Re; TDC 4' Lenses

[P3D David W. Kesner <drdave@xxxxxxxxxx>]

In photo-3d Dr. T says:

>You have not been paying attention :-)

>>- TDC 4" lenses .............. $95/pair

I can't believe I missed this! It must have been while I was gone on
vacation for awhile.

>Since the 4" lenses are usually found in projectors (I got my only
>spare pair of 4" advertised above from a projector that was not
>working and I kept for parts), it might be a good idea to buy a
>projector with 4" lenses, remove the 4" lenses and put them in
>your projector (they are interchangeable) and then sell the
>projector with the 5" lenses.  If you are lucky, you might even
>get the 4" lenses for free...  Here are some past postings
>selling TDCs with 4" lenses from sell-3d:

Since I want the 4" for "self-projecting" and the 5" for "shows" and
large audiences, buying a whole projector just for the lenses is not
a very practical idea. I guess I could just have two projectors, but
that would be like paying $300+ for the 4" lenses.

You do seem to support my assumption that 4" lenses by themselves are
fairly hard (but not impossible) to come across.

>(For the club, even longer 7" lenses might have been better).

I am assuming you are talking about some other lens besides TDC or
did they make a 7" lens? Is this extra length strictly to get more
room for the audience between the projector and screen or are there
other differences such as f-stop or coatings? What is the actual
projector to screen distance for the 4", the 5", and the 7" lens
assuming a 5p format on a 60 x 60 screen?

Thanks for the time,

David W. Kesner
Boise, Idaho, USA
drdave@xxxxxxxxxx
(No I'm not a doctor - just a nickname)


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