sas.jpg (10235 bytes)
techtitle.jpg (9316 bytes)

Shooting Hydrogen Alpha with a Hutech Modified Digital Rebel

Kodak recently announced that it has discontinued production of its wonderful Technical Pan Film.    This film was exceptional when hypered and shot through a hydrogen-alpha filter.  Can the modified Digital Rebel come close to its performance?

Note:  The digital images were taken through an Orion 80ED scope and a Lumicon Hydrogen Alpha filter on 12/20/04.  The moon was just under 10 days old and was approximately 70% full when these were taken!

horsehead-800raw.jpg (80384 bytes)

This is a combination of 10 X 300s (a total of 50 minutes) exposures through a Lumicon Hydrogen Alpha filter.   
Images were stacked in ImagesPlus and a digital development stretch was applied.

horsehead-unsold.jpg (159601 bytes)
The same image converted to grayscale in ImagesPlus based on a method explained by Mike Unsold.
The image was curves adjusted to try to match it with a Tech Pan image of the same object.
Compare this image with the one below  taken through a scope of the same focal length (an Orion 120 ST).
It was shot through a red 25a filter and has a slight noise reduction filter applied.
It is a single 2 hour exposure compared with a total of 50 minutes in the digital image above.
Also note that the moon was only 1/4 full when the film image was taken.
horsehead-60a-02-800.jpg (130841 bytes)
NOTE: This is not meant to be a scientific test.  The film image has everything going for it...
  • less moonlight
  • a filter that allows significantly more light through
  • more than double the exposure length
  • a larger aperture imaging instrument


[Home]   [Techniques page]