What about these:
1. Does it mean that if the flash unit can take GE No. 5 , then it surely can take Sylvania Press 25 or other bulbs that has boyanet base?
2. What is the different between M2, M3 or M25?
3. Why don't we just use Blue bulb since it can be used when taking both B&W and color photo. Why is clear bulb needed since it is only used on taking B&W?