- Posts: 9
- Joined: Thu Aug 12, 2021 10:35 pm
- Real Name: Zack Birlew
BabsDoProd wrote:...I just can't reason why Blackmagic wouldn't have changed their current sensor filters to fix the one clearly visible flaw in their cameras. IR pollution and moire issues have plagued BMD since the beginning, why are they still going along with the same flawed sensor glass covers that don't do anything except to be dust covers?
Supposedly, it was explained back in 2012, as reported in other forum discussions. Though it’d be great if there’s a pinned official explanation.
To put it briefly, the design philosophy emphasized image sharpness, accepting moiré as a tradeoff, therefore disregarding OLPFs. And the sensor glass has mild IR attenuation in favor of letting the near-IR wavelengths reproduce what’s perceived by many as “great” skin tones.
Interestingly, even Arri – they officially state that they use OLPFs in all their cameras – use the same logic for IR filtration (https://www.arri.com/en/learn-help/tech ... ev-sensors), “Arri cameras use a high-end infrared (IR) and ultraviolet (UV) filter, which are custom designed to block enough of the spectrum to avoid false color effects … but that leaves enough of the near red spectrum to give skin tones a pleasant look.” At least their sensors’ IR filters seem to be doing a significantly better job.
I couldn’t agree with you more – an OLPF with strong IR filtration is a must for all video-focused and cinema cameras. Image sharpness, although crucial, shouldn’t come at the cost of spatial aliasing in the footage. And while a little bit near-IR wavelengths can be acceptable, it’s preferable to have a strong cut-off at a certain point beyond which the IR pollution cannot be mitigated well.
You’re not the only one puzzled by it. Here’s Newshooter’s Matthew Allard voicing the same thoughts – “I’m still perplexed as to why Blackmagic doesn’t include OLPFs in its cameras.” https://www.newsshooter.com/2020/07/17/ ... -thoughts/
Until BMD revise their design philosophy concerning OLPFs and IR filtration, I guess we have no option but to live with it.