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Old 01-03-2023, 01:39 PM
glend (Glen)
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Join Date: Jun 2013
Location: Lake Macquarie
Posts: 7,072
Quote:
Originally Posted by Ryderscope View Post
Further to your point Glen, attached is a diagram from the Askar site on the FRA300 that shows the way that the OTA focuses the different wavelengths. If I am correct in interpreting this diagram, it is indicating that the blue light is focused differently than the red and green. If this is the case, it could explain why the blue channel is affected more so by tilt.
Yes I have seen that diagram. Assuming it is correct then the blue light seems like it should be the reference (being the one centred in the field), and red and green are skewed. I suppose which ever ones you can manipulate would give you a result.
When I used to shoot narrowband through my old Bresser f5 (which had a Pretzval rear lenses as well), I had to align the image layers in Photoshop to clean it up.
Have fun.
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