400mm focal length is not the 300mm rule.
The current terms refer to the combined physical length of the camera body + telephoto/zoom lens + hood. That is a different measurement from focal length.
The camera rules in plain English.
Focal length and physical length are not the same thing.
Optical focal length.
Physical length of the assembled setup named in the rule.
A 400mm lens is not automatically banned, and a 200mm lens is not automatically safe. The actual assembled camera is what matters.
Check the exact setup you plan to carry.
- Mount the actual body and lens you intend to bring, including the hood if you plan to carry it attached.
- If the zoom extends physically, check the longest physical state rather than assuming the collapsed length is enough.
- Compare the assembled length with the latest organiser wording and leave yourself a sensible margin rather than planning around a borderline measurement.
This is a conservative way to sanity-check your setup; it is not organiser-issued measurement guidance.
Do not choose the Singapore lens from the rule page alone.
The smaller setup still has to give you enough reach and enough light for the photograph you want. Use the Motorsport & F1 page to compare the actual camera/lens choices, then come back here to check the venue constraint.
Start with the Motorsport & F1 camera/lens picks, then verify the exact assembled combination against the latest organiser terms before race weekend.