Auto exposure algorithm for shooting - auto iso, ae (autoexpo.mo)

Started by pravdomil, July 20, 2013, 10:19:10 AM

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Audionut


alexw

I could have SWORN at one point I had my 70d configured with such an option that, in manual mode, I could hit a button and the exposure would snap to auto-settings. For example, I've got a scene properly exposed at iso 800, 1/250th, and f/1.8. The lighting changes, suddenly requiring 1/50th. Ideally, I go change sensitivity since I've got a few stops of headroom, but I don't have time just yet and want to "just get the shot" before I go chimping for optimal settings. I can just hit this magic button and the shutter speed will snap to 1/50th, and after seeing the properly exposed but blurry image, I can then go fix my settings. Does something like this exist in this module? Am I looking in the wrong place?

Case in point: I was shooting a concert, and leave my camera in M mode. I pick it up the next morning to get some snaps of a dog jumping on my friend, and all of them are way over exposed because I didn't have time to adjust settings. Sure, I could have switched to P, but I don't usually want to be there anyway. I'd rather have the reflexive workflow of auto button>(shoot?)>fine tune>shoot.

This is already kind of a thing in live view with this plugin - Half pressing the shutter auto sets exposure, but if you don't give the half press time, the shot uses the prior manual settings. But looking through the mirror, it's full auto all the time.

seanruddy

noob here first post.
Thanks for all the amazing work!

2 feature ideas:
1 add is to ramp. A dropdown with 3 options sunset ramp and sunrise ramp no ramp.  Basically a one way  falling light or raising light.
If sunset is selected and it ramps up to 800 iso it does not skip back down to 400.  Or shutter jumping between 0.4 and 0.5. 

2 Also saving curve profiles would be sweet!

Again thanks for all the work that has gone into this project!


matija

Hi,

first of all, this module works on 1200D! That is really really great since it normally underexposes in low light.
Now, it does not work in Av mode, as far as I can see, seems by design. As an Av-in-most-situations shooter, I think it can easily be extended to do so.

Basically, if AV range (both limits) is set to Av value, the result is great. The benefit would be that it can be changed on a dial, without diving into ML menus.

So, as far as I can see, if (in Av mode only) these limits are set to Aperture value, thing would work like a charm! (Tv might be similar, at least as far as the lower limit is concerned)

Anyway, the module as is is one of the most helpful when it comes to stills. Now 1200D does what I wnat it to do better than 80D. Which reminds me...

almarsden

Hi all! Newbie here! :-)

Have just installed the latest nightly on my 5DII and when the Auto Exposure module is loaded the aperture, shutter speed and ISO are flickering all over the place, any ideas?

Thanks and keep up the amazing work ML Team!!



garry23

I decided to give this module a go tonight, but after reading from the first post, and playing for hours with the settings and trying to correlate the curves, I must admit to be rather confused as to the use case.

Could someone who uses this module possibly give a few hints on the use case(s) and how to set things up.

Cheers

Garry

PtboPete

Curious, if I have auto exposure turned on and configured can I still use AETTR with or without dual ISO? I'm thinking one competes with the other.

jerome_turmer

This sounds great!
Is there any way to restrict the maximum shutter speed to keep it below fash sync?
Thanks!

scrax

Uhmmm, I was playng with it in those days and can't understand if it works or how is supposed to work...
ISO range works, seems.
But how to set Exposure compensation? Any change I made to EC range or curve seems to not having any effect (in LV, in photo mode nothing changes)
I'm using ML2.3 for photography with:
EOS 600DML | EOS 400Dplus | EOS 5D MLbeta5- EF 100mm f/2.8 USM Macro  - EF-S 17-85mm f4-5.6 IS USM - EF 70-200mm f/4 L USM - 580EXII - OsX, PS, LR, RawTherapee, LightZone -no video experience-

Audionut

The changes aren't immediately visible in LV.  Requires half-shutter to see the exposure changes in LV.
Things work more smoothly in LV with 'Same TV curve' set to ON.  With Same TV curve set to OFF, I have to press half-shutter, release and press again fairly quickly, for the correct exposure settings to stick.

Quote from: garry23 on February 04, 2018, 11:20:06 PM
Could someone who uses this module possibly give a few hints on the use case(s) and how to set things up.

Missed this post earlier.

At the bottom of the module screen is Exposure Value.  You adjust all of the curves, so that at a specific exposure value as measured by the camera, the camera will use the exposure settings as set by the curves.

