Interlace/progressice/shooting formats « Videomaker Community Forums

Damien
Member

Hi guys, i recently purchase a sony EX1R, and i am using a sony hdr fx1000, which shoots in 1080i/p.

The first question is, do i need to de-interlace the progressive scan footage shot on the hdr-fx1000, or do i leave it?

The second question is, what format should i shoot with on my EX1R, as it allows me 1920, 1080 or 720, keeping in mind that i will have a timeline with shots from both cameras on it, which means that the timeline will have at least 50% of 1080 footage shot with my hdr fx1000.

The third and final question is, if i want to do some super slow motion shots with twixtor, what is the best format i should shoot with?

Thanks heaps

Posted 1 year ago #
EarlC
Moderator

Damien, 1080i of course is interlaced, meaning that the image is comprised of horizontal lines divided into odd (1,3,5,7, etc) and even (2,4,6,8, etc.) lines which are alternately played at 30 fps. The resulting image, of course, has jaggies and when you want to smooth the image out you "de-interlace" to remove this stair-stepping problem — sometimes successfully, sometimes not so great. Forgive me if you already know that, but my assumption of your lack of awareness came when you asked about "de-interlacing" progressive scan images. You don't.

So, if you shoot 1080p on your fx1000 there's nothing to de-interlace, so to speak.

Thus, if you shoot 1080P on the 1000, to keep things simply, you should shoot the same on the EX1. Now, I'm not at ALL familiar with either camera, but the convention is the same and I think my logic is sound for keeping your footage and editing efforts simple. If both shoot 1080i and you want to shoot that, keep them the same.

Progressive will give you cleaner super slow motion, regardless of the software used.

Any of you guys who have a better handle on this please pipe in, and DO correct the above if I'm all wet here.

Posted 1 year ago #
Damien
Member

Hi Earl, thanks for that. But you said 'progressive will give cleaner super slow motion' every time i slow down progressive footage it seems to studder and skip. However when i slow down the interlaced it seems to be more smoother, however not as smooth as i wish to have it. Can you reccomend software that will allow me to do super slow mo?

And yeah i understand about not having to de interlace the progressice scan footage, its just ive been told that the progressive scan footage on my cameras isn't really progressive footage as such. its just interlaced footage modified to create a progressive look? Is this correct?

Thanks heaps

Posted 1 year ago #
XTR-91
Member

"slow down progressive footage it seems to studder and skip"

What progressive mode are you shooting in?

12p (0.5x 24p) will definitely look stuttery, more so than 30p (0.5x 60p) if you're shooting 60p. There's no software that will magically transform interlaced footage as if it was shot in progressive.

Posted 1 year ago #
Damien
Member

Im shooting in the 25p mode that is optional on the sony hdr-fx1000

Doesn't de-interlacing interleaced footage make it progressive? Also i ment if there was any software such as Twixtor that allow you too slow things down, as im using it but still cant get the crisp, clean and smooth slow motion that im after.

Posted 1 year ago #
EarlC
Moderator

Damien, as I understand it there are cameras such as apparently yours, and a Samsung model and others, that do this — pseudo progressive "look" thingy. While I am not knowledgeable enough of the existing software options for quality enhanced super slow motion production, I do know that it is often recommended to record footage at a higher rate shutter speed before treating with ultra slow motion effects.

In a simplified terms (and I'm certainly NOT a genius for writing the engineer-level deep technological stuff) yes, it could be said that de-interlacing essentially creates "progressive" footage. I also know there's more to it than that, but like I said ... beyond my pay scale/knowledge :-)

If it were me, given your choices, I'd shoot everything interlaced (since that's looking smoother to you when slowed down), do the de-interlacing if it seems to help, and the stuff I want to super slo-mo I'd shoot at whatever the fastest shutter speed your cameras offer. I'm not intimately familiar with either of your models, or Sony in general. Sorry.

Of course that (faster shutter speeds) might introduce other "issues" due to available light, etc. I hope some of the higher level tech heads here will respond and help get you the answers using your currently available units to acquire the smoothness you want in your super slow motion work.

Posted 1 year ago #
XTR-91
Member

24p is 24 full frames per second, while 60p is 60 full frames per second. 60i is 60 interlaced fields per second. You can't add information that was never there, to turn one interlaced field into a full progressive frame.

Posted 1 year ago #
EarlC
Moderator

Nobody said anything about "adding" information in the process of de-interlacing XTR, just that by removing the interlaced fields and essentially converting them to a solid image you are, after a fashion, creating a type of progressive frame — missing information or not, it's still no longer interlaced. But I do understand what you're saying, that's why I said "there's more to it than that..." in my previous response.

Posted 1 year ago #
Damien
Member

???

Posted 1 year ago #
XTR-91
Member

60i is just 30p with every 2nd line recorded just a bit later.

60i is the thing exclusive to all CRT TVs, while progressive is exclusive to LCD TVs, which have to deinterlace any 60i incoming signal

Posted 1 year ago #
roblewis56
Member

XTR - 91, Your clear and concise explanation of 60i and 30p frame rates should remove any doubts about the fallacy of shooting in 60i, particularly for action subjects. Thank you.

Posted 1 year ago #