NEX VG-30, 30p?

[Ron Little]

What frame rates will the NEX VG-30 shoot. I mostly use 30p so I am trying to figure out if this camera will work with my other cameras. What I glean from the specs is you can shoot 24p 60p and 60i. Do you shoot at 60i and interpret as 30p? I think this is going to be my next camera but I want to make sure it will work.

[Ron Evans]

I would shoot at 60P. Then you full resolution for all the frames.

Ron Evans

[Ron Little]

That sounds logical. So what is the process for converting 60p to 30p? I assume you drop 60p on a 30p time line and speed it up by 50%.

[Ron Evans]

I don't think that you need to do anything more than drop it on the 30P timeline. I don't use 30P so I am no expert but just tried dropping on of my 60P clips on a Vegas 30P timeline and rendered as 30p and it just seems to work. Created a clip of the same length and audio as the original just that the frame rate is 30P not 60P.

Ron Evans

[Ron Little]

Thanks, for the input guys. I am going to wait till after NAB, but this looks like my next cam. Or should I say NEX CAM.

Oh, and while we are talking about the NEX-VG 30... Is anyone using a NanoFlash with one that would like to share their settings?

[Stephen Gradin]

I am very interested in this camera as well and shoot 30p with my older Sony HDV cameras. I do this so I can have the option to reduce my shutter speed to 30 in low light situations. This works great as I do not have to increase gain (gives me cleaner image). I do not think this would be a viable solution if I now have to shoot in 60p. I do not think filming in 60i with 30 shutter would work either. Perhaps I need to rethink this and get EA50 instead, which can shoot 30p natively. Thoughts?

[Stephen Gradin]

Okay, to follow up on my earlier post, I just did a camera test, using 4 different settings on my older Z7U camera to see if not having a 30p option on the VG30 would be a deal breaker:
1) 1080 30p, 60 shutter
2) 1080 30p, 30 shutter
3) 1080 60i, 60 shutter
4) 1080 60i, 30 shutter.
I filmed picture frames and books, doing slow pans and tilts. I normally shoot in 30p for most of my projects, both corporate and events. I like the progressive look, plus the use of 30 shutter with 30p is a better low light alternative than shooting 24p with 48 shutter (I have done that comparison test before). As long as I keep the camera panning slow and to a minimum, change to 30 shutter when the lights are low, I can get away with not having to up the gain on the Z7U in most situations (like wedding receptions). The Zeiss lens on the Z7U is so fast throughout its entire zoom range, I almost always get footage that is clean and noise free.

I dropped all the samples on a 1080 30p timeline. I saw no difference between the two 60 shutter samples or the two 30 shutter samples. So, my thinking is that if/when I get the VG30, if I want to stick to 1080 30p (to match my other cameras), I would set the VG30 to 1080 60i, 60 shutter or 30 shutter (when necessary), drop the footage on a 30p timeline and I should be good to go. The reason for all this is that I want to keep using my older Z7U cameras and add the VG30 for Steadicam shots and corporate gigs and mix the footage when necessary. If anyone has had luck or issues with mixing the VG30 with their older Sony cameras, or the lack of 30p on the VG30, please chime in.

[Craig Marshall]

Although I'm in 'PAL' land, I'm considering switching over to shoot 50i @ 50th or 100th shutter, rather than 50P. The reason for this is to reduce 'temporal' aliasing, ie: the slight jerkiness between 50p/60p frames. Although the absolute resolution of each 50i/60i frame may be slightly less than a 50p/60p frame, you may achieve a smoother pan and here's why: The best way to explain this technically, is to quote from an engineering friend of mine:

"This (ie: 50p/60p) is what gives it that tiny bit of jerkiness. It is tied up with shutter speeds and is apparent in all moderately priced electronic cameras. The higher end and thus more expensive ARRI Alexa and RED cameras apply an electronic shutter filter to the image. This has the effect of dissolving, if you will, between the original and the filtered image, resulting in a more smoother transition between the on/off shutter or exposure. This is done I believe around the 12Hz region.

One of the advantages of 50i/60i material is the fact that any movement of the frame through say panning is shared across 2 fields albeit half vertical resolution per field but the movement is smoother so I think you will get far better results using 50i/60i as your record format and less encoding artefacts during BD production. Temporal aliasing is not anywhere as noticeable using 50i/60i as well which is why broadcasters prefer it. Full resolution Progressive frames or Progressive Sequential Field recordings both exhibit the problem but interlacing results in a halving of the movement within a frame over 2 fields.

