@ternst - Are you using Capture One or another program for your raw processing? While I use a variety of raw processors myself I *strongly* suggest that Capture One (specifically 4.1.1) be used for processing long exposures. I agree "no noise" or "noise free" is a marketing-only phrase. However, using ISO 50 on a reasonably cool night and processing in Capture One I find the long exposure capability of the P45+ to be truly astounding.
@gjazzz - the device separates the camera/lens from the sensor. You then activate the sensor and do whatever you'd like with the camera. This allows you to for instance shoot 10 exposures at 1/125 each with a strobe pop. Or you could mix multiple strobe pops with several long shutter-only exposures. Etc Etc. When you are done you turn off the sensor. Phase files won't start to accumulate noise for many minutes (or hours depending on temperature - see temp-to-time link in paragraphs above) which makes them uniquely able to do this sort of experimentation. I don't know that camera well, but the "multiple exposures" on the S2 is almost surely just digitally adding the exposures the same way you could do in Photoshop.
1) Long exposures in digital are highly dependent on ambient temperature and sensor design. The Phase One max exposure times are shown on our website here: http://www.captureintegration.com/phase-on...one-tech-specs/
2) I 100% disagree with the assertion that negative film is the way to go for long exposures. My thesis
was on time-lapse photography. I spent many hours in the middle of the cold Ohio winter night doing long exposures. The end product only used 30 second exposures, but along the way I shot much longer exposures.
The reasons I put forth that digital is much better for long exposure are:
- No reciprocity failure.
Star trails won't fade, and exposure calculations are strait forward.
- Easy/Accurate estimation of proper exposure
even in very complex scenes. Scenes including both moonlight, artificial light, and areas of important shadows are next to impossible to analyze with a light meter. Instead of bracketing film at the cost of hours of exposures, a single digital underexposed-and-pushed image can give you an exact exposure which can be verified immediatly after.
- Easy path to HDR
(whatever its form) for scenes with inherently extreme contrast.
However these arguments do fall apart if you're targeting an 8 hour exposure :-). So if that's your idea of a long exposure then by all means, film is the way to go!
DougCapture Integration, Phase One DealerPersonal Portfolio