Over and Under-Cranking with Public Beta 1.5.31

[Dan Keaton]

Dear Friends,

We have determined that we do not properly handle the situation where the camera is sending us 720p50 and Crank Rate of 60 is selected.

To be clear, we can not handle a Crank Rate higher than the frame rate of the incoming video.

Please limit your maximum Crank Rate to the frame rate of the progressive video.

For 720p60, the maximum Crank Rate is 60.

For 720p50, the maximum Crank Rate is 50.

For 1080p30, the maximum Crank Rate is 30.

We require progressive images for over and under-cranking, so please do not send 1080i59.94 or 1080i60.

[Piotr Wozniacki]

Dan,

Thanks for heads-up.

However, I still am a bit confused about the whole overcranking mechanism in the nano. Basing on my experience with the EX1 camera, I only can get "real" (like 2:1) overcrank when shooting with the base speed of 25p, and recording it at 50 fps.

How do I get the same (2:1) slowdown from the nano? Please explain the proper settings of both the camera (on the EX1 example) AND of the nano.

Thanks,

Piotr

[Dan Keaton]

Dear Piotr,

Set up your camera for 720p50.

Set up the nanoFlash for 25 frames per second with a Crank Value of 50.

I hope this helps.

[Mark Job]

Hi Dan:
Is it possible to over crank at all in 1080 ? I am assuming I can indeed *under crank* in 1080 ? Is it possible to add a menu switch **to force 720p mode** with a 1080i input in order to take advantage of high over cranking speed with 720p 60, for example ?

Respectfully,

[Cees van Kempen]

Dan,

I suppose just shooting 720p60 in the nanoflash, and slowing down in post, gives the same result? With the only disadvantage that your use more capacity on your storage medium (CF card)? Or am I wrong?

[Dan Keaton]

Dear Cess,

Yes, Post is an option.

I welcome others to post their experience.

[Fletcher Yeung]

Hi!

With the great help of Dan and Tommy, I finally figured out what setting I was doing wrong with cranking and the "Slow card Issue" I could have posted in my previous thread,but I thought that this would be the right place to put it.
To crank 720p(24,25,30,50,60) you have to turn off PsF, and that's all it took. I'm not too technical about why, but that's all I turned off and now I can Under/over crank without the "Slow card Issue".
Now, all I need to to get a camera that can crank out 720p60! I haven't yet tried 1080p25, but will get to it later this weekend.

Hope this helps! And thanks for the great update! I can now sort of get the same results from my PDW-700 close to the 800 that came after it!!

[Piotr Wozniacki]

I have tried everything, but overcranked clips are just mess. Impossible to put on Vegas timeline, anyway.

[Dan Keaton]

Dear Piotr,

We are taking in all of this feedback, then testing the issues in our lab attempting to duplicate the problems, and then making changes to the firmware.

We will come out with a new release as soon as possible.

I believe that we have a bug in our over and under-cranking that we found and have fixed.

We have also fixed, as far as I know, an audio sync issue with SD IMX 50.

We have detected some other audio problems with 8-Channel Audio, in the Channels 3 through 8.

There may be others, our engineers are very busy working on this.

[Piotr Wozniacki]

Originally Posted by Dan Keaton

I believe that we have a bug in our over and under-cranking that we found and have fixed.

Dan,

It would be nice, and save us the beta-testers a lot of time and frustration, if you were more specific in what bugs specifically you have established so far.

I have spent all day testing every and each possible EX1 settings / nanoFlash settings combinations, only to find that most of the nano clips cannot be loaded into Vegas (8 or 9), and those which can, exhibit the following flaws:

1. Some clips have no picture at all
2. Some clips audio is distorted heavily
3. ALL clips audio is recorded TWICE in several seconds long sequences (and BTW, no audio should be recorded at all when overcranking, right?)
4. Whether I set my EX1 to 720/50p (as you suggest), or 720/25p (just for testing), the resulting nano clips play at the same speed. What's more, it doesn't matter whether the Vegas project is set to 25 or 50 fps.

Please keep in mind that using the EX overcrank feature per se, all work well and the logic behind overcranking is simple:

- I set the basic format to 720/25p
- I overcrank to 50 fps (the audio is not recorded)
- I load such EX clip to either version of Vegas, with the project set to 720/25p
- I get a beautiful, 2:1 slow-motion video.

What I was expecting is :

- set my EX1 to 720/50p (no overcranking with audio, recorded to SxS as a backup)
- set the nano basic fps to 25, overcrank to 50 fps
- get video-only, 2:1 slow-motion video clips from the nano, plus 1:1 (base speed) video+audio from SxS backup.

Now, is the above how the nano overcrank feature is supposed to work, or am I still missing something? Are there any aditional limitations not mentioned in the Release Notes (long-GOP vs I-Frame; maximum bitrate limits; anything else)?

[Dan Keaton]

Dear Piotr,

Yes, you understand our over and under-cranking perfectly.

I just learned that we found a problem with our over and under-cranking last night, I posted it this morning.

Our code problem was that if you selected, say 24 for the timeline, and over-cranked to 60, we were setting the timeline for 60 and not for 24. Thus, over and under-cranking was not working as intended. This is now fixed in the code and we are working to release it as soon as we finish some other issues.

If your nanoFlash is set for Long-GOP, and you select over and under-cranking, we change this internally to I-Frame Only so you do not have to do so.

There is no bit-rate limitation for over and under-cranking. In fact, we recommend that you consider using the highest bit-rate that works with your cards, for the best quality.

As always, we want you to test your settings, with your cards, and test it with your workflow prior to doing an important shoot.

I hope this helps.

[Piotr Wozniacki]

Dear Dan,

Thanks for your detailed response. I'll wait for the fixed release before I perform more tests.

However, do you think that my problems in the points 1 through 3 of my previous post will also be addressed by the fix you mention?

[Dan Keaton]

Dear Piotr,

Yes, I expect all items, 1 through 3 to be corrected.

Audio does not make sense when in Over and Under-Cranking mode.

[Mark Job]

Hi Dan:
Could I please get a clarification of this feature in regards to its use with the Flash XDR ? In short, do I need to connect an HD 720p camera to the XDR to be able to use the Over crank feature ? Is it possible to do any over cranking in 1080 ? Is there a way to enable a 720p down convert setting which would allow a 1080 camera to be used for over cranking in the case it is not possible to do so with a 1080 camera ? Please advise ?

Respectfully,

[Dan Keaton]

Dear Mark,

With 1080 cameras, one should set the camera to 1080p mode (or Frame mode for Canon).

Then, if one wants to overcrank, one should use the highest frame rate possible.

Thus, for the XL H1 and other 1080p cameras, this is 1080p30.

This gives an over-crank ratio of 1.25 (30/24).

The over-crank ratio for 720p60 using a 24fps timeline is 2.5 (60/24).

For the XL H1, the maximum frame rate is 30 (29.97) frames per second.

Converting your 1080p29.97 to 720p would only give 720p29.97, so it would not be any better.

The nanoFlash accepts single-link HD-SDI, 1.485 Gbps. In 1080 mode, this is limited to 30 frames per second, (1080p30, 1080p29.97) or 60 fields per seconds (1080i60, 1080i59.94).

So with a XL H1 and any other 1080 single-link HD-SDI camera, you are limited to 1080p30 for over-cranking over HD-SDI.

The Sony PDW-F800 can over-crank at 1080 and 48 frames per second, but this is done in camera and not over HD-SDI.