Blackmagic Forum

Sorry if this has been asked before but can Blackmagic retrofit an OLPF to a non-OLPF Ursa Mini 12K? And does anybody have an indication of cost for that?

Many thanks.

Last I heard: yes.
$650 for the swap.
~10 days in shop.

That is not too bad. Thank you Adam.

one thing I'd like to see is:
Ursa Mini 12k OLPF
vs
Ursa Mini 12k Rawlite OLPF

I had a Rawlite installed in my old 12k, but I sold it during a big lull in work. I'm curious as the price for used 12ks is fairly cheaper than the OLPF version...

For what it may be worth: I have had an original 12K for several years and have not had any problems with moire. Maybe some lenses would cause issues... I have used Sigma 20mm, Irix 45mm, Tokina 100mm Macro and 25-75mm zoom, Zeiss Otus 28mm, and Arles 35mm and 180mm on this camera with no moire issues.

That said, I can create moire patterns intentionally, especially with the Otus... but can also avoid them with several techniques. (Note that this moire would likely not be eliminated by an OLPF.)

I believe that the high density of the photosites makes this sensor less prone to moire... maybe why the Cine 12K includes an OLPF.

Some things to try to reduce or eliminate moire:
lens with less resolving power than sensor
diffusion filter (such as pro-mist)
controlled focus (maybe including larger aperture)... softer focus where suspect patterns are in subject
use a smaller aperture (sort of opposing twin of controlled focus)
adjust camera angle to the offending subject
at times a polarizing filter can help

Jeffrey D Mathias wrote:… Some things to try to reduce or eliminate moire:
…adjust camera angle to the offending subject…

Even with the larger photosites on the UM4.6K, I rarely experienced moiré except for the audio monitors set on stage for the music performers. I finally mentioned to the audio tech to set them at a slightly different angle to my camera and voilá, no moire since then. The monitors have a mesh portion that reflected the stage lights and caused the moiré.

You can provoke some moiré even on an Arri.
When we tested the original 12K for "Digital Production" (Munich), we could only spot some on test patterns with the sharpest lens around at its best aperture. IIRC, that was a Leica cine prime.
I'd say that with the 12K you will normally not have such issues, as long as you don't work with virtual environments using LED walls. I'd assume BM introduced the OLPF version just because of that.

I’ve had a similar experience — even without the OLPF the Ursa Mini 12K rarely exhibited moire and as others have noted, relatively minor adjustments are often enough to remedy when it does appear.

However, I still chose to add an OLPF to my Ursa Mini 12K because the OLPF (whether by BMD or the one from Rawlight) has better IR filtering than the IR filter that ships with the original non-OLPF version of the Ursa Mini 12K.

Moiré can be provoked even where there is no camera in use, a veil, a curtain, a window screen, a fence. All you need is interference.