Auto Preview for long exposure.

[LaMax]

Hi, all.
First of all i wanna say tanks to all community of ML. your firmware rock!

In the past day i had to make some firework shot in a wedding shoot session.
when i check the photos i think that it would be very useful if I can check the live result on camera display (when i'm shooting), and stop the shutter when the result seems good (in B mode). a sorta of live view but with the exposure updated by increasing time.

The workflow would be like this:
Place the camera in B Mode -> Activate Live View -> Check Focus (obviously) -> press the shot button (or another button) -> check the result on camera display and when the exposure it's good for the shot -> release the shoot button.

Sorry for my english, it's difficult to me just to explain in my own language (italian).

It's possible to make this real? It's stupid? what do you think?

[a1ex]

Use FPS override.

[brapodam]

Actually what he's suggesting is to have a function where live view "bleeds in" the image to show you what you are capturing. FPS override can allow you to use live view in very dark conditions, but what he wants is to capture a picture in bulb mode by holding down the shutter, and in order to know when to stop the exposure, the live view image updates according to the exposure time.

I don't know how this can be done, in fact it's impossible for a full res picture, but I think it might be possible to do it for something like silent pic.

[a1ex]

Ah, I've researched that here: http://www.magiclantern.fm/forum/index.php?topic=1915.msg23797

and the sensor is polled periodically during a long exposure (2-3 times per second iirc), but I couldn't find any EDMAC activity.

I thought you want to preview the motion blur, and for this, link FPS override with shutter speed, play with it, and when you are ready, snap the picture.

[LaMax]

Thanks for attentions. It's a little bit strange but today i found this iOS app on twitter, and this app make exactly what i want (and more). take a look:

https://itunes.apple.com/it/app/magic-shutter/id408256708?mt=8&affId=1885608&ign-mpt=uo%3D4

Here is a video by app developer: http://www.youtube.com/watch?v=5HgaJ4_NzXM

and Here's a test found as related video: http://www.youtube.com/watch?v=1pAtdLuTAIs

[Straight_Shooter]

Hi,

I am not sure if I understood everything in this thread correctly. Could somebody please tell me: Does this feature exist in Magic Lantern?

Description of the feature:
1.) You set up a long-exposure in your Canon camera
2.) You start the exposure
3.) While the camera is busy taking the picture, the Live View monitor shows the picture as it is being generated. (perhaps updated e.g. once per second)

The purpose of this would be to stop the exposure when the "preview image" on the monitor looks just right.
This would be extremely useful for night photography and light painting.

[a1ex]

Nope, this one doesn't exist yet.

You can preview the brightness of a long exposure, in LiveView, with:
- ExpSim on
- Expo Override on
- FPS override in Low Light mode, as needed

More details here or here.

On DIGIC 4 models, FPS override goes to very low values (close to one frame every 5 seconds), so you can preview motion blur in some cases as well (but not on the actual exposure).

Here's a script that gets somewhat close to your request (though it doesn't add the frames in camera).

[Straight_Shooter]

Nope, this one doesn't exist yet.

I see. Could you please remove the [ALREADY DONE] tag then, it seems to be kind of a misnomer.

Also, I am wondering: Would this be possible to do at all? Do you perhaps have a rough estimate how difficult it would be to do (if at all possible)?

You can preview the brightness of a long exposure, in LiveView, with:
- ExpSim on
- Expo Override on
- FPS override in Low Light mode, as needed

More details here or here.

On DIGIC 4 models, FPS override goes to very low values (close to one frame every 5 seconds), so you can preview motion blur in some cases as well (but not on the actual exposure).

Here's a script that gets somewhat close to your request (though it doesn't add the frames in camera).

Thanks a lot, I will look into those.