Complete List of Compatible Models:
A Series (Best Compatibility)，Canon AE-1，Canon AE-1 Program (AE-1P)，Canon A-1，Canon AT-1，Canon AV-1，Canon AL-1

 

F Series (Professional Grade)
Canon New F-1 (for use with AE Finder)，Canon F-1 (Original Version)，Canon F-1N

 

T Series
Canon T50，Canon T70，Canon T80，Canon T90

 

Other FD Mount Bodies
Canon EF，Canon EF-M，Canon FTb / FTb-N，Canon TX，Canon TLb

 

Compatibility Notes
Mount System: All Canon film SLR cameras equipped with an FD lens mount support basic flash functionality.

 

Special Features: The 155A enables Program Flash via additional contacts, fully functional on A-series models (especially AE-1, A-1, AE-1P)

Era Classification: This flash belongs to Canon's 1970s-80s FD system dedicated flashes alongside the 177A, 188A, and 199A

 

Important Notes
Not compatible with any EOS series (EF mount) digital or film cameras.
Not compatible with early FL mount cameras (partial manual mode support only).
All models are manual-focus film cameras; no digital variants exist.
To verify full functionality with specific camera bodies, check if the camera's hot shoe features dedicated sync contacts compatible with the 155A.