Solutions for moire and IR contamination?
 

I was looking at getting 2 Hoya IR Cut filters (my lenses have different thread sizes, unfortunately) to safeguard against IR contamination. But I’m also concerned about possible moire, as I’ll be filming kitchen staff who wear pants with those fine check patterns. I noticed that a company called RAWLITE make an OLPF which they claim also cuts IR (sort of a “two-for-one” solution). They have one for the “BMPCC”, but I’m not sure if they’re talking about a much older version of the camera.

Has anyone used one of these on a 4K or 6K camera?

https://rawlite.com/olpf-bmpcc-bmmcc-bmcc-2-5k/

Re: Solutions for moire and IR contamination?
 

So, I emailed Hans at the Rawlite company and he said that they're currently looking into whether the BMPCC 6K needs an OLPF and whether it's possible to implement one in this model.

He also asked me why I thought it needed one (I guess he wants to survey more people before he decides if they'll produce one or not).

My rationale is based on a link provided by Brian Drysdale on another thread (one of the Ryan threads) to the ProVideoCoalition website where they tested the BMPCC 6K:

https://www.provideocoalition.com/re...gic-pocket-6k/

The article mentioned a "horrendous" amount of IR interference when they used their ND filter. Plus they mentioned "a bit of moire in certain situations".

That comment about the moire is what concerned me the most. Because I'll be filming a LOT of scenes with actors wearing those fine check pants! And I'd rather buy an OLPF filter as a precaution than run the risk of having to fix all of those shots in post if there are moire problems.

But it seems that I might be the only one asking for it. So I'll probably go ahead and buy those two IR Cut filters. And cross my fingers on the moire aspect!

Re: Solutions for moire and IR contamination?
 

Shortly after I posted that, I received another reply from Hans which said, "You are certainly not the only one asking for an OLPF for the BMPCC 6K."

He also gave some great info about the IR Cut: "Like all our OLPF’s we would add a very effective IR-cut coating."

They are still investigating whether it's going to be feasible, of course.

He also gave some good info on the need for an OLPF: "Without OLPF moiré will occur with certain frequencies of detail."

I certainly hope they do make one and that it's ready by November (when I'll be filming those fine check pants)!

Re: Solutions for moire and IR contamination?
 

I received an email from Rawlite about their new OLPF for the Pocket 6K. I'm not looking to get one at the moment but, for any Pocket 6K owners who might need this, here's their webpage link:

https://rawlite.com/olpf-for-blackma...ema-camera-6k/

Re: Solutions for moire and IR contamination?
 

Might be worth checking to see if Mosaic Engineering is doing anything. They have done some pretty neat filters for Canon 5D's in the past. They also list the Blackmagic Ursa Mini 4K & 4.6K and Ursa Mini Pro 4.6K as having anti-moire filters available.

Check this video:


and here is their site:

Mosaic Engineering Home

Chris Young