Blackmagic Forum

How bad is CMOS Blooming in properly exposed images shot with the Pocket Cinema Camera 6k at 400 - 1000 ISO?

Comparison between the 6k Pro and the GH6 at 8:50.

Lyn, it is strongly recommended not to shoot any of the current BMD Pocket cameras with ISO 1000. That is the upper end of the ISO 400 base range of the Dual ISO range sensor. You will get much less noise shooting ISO 1250 compared to ISO 1000. ISO 1250 is the lower end of the ISO 3200 upper range.

I use the BMPCC4K so I’ll let someone with the BMPCC6K Pro comment on blooming.

Apart from the ill-advised iso 1000 (and his workflow is not well explained), you're dealing with inexpensive cameras which perform remarkably well in most situations, but don't perform faultlessly in extreme situations.

If your work demands more, then rent. Otherwise, be assured, no movie ever failed thanks to blooming.

rick.lang wrote:Lyn, it is strongly recommended not to shoot any of the current BMD Pocket cameras with ISO 1000. That is the upper end of the ISO 400 base range of the Dual ISO range sensor. You will get much less noise shooting ISO 1250 compared to ISO 1000. ISO 1250 is the lower end of the ISO 3200 upper range.

I use the BMPCC4K so I’ll let someone with the BMPCC6K Pro comment on blooming.

Thanks, Rick. I have not had any problems out of my BMPCC4k, but I have been thinking about getting the BMPCC6k G2. I remember reading about the blooming issue a couple years back.

I couldn't reproduce it on the P4k, but I have seen it on the Lumix GH6.

Lyn Collins wrote:

rick.lang wrote:… I have been thinking about getting the BMPCC6k G2...

Me too because I don’t need the built-in ND. But if I did, I’d pair BMPCC6K G2 with the convenience of the BMEVF for use outdoors. The BMPCC6K Pro with the 1500 nits screen could work outdoors by itself.

I've never seen blooming or smear on the 6K and the G2 has exactly the same sensor. Without the internal ND, there's even one optical element less to contribute to flaws, like interior reflections.

I want blooming and smearing as it's 'cinematic'

Well, if a digital sensor did this:



you'd get 2000 hysterical youtubes. And yet people pay good money to emulate it. Every comprehensive film emulation package has an halation/bloom effect.

Nobody bothered to do this kind of analysis for film -- halation will destroy your happiness and ruin your movies! -- because there was no choice. But it also never occurred to anyone that movies would be "better" if you somehow eliminated photochemical and projection artifacts. There were evangelists for high frame rate projection (in the analog realm), but we saw where that went.....

Now there are two opposite schools: youtubers who live to point out sensor defects, and film emulators seeking to reintroduce photochemical defects. It doesn't look like they'll ever get together.

Well said, John!

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John Paines wrote:Apart from the ill-advised iso 1000 (and his workflow is not well explained), you're dealing with inexpensive cameras which perform remarkably well in most situations, but don't perform faultlessly in extreme situations.

If your work demands more, then rent. Otherwise, be assured, no movie ever failed thanks to blooming.

Thanks, John. I do understand what you mean. I also agree that his workflow was not well defined. I am interested in a more practical sense. I should have been more clear.

So, in short: stop worrying and start shooting!

Uli Plank wrote:So, in short: stop worrying and start shooting!

lol. Yes, indeed. I was just about to thank you for your earlier post.