Questions about 24p modes with HMC150.

L

lalittle

New member
I did try searching for this information, but I couldn't find it with the search terms I was using, so please forgive me if this has already been covered.

I'm a bit unclear about some aspects of the HMC150's 24p mode/s. According the documentation for this camera, it uses 1080/60p "as a basis for all captures." It says that everything "starts with the 1080/60p scan." Does this apply to 24p modes as well? In other words, are 24p modes (1080 or 720) actually natively captured as 23.98 fps off the chip block, or is there some sort of 60p to 24p conversion? Based on the discussions here, I get the impression that the camera actually does do native 24p captures off the chip block, but the wording "1080/60p... as a basis for all captures" makes me wonder.

Also, where the documentation lists "1080/24p (Native)" and "720/24p (Native)," it has the note "In Native mode, AG-HMC150 record only active frames." What does this mean?

Thanks,

Larry
 
Check out page 35 of your camera user manual. The image is captured naively in 24p on the chip, but is converted into a 60 frame format.
 
MonkeyjoeBla said:
Check out page 35 of your camera user manual. The image is captured naively in 24p on the chip, but is converted into a 60 frame format.
Click to expand...


I don't remember what page 35 says -- but I'm guessing MonkeyjoeBla got the frame rate numbers mixed up.

Relative to you, the user, the "1080/60p" is essentially irrelevant. It refers to what's going on in the camera, and the recording format you select is rendered from that -- meaning it's irrelevant to you the user.

24p, either 720 or 1080, is native -- there's no pulldown. Just forget the "1060/60p" thing if it's confusing.
 
AGMedia said:
Relative to you, the user, the "1080/60p" is essentially irrelevant. It refers to what's going on in the camera, and the recording format you select is rendered from that -- meaning it's irrelevant to you the user.
Click to expand...
It would be relevant if it were true. This would mean that the 150 records is some sort of Cineframe mode. But it does not.

I think someplace else Barry clarifies that 60p/60i and 30p modes start from 1080p60. 24p modes start from 1080p.... umm... 24? Or 48?

Barry's book is not a cohesive manual, it is an assortment of essays. Always read operation instructions first, and get the missing parts from Barry's book. Do not use the book INSTEAD of the operating instructions.
 
Cranky said:
It would be relevant if it were true. This would mean that the 150 records is some sort of Cineframe mode. But it does not.

I think someplace else Barry clarifies that 60p/60i and 30p modes start from 1080p60. 24p modes start from 1080p.... umm... 24? Or 48?

Barry's book is not a cohesive manual, it is an assortment of essays. Always read operation instructions first, and get the missing parts from Barry's book. Do not use the book INSTEAD of the operating instructions.
Click to expand...


Yeah...

SOURCE: PANASONIC

"The digital signal processor developed for the AG-HMC150's 1080/60p video signals uses 14-bit A/D conversion and 19-bit inner processing to attain unprecedented accuracy. While the camera does not record 1080/60p, it is from this capture that all other signals are made."

LINK: https://eww.pavc.panasonic.co.jp/pro-av/sales_o/02products/products/ag-hmc150/ag-hmc150.html

Regarding MonkeyjoBla and "page 35," the 60i there relates to the camera's "output signal" in 1080 -- and this is entirely different from the native 24p recorded to the SDHC card.
 
AGMedia said:
Relative to you, the user, the "1080/60p" is essentially irrelevant. It refers to what's going on in the camera, and the recording format you select is rendered from that -- meaning it's irrelevant to you the user.
Click to expand...

Wait... I'm confused again. With regard to this quote:

"The digital signal processor developed for the AG-HMC150's 1080/60p video signals uses 14-bit A/D conversion and 19-bit inner processing to attain unprecedented accuracy. While the camera does not record 1080/60p, it is from this capture that all other signals are made."

Are you guys saying that this is NOT true -- i.e. that for 24p captures, the chip block does NOT start with the 1080/60p capture? I don't see how you can start with a 60p capture and end up with 24p without "conversion," which would mean that if the camera truly captures "native" 24p, that quote has to be incorrect.

