Blackmagic Pocket Cinema Camera 4K

[Slothorp]

I dit another test with a simple domestic RGB led (hence the flickering) to show how the BMPCC4K reacts in the red channel, both in raw and prores. With other colors, when overexposed, there is a gentle roll-off, but in the red, it clips with a very harsh way, and a strange color shifting. There is also much more noise in the reds. 

 

[tonysss]

Red channel also flashes more... , I'm afraid that this is a chip or hardware problem and that it will not solve fw. much ?

[MattH]

ISO 1250 is the WORST iso to choose to test the red clipping issue.    It is pulled 3200 iso, so even properly exposed it only has 2.3 stops of latitude above middle grey.  So of course the highlights will clip and look shitty.  ISO 1250 will be the number one noob trap on this camera.

Im more worried about the wide angle lens blurryness.  Yes, lenses have field curvature that is more aparent wide open and yes the Pocket 4k has a wider field of view that shows more of it, but that alone doesn't account for what the examples in that thread show.  It must be the sensor stack thickness also.  If stopping down to 2.8 doesnt resolve that issue then that is going to be a way bigger deal breaker than red clipping.

[Slothorp]

Well, if you don't want to show the red clipping, by preventing it with your exposure, you can. It is not the purpose of this test. The purpose is to show how the camera reacts specifically in the red channel, by comparison with other colors (and the problem is still there at 3200 iso). And I find it problematic in some situations : a night street scene, with its many red car lights will cause many problems, with disturbing hyper saturated  red blotches all over your image (whereas the greens, the blue and the yellow react normally). You can bypass it if you shoot in raw, but it will affect the entire image if you shoot in prores. 

[DBounce]

25 minutes ago, Slothorp said:

Well, if you don't want to show the red clipping, by preventing it with your exposure, you can. It is not the purpose of this test. The purpose is to show how the camera reacts specifically in the red channel, by comparison with other colors (and the problem is still there at 3200 iso). And I find it problematic in some situations : a night street scene, with its many red car lights will cause many problems, with disturbing hyper saturated  red blotches all over your image (whereas the greens, the blue and the yellow react normally). You can bypass it if you shoot in raw, but it will affect the entire image if you shoot in prores. 

It will definitely be a problem if you ever shoot scenes with neon signs.

[photographer-at-large]

4 hours ago, TILT said:

Did you set infinity focus on the Viltrox, that could be the issue. You need to turn the optical element inside to make sure infinity focus is correct. I have the Nikon Version and no problem on a Pana M43. Still waiting the BMPCC4k to try it on though. Maybe the Viltrox covers the sensor a bit too much. Their factor is wrong it is not 0.72x but a little bit more.

Would you know if the Canon version works this way as well?

[Shirozina]

32 minutes ago, photographer-at-large said:

Would you know if the Canon version works this way as well?

All focal reducers have this adjustment.

[TurboRat]

3 hours ago, Slothorp said:

I dit another test with a simple domestic RGB led (hence the flickering) to show how the BMPCC4K reacts in the red channel, both in raw and prores. With other colors, when overexposed, there is a gentle roll-off, but in the red, it clips with a very harsh way, and a strange color shifting. There is also much more noise in the reds. 

 

Yeah I think I saw some night shots with the red lights on the cars clipping but didn't see the noise. On your test the sudden noise was quite distracting. Hope Blackmagic addresses this

Looks like the stronger red lights have a tendency to get clipped:

https://www.youtube.com/watch?v=54153YyAUVY

 

[webrunner5]

Well instead of Black Hole Sun we now have Red Hole Sun. Damn now Every video, or shot I look at I am looking for it. It just F ing ruins the viewing experience of it now.

[JordanWright]

A few people over at bmcuser are complaining that batteries are getting stuck inside the P4k

[webrunner5]

Just now, JordanWright said:

A few people over at bmcuser are complaining that batteries are getting stuck inside the P4k

Now that would be fun on a paid shoot.

[jagnje]

I think the red clipping has beed adressed somewhat already.

quoted, not my words.

"The overexposed super saturated LEDs are clipping the gamut. This will happen with Gen 4 on 4.6K too. You can reduce the issue by soft clipping the gamut using the colour space transform Resolve FX plugin. Here I am using the Broadcast gamut because the Pocket 4K option isn't in the colour space transform plugin at this time but they are actually the same gamut/primaries anyway."

 

Give it a shot, to see if it helps, this interests me as well.

Best regards

[mnewxcv]

4 minutes ago, jagnje said:

I think the red clipping has beed adressed somewhat already.

 

quoted, not my words.

"The overexposed super saturated LEDs are clipping the gamut. This will happen with Gen 4 on 4.6K too. You can reduce the issue by soft clipping the gamut using the colour space transform Resolve FX plugin. Here I am using the Broadcast gamut because the Pocket 4K option isn't in the colour space transform plugin at this time but they are actually the same gamut/primaries anyway."

 

Give it a shot, to see if it helps, this interests me as well.

Best regards

would be good to see a before and after.

[Slothorp]

I have already tested this method. It works very well as far as you manipulate raw files. It desaturates the reds, providing some high light roll off without touching the rest of the image. 
But it is more difficult with prores files, because it can slightly desaturate not only the reds but also some other parts of the image, including skin tones. And it is worse with files recorded with a baked lut. 

[jagnje]

The user says that it happens with Ursa 4.6 as well...I have shot tons of footage with it and have not noticed it yet, so maybe it`s not that big of a deal. But then again I didn`t shoot that much ultra saturated reds.

[Andrew Reid]

Does it clip the blues as well?

[Slothorp]

I have never used an Ursa, so I don't know, but I believe it's true, coming from Captain Hook own's words. Concerning the BMPCC4K, once you spot it one time, yo can see it in every night city scenes. Maybe you don't notice it on youtube, but on a big screen, it's very disturbing. 

 

6 minutes ago, Andrew Reid said:

Does it clip the blues as well?

No, the blues are much better handled. 

[Deadcode]

4 hours ago, Slothorp said:

I dit another test with a simple domestic RGB led (hence the flickering) to show how the BMPCC4K reacts in the red channel, both in raw and prores. With other colors, when overexposed, there is a gentle roll-off, but in the red, it clips with a very harsh way, and a strange color shifting. There is also much more noise in the reds. 

 

Could you please upload few DNG from the video above?

[Slothorp]

Later in the evening, yes. 

You can also download a prores file from my previous test here : 

 

[Deadcode]

9 minutes ago, Slothorp said:

Later in the evening, yes. 

You can also download a prores file from my previous test here :

 

The prores is already clipped. RAW is cannot be clipped, because gamut is chosen in the post process. And i think this is the same problem what we already saw with sony cameras.

Probably the raw is perfectly fine with proper post processing. It should be. I hope so.