basic questions on the EX

[Piotr Wozniacki]

Forgive me the naivity of my questions, but here they go:

1. The EX is advertised as 'native 24p' capable; does this mean it writes full frames rather than segmented frames (fields), like the V1?

2. What exactly does the SHUTTER on/off switch do? What does it mean to switch shutter off?

[Chris Hurd]

Originally Posted by Piotr Wozniacki

2. What exactly does the SHUTTER on/off switch do?

On other cameras where I've seen that before, it refers to "Auto Shutter Control On or Off." In other words, most likely it's a switch for auto shutter vs. manual shutter.

[Piotr Wozniacki]

Yeah, this sounds like the only possible explanation to me. But why drop "Auto"? We're all used to switching between auto and manual settings of many things, including the shutter - so seeing the SHUTTER ON/OFF switch underneath the EX's lens barrel made me wonder...

[Don Bloom]

the Sonys are weird. To control the shutter speed manually you need to switch the shutter switch on the front of the camera to ON that is if it's anything like the DRS250.
Confusing but that's how it works. Otherwise the shutter is in the auto mode.

Don

[Thomas Smet]

Originally Posted by Piotr Wozniacki

1. The EX is advertised as 'native 24p' capable; does this mean it writes full frames rather than segmented frames (fields), like the V1?

I'm not sure 100% but I think they are true 24p frames. At least this is how I understand the higher end XDCAMHD cameras to handle 24p. With those cameras it is my understanding that the progressive modes really do encode the mpeg2 video as progressive. This explains why keying works so well with progressive footage from the XDCAMHD cameras. As for the EX using this same method I do not know. I would like to think they would since this camera is supposed to compliment the higher end cameras. I'm sure there would be a lot of grunts and complaints if SONY did it in a different way for the EX.

[Tom Vaughan]

Originally Posted by Piotr Wozniacki

Forgive me the naivety of my questions, but here they go:

1. The EX is advertised as 'native 24p' capable; does this mean it writes full frames rather than segmented frames (fields), like the V1?

This would imply (or guarantee) that each frame is captured, encoded and stored as a full field, as opposed to capturing, deinterlacing and gluing together 2 interlaced fields to make a pseudo-progressive frame.

The same should be true for other progressive frame rates, including 720p60.

Tom

[Piotr Wozniacki]

Tom, it sure would, but my question is if it actually does:)

[Greg Boston]

XDCAM HD captures as 24PsF which is progressive segmented frame. The sensors are progressive and capture a progressive image, but it gets segmented into two fields. However, those two fields don't have any motion delay between them because they are captured at the same point in time.

As to the shutter switch... it's fairly common for high end video cameras to have this switch. Basically, in the off position, the shutter speed is identical to your frame rate (24p=1/24, 30p=1/30, etc.). When you turn on the shutter switch, you are informing the camera that you wish to alter the point at which the charge is read from the CCD pixels as opposed to the time period equal to 1 frame... effectively creating an electronic shutter. For the slow shutter mode, the charge is allowed to accumulate longer than the period of a single frame before being dumped and read out into the registers.

I suspect, but can't confirm, that the XDCAM EX will employ the same method of 24 and 30 fps to maintain compatibility with the existing models as far as NLE's are concerned.

-gb-

[Alister Chapman]

Reading between the lines I expect the EX will have the same shutter features as the F350/F330, so as well as the usual shutter speeds that are fractions of the actual shooting frame rate there will probably also be a range of slow shutter speed.

The advantage of PsF frames is that they can be handled by interlaced systems as well as progressive systems. By using PsF you can drop progressive material into interlaced projects with ease. HDCAM also uses PsF.

[Piotr Wozniacki]

Thanks Greg. It surprises me a little that the XDCAM HD also uses 24(5)PsF, like the V1 I'm using now. Many viewing devices (even high-end HDTVs) have problems with properly interpreting the progressive segmented frames when fed withing a standard 1080/50(60)i stream, in that they try to deinterlace it which causes heavy line twittering. I hoped this wouldn't pose a problem with the EX...

Another disappointment arises from the fact that using 24PsF means the whole pull-down removal stuff will still be there to complicate things... Since (due to the BD-HD DVD specs promoting 24p over 25p even in Europe) I'd probably be using 24p more often than 25p, I was hoping it's coming without those probs that we the PAL users didn't have so far...

Regarding the shutter thing, yes I remember somebody saying something like "I only use (switch on) the shutter when..." or something like this, and it was a high-end professional cameramen talking. After your explanation, the SHUTTER ON/OFF switch does make a perfect sense.

[Piotr Wozniacki]

Originally Posted by Greg Boston

As to the shutter switch... it's fairly common for high end video cameras to have this switch. Basically, in the off position, the shutter speed is identical to your frame rate (24p=1/24, 30p=1/30, etc.).

