View Full Version : Overcranking HPX502


Vince Sofia
September 4th, 2011, 02:23 AM
What would be the the best set up option for overcranking the HPX502?? I have to film some fast paced sport and the client wants good quality slo-mo. I have limited experience in VFR but ubderstand the principles. One of my decisions is 720p vs 720pn???
It will be edited on an Edius system...
Any feedback and examples would be greatly appreciated!
Many thaks, Vince

Sanjin Svajger
September 4th, 2011, 03:41 AM
I don't think that you really have a choice there. 720 50p or 720 60p. As for the quality... The picture IS going to be soft. If your client wants a sharp HD picture he's not going to get it with the hpx500 especially not if shot in 720... If sharpness is not a problem then I guess your all set to go:)

But I don't own the camera so maybe somebody else will be more of help to you.

Vince Sofia
September 4th, 2011, 05:08 AM
Thanks for your reply....
I am aware that the 500 is not the sharpest tool in the shed by a long shot, but its fine for what is required. What I am still a little unsure of is the "best" setup to go with. Should it be 720pn/25(25native) with a FR of 50....720p/25(25 over 50) with a FR of 50? 720p/50? If I go with 720p/24, I can then run the FR right up to 60FPS....would this be an okay option? Preferably after looking at it all I would like to go with 720p/25 at 50FPS or lower, this would let me still keep audio and be better suited to for the client to keep the wilds as an image library, but I am not sure if this gives the smoothest play back results. There are so many different opinions as what is the prefered setup out there....I just want to keep it smooth & reliable.....

Mike Blumberg
September 4th, 2011, 01:23 PM
Contact,

Noel Evens,

Showreel (http://www.sdcproductions.com.au)


He has been filming with the 500 for years, I think he just sold his, but he would be a good man to answer your questions.

Have a great day.

Sanjin Svajger
September 4th, 2011, 02:24 PM
720 25pn isn't this 25 frames? Where do yo get 50? If you want to shot slo-mo just shoot 720 50p. I don't see where you can go wrong with this...

Konstantin Kovalev
September 5th, 2011, 02:30 AM
I agree with Sanjin. Depending on the intended playback rate, as well as the capture rate, you can determine what the maximum slowdown is.

If you capture 60p and play back 24p, it's going to be a 2.5x slowdown.

If you capture 50p and play back 25p, it's going to be a 2x slowdown.

Software can always drop frames to speed the footage up to whatever you want it to be, but you can't slow the footage down past what the capture speed allows for, or else the motion will have to be interpolated and that looks bad; it's generally a good idea to shoot as fast as possible.

One more thing - the Variable Frame Rate function on HPX cameras is useful if you want to capture odd speeds that don't coincide with the standard acquisition speeds. For example, I want to capture at 48 fps instead of the default 50 to get a 2x slowdown at 24p, in this case I would choose to record 720 24p with the frame rate set to 48. This appears as 48:24PN on my 370, which I assume should be similar enough to the 500.

David Jimerson
September 28th, 2011, 03:40 PM
The whole point of VFR is to do exactly this without having to slow down in post.

Shooting 25pN and using 50 fps as your VFR (set in the Scene File) will give you 50% slo-mo recorded directly to the card, no slow-down in post needed. This is much, much better because if you slow it down in post, the slowdown will only be as good as the resampling software. Using VFR avoids that; you're getting full, whole frames created by the camera, not interpolations created by an NLE.

And you have many more options for frame rates than you do in post, all at the same, camera-best quality and not at the quality of some NLE's interpolation. You will have full-quality slo-mo or fast-mo at varying rates; you're not stuck with just one rate.

Doing the overcranking in the camera is better in every respect. That's why it's there.

Gary Nattrass
October 6th, 2011, 09:47 AM
The overcranking in this promo was done in camera with my HPX371 set at 720p with a frame rate of 50fps:
Greggs Children's Cancer Run 2010 - YouTube (http://www.youtube.com/watch?v=0gV3eK0RuE4)

The edit timeline was 25fps and I think it works very well.

As a footnote we lost our 12 year old son Henry to cancer a year ago, I did the video for the charity to promote their fundraising for the run, my 31 year old daughter Sarah is also in the video waving at the camera.