Look at this image from the OP.


At EV 8, the camera will shoot ISO 100, 1/500, f/4.0.  You can adjust the curves so the the camera will use some other exposure settings at that EV.  Higher ISO, more narrow aperture, faster shutter, whatever.
In the above module settings image, the orange EC line is indicating underexposure at those current settings.

Here's another curve arrangement.


At EV 8, the camera will shoot ISO 100, 1/4000, f/1.4

You basically use the module to tell the camera, at this EV, use these exposure settings.
Canons auto mode has some quirks.  And you're stuck with the exposure settings that Canon decides to use, only having EC to apply some changes to Canons auto mode.  This module is full customization of exposure settings that will be used.  Once you have the initial setup done (curve arrangement), then it works exactly like an auto mode.  Point and shoot!


Another nifty trick is being able to meter the scene.  Press half-shutter then enter the module.


The blue vertical line shows the measured EV.
The above image is the same settings as the next image above, with EC +0.5 dialed in.  You can see the effect on the exposure settings.

garry23


scrax

Quote from: Audionut on April 23, 2019, 01:59:34 AM
The changes aren't immediately visible in LV.  Requires half-shutter to see the exposure changes in LV.
Things work more smoothly in LV with 'Same TV curve' set to ON.  With Same TV curve set to OFF, I have to press half-shutter, release and press again fairly quickly, for the correct exposure settings to stick.


Seems tha don't work for 600D. I've set ISO range from 200 to 800 in the module, then set M to 3200 ISO and it never changes, in LV or Photo mode still 3200 even if halfshutter pressed.
Same for aperture range set from f4 to f16, on camera f22 and it never changes.
I'm using ML2.3 for photography with:
EOS 600DML | EOS 400Dplus | EOS 5D MLbeta5- EF 100mm f/2.8 USM Macro  - EF-S 17-85mm f4-5.6 IS USM - EF 70-200mm f/4 L USM - 580EXII - OsX, PS, LR, RawTherapee, LightZone -no video experience-

Walter Schulz

Expo override is off and it doesn't work outside LV, too?

scrax

Quote from: Walter Schulz on April 23, 2019, 09:25:47 AM
Expo override is off and it doesn't work outside LV, too?

Yes to both.
Will try with exp. over. ON now and report back

I've disabled clear override with halfshutter and now I can see it change shutter and iso but not aperture (with exp. over. OFF), I suppose I'm doing something wron in setting up properly the module...

In photo mode i can't "change" shutter time or ISO (they are reset by the module as soon as I've changed them, so this is ok)

Only thing that don't change now is Aperture (set at f16).
I'm using ML2.3 for photography with:
EOS 600DML | EOS 400Dplus | EOS 5D MLbeta5- EF 100mm f/2.8 USM Macro  - EF-S 17-85mm f4-5.6 IS USM - EF 70-200mm f/4 L USM - 580EXII - OsX, PS, LR, RawTherapee, LightZone -no video experience-

Walter Schulz

Just to be sure: You set ML to defaults before enabling autoexpo and haven't played around with Expo. Lock, ETTR ...?

scrax

Quote from: Walter Schulz on April 23, 2019, 09:54:31 AM
Just to be sure: You set ML to defaults before enabling autoexpo and haven't played around with Expo. Lock, ETTR ...?
I've tryed it on my usual config so yes played a lot  :P

Then backed it up and started with default settings (form ML and module too), works in LV but on photo mode not always (if I go to LV and back it start working in photo mode too, but if EV changes it keeps value for previous EV).

Need to make more test and find out if there is some setting that conflicts with it.

I'm using ML2.3 for photography with:
EOS 600DML | EOS 400Dplus | EOS 5D MLbeta5- EF 100mm f/2.8 USM Macro  - EF-S 17-85mm f4-5.6 IS USM - EF 70-200mm f/4 L USM - 580EXII - OsX, PS, LR, RawTherapee, LightZone -no video experience-

jerome_turmer

It works great on my 6D. It would be great to be able to set a maximum speed for cases when you use flash and need to keep the speed below flash sync speed.

Thanks for all your work!

Bests!

ncdog

The bitbucket link sadly doesnt work anymore. Anyone has a new link to download it ?
Would be really helpful to me!

Audionut

Which links were you after specifically. The pre-compiled module is available in the main ML downloads, the source code has moved over to here: https://foss.heptapod.net/magic-lantern/magic-lantern/-/tree/branch/unified/modules/autoexpo