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Author Topic: Why no digital ND filter in DSLR's?  (Read 10321 times)

lensfactory

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Why no digital ND filter in DSLR's?
« Reply #20 on: June 24, 2009, 10:00:43 pm »

Quote from: DarkPenguin
What are you looking for?  A jpeg mode that does this?  Otherwise you have it with raw.  Just over expose by 3-4 stops.  Develop appropriately.  Your DR will be greatly reduced but that's how sensors work.
Huh? Im talking about getting proper exposure...not some blown out mess by overexposing by 3-4 stops. Shooting RAW doesn't allow you to shoot 3 stops over.
It's simple...a digital ND filter built into the camera or rather, the digital equivalent.....ISO expansion. The 'true' ISO is not really lower...same as Canon DSLR's now with their ISO 50 setting. Only multiply that times four...y'dig?
Perhaps you don't see a use for this....but I'd love to shoot longer time exposures in broad daylight, or shoot at F1.4.
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DarkPenguin

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Why no digital ND filter in DSLR's?
« Reply #21 on: June 24, 2009, 11:15:57 pm »

You can't figure that out?  Really?
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AJSJones

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Why no digital ND filter in DSLR's?
« Reply #22 on: June 24, 2009, 11:46:35 pm »

Quote from: lensfactory
Huh? Im talking about getting proper exposure...not some blown out mess by overexposing by 3-4 stops. Shooting RAW doesn't allow you to shoot 3 stops over.
It's simple...a digital ND filter built into the camera or rather, the digital equivalent.....ISO expansion. The 'true' ISO is not really lower...same as Canon DSLR's now with their ISO 50 setting. Only multiply that times four...y'dig?
Perhaps you don't see a use for this....but I'd love to shoot longer time exposures in broad daylight, or shoot at F1.4.

The system does not become digital until the image data are read from the sensor - by which time the sensels have been overflowing for some time and most of the image will already be blown out     They could overlay a simple LCD on top of the AAfilter assembly that would be a variable gray ND, but it would be a bit costly
« Last Edit: June 24, 2009, 11:47:14 pm by AJSJones »
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Panopeeper

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Why no digital ND filter in DSLR's?
« Reply #23 on: June 25, 2009, 11:34:27 am »

Quote from: lensfactory
It's simple...a digital ND filter built into the camera or rather, the digital equivalent.....ISO expansion. The 'true' ISO is not really lower...same as Canon DSLR's now with their ISO 50 setting. Only multiply that times four...y'dig?
The Canon DSLRs with their ISO 50 setting are plainly overexposing the shot; the same with ISO 100 on some Nikons. That is not what you are looking for.

I guess it could be done, but at a very high price. The sensels would have to be read several times during the exposure and those, which reached a certain saturation level, would have to be reset (and that fact would have to be recorded). However, the electronics on the sensor chip would have to be much more complex than it is now: resetting individual sensels is not in the cards by the row or column oriented processes.

This way practically unlimited exposure could be realized. Dynamic range 15 EV, 20 EV, 30 EV - how about that?
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Gabor
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