I've recently replaced my old Vixen Polarie mount with an iOptron Pro for photographing deep-sky objects. However, when trying to make a shot of the M 101 galaxy, all the objects on my pic were motion-blurry due to the Earth's rotation:
This is my equipment:
- Canon EOS 70D (astro-modified)
- Canon EF 100-400 mm f/4.5-5.6 L IS
- iOptron Pro with counterweight and Vixen ball-head
- Slik tripod
These are the parameters of my shot: - 400 mm - f/5.6 - 5" - ISO 2000 - Image stabiliser switched off - 2020-04-12 01:51 CET - 53.06434° N; 8.22302 E
M 101 was almost at the zenith at that time.
What puzzles me, is that the motion blur already appears at 5" exposure time! With my Polarie, 10" @ 300 mm focus (with an EOS 1100D) were not problematic at all when the mount was properly adjusted. The iOptron features a polar alignment lens to adjust the mount, which the Polarie lacked.
What's wrong here? Would the stabiliser in the lens help a bit? And: Is there a possibility to remove motion blur afterwards (I'm using Gimp)? Thank you.
UPDATE: The camera body weighs 755 g, the lens 1460 g. The counterweight on the other side 1500 g. Did I maybe position the counterweight incorrectly?