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View Full Version : Lenses and numbers.



kosmodave
05-29-2010, 12:00 PM
Hi everyone,
I would like to enlist the help of you camera experts out there if I may. I have a Sony HVRZ1E HDV camera which according to the specs has a lens as follows;
12X Optical
Focal Length of 4.5 - 54mm (3/16 - 2 1/4in. )

When converted to 35mm still camera
32.5 - 390mm ( 1 5/16 - 15 3/8 in. )
(40-480 mm ( 1 5/8 - 19in ) in 4:3 TV Mode (from manual)

My question is, what do I enter in Lightwave to match lenses at full wide angle position?

And now to really complicate the issue, what numbers do I use if I attach my Wide Angle add-on lens which is marked as follows;

Power: 0.48X time conversion factor of your current lens setting.

I knew I should have gone to photography school :stumped:

Many thanks in anticipation of your replies.

Dave.

Silkrooster
06-01-2010, 11:58 PM
You are suppose to use the number that is on the lens it self(I could be wrong, but makes the most sense). As for the add on lens take the focal length and multiply it by .48 Example: focal length of 30mm x .48 = 14.4mm

Red_Oddity
06-02-2010, 01:28 AM
Those focal lengths only mean something in LW if you also know the film back.

So if you know the size of the film back and enter that in LW, you should be able to use the numbers on the lens.
If you don't know it, you probably need to set the film back to full aperture and use the 35mm equivalent values (not always the case though unfortunately)

I'm always amazed how hard it is to find actual usefull info on camera filmback sizes (we've even had trouble finding the proper filmback sizes for cameras like the HDW F900R or the ARRI D-20), something that is paramount to get a proper track and CG integration in plates.

RebelHill
06-02-2010, 04:47 AM
Set the frame heght to 135 (35mm slr) and use the focal lengths given as 35mm equivolencies.

kosmodave
06-03-2010, 10:58 AM
Many thanks for all your replies, I will shoot some test footage and have a play next week. :hey:

Dave.

shrox
06-03-2010, 11:30 AM
Here's a resource I found:

http://www.jfi.net/jfisite/resources.html