iOptron SkyGuider 3550A Instruction Manual page 12

For a heavy DSLR, especially with a long lens (more than 1.5kg or 3.3lbs, including lens)
A DEC Mounting Bracket with a counterweight (CW) and CW shaft (or Balance Package) is
needed for better balance and performance.
To install the DEC Mounting Bracket, remove the Camera Mounting Block from the mount.
Remove the polar scope cap. Install the DEC Bracket and tighten the locking screw to secure it.
Install the CW shaft and load the CW.
Loosen two DEC Camera Mounting Block locking screws to remove it from the DEC Base on
the DEC Mounting Bracket. Attach the DEC Camera Mounting Block to the bottom of the DSLR
camera and secure it by turning the block. Reattach the DEC Camera Mounting Block to the DEC
Base and tighten the two locking screws.
Figure 14. Mounting a camera with DEC mounting bracket and CW
Figure 13. Attach a camera
DEC Camera Mounting Block
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