Magic Lantern Forum

Hello,

I read trough http://acoutts.com/a1ex/dual_iso.pdf (http://acoutts.com/a1ex/dual_iso.pdf) and was wondering if it is technically possible to alternate ISO within one frame. If you shoot with a exposure time of 1/50 of a second, could you tweak the CMOS registers dynamically to have the first and last 1/10 of a second to be e.g. in ISO 100 and the in between 1/30 of a second in the ISO 400 mode, or is it only can be set before each frame? This way you could change the characteristics of the motion blur and kind of emulate the "tessive time filter" for a softer shutter look.

https://vimeo.com/46701641

EDIT: Oh gosh, I just realized how stupid this post was on so many levels. :D

ISO setting does not apply during exposure but only only during readout of the sensor, i.e. when the exposure is already finished.

I got something in that direction working while modifying two regs on my eosm:

MLV files(shortened):
https://bitbucket.org/Dannephoto/magic-lantern/downloads/half_iso.zip


adtg register 8183 set to 0x18b
(https://i.postimg.cc/ZKD5Nc5K/Screenshot-2019-02-27-at-11-03-08-png-scaled.png)

adtg register 8184 set to 0x1a7
(https://i.postimg.cc/0jXPpkxH/Screenshot-2019-02-27-at-11-03-01-png-scaled.png)

What camera do you have? If eosm I put in those two regs in crop mode sub menu. They are called reg_8183 and reg_8184. Can be used with rewired MC mode.
https://www.magiclantern.fm/forum/index.php?topic=9741.msg208959#msg208959

Unfortunately I have the 5Dmk3, not the eosm. So did you do the brightness alternation within one frame? My ultimate goal would be to be able to somehow lower the exposure/brightness at the beginning and End of the frametime (or increase it in the middle of the frametime). It does not have to be a gradual change but could just switch from two states. "darker / ⇢ bighter / ⇢ darker" That would be enough to modify the look of the motion blur.

Within one frame. You have the MLV files uploaded, trouble downloading?

Updated MLV files with below example as well:
https://bitbucket.org/Dannephoto/magic-lantern/downloads/half_iso.zip

By the way. Exact same registers can be tweaked on the 5DIII so if you mean business run adtg_gui module and tweak away.

This is also working:
(https://i.postimg.cc/9F8VQBLc/Screenshot-2019-02-27-at-13-51-27-png-scaled.png)

Quote of the Day!

Quote from: johannsebastianbach on February 27, 2019, 01:03:40 PM
Unfortunately I have the 5Dmk3, not the eosm.

Hahaha, missed that one.

Nice work @Danne and gotta love ur sense of humor @dfort!