GH2 in Europe: 25PsF, or not?

GrahamH

GrahamH

Well-known member
I got yelled at in the forum last week for expressing doubts that the PAL GH2's 50i is actually 25PsF, as claimed by some (i.e., progresive segmented frame, used by the Sony NEX-VG10).

Retail PAL GH2's have been roaming the streets for some days now - can someone please resolve this!
 
greymog said:
the nexvg10 is 25 segemented in 50i? you can get 25p out of it?
Click to expand...

That's what I understood from the Luminous Landscape VG10 review: "So if you are looking at a Sony AVCHD camcorder that is speced as 60i, be assured that where the rubber meets the road (in your NLE) you will likely be working with true 30P footage. I can't imagine how many camcorder sales Sony loses each year because of this confusion." http://www.luminous-landscape.com/reviews/camcorders/vg10.shtml

This comment is about the NTSC cam, but I believe the same is true for the PAL version.
 
GrahamH said:
That's what I understood from the Luminous Landscape VG10 review: "So if you are looking at a Sony AVCHD camcorder that is speced as 60i, be assured that where the rubber meets the road (in your NLE) you will likely be working with true 30P footage. I can't imagine how many camcorder sales Sony loses each year because of this confusion." http://www.luminous-landscape.com/reviews/camcorders/vg10.shtml

This comment is about the NTSC cam, but I believe the same is true for the PAL version.
Click to expand...

That is correct they use 1080i psf. You can download samples from dpreview and check for yourself. However, I wouldn't think this would make them lose sales. The average person can't tell the difference between 1080i and 1080i psf. They won't complain at all. The user that does know the difference should ask for the psf. Progressive video is ALWAYS better than interlaced since all displays are now progressive.

I dream of a day when we no longer have to discuss interlaced footage. Its like going back in time to the civil war era with a machine gun and saying yes it can fire many shots in a row with one single trigger press. However, we thought you were just too accustom to pressing the trigger every time so we made it semi-automatic for you. The soldiers would just remove the mechanism that prevents it from being fully automatic and then shoot you in the back for taking it away in the first place.

Maybe Vitaliy can be our soldier? Just in a more peaceful manner.
 
They can lose sales because people ask for 25p and see only 50i in the specs.
So they have it, but they only give it under 50i Psf, resulting in a quite stupid commercial strategy.
 
Chaps

I've just taken 2 very crude indoor clips, shot at ISO 3200 1/50 and 1/40 (to try to fudge 25p) f4.0 with the 14-140, in FSH mode 1080/50i. This is on a brand new EU GH2 (UK) delivered this morning from Mathers.

Playing back both clips in VLC shows that the video is completely interlaced as presumed. I'm not sure what's happening with the 1/40, but it's still interlaced on playback.

EDIT: Further to this, I've analysed both clips in Stream Parser, and it shows as 1080/50i

Clip 1 (1/50):
File: D:\PRIVATE\AVCHD\BDMV\STREAM\00079.MTS
Size = 50,632,704 Bytes (263,712 Packets)
Stream: Max Speed = 18,382,980 bps
Mode = 1080/50i
PCR Timing Interval = 0.095 seconds
Clip Time = 0:00:24.04
Average Total Bitrate = 16,849,485
Average Video Bitrate = 16,132,214
Average Audio Bitrate = 235,234
Average Other Bitrate = 482,036
Max GOP Size = 1,094,016 Bytes (8,752,128 bits)
Video Frame Size (Min/Ave/Max)= 29,376 / 82,261 / 207,168

Clip 2 (1/40)
File: D:\PRIVATE\AVCHD\BDMV\STREAM\00080.MTS
Size = 43,905,024 Bytes (228,672 Packets)
Stream: Max Speed = 18,382,980 bps
Mode = 1080/50i
PCR Timing Interval = 0.095 seconds
Clip Time = 0:00:20.68
Average Total Bitrate = 16,984,535
Average Video Bitrate = 16,264,363
Average Audio Bitrate = 235,272
Average Other Bitrate = 484,899
Max GOP Size = 1,107,840 Bytes (8,862,720 bits)
Video Frame Size (Min/Ave/Max)= 22,464 / 82,988 / 227,520
 
jazzroy said:
They can lose sales because people ask for 25p and see only 50i in the specs.
So they have it, but they only give it under 50i Psf, resulting in a quite stupid commercial strategy.
Click to expand...

If you know what 25p means and when you actually need it then you will certainly know to look for 1080i psf. If you don't know to look for 1080i psf then you probably don't actually need 25p.
 
Upload some 50i clips when yo get chance, native, so we can have a look with stream parser? wonder what the technical hitch was with the 2 week delay, wonder if they may add f/w update at some stage? mine wont come until next week, weather has completely screwed the delivery system in the NE of UK.
 
Just uploading said 'very' crude clips. ISO 3200 and a baby toy swinging about. AF all over the show :)

Be about 12-15 mins according to dropbox.
 
Dropbox uploader crashed first time round. Using the basic uploader now...hang tight, I know how crazy everyone gets on these new releases :)
 
Converted the first clip to Cineform and examined frame by frame and field by field (using Viewfields 1.2). There are 50 distinct field per second. It is definitely not PsF.
 
What about clip 2. I'm wandering what it does when the shutter is longer than the frame rate. It looked markedly interlaced to me, so wasn't sure what was going on.
 
Interesting ... the second clip, shot at 1/40th apparently, has pairs of fields that are the same. But their frame by frame sequence is not AA BB CC DD EE, but instead is AB BC CD DE EF. So each frame still exhibits interlacing, but if you unweave, delete the very first field, and then reweave it doesnt.

I have seen exactly this before ... with my 60i Sony HC1 when shooting at less than 1/60th.
 
GrahamH said:
Interesting ... the second clip, shot at 1/40th apparently, has pairs of fields that are the same. But their frame by frame sequence is not AA BB CC DD EE, but instead is AB BC CD DE EF. So each frame still exhibits interlacing, but if you unweave, delete the very first field, and then reweave it doesnt.

I have seen exactly this before ... with my 60i Sony HC1 when shooting at less than 1/60th.
Click to expand...

So with the frig from hell, you've got 25P :) Bonus! (joke)
 
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