SHUTTER SPEEDS AND SHUTTER ANGLE OPTIONS

An advantage to digital video cameras that I have found over most film cameras, is the ability to "drag" the shutter to induce motion blur, as you might in a still camera image, but this is also excellent for obscuring any "jello" rolling shutter when fast camera action or fast action close to the camera occurs.

With the limit of the setting for the Blackmagic set to 360 degree shutter angle, this will not really be possible, as say shooting at 24p, at 360 degree gives you 1/24 shutter speed, but I would like to go 1 more stop to 1/12, (equivalent to 720 degree shutter), as 1/10 to 1/15 can give beautiful results for 24p imparting intensity of motion, and I have never had anyone say they can see "rolling shutter," in my shoots using this. (Think of some of Director Tony Scott's in camera effects.) This is simple to do with, for example, the Panasonic GH2 and many other cameras. And it is not (I believe) something the Arri Alexa or Red cameras do. I nice possible marketing advantage for BMCC as well.

360 degree shutter setting limits on the BMCC may be to conform to "cinema" and not a technical limitation, so please consider this option if technically feasible.

I would be happy to supply footage examples, that clearly illustrate the quite useful result to the folks at Blackmagic.

Regards,

Dean Hadlock / Director & Cinematographer
deanimage@gmail.com

I'd be interested to see an example

I will arrange a link to be posted within the next few days, to illustrate.

Thanks for your interest. Hopefully we can get Blackmagic's interest as well.

Dean

How would it be possible though? The sensor is reset before exposing for the next frame. You can't make a single sensor be exposing for two frames at the same time. Same in film. The next film frame is brought into place and the exposure begins for a maximum time of 360 degrees (1/24th for 24fps).

How would it be possible though? The sensor is reset before exposing for the next frame. You can't make a single sensor be exposing for two frames at the same time. Same in film. The next film frame is brought into place and the exposure begins for a maximum time of 360 degrees (1/24th for 24fps).

simple terms, the shutter is a circle with 360 degrees. No more. Is it perhaps long exposure still frames i.e. following a bike at the same speed so the biker is sharp and the background is blurred ?

Thats why the GH2 can do it because it is a still camera, not the alexa or red.

[CaptainHook]

I think it would be useful for the timelapse function. I would definitely use it.

An advantage to digital video cameras that I have found over most film cameras, is the ability to "drag" the shutter to induce motion blur, as you might in a still camera image,
....... (Think of some of Director Tony Scott's in camera effects.) This is simple to do with, for example, the Panasonic GH2 and many other cameras. And it is not (I believe) something the Arri Alexa or Red cameras do. I nice possible marketing advantage for BMCC as well.

Hi Dean.

Most of the time this effect, including in Mr Scott's case, is done with a film camera.

It can be done with a digital camera using a regular 180 Deg shutter.

It''s also been used a lot by Chris Doyle with a lot of Wong Kar-Wai's earlier films.

It's known as step printing.

What you do is take your distribution frame rate, in most cases it's 24 fps...

Then you divide that in half. That equals 12 FPS. Then you shoot a scene at that frame rate with a 180 deg shutter. at that frame rate, your shutter speed is halved from regular motion to 1/24th of a second instead of 1/48th of a second at 24 FPS.

Everything though when played back is twice as fast. So you DOUBLE PRINT every frame....in other words you slow it down in post by the same amount (50%) and the motion ends up being back to normal, BUT you've added extra motion blur.

Or you can do it as 1/4 of the distribution frame rate of 24 fps. This would be 6 FPS.

So shoot at 6 FPS with a 180 DEG shutter, yielding a shutter speed of 1/12th of a sec and then slow the shot footage down by 1/4 so it's back at normal speed. again with the motion blur now of 1/12th of a second.

Shoot at 3FPS for a shutter speed of 1/6th of a second etc......

Yeah, RED's can do it. Alexa can do it. And it was invented in the FILM era.

jb

Well, that is a great explanation, thank you, one I understand as I am of the film generation.

On these newer still/video cameras I have been pleasantly surprised that the entire process you have describes seems to automated by allowing the shutter speed to be set at ANY speed with your FPS speed.

In my case as I described shooting at 24P at 1/10 and 1/15 shutter speeds I have achieved this effect in-camera, it is predictable, repeatable and VERY useful. Available on many current cameras, in this case I used the Panasonic Gh2. Please see the footage on my reel at .

1st sequence : shot 1 at time 0:14 seconds shows 24p at 1/50 shutter speed, effectively a 180 shutter angle (no 1/48 avail.). Shot 2 at time 0:15 shows 24p at 1/10 shutter speed and shot 3 at 0:17 shows 24P at 1/10 shutter for the final composition to achieve the speed effect, no post.

A second example at 1:39 shows a more subtle action shot at 24P and 1/15 shutter speed, with slower camera motion and a little faster shutter it achieves the added urgency I wanted while no obscuring the imagery as much.

Yes, all old school film and still camera techniques. Now, can we get shutter adjustments that allow this on the BMCC, either shutter speed or shutter angle setting? This question is for the marvelous folks at Blackmagic and their lovely camera would make my day.

Thanks for the feedback to date, any other opinions on the matter?

Regards,

Dean

Okay, the new TIMELAPSE feature, if allowing shutter angle control, starting from every other frame, (12fps when using 24P) and on down with fine adjustment, may actually have the makings of this desired control...if that is how this is actually achieved. And depending on how this integrated into the camera interface.

Curious if people viewing the samples I have shown recognize this is a lower frame rate to achieve the effect?

So many helpful people, thanks for pointing how I have been doing this in productions...some things are just not that transparent with all the new toys. Hope you liked the samples.

Dean Hadlock (deanmachine)
San Francisco, CA, USA

[CaptainHook]

What i would like to do is use timelapse with reasonably long shutter times so that things are moving quickly with a substantial amount of motion blur.

Please check out the above post with VIMEO link (and the description of what is done and where to look for the shots) to see if the result is what you have in mind.

Thanks,

Dean

Please check out the above post with VIMEO link (and the description of what is done and where to look for the shots) to see if the result is what you have in mind.

I just had a look at it. I can see that there might be some use for this method, but I personally find it too flickery due to the low frame rate needed to achieve that effect. I wouldn't say no to having the feature added to the BMCC though, the more the better.

What i would like to do is use timelapse with reasonably long shutter times so that things are moving quickly with a substantial amount of motion blur.

+1 for light trails! I'd definitely use this feature.

What i would like to do is use timelapse with reasonably long shutter times so that things are moving quickly with a substantial amount of motion blur.

You can get a faux version of this by using heavy noise reduction in post and turning off motion detection.....

jb

[CaptainHook]

Thanks John, what app/software have you seen this done with? Would love to try it out. I assume not Resolve because i haven't seen controls like that (although handy if there is!).