Canon Digital Rebel (300D) Modification

First Astro Images with Modified Rebel

Comet Machholz and M42

by Gary Honis

It had been over a month since I did the mod waiting for cloudy night skies to clear over PA. I was finally able to take the first astro-images with the modified Rebel on 1/15/05. Skies were very hazy with some high clouds along with light from a 5 day Moon and a snow covered ground. Comet Macholtz was near Zenith so I tried imaging it and also M42 with an Orion ED80 refractor and f/6.3 focal reducer. The ED80 was piggybacked on a 10" LX200 classic. The poor sky conditions and moonlight allowed for only short exposures and capturing of the comet's tail was difficult. I noticed that the RAW images of the modified Rebel had a very red-ish cast as compared to the unmodified camera as expected. Ambient temperature was 15 degrees Fahrenheit so no dark frames were needed. Images were unguided.

This is a photo of the modified Canon Rebel, reducer and baader filter as they were used in the ED80 refractor:

For a comparison of .8X, f/6.3 and f/5 focal reducers used with the Canon 10D/ Rebel camera & Orion ED80 Refractor CLICK HERE.

Comet Machholz: Used Images Plus to combine four 1-minute exposures at ISO 800 using Normalized Median combine:

Comet Machholz: Combined twelve 1-minute exposures at ISO 400 using Median combine with processing to help reveal comet tail:

M42 Orion Nebula: Used Images Plus to combine eight 1-minute exposures at ISO 800 using Average combine:

The camera tested okay considering the poor sky conditions and it should perform well under darker skies. I will need to learn how best to handle the greater red response when processing images with the modified camera.

Canon Digital Rebel Modification Pages:

Part 2: Plans for Peltier Cooling



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