Help with lens f values

Discussion in 'Displays' started by ednjude, Jan 17, 2012.

  1. ednjude

    ednjude Auditioning

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    Hi, I hope this is the right place to post this... I'm looking into buying a projector and have been given a choice between 2 almost identical units. The only difference I can see is one (Hitachi CP-A300n) has a lens f value of f=1.2 and the other (HItachi CP-A301- the more expensive one) has a value of f=4.1. I've been researching but can't really get a good grip on which would be better. We plan on using the projector in an auditorium that seats about 250 people and space is limited so we decided to go with a short thrown projector. It can be mounted as close to the screen (a 10 foot wide screen) as we need. Any ideas which would be better for our situation? thanks for any help you can offer. Ed
     
  2. Adam Gregorich

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    I can't find any info on the A301 on Hitachi's or any other site. I would be less concerned with the F value and more concerned with if its a different lens is the throw any different which could affect placement and screen size.
     
  3. Gregg Loewen

    Gregg Loewen Video Standards Instructor, THX Ltd.
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    Not sure. 1.2 then 1.4 then 1.8, then 2.8 (if I remember correctly). Each time you go down you cut the light output in half, so 1.2 vs 4.0 should have a large difference in light output. What do the specs say for Lumen output?
     
  4. ednjude

    ednjude Auditioning

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    They both claim to have 3000 ansilumens...
     

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