Video: Limiting Magnitude in Astrophotography Systems

This video presentation examines multiple factors affecting Astrophotography System sensitivity (i.e. the Limiting Magnitude), and see how much they individually contribute to overall system degradation (actual data in magnitudes).

The presentation quantifies the dependence on Aperture, OTA type, Optics Coatings, Camera QE (with imager comparisons), Seeing, Light pollution, Extinction…


This is a must see for all astrophotographers, beginners and experienced alike.

PDF of this presentation and other goodies are available from:

Presented data has been derived from Astrophotography CAD numerical simulation engine, and covers all Stellar Classes.

Astrophotography CAD is inexpensive, and helps users better understand how their Astro-imaging system will perform, what its limits are, and which parameters will enhance the results.

Calculate your system’s Limiting Magnitude, predict SNR and see how changing components will affect it. See the impact of seeing, sky pollution, haze, target and site elevations, aperture, cameras and filters. Find true optimal binning and system F# for best sensitivity. Discover which manufacturer’s camera, OTA or filter will perform best in your system.

The included library contains over 139 Cameras and Imager Sensors, 110 OTA’s and 70 filters from various manufacturers.

• Compare, optimize or design Astro-imaging systems by simulating OTA, Imager and Filter combined performance from 350nm to 1000nm. This is particularly important before significant purchases, such as telescopes and cameras. You will be reasonably assured that the system will really do what you need it to do.

• If you are looking to purchase new camera, OTA, focal reducer or filters, this application will help you make the right decision.

• If you already have an existing imaging system, this application will help you optimize its optical train, and select the correct imaging parameters, such as the sub duration and total exposure length.

• If you have a particular goal in mind, this will help you determine how long of a total exposure time you need, which filters to use etc.

• When designing your system from the available components, or looking to make an upgrade, this application will predict what you can expect from the finished product – before you actually spend the time and money purchasing or making it.
~Chris K.