When I give it a second thought, it sort of answers another questions the V1 and Canon A1 users often ask: why - when you switch from interlaced to progressive, and the shutter is auto - does the camera always default to the shutter speed identical to the frame rate? E.g. with my PAL model, the default shutter speed is 1/25th and the progressive frame rate is 25fps... Now it seems logical, and answers the doubts of those who claimed that in progressive mode (considered also to be the most 'filmic' setting), the default shutter speed should be that of a film camera, i.e. 1/48th for 24p etc...To use the analogy with high-end cams, in progressive mode the shutter is being switched off by default on those semi-pro machines.

I never used film cameras, so I've always been happy with my V1 switching to 1/25th when in progressive (25PsF) mode. Apart from very bright conditions, when even ND2 filter is not enough and I would have to close the iris beyond 5.6 (which I never do because of diffraction softening) - I use 1/25th a lot. Which means, that should I be lucky enought to buy the XDCAM EX one day, I'd not be using the shutter at all (to translate it into the high-end cams jargon) :-)

[Todd Giglio]

Originally Posted by Piotr Wozniacki

Thanks Greg. It surprises me a little that the XDCAM HD also uses 24(5)PsF, like the V1 I'm using now. Many viewing devices (even high-end HDTVs) have problems with properly interpreting the progressive segmented frames when fed withing a standard 1080/50(60)i stream, in that they try to deinterlace it which causes heavy line twittering. I hoped this wouldn't pose a problem with the EX...

Another disappointment arises from the fact that using 24PsF means the whole pull-down removal stuff will still be there to complicate things... Since (due to the BD-HD DVD specs promoting 24p over 25p even in Europe) I'd probably be using 24p more often than 25p, I was hoping it's coming without those probs that we the PAL users didn't have so far...

Hi Piotr,

I'm pretty sure that the XDCAM EX does not use the same progressive format that the V1 uses. The V1 places it's 24p in a 60i stream thus requiring the pull-down that we all are facing. The XDCAM EX encodes in two fields creating the progressive image (your NLE will detect this as true 24p meaning no pulldown; I'm going off what I've studied, so forgive me if any info is incorrect). Trust me Piotr, if the XDCAM format had the same 24p issues the V1 has we would have heard about it all over this forum (and the XDCAM would have definitely been referenced in the V1 forum... so there is hope)

Todd

[Piotr Wozniacki]

Originally Posted by Todd Giglio

Hi Piotr,

I'm pretty sure that the XDCAM EX does not use the same progressive format that the V1 uses. The V1 places it's 24p in a 60i stream thus requiring the pull-down that we all are facing. The XDCAM EX encodes in two fields creating the progressive image (your NLE will detect this as true 24p meaning no pulldown; I'm going off what I've studied, so forgive me if any info is incorrect). Trust me Piotr, if the XDCAM format had the same 24p issues the V1 has we would have heard about it all over this forum (and the XDCAM would have definitely been referenced in the V1 forum... so there is hope)

Todd

So basically what you're suggesting Todd is that it's NOT going to be 24PsF, right? But hey, the EX is not going to differ from the current XDCAM HD in this department, so there are people around who actually know rather than speculate on this!

[Todd Giglio]

Originally Posted by Piotr Wozniacki

So basically what you're suggesting Todd is that 24PsF will be edited just like the 25PsF is now with the V1E?

Actually I believe that your NLE will recognize that the XDCAM EX footage is already 24 'true' progressive (where the V1 us recognized as interlaced; the NLE has no idea that the footage from the V1 is progressive).

I really don't think you have to worry about the way you'll have to edit the XDCAM footage (I'm in the same boat as you with the V1).

There is a gentleman named Greg Boston who posts quite frequently who owns a couple of XDCAM's so he could probably give you more information about the capabilities of the way the camera handles 24p.

Todd

[Piotr Wozniacki]

Originally Posted by Todd Giglio

Actually I believe that your NLE will recognize that the XDCAM EX footage is already 24 'true' progressive (where the V1 us recognized as interlaced; the NLE has no idea that the footage from the V1 is progressive).

I really don't think you have to worry about the way you'll have to edit the XDCAM footage (I'm in the same boat as you with the V1).

There is a gentleman named Greg Boston who posts quite frequently who owns a couple of XDCAM's so he could probably give you more information about the capabilities of the way the camera handles 24p.

Todd

Well, actually it was Greg himself who stated a couple of posts ago the XDCAM HD uses segmented frames, Todd:)

And BTW: I have no problems editing the 25PsF from my V1E using Vegas; it recognizes it correctly as progressive even though it's burried within the 1080i stream. My problems start when I play back my clips with anything other than a software MPEG2 player that has the option of switching deinterlacing off - there's been a long and detailed thread on this in the V1 forum, you can search for it and see why.