Matching 50i and 60i

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Nintembo
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I remember hearing once that its not good to match 50i and 60i footage. I am in need of doing so however, what would be the best way going about this?

Alan Roberts
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It's hardly possible to 'match' them at all. What do you mean by this?

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Nintembo
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I have some footage shot in 60i, I need to edit it alongside 50i footage and master 50i.

Is it a case of converting the footage first, and if so, are there any quality issues I should be aware of?

Dugi
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Nintembo wrote:
, are there any quality issues I should be aware of?

Well yes you should.
I guess this is not NTSC to PAL conversion.
HD 60i Standards Converted to 50i is not going to look great alongside your original 50i footage on a 50i timeline. Nothing you can do about it, except, perhaps put some effects on both (eg B&W, PiP etc) to try and match them.
Really depends on the subject matter as to what will look "right".

Maxwell
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Sorry, could somebody enlighten me what 50i and 60i stand for? Is it year 5o and 60 and he has footage of those periods?

harlequin
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50i = 50 interlaced fields per second.
60i = 60 interlaced fields per second.

http://en.wikipedia.org/wiki/Frame_rate

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Alan Roberts
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It's impossible to construct a project with 50 and 60Hz material mixed, you have to make a decision, which standard are you going to work at? then standards convert the stuff that isn't right. This is highly fundamental. Some NLEs will accept mixed footage, but all that does is postpone the time when the conversion is done to the time of rendering, it has to done sooner or later.

Far better not to used mixed footage.

Get my test cards document, and cards for 625, 525, 720 and 1080. Thanks to Gavin Gration for hosting them.
Camera settings documents are held by Daniel Browning and at the EBU
My book, 'Circles of Confusion' is available here.
Also EBU Tech.3335 tells how to test cameras, and R.118 tells how to use the results.

Nintembo
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Joined: Jun 22 2004

Alan, its not through choice!

I am putting together a music montage for a client, I have filmed 80% here in UK, but he wants to use archive footage shot in the States for a small portion.

Nin

Mark M
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Nin, what program are you editing with?

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Alan Roberts
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Then convert the US footage to 50i so that the project is consistent. You can't work with differing frame rates, it isn't possible.

Get my test cards document, and cards for 625, 525, 720 and 1080. Thanks to Gavin Gration for hosting them.
Camera settings documents are held by Daniel Browning and at the EBU
My book, 'Circles of Confusion' is available here.
Also EBU Tech.3335 tells how to test cameras, and R.118 tells how to use the results.

Mark M
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Alan, the reason why I ask what NLE she's using is that it may not be necessary to convert the US footage to 50i as a first step.

Aren't you an Edius user, Alan? One of Edius' claims-to-fame is "Real-time editing and conversion of different frame rates, such as 60p/50p, 60i/50i, and 24p" which I take to mean editing different frame rates on the same time line in the same project. (Certainly I can do this in Premiere CS5, create a 50i timeline and put a 60i clip in it, and the conversion will be done in the final output, but I can edit them together in realtime just fine.) In fact reading further in Edius blurbs it says "Exceptional Mixed Format Editing
Featuring unrivaled real-time video transcoding technology, EDIUS converts between HD and SD resolutions, aspect ratios, and frame rates—all in real time. You can edit in HD and place 4:3 SD video, or mix NTSC and PAL sources, or combine them all into projects in other resolutions and frame rates without wasting a single moment on conversion or rendering."
Am I completely misunderstanding this?

Cheers

Mark

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Alan Roberts
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Absolutely right Mark, and I already mentioned exactly that. But simply having the differing footage on the time-line doesn't eliminate the need to convert it, it just puts it off to the rendering stage.

Get my test cards document, and cards for 625, 525, 720 and 1080. Thanks to Gavin Gration for hosting them.
Camera settings documents are held by Daniel Browning and at the EBU
My book, 'Circles of Confusion' is available here.
Also EBU Tech.3335 tells how to test cameras, and R.118 tells how to use the results.

Nintembo
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Joined: Jun 22 2004

Going on from this topic, I will be shooting PAL out in the States, with a PAL camera.

AM I correct in my figures in thinking that it has to be shot 50i, at 1/60 shutter speed in order to compensate for the United States lighting cycle?

Dugi
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Nintembo wrote:
Going on from this topic, I will be shooting PAL out in the States, with a PAL camera.
AM I correct in my figures in thinking that it has to be shot 50i, at 1/60 shutter speed in order to compensate for the United States lighting cycle?

What are you shooting? What camera are you using? What format do you have to deliver?
If you have to shoot 50i then shoot at 1/50 shutter speed. Keep everything to a PAL standard.
Use flicker free lighting if you have to light.

Nintembo
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Joined: Jun 22 2004
Dugi wrote:
What are you shooting? What camera are you using? What format do you have to deliver?
If you have to shoot 50i then shoot at 1/50 shutter speed. Keep everything to a PAL standard.
Use flicker free lighting if you have to light.

But US lighting, will not be PAL standard, whilst filming in America.

steve
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Joined: Apr 8 1999

Nin,

Using 1/50 shutter with 1080i/25 will reduce the amount of flicker. Dugi is suggesting that if you need to light the subject yourself, use flicker free lighting, (essentially DC or very high frequency) rather than bog standard 60Hz lighting which may strobe badly with a 50 field per second camera.

Steve

p.s I will answer your PM tomorrow.

Steve

JosephAwo
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Joined: Jan 30 2014
Re:

Dear Mark,
I am new to this forum. Can you please guide me on how to convert 1080 60i signal to 1080 50i signal using either hardware or software.
Thank you very much

Joseph

Mark M
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Joined: Nov 17 1999
Re: Matching 50i and 60i

Hello Joseph and welcome!

What software do you have at your disposal?

What is your final output?

Maybe you don't need to convert at all.

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