Shutter angle/speed for 50p shot for 25p edit? GH5, Atomos Ninja Inferno, FCP X

[Claude Lyneis]

Really looks great. Love the bokah and the color depth.

[John Wildgoose]

I think most of this was shot on a 70-200 f2.8 as it’s very adaptable for fast changing subjects that move around without control.

More predictable shots are done on f1.4 and f1.2 primes. This was all shot on 5DIIIs with a SmallHD monitor. I’ve changed a lot of the workflow now and I think I’d get a lot more detail in the shadows and highlights. But for small videos embedded in a web site it worked, the editor was certainly very happy with what I supplied, so that was my benchmark for quality at the time.

I have changed the gear too. I now shoot with a GH5, metabones speed adaptor and primarily a 16-35 f2.8 (giving me an effective open iris of f1.8). This allows me to get closer and still see a lot, and it works nicely with my favoured compositions. On a shoot I’d take the 70-200 f2.8 as well. I have a problem with the faster 24-70 as the zoom telescopes making it impractical to use in my Tilta rig with the matte box. But that might mean giving up a stop (f4 which would make me unhappy).

[John Wildgoose]

thanks Claude,
I have to say given how much I’ve moved on since that shoot, I’d love to have another stab at it, I’m sure I’d get a lot more from it (and the highlights and shadows too!!).

[Kevin Rag]

Thanks John:) Just picked up a GH5. I already have a few MFT primes. Will get a Speedbooster and the Sigma soon.

K

[John Wildgoose]

ok, I’ve done some tests to see and my conclusion is that you can’t shoot 50p and run it at normal time in a 25p project as it looks too staccato, even shooting it at 80th (compromise!).

Oddly, I did my test of the 25p shot clip at 40th as I like the little bit of extra motion blur it gives, but if you do that with a 50p clip at 80th/s slowed down by 50% it shows a bit too much motion blur, so I went back to 100th/s and… much better! So that doesn’t add up! I’ve added that clip to the test (last one) for you to see what I’m on about.

Anyway, here you go.

https://www.youtube.com/watch?v=Ie8PztNSv3o
Interestingly, I just watched this on a 49inch 4K monitor and the 1080p at 10bit from the GH5 almost cuts it!

I’ve avoided adding the ubiquitous heavy metal track to make it appear more exciting than it is!

[Claude Lyneis]

Very interesting. After a few tries, I could see a difference in how your fingers looked as you tightened a screw. The 50p inserted into a 25 p project did show a slight lack of smoothness (less motion blur). Of course this is viewed on a 27 inch mid 11 Mac not a 5k screen.

One thing I am not sure of. If some a video using some 50 p and some 25 is mixed as you have done first with the 50p inserted into to 25p project and then second with the 25p inserted into a 50 p project, is the result the same?

[John Wildgoose]

Hi Claude
It didn’t occur to me to test it this way, as I can’t see any material benefit. But if it’s a 50p project then I’m assuming shoving a 25p clip in it is going to make the clip stagger horribly due to a 2:1 frame deficiency. Unless you sped the clip up of course, and why would you do that, other than to replicate that old 1960’s trick of making a car chase look faster, but horribly, horribly wrong at the same time?