PDA

View Full Version : Question about OPLF for Helium Sensor



Anton Esteban
12-13-2016, 07:17 PM
I have a question about the Helium sensor and the RED OPLF system. Did RED develop a new OPLF for the Helium sensor or is RED Recycling what it developed for the Dragon sensor. Sueely if the Helium sensor is more sensitive than the Dragon sensor and has properties unique to it, the Helium sensor would need its own specialy tuned OPLF. Does anyone know the answer to this question?

Phil Holland
12-13-2016, 08:27 PM
There are various things going on here. What is sensor specific is the crystal that provides the birefringence for each sensor. This is now moved to the coverglass. That low pass/anti-alias effect is tuned to the sensor technology's unique pixel size.

What's left in the OLPF (which is now an inherited term really) is the various coatings and layers that provide filtration fir cutting or absorbing things like Infrared and Ultraviolet light as well as different levels of anti-reflection coatings.

The sensor has an underlaying calibration that is tuned to each OLPFs unique properties to produce consistent color.

That all said, RED could certainly develop new OLPFs, but the ones we have today work well on Dragon and Helium.

Anton Esteban
12-14-2016, 02:38 AM
Thanks for the quick reply Phil. Reusing the coatings to help control ultraviolet and infrared light make total sense. But the standard and skin tone highlight OPLF's have inherent biases towards blue/cyan at different strengths. I wonder if those dyes need to be recalibrated to get the best out of the HELIUM sensor for even greater color fidelity. Recycling the OPLFs makes total sense from a business perspective but I wonder how much a new specialized OPLF would help. I've read, for example, that Panavision is developing its own OPLF for its dragon based camera.

I've noticed my Helium weapon clips highlights in a certain way which doesn't always look as pleasing as the way my dragon handled the same clipping. I was thinking a newly developed standard or skin tone OPLF might help this especially since the Helium sensor can handle larger iso's in a much cleaner fashion.

John Marchant
12-14-2016, 01:45 PM
I would hesitate to call it recycling. Colour separation filter design and bayer filter design are integrated, so there's no compromise in helium using the prior 'OLPF' - and as Phil says it's really not an OLPF we're discussing any more, but its a handy tag to continue with. Red aren't taking shortcuts here :)

There are a raft of regular options in place, which is more than other manufacturers do in this one regard... Now I would say this, but if you're looking for yet more, third parties are the place to look IMO.

Michael Lindsay
12-14-2016, 01:57 PM
I do think we should call the swappable filter stack something other than a OLPF... the convienance is not worth the confusion imho

Anton Esteban
12-14-2016, 06:47 PM
Ok that makes total sense. John, on a total different tangent, I purchased a couple of Kippertie OPLF's for my 2 Dragons but now that I'm slowly replacing them for Weapon's I was wondering if you'd ever do some kind of swap or upgrade program? I love them but its a bummer that I have to buy new ones.

Minu Park
12-14-2016, 08:24 PM
I am just wondering, whether these OLPFs are optimized for Helium sensor in the beginning....

Michael Lindsay
12-17-2016, 03:31 AM
Hey Anton which ones do you have?


Ok that makes total sense. John, on a total different tangent, I purchased a couple of Kippertie OPLF's for my 2 Dragons but now that I'm slowly replacing them for Weapon's I was wondering if you'd ever do some kind of swap or upgrade program? I love them but its a bummer that I have to buy new ones.