View Full Version : Shooting format for Cable TV using F3


Les Wilson
February 21st, 2017, 10:10 AM
Camera and NLE are different last time I did one of these. I'm a little confused by the 1080i in brackets in the specs for a 30 second spot on Comcast. Is 1920/29.97p the best format to use on the F3 or should I shoot 720p? I'm using FCP X and it has a 720p, 1080p/29.97 and 1080i/29.97i timelines.

Recommendations?

Jeff Pulera
February 21st, 2017, 11:11 AM
1080i is INTERLACED video, 1080p is PROGRESSIVE. They are requesting 1080i. Shoot, edit, and deliver as 1080i then.

HD HQ mode: 1920 x 1080/59.94i

Thanks

Jeff

Les Wilson
February 23rd, 2017, 03:39 PM
Thanks Jeff. I did some tests and found that the F3 60i had scan line artifacts when FCP X converted it to 30i. I shot at 30p and converted it to 30i no problem. Also shot a 720p safety.

Jeff Pulera
February 23rd, 2017, 03:56 PM
"60i had scan line artifacts when FCP X converted it to 30i"

Camera manufacturers and NLEs play loose with the format labeling, but there is only ONE kind of 1080i. It has 29.97 frames per second, and 59.94 fields. It is sometimes called 30i or 60i, but it refers to the exact same format. There are no different frame rates (except overseas it is 50i).

Computer displays are not interlaced, so if FCP X is trying to show you both fields at once, you may have seen artifacting. In Premiere, it by default only shows one field or the other unless the user specifically chooses the "Both Fields" option. You can't judge interlacing on the computer, you would have to export and view on a TV, such as using a 1080i Blu-ray. Or use an output device like AJA or Black Magic, which can output a proper 1080i signal to a TV display (not computer display). That's the trick to working with interlaced material, preview outside the computer.

Please see attached, Adobe calls it "1080i30 (60i)". Confusing for sure!

Thanks

Marshall Staton
February 24th, 2017, 04:37 PM
30i isn't a format that anyone uses. Ask your client to specify an exact format request and go with that.

Sander Vreuls
February 24th, 2017, 05:14 PM
Actually some organisations call it 1080i25 or 1080i30 instead of 1080i50 and 1080i60.. They refer to the frame rate instead of the field rate.. Like the EBU

You don't often see that being used anymore though..

Les Wilson
February 24th, 2017, 05:22 PM
@Marshall... sorry... I was lazy. I should have said 29.97 and 59.94 where I used 30 and 60. My bad.

Marshall Staton
February 24th, 2017, 05:25 PM
Standard shooting specs (USA) are 1080i 60i/30p/24p or 720p 60p/30p/24p. That's what I was getting at. Either way getting the client to specify their requested/required format shouldn't be a big deal. I get it confirmed by email for all shoots unless it's a standard client of mine, even then it's good practice. Good luck on your shoot.

Doug Jensen
May 16th, 2017, 02:55 PM
What you ultimately DELIVER to a client often has nothing to do with what you SHOOT. With the F3, I'd shoot 30P and deliver it as 1080i. That way, you'll retain the higher-end look of progressive video while delivering it in their requested format of 1080i. The best of both worlds. A 30-second spot shot in 1080i is going to look like cheap home video -- you want the look of progressive.

Ron Evans
May 16th, 2017, 07:05 PM
Depends what the spot is of I think. If its sports related or has lots of action then 720P60 is likely the best and of course 60i would also meet this need. Which is what they have asked for in their spec. I am not a fan of the slow frame rates and like the real look personally. Too often poor camera work displays really bad judder that I find really disturbing. Higher frame rate is more forgiving.

Doug Jensen
May 16th, 2017, 07:13 PM
Show me any national TV spot done in the last 10 years (probably longer than that) that wasn't shot 24P or 30P. This excuse that 30P and 24P frame rates can't handle motion is complete bunk. Ever go to the movies? 24P. Even action movies are 24P. Nobody in their right mind would shoot 1080i or 720P in 2017 for a TV spot.

