Photodiode or LDR?

[cameron_15]

Which is preferred and in what conditions. ie are their conditions where one is better suited then the other?

Thanks in advance!

[olly_s15]

Photodiodes are better suited for optic-fibre light intensity modulation systems because they have a much faster response time.

[lachymm]

LDR's are suited more towards Vin>Vout situations, Eg a spinkler system etc

[Chavi]

LDR's are cheaper more durable and have an inverse light intensity/resistance relationship.
They are useful as street light sensors, Light levels sensors in a Museum, etc.
The response is relatively slow, and they have a low optical gain (sensitivity to light)

Photo-diodes are reversed biased diodes with a photosensitive region that detects light
They have a fast reaction time (~down to a couple of nanoseconds) and are useful for decoding and converting quick time varying wave signals to electric signals.

[lachymm]

Well said Chavi...