shutter instead of ND?

[Johan Pabon]

Today I made some slowmotions using the only ND filter I have: 0.6 ND.
When recording at normal speed (25) I forgot to put the shutter back to 50.
The shootings look good which gives me following question: Why not use the shutter to regulate the amount of light?

[Raul Gonzo]

Corrected below.

[Julio Quintana]

Shutter can not change the amount of light in your raw file like an ND or closing the iris.

Uh, yes it can. The reason people typically do not change the shutter angle to control exposure is that it changes the look of the motion. Fast shutter angle = Saving Private Ryan. Slow shutter angle = Miami Vice.

[Brandon Fraley]

Shutter can not change the amount of light in your raw file like an ND or closing the iris.

it certainly does change the amount of light in your RAW file. Your choice of shutter is burned into your footage, it's not metadata that can be changed later. I've heard the shutter controls referred to as "the Poor Man's ND". If you're in a pinch, you can increase the shutter angle and to decrease the amount of light hitting the sensor, but it will change the look of the motion in your footage. Sometimes this if fine, or preferred, but other times it can be very distracting.

[Raul Gonzo]

Ha, I thought about that after I said it. Thanks Julio!

[David Mullen ASC]

Depends on the amount of motion in a scene. I recall a James Bond movie ("View to a Kill" I think) where they must have closed the shutter a little in bright sunshine, and some horses were galloping by the shot and strobing badly. So generally you would avoid short shutter speeds outdoors unless you wanted more motion strobe.

[Jeff Kilgroe]

Also be aware that on the RED One (and pretty much any other CMOS camera) the read reset times of the sensor are constant. So by decreasing the exposure time (faster shutter speed), you can exaggerate the "rolling shutter" skew effect. This happens due to the decreased overall exposure time relative to the CMOS reset time and also due to the reduction of motion blur, which normally softens the skew effect somewhat.

Typically, your motion will become extremely stuttery or stacato or will strobe severely before the annoying skew effect takes over. But just something to keep in mind if you start to really use faster shutter speeds / shorter exposures.

[Johan Pabon]

Okay, everything you describe happens in a very slight way indeed because the movements are not that fast. There also seems to be some inteferention in some shots, whereas the slowmo's are great.
Thanks for all your comments on the question.

[Johan Pabon]

Uh, yes it can. The reason people typically do not change the shutter angle to control exposure is that it changes the look of the motion. Fast shutter angle = Saving Private Ryan. Slow shutter angle = Miami Vice.

Do you know which shutter speed they use?

[Brandon Fraley]

Not specifically, but 45deg is standard for the "Saving Private Ryan" look, and Michael Mann shootis a lot with a 360deg shutter, which a lot of people here, myself included, think ruins the cinematic look, but if you need the extra light it's there.