at iso100 , a few at iso 800 and some at iso1600 and then combine them as to get a nice bit of nebulosity with surrounding areas and a detailed core.
i think this is done in photoshop but i have no idea of how it is done , does anybody have a good guide
many thanks colin

[[1ponders]]

Hi Colin.

There are many talented people here who will be able to guide you in the art of layer masking in photoshop, but if you really want to learn how to use photoshop for astrophotography then I can highly recommend THE BOOK.

Photoshop Astronomy by R.Scott Ireland (http://www.willbell.com/ccd/photoshop_astronomy.htm). ISBN 0-943396-85-9. A must have on any budding astrophotogaphers bookshelf.

[joe_smith]

http://www.astropix.com/HTML/J_DIGIT/COMP2.HTM

Just the thing you want to do and it dose it with M42 as well :thumbsup:

[little col]

:thumbsup: brilliant thanks very much , should be a good read while the weather does its worst.

[ballaratdragons]

Or for an easier way to do image combining of differing exposure rates and get ALL detail showing, is to use the program EasyHDR.

I used it on my M42 to see the trap stars AND the whole neb. Works a treat.

Here is the Free download site: easyHDR Basic (Free) http://www.easyhdr.com/download.php

And here is my EasyHDR combined image of M42 showing both the Trap and the Neb. :thumbsup:
http://www.iceinspace.com.au/forum/showthread.php?t=20807&highlight=easyHDR

[little col]

:thumbsup:cheers ken , never heard of this method but i am sure it will improve the processing for me .
colin

[Geoff45]

This is an old article by Jerry Lodriguss. He does something similar with more bells and whistles in his ebook, which is well worth getting.
see http://www.astropix.com/GADC/INTRO.HTM

[ving]

as ken has stated... go the easy hdr :)