How do I use the M54 Fine-Adjustment Rings to change my camera's orientation?
Simply insert a ring (start with the thinnest, 0.3mm) between the two M54-threaded accessories you are connecting. When you tighten them, the accessory will stop at a different rotational position. If it's not the desired angle, try the 0.5mm, 1mm, or a stacked combination until you achieve perfect framing.
Can I stack M54 Fine-Adjustment Rings?
Yes. The rings are designed to be stacked to create intermediate spacing values. For example, to get 0.8mm of spacing, you can use the 0.3mm and 0.5mm rings together. You can combine all three thicknesses to get 1.8mm of spacing.
Will these M54 rings affect my back focus calculation?
Yes, and that is one of their primary functions. Each ring adds its specified thickness (0.3mm, 0.5mm, or 1mm) to the total back focus distance of your imaging train. You must account for this additional spacing when calculating your optical path length.
Should I buy the set or a single ring?
If you know the exact gap, a single ring is enough: for example, if your flattener requires 55mm and your setup is at 54.5mm, the 0.5mm ring brings you to the required 55mm. If you are still dialing in back focus or camera orientation, the set gives you all three thicknesses (0.3, 0.5 and 1mm) and their stacked combinations.
What is the thread pitch for these M54 Fine-Adjustment Rings?
These rings are designed to work with the standard astronomical M54 x 0.75mm thread pitch used on a wide variety of focusers, field flatteners, reducers, and large-format astronomy cameras.
When trying to frame the Horsehead Nebula (B33), my camera is always upside down when tightened. How do the M54 Fine-Adjustment Rings help?
These rings are the perfect solution. By inserting one or more rings between your camera and the rest of your imaging train, you change the point at which the threads lock. This allows you to rotate the camera to the correct orientation to properly frame the Horsehead Nebula and Alnitak before fully tightening the connection.
