C7 and C9 refer to bulb size, not brand or quality — the number is roughly the bulb's diameter in eighths of an inch. C9 bulbs are larger and bolder; C7 bulbs are smaller and better suited to detail work.
Choosing between them comes down to viewing distance and where on the property the bulbs will be used, not which one is objectively "better."
C9: built for visibility at a distance
C9 bulbs are the larger, classic roofline bulb — visible clearly from the street or across a large yard. Their scale reads well against long eaves and peaks.
- Strong choice for primary rooflines and long eaves
- Reads clearly from the street or a commercial parking lot
- Spacing matters more with fewer, larger bulbs per foot
C7: built for detail work
C7 bulbs are smaller and less overpowering up close, which makes them a better fit for entries, windows, railings, and landscaping where viewers stand closer to the display.
- Common choice for entries, columns, and window trim
- Better scale for detail-oriented, closer-viewing areas
- Can complement a C9 roofline without visually competing with it
Choosing between them
Many full displays use both: C9 on the primary roofline for street presence, and C7 on entries or secondary detail areas. The right combination depends on the property's scale and the main viewing distance.
Confirm with your installer which sizes are part of the current product catalog before finalizing a design.
Frequently asked questions
Is C9 brighter than C7?
Not necessarily brighter per bulb in every product line, but C9's larger size and typical spacing generally reads as bolder from a distance.
Can C7 and C9 be mixed on the same display?
Yes — a common approach uses C9 for the main roofline and C7 for entries or detail areas, though the specific product lineup should be confirmed with your installer.
What's the difference between C7 and C9 bulbs?
C9 bulbs are larger and bolder, typically used on rooflines for visibility from the street; C7 bulbs are smaller and better suited to detail work like entries and landscaping.