BMCP4K -Timelapses -Extending the OFF SPEED FRAME RATE range

Hello.

Blackmagic Pocket 4K and 6K cameras have the ability to perform timelaps. I often took them but only with a Canon camera. I decided to use a Pocket 4K camera this time. Everything is ok, it even works very well, but I have a serious problem with the range of frames in the "OFF SPEED FRAME RATE" option. The smallest number of frames is 5fps. To be honest, this is too low to capture great night time timelapse shots. The TIME TRIALS or LIGHT TRIALS effect cannot be captured. Blurring lights or achieving a "blur" effect is not possible at 5 frames. This greatly limits the possibility of taking better shots, especially at night. Limiting the range only between 5-60fps is much too small.

My suggestion is that Blackmagic, bends over this issue and extends the time range to at least 1fps or even longer, e.g. to 0,5", 1", 2",3" and 5" seconds. BULB mode is not so necessary but the possibility of exposure for a long time would be very helpful. In my opinion, the TIMELAPSE function is currently very limited. I hope it doesn't go beyond technical possibilities and that it could be done in next system updates.

Would I just wish it or would there be other users who would support me?

Best wishes. Chris.

Hi!
I could have copied Krzysztof Sobieranski's request...Identical experience with Canon and satisfied with the BMPCC 4k, but being able to manage timelapse and night video, extending the shutter speed beyond this limit, would be another reason for new Blackmagic enthusiasts ...
(having also worked with the MagicLantern software on Canon 5D mkII, I think it's not even a problem ...)
Highly hoping for the next update!
Thank you,

Massimo Santopaolo

great idea! waiting for answer Blackmagic

[Brendan Dower]

Hi Krzysztof,

Unfortunately, the 5fps off-speed frame rate is a hardware limitation of the cinema camera and is not something that can be changed.

When taking any long-exposure images such as what you describe here, noise is introduced into the sensor which can compromise quality. With still images, this isn't too much of an issue because DSLRs can apply time-consuming noise reduction processing on a still image. They do this by taking an additional dark photo and using that still image as a basis for this processing. This is why it takes a long time to process a long-exposure still image - it's essentially taking 2 long-exposure images. And your camera is completely unresponsive during this time.

Unfortunately, with a video device, this isn't really feasible. The video device will be continuously capturing video frames and is unable to stop the camera for time-consuming processing that is possible with still images.

Sorry if this isn't the answer you were hoping for, but I hope this helps to explain why.

Now that you got it officially what I already assumed in the other thread, let's talk about the competition. Red is only going to one fps (and some are complaining about that), but they play a nice trick in-camera by averaging over 16 frames (max). This is getting you much cleaner images since it works pretty much like a temporal NR as long as nothing moves, the single frames at 1 fps are really noisy.

I'm not sure BM can do this in-camera, depending on hardware. But you can definitely do it in post. After Effects has a filter called Wide Time, which works nicely for me (albeit slow). Boris Sapphire has S_TimeAverage which has more possibilities in combination with Mocha, but you'll need a fast CUDA card.

Chris,
I've read your topic, and I'm not sure if you talking about the right thing.

When you going to perform a Timelapse, leave your project frame rate to your final Timeline FPS. 25/30 or so. Ignore the off speed frame rate option in this case.

Got to the main Menu - switch to page 2.
Here you can find a separate Timelapse option. You be able to go down to 1 frame or even seconds. When you need long exposures set your shutter to 360 degrees.

Patrick

Exposure doesn't get longer than 1/5th of a second.
BTW, you are lucky, a UMP G1 is doing nothing longer than 1/12th and it seems that it is not even doing full 360 degrees, more like 358.

Here's something I think might work, have yet to try.

Capture your footage at 24 fps with a 360 degree shutter angle, best to have the camera on a fixed tripod. In DaVinci Resolve, stack up 12 copies of this with each track offset by exactly one frame in the same direction relative to the track below. Blend these tracks together with equal weighting. Then retime the result to 24x speed.

Hi Krzysztof,

Unfortunately, the 5fps off-speed frame rate is a hardware limitation of the cinema camera and is not something that can be changed.

When taking any long-exposure images such as what you describe here, noise is introduced into the sensor which can compromise quality. With still images, this isn't too much of an issue because DSLRs can apply time-consuming noise reduction processing on a still image. They do this by taking an additional dark photo and using that still image as a basis for this processing. This is why it takes a long time to process a long-exposure still image - it's essentially taking 2 long-exposure images. And your camera is completely unresponsive during this time.

Unfortunately, with a video device, this isn't really feasible. The video device will be continuously capturing video frames and is unable to stop the camera for time-consuming processing that is possible with still images.

Sorry if this isn't the answer you were hoping for, but I hope this helps to explain why.

Thank you for a thorough explanation of the subject. Well, since it is a technical limitation, there is no point in continuing. It's a pity, but at least now i have a calm head. Thanks.

Thank you for clarifying the topic.