Take shot without triggering shutter?

[LebedevRI]

Why would this be useful: taking picture with closed shutter equals to taking picture with body cap on, but without necessity to disconnect lens, put lens & body caps on.
It also will help in not killing shutter too yearly.

Purpose of this is to take a so-called Black Frame.
They used mainly in astrophotography.
Usually, several(!) of them are taken, averaged and subtracted from actual Light Frames.

Canon can automatically take them after taking image, and subtract them ("Long-Exp noise reduction"), but only resulting file is stored.

[ItsMeLenny]

This has been requested but the other way around. To keep the mirror up and take photos.
I don't think control of the mirror swing has been discovered. It's possibly hardwired in.
The only way people have gotten around it is to rip the mirror out.

[dmilligan]

This would be wonderful to have, and certainly possible, but nobody knows how.

[Audionut]

http://photo.net/learn/dark_noise/

Calibrating Images:

The first image is a bias frame - a zero-duration exposure in which the sensor is reset and immediately read out, without any light falling on the sensor and with no time gap between the reset and readout. The image that this process creates is a snapshot of what the sensor's bias noise looks like, since the only contribution to the resulting image is the readout amplifier's static. ........................................However, most digital cameras do not allow a zero-duration exposure without the use of special software - such as testing software used by camera service departments, or expensive software written specifically for science and engineering applications, which might require that physical modifications be made to the camera to operate properly. For this reason, most photographers who are calibrating their digital SLR images are doing so with a single combined bias and dark frame, taken as an exposure at the same ISO, shutter duration, and ambient temperature as the photograph.

Currently I think the standard practice is to take an exposure with 1/8000 shutter.  But a proper zero-duration exposure and dark frame exposure without shutter movement would be welcomed.

[a1ex]

The starting point for research would be the SBS state.

Start here:
www.magiclantern.fm/forum/index.php?topic=1915
http://magiclantern.wikia.com/wiki/ADTG

In LiveView, I can take bias frames by setting shutter blanking register equal to FPS timer B - 1.

I can also take some sort of black frames (at ISO 0 or something) by setting CMOS[0] = 0 in ADTG GUI. What exactly are these frames and whether they are of any help, I have no idea.

[Audionut]

I can also take some sort of black frames (at ISO 0 or something) by setting CMOS[0] = 0 in ADTG GUI. What exactly are these frames and whether they are of any help, I have no idea.

AFAIK, dark frames should be taken at the exact same settings as the images being processed, including the temperature of the sensor, so I don't think that one would be useful.

[LebedevRI]

I don't think control of the mirror swing has been discovered. It's possibly hardwired in.

Shutter can be opened without taking shot in two ways:

• Sensor cleaning -> Clean now
• Enabling Mirror lockup and pressing Shutter first time (second press will take pic & close shutter)

[Audionut]

Enabling Mirror lockup and pressing Shutter first time (second press will take pic & close shutter)

That doesn't open the shutter, it moves the mirror.  Second press opens shutter, takes pic, closes shutter after set Tv.