Oh, I wasn't referring to that - just that you need a different (smaller) exposure range (and thus more images) if you're working with 8bit jpegs compared to 10-12bit RAWs.
I wonder if Camera can not just take 3 .jpgs with different exposure, but take 1 RAW quickly, and then post process it in 3 jpgs or tiffs and then combine it into 1 HDR image. No tripod, everybody happy
Let's suppose we are taking 3 photos (theoretical times):
- 1/12s
- 1/6s
- 1/3s
We would have the following timeline:
0s: open shutter (light goes in the sensor, software starts "capturing process")
- 1/12s: take first snapshot (JPG image with 1/12s exposure. Shutter remains open)
- 1/6s: take second snapshot (JPG). Shutter remains open.
- 1/3s: last snapshot of the sequence. Save the third image and finish process.
What do you think?
I'm dreaming of a better way to take HDR Photos Single Pass in this case in 1/3s:
Take a 1/3s Picture at once and reading the Picture from the CCD in three runs!
Open the Shutter, read after 1/12s, still exposuring, after 1/12s the 1/6s picture and still ongoing after 1/6s the 1/3s picture. Then you can close the shutter.
CCDs don't work that way. Also, there is the problem that every readout itself introduces some (fairly constant) amount of noise. That's one of the reasons why (except for specific cases like astrophotography) it's better to have ONE longer exposure than several short exposures stacked (as they all carry the readout noise, and so have a worse signal-to-noise ratio).
Do you think that using the DBus commands to take pictures we can adjust the exposure and do a -2, 0, +2 pictures in sequence in a script and have them piped into an HDR editor/creator.
Do you think that using the DBus commands to take pictures we can adjust the exposure and do a -2, 0, +2 pictures in sequence in a script and have them piped into an HDR editor/creator.
The main question for me is how to make the bracketed pictures. The rest can be done on the desktop. I have come to the conclusion that a little C is neccecary in order to do this.
I compiled a quick and dirty script which uses this C utility and takes a -2, 0, +2 sequence with the current settings in focus and exposure.
to run it
1) Place the files contained in the attached file in a non vfat folder eg., ~.
2) Compose and take a picture in with the default camera application.
3) Close camera application without moving the camera too much.
4) Run photo_bracketing.sh from the command line. Wait.
the three files will be called rawHDRtest0.png rawHDRtest1.png and rawHDRtest2.png
.