HV20 really has 1920x1080 resolution?

[DrTom]

I've enjoyed reading through this thread. I'm going to get a Blackmagic Intensity card and use it record from my Canon HV20 directly to my PC. I also recently enjoyed listening to the video review of the Intensity card at

http://www.4videoequipment.com/video...x1+Lane+MAC/PC

Where it clearly states (at about 1:10) that recording with the Intensity card via HDMI bypasses the compression chip in the camcorder. If so, I think is of interest to us.

I hope this helps.

DrTom

[2Bdecided]

I think this thread was "better" in terms of nailing what resolution "is"...

http://www.hv20.com/showthread.php?t=10886

...though it's a bit painful to read.

Cheers,
David.

[capitanfracassa]

I did some Imatest tests on an ISO 12233 resolution chart.

Horizontal resolution at center, camera @f/3.2

MTF @50 corrected for sharpening:
825 LW/PH in photo mode
644 LW/PH in video mode

MTF @30:
1030 LW/PH in photo mode
758 LW/PH in video mode


Hope this helps.

[joe12south]

Getting 600-700 lines out of a 1920x1080 bayer sensor is pretty damn good. Remember, the sensor has 1920x1080 photo sites, but they're divided between different colored cells, so the images pixels are actually being fabricated from much less actual data.

The huge increase in perceived resolution gained by recording live from the HDMI port is not the difference between 1920x1080 and 1440x1080, but rather the lack of picture mangling by the low data-rate, low color resolution HDV compression.

[Dleo]

I captured some footage recorded on tape via Fire wire, and recorded same footage from HDMI, and the HDMI looked better, and it corrected better, and it shows in the data that the color range is 4:2:2, in stead of 4:2:0. The footage captured firewire is good, but just slightly better through HDMI. I can't figure this out

Because isn't it recorded as HDV 1440x1080 anyway on tape.

Dleo

[Ian-T]

You are not the first person to say this. Yes it's recorded as 1440x1080 on tape. But the size is upconverted from tape 1440x1080--thru HDMI---back to 1920x1080 (still compressed...but bigger picture). It's still compressed though. With Live HDMI capture I think where you will tell a big difference is when something (or someone) moves. Motion will look much better thru HDMi than compressed MPEG-2. Of course color also.

[Dleo]

Wow!!

Ian-t,

I just looked this up, and there are lots of threads on this. I didn't realize.

Thanks for the info.

I'm going to check those out.

[Dleo]

I'm going to try the HDMI live capture thing, but it's real constrictive for on location shoots.. lol!!

dleo

[Dleo]

Well using the BM intensity card, and capturing live into my Raid 0 harddrive, and I keep getting these weird rolling lines in my captures. Thank god I also captured on MiniDV tape so I'm not screwed.

I'm returning the BM intensity today. I just don't think that capture card is meant for field work. It's a shaky piece of hardware at best.

I should have known by the price.

I advise to not use the BM capture card, it seems to be quite qwirky, and somewhat not stable.

Dleo

[Ian-T]

Weird rolling lines? Do you mean interlaced footage? I wish you could upload a sample of what you are describing. I'm not sure how the card works but when set up correctly it should capture better looking footage than what the HV20 can produce using HDV. There might just be something simple in the application you have to adjust.

[Dleo]

The rolling lines are caused by a bad signal, the card was set up right. I thought at first it might be the HDMI wire, but I tried it on a shorter really good quality HDMI cable, and it was the same issue. It worked perfect in my home.

I had this issue years before with a dazzle thingy I bought for SD analog stuff. Different pc -- Well different everything actually, and that turned out to be a bad card.

THE BM card worked well before I took it on location, but I must have damaged the card in the move some how(and yes I was careful--it's a$3,000PC),

All I can think of is the card is really sensitive, and I broke it during move, or something -- either way -- I'm done with that card.

The quality is great, bringing a PC with 4 500gb hardrives in a raid 0 configuration sucks, and i won't do it again.

So it's back to MINIDV and firewire for me.

I'll probably only burn SD DVD's anyway, and if I sell the film I'll let the distributors deal with the HD. lol!

Dleo

[sedate]

I've enjoyed reading through this thread.
i have hg10 and sr12 both records 1440x1080
sr12 sensor much more better than hg10
,,and,,sr12 have 10MP still picture quality is much more better than hv20, too( i used hv20 before)
what i understood that:
if 1920x1080=2.07 MP right? sr12 has ...........X........=10MP and records 1920x1080 full HD and HG10 ahs 3.1 MP sensor . it is s also 1920x1080 full HD records
why it records 1440x1080? am i doing wrong setting?
Can i think these 2 toys are 1920x1080 records ?
i was planning to buy canon hg21. do i have to cancel to buy????