Ron Evans
May 17th, 2017, 01:13 AM
I did say what was the spot. 24fps is a distribution frame rate was economic not esthetic. There was a need to find the lowest cost of celluloid for distribution to the movie houses while meeting the needs of quality from the optical sound tracks as well as flicker rate over 48. 24fps met that need with a 2 blade shutter. If sound was not an issue then lower frame rates with 3 blade shutter would have worked just like the consumer 8 mm projectors I have now. One with 3 blade and the other 5

Feature films are not always shot at 24fps as individual scenes can be shot lower and at much higher rates. You did know that Doug ?

As to video, the refresh rate in North America is 60hz so 24 P requires 2:3 pulldown to display within this refresh rate. So will not look the same on TV as in the cinema.

Now I feel the ideal acquisition is 4K 60P as this gives the freedom for post.The smooth motion that I like as well as the ability to extract 30p for a more film like esthetic or slowdown for a 30P slowmotion effect and crop into the image for a straight HD output. If you shoot at 30P its all you got.

Cliff Totten
May 18th, 2017, 04:30 PM
For me personally, I'm not a fan of 24p or 60p. To me 60 frame just screams "video" look too loud. Its nice sometimes and i will use for 1/2 speed slowdown sometimes. To me 30p is where its at. It lives nicely in a 60hertz world. It plays back smooth and can be formatted into 30/60psf perfectly over existing TV 60i standards. (And blu-ray)

For me, 30p is the perfect sweet spot between 24p and 60p and 60i broadcast without pulldown artifacts.

No? Anybody a fan of 3:2 or 2:3 pulldown to match 60i broadcast? Im not.

Doug Jensen
May 18th, 2017, 06:03 PM
Cliff, I completely agree and I am also a big fan of 30P. I shoot all my stock footage 30P because it's the most versatile frame-rate. It's easy for a stock footage customer to convert 30P to 24P by just letting their NLE drop frames, but going from 24P to 30P means artificially manufacturing six frames that never really existed before.

Someone might argue that 60P is even more versatile, and in some ways it is, but it's also a huge waste of data because file sizes will be 2x larger. There are very few outlets to deliver 60P so usually 50% of the frames that were captured are just going to be left on the cutting room floor anyway. 30P is the sweet spot between smooth motion, a progressive look, and economical files sizes. I generally only shoot 60 fps or faster when I know in advance that I will use the footage for slow motion.

Ron Evans
May 19th, 2017, 12:19 PM
I think it may well be worth some of you comparing the file sizes for 60P and 30P if you are using a Long GOP codec. As an example, using my AX100 for a 2min clip of the wind really blowing the tree around in my back garden, so lots of movement of leaves and branches filling the frame. 30P had a file size of 742MB and the 60P file was 749MB. The codec is the Sony XAVC-S at 50Mbps in both cases. Of course an i-Frame only codec or RAW would be double.

Doug Jensen
May 19th, 2017, 07:34 PM
I don't shoot anything that isn't RAW or XAVC-I so the data sizes are definitely double for me.

But isn't he reason you are getting similar file sizes for 30P and 60P long-GOP is because they are both being captured with a 50Mbps data rate? It's the same amount of data being captured every second regardless of how many frames it is being divided into. So obviously the trade-off is that 60P is having twice as much compression being applied to every frame as 30P. So even if 30P and 60P might result in files of similar sizes, I'd still rather shoot 30P with half the amount of compression being applied.

Ron Evans
May 19th, 2017, 09:14 PM
Yes you are correct with the average data rate but with Long GOP only the differences between i frames are recorded so there will be less movement difference between the 60P frames than 30P frames so more data is needed to be recorded for the differences for the 30P than the 60P per frame GOP making up for the fact there are twice as many i frames for 60P. Essentially using the data rate for i frames or difference data. The encoders are VBR too so peak data rate for 60P may also be higher. For a nominal 50Mbps XAVC-S the peaks are normally around 60Mbps for 60P in my files. So in practice there is not a lot of difference for lower resolution HD images. When the resolution goes up to UHD there is though. 30P at 100Mbps is about the same quality as 60P at 150Mbps. So potentially 50% more data for 60P at these higher resolutions a saving over RAW or I frame only encoders.. We are dealing with 4 times the image data moving from HD to UHD with double the data rate for 30P and 3 times for 60P. I believe to get similar quality from an I frame only encoder one needs over 400Mbps for 30P and even more for 60P of course.