[sci.electronics] light meter, Blue Diodes, visible light phototransistors

ieee@ecf.toronto.edu (IEEE Student Branch) (12/24/90)

This is my first time reading sci.electronics: I hope these questions have
not been asked before.

I am building a light meter. Can anyone recommend a visible light  
phototransistor for this purpose.  I have only come across phototransistors
that work in the IR range.  I noticed my camera uses a "Silicon Blue Cell". 
Is this a phototransistor or ...?

Are blue diodes available? If so, who makes them. Any suggestions for Canadian
distributors?

Any help would be most appretiatied,
Linas Dauksa  ieee@ecf.toronto.edu  or  dauksa@ecf.toronto.edu

 

dunphy@col.hp.com (Dan Dunphy) (01/27/91)

Silicon light sensors are deficient in blue sensitivity. The
device you refer of is a blue enhanced silicon cell. I really
don't know how this is done, possibly a dopant, or a filter.A
This type if cell is what is used in most if not all
photographic light meters.