[Duke]

The HV20 has ~3.1 megapixel sensor, which is for still pictures. It uses 1920x1080 portion of the sensor for videos. It saves the video onto tape within HDV specifications, which all HDV videotape cameras use 1440 wide.

If you want to get a full 1920x1080 out of the HV20 you need to use HDMI, a black magic card and a raid 0 computer.

Some CF card cameras record True HD, but the bit rate and size of sensor are also important.

[Duke]

Well using the BM intensity card, and capturing live into my Raid 0 harddrive, and I keep getting these weird rolling lines in my captures. Thank god I also captured on MiniDV tape so I'm not screwed.

I'm returning the BM intensity today. I just don't think that capture card is meant for field work. It's a shaky piece of hardware at best.

I should have known by the price.

Price has nothing to do with it unless you bought a knock off, or second. The Intensity is the only card and many have used it without problems.

Rolling lines means something is defective. I've never had that with my intensity card, ever. I have it in a field unit. Maybe your card worked it's way loose? Maybe you're capturing at the wrong speed? If not return it for another card.

Oh, and make sure all your antivirus, etc software is off. Your CPU is loafing, but if something makes a read on a hard drive it could be interupting.

And i'm presuming you're capturing uncompressed. Don't use Mjpeg, it defeats the purpose. Of course uncompressed makes BIG files, like a terabyte in a few hours. Compress with loseless compression later when you're ready to edit.

[Dleo]

Rolling lines means something is defective. I've never had that with my intensity card, ever. I have it in a field unit. Maybe your card worked it's way loose? Maybe you're capturing at the wrong speed? If not return it for another card.

According to B&H they have had this problem before, and according to Black Magic it happens sometimes. I can't afford for it to happen sometimes.

It's the Card for sure not my processor or PC. I tested the card on another PC, and it happened again.

I returned it! I will never use a Black Magic product ever again. I'm lucky I recorded on tape is well or my whole day of shooting would have been waisted. I had 6 actors and crew people at the shoot at a cost of $500 that day of shooting, and I'm lucky I shot with the tape in, because nothing captured through the card was usable.

dleo

[Ian-T]

Wow...you are actually the first person I've heard of that happening to.

[Dleo]

To Black Magic's credit they sent me out a new card, and still refunded my money. They said, after checking out the one i sent them
"the card was defective." So I'm back to using the BM intensity card again.

The people at Black Magic were quite reasonable, and very apologetic. I retract my statement.

I will never use a Black Magic product ever again

And will try using it again. They said they tested the new one they sent out to me, and it should be fine.

dleo

[Dleo]

It should be here next week if the xmas craziness doesn't slow it down to much.

Dleo

[nobbystylus]

The HV20 has ~3.1 megapixel sensor, which is for still pictures. It uses 1920x1080 portion of the sensor for videos. It saves the video onto tape within HDV specifications,

wouldn't it be nice if it used the 'entire 3.1 megapixels' of the sensor and scaled the results down to 1920x1080. We'd get better control of depth of field for sure..

[Duke]

Have a look at Ian-T's thread HERE. It may well work.

[APXIAC]

With the HV20/HV30 you can bypass the tape compression and capture live HDMI.
So with that being said, I have two questions...

1: Can you capture live via FIREWIRE and still get passed the compression?
2: Does the Canon XH A1 work the same way? Could I bypass the tape compression on this camera as well? Whether it be via FIREWIRE or HDMI?

[um3k]

Capturing live over Firewire gives the exact same result as capturing from tape. So, no, you cannot bypass the compression with Firewire. In the case of the XH-A1, I think it has HD-SDI instead of HDMI, which carries a similar signal, but perhaps higher quality.

[Ian-T]

No the SDI is not higher quality...it would be the same but is used for more professional use because it has the ability to send timecode (I believe) and other things over its signal. And the A1 does not have either HDMI or SDI....only component which is just as good even thou it's analog (IMO).

I know that's a controversial statement for some folks but component is just as good as HDMI/SDI (in terms of video quality). But that really depends on what you are capturing with.

[Duke]

The Xh-G1 has HD-SDI, the XH-A1 does not. It is my understanding that HD-SDI is the same signal as HDMI so only a simple adapter is needed. The G1 breakout box has timecode/gen lock. The A1 is only component, which is HD analog rather than digital. A $50 powered adapter is needed to convert component HD to HDMI, which it does rather nicely.

I use the A1 for capture and the HV20 for HDMI and firewire playback. The HV20 has no problem recognizing the 24F format in addition to it's own formats. (I always thought it was interesting that Canon designed it to do that.)

[APXIAC]

So I could bypass compression with the Xh-G1 via HD-SDI then?