ASA Values

[Charles_Boileau]

Hi Again,

Another question. And again each time I searched ASA on the forum nothing would turn up.

I see there is a thread discussing ASA vs DB. But what ASA values can we set the Red Cam to.

Can we go as low as 50? as high as 3200?

Thanks

[Stephen Williams]

Hi,

It's native about 320 - 500 asa.

Set it to 50 asa and you risk blowing out your highlights, 3200 will be noisier as the raw images are boosted.

Stephen

[Charles_Boileau]

Ok but can you change the ASA value or is it stuck on 320?

[Chris Kenny]

Ok but can you change the ASA value or is it stuck on 320?

The sensitivity of the sensor is what it is. You can artificially lower the ASA, at the cost of dynamic range, or artificially boost it, at the cost of higher noise. This is true of any sensor.

Some cameras have adjustable analog gain. Red is somewhat unusual in that uses exclusively digital gain. Because of that fact, and the fact that it shoots RAW, the ASA you set on camera doesn't actually change the data that gets captured -- it just changes the way the image looks on the live video taps and it goes into the post pipeline as metadata.

[nawaf65095]

So now Can i shoot without noise when lowering the ASA? Same any Cinema Camera??

[donatello b]

think of RED as ASA 500 film - you don't really get lower grain or better blacks if you shoot it at ASA 50 ... you do get little better blacks at ASA 320 ...

[Chris Kenny]

So now Can i shoot without noise when lowering the ASA? Same any Cinema Camera??

From what I've seen, Red footage already looks basically noise-free at 320. Going lower should reduce noise even more, but your highlights will clip sooner.

[Rob Lohman]

without noise....Same any Cinema Camera??

There's always noise (or grain). As indicated above, changing ASA on the camera is a DIGITAL POST gain. The value is stored in the metadata and the post software automatically applies it and you can reverse that.

But when you change the ASA on the camera (which also influences the monitor path, of course) you run the risk of loosing information (since you're adjusting what you're seeing)