Author Topic: [DONE] Method to lock auto-ISO value in manual mode  (Read 447 times)

GamerGuppy

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[DONE] Method to lock auto-ISO value in manual mode
« on: December 19, 2019, 03:09:46 PM »
Implemented via LUA: https://www.magiclantern.fm/forum/index.php?topic=24723.0



Hello! First of all, thanks for all you guys hard work! I've been shooting my Canon 7D for nearly 10 years now, and am a happy user of Magic Lantern for a year or two. Magic Lantern really breathed new life into my old device. I feel I am really missing one small yet essential feature. Almost all new Canon camera's these days are shipped with this feature too: the ability to lock exposure in manual mode with auto-iso enabled. This feature would greatly broaden the use-cases of the "auto exposure" and "exp. lock" modules as well.

TL:DR at the bottom.

MOTIVATIONS
I shoot a lot of indoor sport and theatre performances at my university. Performances can rapidly evolve in fast-paced dancing acts, requiring me to be able to quickly ramp-up shutter speeds to freeze motion. But the number of actors on stage, as well as their interaction with the background, fluctuates a lot too. Therefore I need control over the aperture too, as to determine the DOF. Light is constantly changing and actors on stage are unevenly lit, making auto-ISO a must to get a proper exposure quickly. Also, my clients as well as myself, do not really care about a little extra grain, as long as the motion was captured with little to no blur.

So that leaves me with one option: shooting manual with my camera set to auto-ISO. The problem is however, that I have no way to lock the exposure (ISO) in Manual mode and recompose. This way; whenever a black backdrop would form the center of my image, my image turns out overexposed due to auto-iso metering for the black backdrop. My sub-optimal solution right now, is to either shoot in full manual which results in many missed images since I am modifying my settings, or shoot in Tv mode and try to work around my small DOF (as chosen by the camera).

The absence of a proper AE-lock in manual mode is also the reason why I still occasionally use P-mode over the otherwise superior "auto exposure" module. The auto-exposure module is amazing as to prevent too slow shutterspeeds or too narrow DOF's. However, the module only works when the camera is in manual mode. Since manual mode does not allow exposure lock, it frequently messes up my exposure reading when recomposing my image.

SOLUTIONS
-> I can occasionally use my friends 7D mkII or my dad's RP. These camera's do allow AE-lock of the auto-ISO in manual mode. And this little feature triples my keeper-rate: just spot-meter for an actors face, hold AE-lock button, recompose and shoot. If this could be added to the (*) button it would be amazing. This could be implemented in two ways. Either a single press locks the current exposure values untill the next press. Or pressing the (*) button holds the values as long as you hold the (*) button. My preference would go to the first of these two methods.
-> The "exp. lock" module could be expanded to add this feature as an optional setting: just allow the user to click the "*" or e.g. the "set" button shortly to lock in their current shutterspeed, aperture & ISO value. When the user clicks the button again, the exposure will unlock and their camera will revert back to auto-ISO manual. Now the user can again point at e.g. a person's face as to read an exposure and obtain an ISO value. While pointing the camera at their main subject, the user can then just click the dedicated button again as to lock their exposure reading and modify the Aperture/Shutterspeed/ISO reciprocally again (just like the module does right now).

ALREADY ASKED FOR?
Another thread that asks for this feature:
https://www.magiclantern.fm/forum/index.php?topic=9650.0
Two other people that want this feature but worded their request a bit poorly:
https://www.magiclantern.fm/forum/index.php?topic=13435.0
Drfrogsplat gave an excellent motivation in this thread:
https://www.magiclantern.fm/forum/index.php?topic=2910.0
Someone that proposes the same solution as me:
https://www.magiclantern.fm/forum/index.php?topic=7929.0
Someone that also wants to engage/disengage exp. lock module on the fly:
https://www.magiclantern.fm/forum/index.php?topic=15294.0

TL:DR. If for artistic or practical reasons you need control over aperture and shutterspeed simultaneously, but don't care about introducing some extra grain. Then AE-lock for auto-iso in manual mode is an absolute must and therefore available on all newly released camera's.

Audionut

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Rules - please read before posting!

1. Check if the feature was already requested. Do not open duplicate threads.

Audionut

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