On Jan 15, 2019, Whisky-dave wrote
(in ):

On Monday, 14 January 2019 22:10:08 UTC, nospam wrote:
In , Carlos E.R.
wrote:


Double exposure in film, I can understand.

But a digital camera would just add the pixel values from two files,
thus being no different from postprocessing on the computer.

To be valid, the sensor would have to be exposed, and then, without
reading it, exposing it again. Are they really doing it?

Nikon, Canon, and Fujifilm (and probably others) have a multi-exposure
feature/mode which allows for two separate exposures, on two frames, which
are blended into a single file. It is a bit of a novelty and nothing that
cannot be done in post.

Ok, so they do two frames, then merge or blend them into a single file.
That's postprocessing, not really "double exposure" in my book. It
simply emulates it, but it is not it.

are you channeling eric?

it's double exposure, without any emulation whatsoever.

It's not a double exposure it's two seperate exposures on two seperate frames.
Which is what happenes whenever you take two photos. Then they are merged
together something that doesn't happen when taking single exposures.

Is HDR a multi-exposure technigue I'd say yes but it isn't the same as what
was done in film multi-exposures.

While HDR shot in a digital camera is a digital multi-exposure technique, I
would consider it an exposure bracketing rather than an analog double
exposure.

Then you have Focus Stacking/Bracketing which is another digital
multi-exposure technique which would be a royal pain to execute with film.

So I'd say it was emulation of double exposure, or it could be a simulation
if exactly the same method was used as would be used in film.


also, a double exposure of the same scene will have less noise,

The vast majority of double exposures wouldn't be of exactly the same scene
otherwise they'd be little point in doing it, unless for HDR of course which
is when you do take multiple shots of the same scene.

Once you have the CPU of the digital camera available a whole World of
possibilities opens up none of which other, than the classic double-exposure,
are easily available to film. For example with my Fujifilm cameras with a
single press of the shutter release, with WB/bracketing, ISO/bracketing or
Film Simulation/bracketing I can obtain three individual exposures of the
exact same scene with either different WB, ISO, or Film Sim all generated via
the in-camera CPU. You just cannot do that with film.

All of those digital multi-exposure techniques can actually be quite useful,
whereas, I consider the digital ‘double-exposure’ a novelty as it can be
done far better, and more deliberately in post processing, even on different
days, months, or even years. Not so with film, unless by some freak accident.

--
Regards,
Savageduck