please post 60i-footage with 1/30 shutter

[ib84]

Hello,

could please someone make an easy test?
if the shutter takes as much time as 2 fields, the two fields could contain the two parts of the identical image. So, deinterlacing in the most simple form ("blending" or "combine fields") should result in >effective 30p< !!
Also 1/50 could be this hidden "progressive" (everything longer than 1/60), otherwise the shutter and the frames would get asynchronous.
Only drawback is the need of long shutter.

So could please someone make two identical records in 60i:
at 1/30 and
at 1/50 shutter.

set with manual shutter (can you set the shutter?). Alternatively choose a rather dark environment. also do some movement in each of them to see effect of motion blur.

thanks a lot for trying, it could give us 30p !

[Mal]

I know what you are saying, unfortunately the logic is slightly flawed.
Yes, you can "convert" ANY interlaced signal to a deinterlaced one; but that holds true then for all video cameras, even old tube cams, vhs and all that.

The best deinterlacing is still not as good as a progressive capture though. Which is why cams such as the DVX100 and now the HV20 are such a success.
But sure, you can easily convert a 60i signal to 30p.

[ib84]

I know what you are saying, unfortunately the logic is slightly flawed.
Yes, you can "convert" ANY interlaced signal to a deinterlaced one

i know that. it´s not what i meant. deinterlacing stinks.

did you never ever wonder how is it possible that there even exists 1/30 shutter in 60i mode?

[bruny]

I'm not sure what you mean by 1/50th. the settings on my HV20 are 8,15,30,60,100,250,500,1000,2000. Is 1/50th for the PAL version?
<edit>
I shot a clip of one of my dogs (fresh from the dirt pile out back) wagging her tail and with her favorite bone - shot it at 60i on the Tv setting, with 4 seconds at 1/30th, and 4 seconds at 1/60th. No sound. Rendered it out of FCP at the "current settings" (HDV 1080 60i). it can be found here, for a while (http://www.gate4productions.com/HV20-1080-60i-shuttertest.mov): (27MB download or so). The tail wag is the important part, as far as interlacing goes...

Going frame by frame through that, it appears that the conjecture is correct. I see no interlacing at 1/30th. Although, I think the more strange thing is that we would see any interlacing at all...the interlacing must be manufactured to conform to the 60i spec. After all, it is a *single* chip camera...so by definition it's progressive, right? Or am I missing an important part of the puzzle?
</edit>

[Tomtebo]

nice footage. Dose anybody use the cinema mode on the hv20?

[ib84]

thank you bruny for the clip! great news it seems to work the 30p!!


I'm not sure what you mean by 1/50th. the settings on my HV20 are 8,15,30,60,100,250,500,1000,2000. Is 1/50th for the PAL version?

i don´t know what settings there are, unfortunately in europe they don´t have HV20 yet...:hv20-smilie36:
that´s why i was asking for footage...
yes, maybe for PAL there will be 1/50.



I shot a clip of one of my dogs (fresh from the dirt pile out back) wagging her tail and with her favorite bone - shot it at 60i on the Tv setting, with 4 seconds at 1/30th, and 4 seconds at 1/60th. No sound. Rendered it out of FCP at the "current settings" (HDV 1080 60i). it can be found here, for a while (http://www.gate4productions.com/HV20-1080-60i-shuttertest.mov): (27MB download or so). The tail wag is the important part, as far as interlacing goes...

nice dog... :-)



Going frame by frame through that, it appears that the conjecture is correct. I see no interlacing at 1/30th.

:hv20-smilie70: (good occasion to try out these smilies...)

that´s great! no interlacing!
Like this you have much more fluid and NTSC-compatible progressive, at least for low-light!
Otherwise you just overexpose...

how dark was it in your room? do you think it is of any use outside? probably only when sun is gone already...


I hope in the european version there will be 60i too... otherwise i won´t have this 30p thing. 50i would allow only for artificial 25p, but this is no advantage over regular 25p...
But still PAL brings the advantage of 15% more bits in 25p than 24p (if HV20 really uses >hard< -telecining) and 20% more bits in 50i (the 25mbits distribute over 20% less fields)




Although, I think the more strange thing is that we would see any interlacing at all...the interlacing must be manufactured to conform to the 60i spec. After all, it is a *single* chip camera...so by definition it's progressive, right? Or am I missing an important part of the puzzle?


you are right, for me it´s a complete miracle too, why they still maintain interlacing, if all the camcorder itself is progressive... (most 3CCD are progressive too).
anyway, for TV-compatibility they could probably interlace it in real time with no problem and give the rest of us peace of interlacing...


thanks bruny!!

[bruny]

that short clip was shot in the garage, which, while having recessed lighting (recessed lighting in a garage? wtf?!? :-) was not very bright. I would equate that with a dimly lit room. She was laying between the pools of light.

:-) You asked for movement in the picture and I knew the happy dog would eagerly comply....

On the XH-A1 I use at work, there's a switch to turn off the automatic gain. I wish I had that here. I don't mind dim, but I would prefer to avoid the grain.

Shooting at 1/30th shutter outside...I think it may be too bright for that on a normal sunny day...don't know. I'm just learning about Aperture/Shutter and how they affect the picture, so I'll let someone a lot smarter than me chime in on that...

[nodeal]

(recessed lighting in a garage? wtf?!? :-)


Ha :hv20-smilie03:

[Alsone]

On the subject of unusual shutter speed choices, I know someone who uses 1/25th @ 25P instead of the more usual 1/50th. It produces very good low light results and no real blur, which surprised me. Only thing is its a little too light for my tastes as in my opinion it takes away from the lighting / lasers etc but I really can't fault the quality of the video footage. Shot on an A1.

You may or may not be able to view this. If not and you have a Facebook account, log in the retry:

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PS I'm not responsible for the quality of the dancing!!!