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Sensors with adjustable sensitivity?

Mark K.

Mark K.

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Having recently reviewed the video capabilities of Nikon's new D90 DSLR, one element of that camera's abilities really struck me - that is, adjustable sensitivity.

The camera has an ISO range of 200-3200 for shooting video, which gives you an awful lot of flexibility for your shooting. And even at the highest ISO settings, noise and overall IQ remain good.

Now my understanding of the R1 is that sensitivity is fixed (at ISO 250-320 depending on who you talk to). So I'm wondering whether the flexibility that these new DSLRs offer, in terms of sensitivity, could be transferred into the new Epic and Scarlet cameras?

Thoughts?
 
Fredrik Harreschou said:
I had a similar question some time ago. Graeme responded, post #6.
http://www.reduser.net/forum/showthread.php?t=5242
Click to expand...

Very interesting, I was quite surprised by the replies you got Fredrik. I've never heard of pushing an exposure by multiple stops, yielding better results than shooting at a higher gain in the first place before.

I wonder how far the technology has come since then. Increasing the analog gain on the D90 certainly seemed to turn in impressive results even at the highest sensitivities.

It's one area of the new cameras that I hope leans more towards the still-camera side of the equation. Having the flexibility to shoot between ISO 200-3200 natively (like a regular DSLR) would certainly be appealing. And it's one element of the cameras that (given their intention to be used as still cameras in additional to motion-pictures) I assume will be possible. (if you can adjust the sensitivity for still images, why not motion ones as well?)
 
Yes, it is interesting. Just remember that the thread is a year old. Things could have changed since then. Maybe Mysterium-X or Monstro will be different. I would love ASA 100 (or 50) for outdoors shooting. And very usable ASA 2000...
 
The sensor is fixed sensitivity. To reduce that sensitivity, you can ND, or you can reduce analogue gain into the A-to-D. Similarly to boost the sensitivity, you can boost the electronic gain.

Now....

You really have to options on boosting sensitivity, but both involve gain. You can gain up the analogue before digitization, or do it afterwards with digital gain.

The digital gain method uses the full dynamic range of that which was recorded. The analogue gain method throws away a stop at the bright end for every stop you gain up. With digital, you can either throw away that stop, or put in a curve and get a nice highlight roll-off.

Some cameras look better on analogue gain. Some look better on digital gain.

Graeme
 
Now you're asking detailed questions about announced, but not quite finished products. Ask again later...

Graeme
 
...shoe drops...
Red does Digital gain post side, but has room for analogue gain as well I would think.

Nothing wrong with a little bit of analogue gain if you don't mind throwing away a known amount of highlight material and/or the scene is low contrast and has little to no highlight material to throw away, think underwater/ fog or overcast dusk scene. Am I wrong? Noise introduced through gain would have to be balanced against noise in underexposed parts of the frame I would think.

Any thoughts?
 
You end up just trading digital noise for analogue noise and loosing a stop in the hightlight into the bargain.

Graeme
 
Well Ok then! No analogue gain or us.
Thanks for the quick reply.
 
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