johnnydecimal wrote:robedge wrote:Don't Be Confused - Adjusting Exposure in the Blackmagic Camera App
Note that if your shutter speed is locked – and in what situation is it not? – the +/- button turns in to pure ISO control.
A bit of a weird button to be sure.
The real problem is, that when shutter speed is locked,ISO also seems to be locked (completely unnecessary unless specifically required). Display does NOT show ISO locked, but the value does stay at the value used, when speed is locked (in order to - for example - set 25fps and 1/50 shutter or 180 degrees).
This rather severe “side effect” still exists in version 1.3.00111 (also found in 1.2.10033).
This effect does NOT exist in Cinema P3 Pro.
Example: Point x1 lens towards light. Set 25fps and 1/50 sec (or your personal preference). Lock shutter speed. ISO will (most probable) show 55 ISO (or some other low value). Now cover all lenses (ISO should shoot to maximum).
On BlackMagic camera ISO stays at 55 (or your initial low value, instead of reaching maximum).
On Cinema P3 Pro camera ISO reaches maximum in the same situation (Shutter Priority).
In real life, it’s rather nice, that ISO reflects conditions during use - not only condition, when shutter speed was locked. On walkabouts, where conditions cannot be controlled, this may actually have some importance for the outcome.
Let’s say, you lock the shutter speed at 1/50s inside a café, after paying the bill, preparing to leave and enter pulsating outside life. ISO defaults to somewhere between 1000 and 2000 if you do it in a dark(ish) corner. Now you go outside, start recording. ALL highlights are completely blown in the noon sun.
Doesn’t happen with Cinema P3 Pro (Shutter Priority).
Personally I find the “auto ISO” valuable in a lot of reportage (and some Travel) like situations.
Regards