Gobo size looks like a simple choice between small and large. It is actually a question of what fits the projector and how much of the disc is usable. The outer diameter and the image area are different numbers, and confusing them is how reorders end up not seating.
Outer diameter vs image area
A 53mm gobo does not project a 53mm image. The holder clips the edge, so the usable area is smaller — often around 45mm. Always ask for both figures and design the artwork to the image area.
The two common sizes
37mm suits smaller, lower-power projectors and tighter logos. 53mm is the more common standard for full-size fixtures and gives more room for detail.
| Size | Typical use | Detail room |
|---|
| 37 mm | Compact / low-power | Limited |
| 53 mm | Standard fixture | More |
| Other | Specialist holders | Check holder |
Holder compatibility
The gobo must match the holder in the specific projector. A 53mm gobo will not seat in a 37mm slot, and forcing it damages both. Confirm the holder size before ordering.
Detail and throw
Larger gobos carry finer detail and survive longer throws without the image breaking up. For a logo with small text, 53mm is usually the safer bet.
Standardising across sites
If you run multiple projectors, standardise on one size. Every later reorder becomes quick and cheap, and a spare gobo fits any unit.
How to order
State the holder size, the image area you need, and the artwork. Suppliers quote the outer diameter; you design to the image area.
Common questions
Will a 53mm gobo fit a 37mm projector?
No. The holder size is fixed; a 53mm disc will not seat in a 37mm slot. Match the gobo to the holder.
Is the image the same size as the gobo?
No. The holder clips the edge, so the usable image area is smaller than the outer diameter — often around 45mm on a 53mm gobo.
Which size for small text?
53mm, generally. The larger area holds finer detail and survives longer throws.
Why did my reorder not seat?
Likely a size mismatch or a different holder. Always confirm the holder size, not just the outer diameter.
Should I standardise gobo size?
Yes, across a fleet. It makes reorders fast and lets one spare fit every unit.
Does size affect brightness?
Indirectly — a larger image area spreads light thinner. Size is mostly about fit and detail, not raw output.
Need help specifying this?
Send us the throw distance, the image size you need and your artwork — we will recommend the right model and quote within 24 hours.
