Blackmagic Forum

I know the Blackmagic has a high dynamic range, but I've recently been playing with "HDR" techniques on a friend's stills camera, and on my iPhone. The technology (as I'm sure most of you are aware) takes three images with a normal exposure, an over and an under exposure, then analyses the image and takes the "best bits" of each to give extraordinary images.

These images are equally amazing in black and white, something I'm especially interested in as I'm shooting a black and white film soon - the type of results are demonstrated well here: http://www.denzomag.com/2010/09/black-and-white-hdr-photography-amazing-examples/

I'm presuming that as RAW retains so much information, it should be possible to do something similar with the Blackmagic and Da Vinci resolve. Has anyone experimented with this and do they have any idea how to do it with moving images using this workflow? Is it even possible and is there a straightforward way to do it?

Some of the RAW DNGs have been tweaked by some over on another site, using stills by John B and produced some nice subtle colour HDR effects taking a still and pushing the exposure both up and down then combining.. it might be a slow process (till a batch process comes along) but it might produce some interesting outcomes

http://www.bmcuser.com/showthread.php?5993-Pocket-Camera-RAW-now-testing/page6

second post by Razz16mm

HDR combines low dynamic range images to compose a high(er) dynamic range, e.g. using three images of 8 stops DR to produce one image spread over 20 stops DR. The BMD cameras have about 13 stops DR at best (that means: when exposed correctly), so that's still a large step up to "real" H(igh)DR. If you want to get the most out of it you should film in RAW, conserving 12 bits instead of only 10 in ProRes.

You can achieve an effect that's very close to HDR with the BMCC by importing the RAW DNGs into After Effects as a raw sequence. In the Adobe raw importer dialog you simply increase the exposure of the shadows to the maximum and decrease the exposure of the highlights to the minimum and voila... HDR.

The only issue with that method is that Adobe's raw processing is very inefficient at present (and as a result slow).

Aaron Scheiner wrote:You can achieve an effect that's very close to HDR with the BMCC by importing the RAW DNGs into After Effects as a raw sequence. In the Adobe raw importer dialog you simply increase the exposure of the shadows to the maximum and decrease the exposure of the highlights to the minimum and voila... HDR.

The only issue with that method is that Adobe's raw processing is very inefficient at present (and as a result slow).

There is another issue with ACR: because those settings are based on statistics derived from the histogram in shots were the histogram changes a lot the resulting image exposure is pumping like having used cheap auto-exposure.

Robert Niessner wrote:There is another issue with ACR: because those settings are based on statistics derived from the histogram in shots were the histogram changes a lot the resulting image exposure is pumping like having used cheap auto-exposure.

Are you sure about that, isnt it just if you use auto. If you ad lets say +10 in saturation, it will ad +10 to every frame no matter what it looked like from the beginning. In other words the oposite of auto.

I am 100% sure as I have several shots with that problem after developing in ACR.
ACR originally has been made for single photo development were that doesn't matter as it is just one single picture you take.

Settings like exposure, saturation, contrast, and curves are not statistics based - so those are pretty save to use.
Settings like shadows, highlights are heavily based on the histogram to determine which parts of the image should be adjusted.
I am not completely sure how the settings for Whites and Blacks work.

Aaron Scheiner wrote:You can achieve an effect that's very close to HDR with the BMCC by importing the RAW DNGs into After Effects as a raw sequence. In the Adobe raw importer dialog you simply increase the exposure of the shadows to the maximum and decrease the exposure of the highlights to the minimum and voila... HDR.

The only issue with that method is that Adobe's raw processing is very inefficient at present (and as a result slow).

Thanks but unfortunately I don't have After Effects - is it possible with either Motion and/or DaVinci Resolve?

Robert Niessner wrote:I am 100% sure as I have several shots with that problem after developing in ACR.
ACR originally has been made for single photo development were that doesn't matter as it is just one single picture you take.

Settings like exposure, saturation, contrast, and curves are not statistics based - so those are pretty save to use.
Settings like shadows, highlights are heavily based on the histogram to determine which parts of the image should be adjusted.
I am not completely sure how the settings for Whites and Blacks work.

Ok, just checking since I use ACR only and have yet done any adjustments that causes flickering.
But then again, I only use the once that I guess works, but I sometimes adjust the darks, shadows, mids and highlights without any problem so far.

Im doing some tests with B&W as we speak but I guess the clip Im using isnt enough to really push the histogram.

Try this: http://www.crumplepop.com/hdr-tone-mapping/

A lot of what is being described here is tone mapping - which ironically enough crushes the dynamic range of an image. Strictly speaking a HDR image is one which still has the large range of data - usually a 32 bit image.

A real HDR image looks normal on a normal monitor, but when the monitor displays black or white, there is still data there. Unless viewed on a HDR monitor (which do exist, but very expensive), they look like a normal photograph.

Its worth while making this distinction because in such applications as CGI, whereby 32 bit HDR environment maps are used, a tone mapped HDR image is useless - as it actually has lost its range. Its range has been shrunk into the LDR of a typical monitors range of reproduction.

You can tone map any image, with varying results obviously. But generally with most colour grading, its common to lift shadows or bright down highlights - so really most users will have done this with their camera already.