"...high frequency details (trees and leaves particularly) really pushes the ability of the sensor to charge and discharge at 50p/60p whereas halving this high frequency with 50i/60i recordings, minimises the aliasing requirements. 50P/60P recordings are wonderful, don't get me wrong but they really shine as static images rather than pans or where there is fast action contained within the frame. This is why the higher end cameras use shutter filtering circuits."

[Ron Evans]

At the same shutter speed the temporal motion for interlace 60i or progressive 60p is the same. One just takes a field the other a full frame. So motion blur is the same whether panning or zooming. That is governed by shutter speed, same shutter speed, same blur. I see no difference with either my CX700 or NX30 shooting in 60i or 60p with the same iris and shutter speeds.

60i and 60p take the same number of exposures. One records fields the other frames. On playback 60i also plays back 60 exposures as fields and the TV de interlaces to 60P for LCD or plasma and displays all 60 fields on a CRT .

There is a big difference shooting 30p and 60i as 60i is much smoother since there are twice as many exposures of the camera even if they are just fields. In my mind 60p is much better.

As far as sensor refresh is concerned I think most have been progressive for a while it was the rest of the processing that was the problem in encoding for recording or direct output encoding. Since earlier sensors were also not full 1920x1080 they also had to be interpolated to make full HD, more compute power or they had to be de Bayered from a single sensor. That compute power is what makes the camera hot !!! So yes it was easier to processes every other line as an interlace output. At least that is how I understand it. When you think about it the sensors have to be read out through a shift register so all the pixels get read ( progressive content) but not all need to be processed further depending on output needs. However, they probably are used for electronic image stabilization, noise reduction, face recognition, etc etc. With no deliver spec for 50P/60P at full 1920x1080 there was little incentive to provide output for Pro cameras ( most still do not have the frame rate) however for the consumer feeding their TV directly from the camera the progressive output is beneficial. TV shows what the camera took not the result of the TV de interlacing circuits. Smooth clear images and much better stills captured from the video if needed. Its why I shoot 60P for all my family stuff. You of course need to tell the TV that the input is progressive !!!

Ron Evans

[Kate Spiegel]

I find 60p to be darker than 60i even though all the other settings are exactly the same. Has anyone else noticed this or am I doing something wrong? I use a vg20.

[Stephen Gradin]

One of the things I mentioned in my earlier post is that I like to shoot 30p with my older Sony HDV cameras. The 30p setting on my cameras defaults to 30 shutter anyway but I use 60 shutter most of the time and only 30 shutter in low light situations to avoid increasing the gain. (I have not tried using 30 shutter with 60i in a 60i project but I hear it looks bad). The 30p/30 shutter combination I have found to be better in low light than 60i/60shutter or 24p/48 shutter (24 shutter is too blurry for my taste). I make sure though that I do not shoot too tight if there is a lot of side to side movement in the frame. For instance, during side to side slow dancing, Greek dancing, the Hora, or someone who rocks sideways when doing a toast. I will only shoot tight when I can pan the camera with them (like when someone is walking). If there is a lot of pixel movement in the frame, yea, things will look a little blurry. If I adjust my framing a bit wider when using 30p with 30 shutter, I have good results and a lot less grainy image than if I shot 30p/60 shutter under low light.

30p is 30 frames per second. 60i is 60 fields (2 for each frame), but it is still 30 frames per second. 60p is 60 frames per second. I do not yet have a camera that shoots 60p, but I assume this would not be the way to go in low light situations since the higher the frame rate, the more light loss occurs (and vice versa). This is why I plan on filming with the VG-30 in 60i and then bring the footage into a 30p timeline. I am almost certain this will match my older cameras that are recording 30p for that progressive look which I like and use 30 shutter when the lighting is low. I believe this is the best scenario in low light conditions. I will certainly try 60p when the lighting is good and see how it compares to my older cameras, when the time comes of course.

[Ron Evans]

60i and 60P take the same number of exposures and have the same temporal motion . Timecode for 60i is 29.97fps , timecode increments every 2 fields, but you are actually seeing 60 exposures just like 60p, not 30 exposures, they just happen to be half the vertical resolution, fields. They don't get combind into 30 frames. I know its very confusing the timecode being different to the exposure rate.

Ron Evans

[Stephen Gradin]

But if I shoot 60p and drop this footage onto a 30p timeline (with my older cameras at 30p), will this 60p footage drop to half speed? This is the impression I get. Let me know if I am wrong here.

[Ron Evans]

No it will play at its normal speed. If you export or render then it will be converted to 30P. You can of course slow down to half speed with full resolution as there is more data to work with.

Ron Evans