Progressive for TV?

[Michael Sacci]

[Casey Petersen] “The shutter speed on this footage was at 1/50”
That correct.

[Casey Petersen] “Someone on another forum suggested adding a motion blur…what do you think about that?”
If you did, I would recommend a very light blur.

Check your Chroma levels, maybe reducing the saturation and lowering the highlights might help also.

I do think you are fighting a little bit because this is a different look from what you have been watching. Like I said I love the look of what you have, personally I like things a bit darker but your footage looks good.

[Casey Petersen]

Thanks for looking at it and for your feedback…that’s good to know.

It appears that I’m doing things right…maybe I like the video look too much!

I’ll look into those other encoders…I’m sure that hollywood is not using Compressor. And again…the problem is in the standard def DVDs, not online or Blu-ray.

Casey

[Ken Pugh]

Interesting stuff – If Casey feels his footage looks strobey on his CRT tube monitor – but it looks fine on Michaels monitor, then assuming there is not a totally different aesthetic at work here – then it must come down to the monitor, no? CRT screens cannot playback progressive frames, instead they repeat them to get 50i, hence the strobe effect because the image is jumping backwards and forwards. However a good flat screen broadcast monitor, which I suspect Michael has, will play both, switching as necessary. This is my conclusion. However it follows that DSLR footage and progressive video will only look good on a screen capable of playing progressive, which most of the world don’t have.

Personally I think the only thing to do is to correctly interlace the progressive footage prior to delivering for broadcast, or screening on a CRT monitor, as indeed Hollywood movies were prior to recording to VHS (which was also a interlace only format).

There is a great way to do this outlined on this forum in the link copied below – but you wouldn’t want to do this to the rushes. So for me I think the solution is buying a progressive capable monitor for editing, and keep the broadcast standard interlace only CRT for viewing the final interlaced master – so one can check the CRT viewers get a correctly interlaced final product.

https://magazine.creativecow.net/article/interlacing-progressive-footage

Having said all that I do accept Michael’s point – I’ve discovered that some digital broadcasters do transmit progressive video – so in this case the domestic receiver must correctly handle the interlacing process – just like the process Michael was describing with some DVD players. So I don’t think I’ve quite got to the bottom of this yet! Otherwise all those Paul Greengrass films would be totally unwatchable on my domestic CRT…

Thanks for all the feedback,

Ken.

[Casey Petersen]

Thanks Ken, I’ll give that a try.

I also should clarify that I am not testing this on a high quality CRT monitor, but rather an inexpensive tube tv set (I’m trying to play to the lowest common denominator, or at least low).

Casey

[Ken Pugh]

I tried the re-interlace method using After Effects – works really well! Super smooth pans with no judder. However I did get quite a bit of jelly vision, where the vertical lines ‘bend’ in proportion to the speed of the pan…. but that’s another story – along with chroma crawl, moire, no fluid exposure changes, pulling focus changing the frame size, overheating after an hour of filming…. but never mind, just think of the lovely soft focus background and the low light capability and be happy!

All the best,

Ken.

[Casey Petersen]

I tried it…not quite the way it was described…I don’t have After Effects and couldn’t figure out how to do it in Motion, so I tried changing the speed in Final Cut to 50% with frame blending off, then rendering that out to a new QuickTime and changing it to 200% with frame blending on. The end result didn’t look very good.

Is it really going to be that different using Motion? How do I do it in Motion?

Thanks!
Casey

[Ken Pugh]

Mark didn’t make the first stage crystal clear (for me at least) – and it took me a little experimenting before I cracked it. The crucial thing is that the software has to make intermediate frames when you slow the footage down. Does FCP do this? I’m not sure it does. After Effects does it really well – and I assume Motion will do as well (but I’m not up to speed with this as I use AE for all my compositing requirements).

So, slow the footage to 50%. Then render and re-import the footage. Make sure interlace is turned off, you must keep it progressive. Then after re-import check as you step through the frames that each one is now different. You don’t want ‘frame doubling’ where the software just repeats each frame in the same position to slow it down, and you don’t want frame blending, where it does a mix to create the new frame, using the frame before and the frame after as a source. Instead you want a new progressive frame in a different position relative to the frame before and after. So if you are looking at a pan each frame must be slightly to the left (if you’re panning left) of the one before.

So now you have a 50% clip – then you need to tell the software that this is not a (in PAL land) a 50% speed clip running at 25 frames – but a 100% speed clip running at 50 frames. Then when you render this (with interlace now turned on), the software takes each frame and makes it part of the interlace – so 50p becomes 50i.

This last stage is the same as shooting 50p in the Canon, then after import rendering as 50i with interlace turned on.

I was amazed how good this technique was, but the crucial part is using software that can create the intermediate progressive frames – ask in the FCP forum I’m sure they’ll know of a few plugins that could do this. Or get some tips how to do this in Motion – if you do let me know as I’d like to try this too.

Best,

Ken.