Lamp vs Bulb vs Module: What You're Actually Ordering

Search for a projector lamp and you will be offered three visibly different objects at three very different prices — all described as the lamp for your projector. They are not the same product, and buying the wrong one means either a part you cannot fit or money spent on housing you already own. The distinction takes two minutes to understand and saves a return.

The three things being sold

• Bare bulb (the burner): the light source alone — a small quartz arc capsule with two electrodes. No reflector, no housing. Cheapest, and the hardest to fit.
• Bulb with reflector: the burner bonded into its mirrored parabolic reflector. This assembly is optically matched and is what actually produces a focused beam.
• Complete module (lamp assembly): bulb, reflector and the moulded plastic cage with connector and mounting flanges. Slides straight into the projector. Most expensive, and what most people should buy.

What the bare bulb actually is

It is worth seeing one up close, because it explains the pricing. This is not a household bulb. There is no filament and no screw thread — it is a sealed quartz capsule containing mercury vapour under high pressure, with two tungsten electrodes almost touching. An arc jumps the gap at extreme temperature. That is a precision component, which is why even the cheapest tier is not as cheap as people expect.

Which one do you need?

• Buy the complete module if: you want a ten-minute job with no risk. This covers the overwhelming majority of owners, and it is what our brand collections list.
• Consider bulb-with-reflector if: you are servicing a fleet, your housing is in good condition, and you are comfortable transferring the assembly. The saving is real at volume.
• Only consider a bare bulb if: you have the equipment and experience to bond a burner into a reflector and align it. Alignment tolerance is tight — a fractional error costs brightness and lamp life.

For most people the module is not the expensive option; it is the option that works. The housing also carries the electrical connector and the thermal design — both of which matter.

Why the module costs what it does

• Optical alignment: the burner's arc must sit at the reflector's focal point. Getting this right in a factory is routine; getting it right on a workbench is not.
• Thermal management: the cage positions the assembly precisely in the airflow path. Fit a lamp slightly wrong and it runs hot and dies early.
• Electrical connection: the ceramic connector handles a high-voltage strike every time the projector starts.
• Handling protection: the cage is what lets you fit the lamp without touching the quartz — skin oils on the glass create hot spots.

The other axis: who made the burner

Separate from the form factor is the question of origin, and the two get conflated constantly:

• Original: manufacturer-boxed complete module. Highest price, zero variance.
• OEM-bulb-inside: a genuine Philips, Osram or Ushio burner in a new third-party housing. Usually the best value.
• Compatible: third-party burner and housing. Cheapest, most variable.

A complete module can be any of these three. Our OEM vs compatible guide covers the trade-offs, and our cost guide puts the tiers in context.

FAQ

Can I put a bare bulb into my old housing myself?

Technically possible, practically inadvisable for most owners. The burner must be bonded and aligned to the reflector's focal point within a tight tolerance. Errors cost brightness immediately and lamp life over time.

Why is the module so much more than the bare bulb?

You are paying for factory optical alignment, thermal design, the electrical connector and a part you can fit without touching the quartz. On a single replacement that is money well spent.

Are lamp and bulb the same word?

In everyday use, yes — and sellers use them interchangeably, which is the root of the confusion. What matters is the picture in the listing: if it shows a plastic cage, it is a module; if it shows bare glass, it is not.

How do I know which my projector takes?

Nearly all consumer and business projectors take complete modules. Look up your model in our brand collections, or start with the complete replacement guide.

Order the right thing once: for almost every owner that means a complete module. Look up your projector by brand and match on the lamp part number, not the projector name.