Nick Outram
June 19th, 2006, 12:20 PM
I have been doing some tests with this resolution chart:
http://www.graphics.cornell.edu/~westin/misc/res-chart.html
-On my Sony HDV-HC1 without Letus I get:
375 vertical and
525 horizontal
with Letus I get:
325 vertical and
475 horizontal
-these tests where done using a tungsten 100w bulb quite close for lighting. The biggest thing that can make the reading innacurate is not having the focus 100% accurate. My sheet was slanted very slightly and this caused an issue at first. When going back to no-Letus I had to decrease the exposure by 1 click to retain no 100% zebra pattern onscreen -this may be 1 stop or slightly more.
My conclusion: The Letus loses about 1 stop of light and a bit over 10% resolution, sharp focusing is critical to maximise resolution. At 1metre with a 50mm f1.4 at max aperture DOF is only a few centimetres...
The vignetting issue reported in a previous post can be solved by zooming just to '2 clicks' in on the HC1 (this is probably about 65mm equiv).
Regards, Nick.
http://www.graphics.cornell.edu/~westin/misc/res-chart.html
-On my Sony HDV-HC1 without Letus I get:
375 vertical and
525 horizontal
with Letus I get:
325 vertical and
475 horizontal
-these tests where done using a tungsten 100w bulb quite close for lighting. The biggest thing that can make the reading innacurate is not having the focus 100% accurate. My sheet was slanted very slightly and this caused an issue at first. When going back to no-Letus I had to decrease the exposure by 1 click to retain no 100% zebra pattern onscreen -this may be 1 stop or slightly more.
My conclusion: The Letus loses about 1 stop of light and a bit over 10% resolution, sharp focusing is critical to maximise resolution. At 1metre with a 50mm f1.4 at max aperture DOF is only a few centimetres...
The vignetting issue reported in a previous post can be solved by zooming just to '2 clicks' in on the HC1 (this is probably about 65mm equiv).
Regards, Nick.