cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 

Good introduction to serious astrophotography

kvbarkley
VIP
1 REPLY 1

TCampbell
Elite

Keep in mind the title is "getting started" ... there's quite a bit not included in this article.

 

Part of the challenge of astrophotography is "image data acquisition" ... and part of the problem is "image integration and processing".  

 

The author didn't mention a lot of the special types of exposures that are gathered (lights, darks, bias, & flats) as well as the image processing steps involved (special software that deals with image calibration, registration & integration ... this is fairly unique to astrophotography).  Ultimately you get a combined "master" integrated image ... but that's just the starting point for the rest of the image processing & adjustment steps.

 

The cameras tend to be specially modified for astrophotography.  You can use a normal camera, but the sensitivity will be weaker and the amount of exposure time will be increased.  The Canon 60Da (the "a" suffix is for "astrophotography) was pre-modded by Canon to remove the normal filter and replace it with a more permission filter.  Normal cameras are filtered so that the light collected will match the sensitivity of the human eye.  But human eyes aren't equally sensitive to all wavelengths across the visible spectrum. We are not especially sensitive to the "reds".  90% of the normal matter in the universe is Hydrogen.  The dominant emission wavelength for Hydrogen is mostly the Hydrogen alpha wavelength (656nm).  Human eyes are only about 20-25% sensitive to this.  Normal cameras gradually ramp up the blocking starting at around 550nm and increase it block 100% by the time they get to 700nm (the end of the visible spectrum on the IR end).  At 656nm, a normal camera blocks around 75-80% of the light.  But this means you have to run much longer exposures to collect this light.  Modded astrophotography cameras replace the factory filter with a much more permissive filter.  

 

 

Tim Campbell
5D III, 5D IV, 60Da
Announcements
01/18/2023: New firmware version 1.1.1 is available for EOS R6 Mark II
01/09/2023: Help ensure your autofocus is properly aligned with a Canon Precision Alignment
01/03/2023: Welcome to CES 2023!
12/08/2022: New firmware version 1.0.5.1 is available for EOS C70
12/07/2022: New firmware version 1.7.0 is available for EOS R5
12/07/2022: New firmware version 1.7.0 is available for EOS R6
11/22/2022: New firmware available for EOS R3, EOS R7 and EOS R10
11/16/2022: We're thrilled to be ranked among the Best Employers for Veterans in 2022 by Forbes.
08/31/2022: New firmware version 1.1.1 is available for RF 70-200mm L IS USM
08/09/2022: New firmware version 1.2.0 is available for CR-N 300
08/09/2022: New firmware version 1.2.0 is available for CR-N 500
07/14/2022: New firmware version 1.0.1 is available for CR-X300
06/10/2022: Service Notice:UPDATE: Canon Inkjet Printer continuous reboot loop or powering down
06/07/2022: New firmware version 1.3.2 is available for PowerShot G7 X Mark III
05/31/2022: Did someone SAY Badges?
05/26/2022: New firmware version 1.0.5.1 is available for EOS-C500 Mark II
05/26/2022: New firmware version 1.0.3.1 is available for EOS-C300 Mark III
05/10/2022: Keep your Canon gear in optimal condition with a Canon Maintenance Service
05/05/2022: We are excited to announce that we have refreshed the ranking scale within the community!
04/26/2022: New firmware version 1.0.1.1 is available for EOS R5 C
03/23/2022: New firmware version 1.0.3.1 is available for EOS-C70
02/09/2022: Share Your Photos is back!
02/07/2022: New firmware version 1.6.1 is available for EOS-1DX Mark III
01/19/2022: READY FOR ANYTHING EOS-R5 C
01/13/2022: Community Update. We will be retiring the legacy profile avatars on 01/20/2022. Click this link to read more.