Any recommendations on the exposure for the perspex image with C1?
For Hasselblad's Phocus software's Scene Calibration tool, it is recommended that the exposure be 1-2 stops under.
Hi,
While it seems not too critical, you generally get the best results if exposure level is 1-2 stops under saturation levels, which means adding the amount of 2 or 1 stops of exposure to an average exposure metering. Do make sure to leave the aperture and (manual) focus (and tilt/shift) itself identical to the aperture and focus settings used when shooting, only adjust exposure time or illumination intensity.
The additional exposure will reduce the
relative amount of noise (improve the S/N ratio), so noise should become less of a factor in the calculations. The influence of read-noise is marginalized, and photon shot-noise becomes a lower percentage of the signal level, that's why.
But C1 can handle a wide range of LCC exposure levels (by blurring the noise, especially when higher ISO is used), so it's not too critical. But proper exposure may help a bit, so why not do it the best way we can.
Cheers,
Bart