24P not good for Steadicam Work?

[Sean Seah]

I have been wanting to shoot in 24P but I'm concerned that it will ghost during quick movements. I love to do those spinning shots around the subjects. So far 50P, 50i is ok. 25P had some ghosting.

I had a bad experience with Canon's 25F which resulted in a lot of shuttering (its like I can see the frame by frame updates!!) even when I was moving straight but at moderate speed.

Any advice?

[Perrone Ford]

Steadicam was invented for film use. That's 24p. It can be done and done well.

[Mark Schlicher]

Not sure what you mean by "ghosting." 24p always has more potential for blurring and/or strobing, just because it's fewer samples per second. This is a consideration that film cameramen have dealt with since the invention of the medium...for instance, care must be taken not to pan too fast.

The additional considerations with various digital camcorders are:

1. shutter speed. High shutter speed=strobing (the "Saving Private Ryan" look.) Slow shutter (like 1/24 at 24P)=excess blurring. Automatic and semi-automatic exposure modes often adjust the shutter speed without you realizing it. "Normal" shutter speeds for 24P are 1/48 (some prefer 1/60). Beware of "shutter off". On some cameras, like the HVX200, "off"= 1/48 at 24P. On others, like the HPX500, off=1/24 at 24P.

2. Shutter design. Some cameras, particularly CMOS-based, use a "rolling shutter' that is known to cause a "tearing" distortion on quick movements, including pans. This is a limitation of the camera design and you must shoot around it.

Originally Posted by Sean Seah

I have been wanting to shoot in 24P but I'm concerned that it will ghost during quick movements. I love to do those spinning shots around the subjects. So far 50P, 50i is ok. 25P had some ghosting.

I had a bad experience with Canon's 25F which resulted in a lot of shuttering (its like I can see the frame by frame updates!!) even when I was moving straight but at moderate speed.

Any advice?

[Sean Seah]

Thank Mark. I meant blurring/strobbing. That is something interesting to me. I have no experience in film so your explaination has given me some insight on where to start. My camera is a CMOS one and it does have a rolling shutter. I'll make some attempts with 1/48 and 1/60. I suspect 1/60 would work better in PAL land.

[Mark Schlicher]

If you're final product is going to be PAL then there is no benefit of 24P vs 25P. US films transferred to PAL have historically just been sped up slightly to 25P.

But, depending on what software you are using to go from 24P to PAL, you will either end up speeding up to 25P anyway, or the software may try to interpolate frames, which I suspect will lead to a whole lot of ghosting/blurring as an artifact of the post process.

The "normal" shutter for a PAL 25P shoot should be set to 1/50 (or 180 degrees, in filmspeak).

[Sean Seah]

I can deliver in 24P as the players here are mostly compatible. I work on the shutter test for both 24P and 25P. As you said, 25P may be a better choice at 1/50 shutter. I am aware some folks here use 1/60 with no issues when shooting in 50i.

[Dave Gish]

The majority of my work has been 24p. This includes:
• Sony EX1
• Panasonic HVX200
• Sony V1U
• Arriflex SR3 (16mm film camera - on a rented Glidecam V-20)
• Sony Z1U
• Sony EX3

All looked great on 24p.

As for shutter speed, I run my HVX200 at 200 degrees, which works out to around 1/43 sec. This seems to give it a more flowing look, and it also lets in more light than the standard 180 degree shutter. I read about this on a forum post somewhere, tried it out, and liked it immediately.

[Sean Seah]

Hi Dave. So that works out to 1/48 on the EX1? I found the article below from Sony's website:

Sony Product Detail Page - PMWEX1

Other than the standard electric shutter speed setting such as 1/100 seconds, shutter angle setting is available on the PMW-EX1 among 180, 90, 45, 22.5 and 11.25 degree. The shutter angle setting is popular in shooting with film cameras and is useful especially when combined with the Slow & Quick motion function. By using the shutter angle, the ratio between exposure time and a frame term is always consistent, whatever frame number per second is selected in Slow & Quick motion. In other words, the shutter "speed" varies depending on the frame number per second. For instance, if the shutter angle is 180 degrees, the shutter speed is 1/48 in 24P, and 1/60 in 30P.

[Dave Gish]

It looks like the EX1 is limited to 180 degrees or less. The HVX can go above 180 degrees. For the HVX200A, this may not matter. But for the HVX200, shooting in low light is not so good, so the longer shutter can help that a little. I also like the look of the longer exposure - seems more fluid. But if go significantly higher than 200 degrees, it gets blurry.

I think the EX1 also does pretty well in low light, so 180 degrees should work fine.

[Perrone Ford]

Originally Posted by Dave Gish

It looks like the EX1 is limited to 180 degrees or less.

Incorrect.

Originally Posted by Dave Gish

I think the EX1 also does pretty well in low light, so 180 degrees should work fine.

The EX1 can do shutter off also, but things in motion will tend to get blurry if they are close to the camera, or you are zoomed way in. I haven't looked at shutter speeds between 180 and 360, but will need to do so today, so we'll see.

[Arild Pedersen]

My experience with 24P:
When spinning around the subject, the DOF is important. It should be clear where the focus point is. Background should be little out of focus. It helps!

[Dave Gish]

Originally Posted by Perrone Ford

I haven't looked at shutter speeds between 180 and 360, but will need to do so today, so we'll see.

Yeah, let me know you like it. I found 24p / 200 degrees to be very nice on the HVX, but I guess it could be different on the EX1.