Critique on my nebula shot made me check my focus routine

Someone in the comments said my M42 photo looked soft compared to others. I always just used the Bahtinov mask manually, but they suggested I check focus after every filter change, not just at the start. I tried it last week on the Rosette Nebula and the difference in star sharpness was obvious. Has anyone else had focus drift between LRGB filters?

2 comments

2 Comments

sarah_mason5d ago

Oh wow, that's a really good catch on their part. Did you notice the focus shift was always in the same direction or random from filter to filter?

hunt.nora5d ago

Two nights of Oiii data actually focused fine for me, it's only been the red filters that shift.