Thanks again,

Larry
 
For 24p captures, the chip block starts out at 1080/24p. For 30p captures it starts at 1080/30p. For 60i captures, or 60p captures, it starts out at 1080/60p.
 
Barry_Green said:
For 24p captures, the chip block starts out at 1080/24p. For 30p captures it starts at 1080/30p. For 60i captures, or 60p captures, it starts out at 1080/60p.
Click to expand...


I'm guessing that you're differentiating "chip block" from the DSP -- meaning that we're talking about different things.

If not -- is Panasonic lying?
 
The CCDs are clocked at the speed you select, from 24 to 60 fps. The DSP processes the signals coming off the chips.

Panasonic isn't "lying", you're taking a marketing statement and trying to interpret it into meaning something that it doesn't. Should they have said "up to" 60p? Yes, probably. But the point is, the question was asked, and the answer is, that the chip works exactly the way it should -- it scans at the frequency you set it to. And when in 60fps mode, yes that means it's running at 1080/60p.
 
Thanks for the responses here everybody.

I wouldn't classify the documentation (both the manual and the brochure) as "lying," but I would definitely say it's pretty "misleading."

Thanks again for the clarification on this,

Larry
 
I just find it hard to believe that I'm creatively interpreting


PANASONIC:


"Progressive to interlace conversion, cross conversion and down conversion all start with the 1080/60p scan. That initial 1080p native progressive scan offers the highest level of vertical resolution possible at this level of camera. Keep in mind that the camera does not record this signal but uses it as a basis for all captures."


and


PANASONIC:


"While the camera does not record 1080/60p, it is from this capture that all other signals are made."


LINK: https://eww.pavc.panasonic.co.jp/pro-av/sales_o/02products/products/ag-hmc150/ag-hmc150.html


You wrote that I'm "trying to interpret" something -- and I respectfully respond that I'm reading what Panasonic wrote.
 
The idea was that all formats start from 1080-line, progressive, then downscaled and/or interlaced.

The "creative" PR people just thought that 60p would look better and would make no difference to 1080-line, progressive.
 
Marketing got it wrong when they wrote it. No big surprise there, it happens.

Thing is, it turns out that the way they do it is BETTER than the way they said they do it. If they were "lying" in this case, it'd be a pretty dumb thing to do. Chalk it up to a mistake, marketing phrased it in a way that doesn't really portray what it does properly.
 
I would ike to think that they would confide in someone like yourself Barry on matters like this. Probably would not leave their marketing statements open to any conjecture.

To me personally, I don't really care too much about the technical aspects being spoken about in this thread, I call it semantics. I just wanna pick up the camera and shoot. If the image looks great, which it does, i'm happy. I don't give a hoot what the chip block can or can't do!!!
 
shaun1970 said:
I call it semantics.
Click to expand...

It's relevant to all of us if the moral of this thread is that no one can believe anything written by Panasonic's Marketing Division -- and the next question is where can we get accurate information? Where does Mr. Green get his information?

This little issue is actually rather significant. Those representations have been published by Panasonic for nearly a year and have been provided to every retailer in the world. Businesses around the world have made investments based on those marketing materials -- including two organizations with which I'm affiliated.

Semantics? Do we all just throw our hands up in the air and laugh off any claim made by any company as some marketing mistake?

And what other marketing representations about these cameras are just some mistake?
 
I did say to me personally, stuff like this really don't bother me. Sure it maybe morally wrong but I tend to think its more of a case that its worded wrong.

Where does Barrys get his info from?? Well he is correct again on this one which makes him a clever person and thats why I said that maybe these so called marketing guru's need to confide with more people in the know like Barry ??? actually they are supposed to be the people in the know but are they really?? Maybe there was a misunderstanding between marketing and technical design?

My whole point is that i'm not losing sleep over it,, my camera HMC shoots awesome looking pregressive and interlaced footage in 1080 and 720 res, i'm happy! regardless of a probable incorrect statement made by Panasonic. I'm sure all camcorder manufacturers have done similar things.
 
AGMedia said:
It's relevant to all of us if the moral of this thread is that no one can believe anything written by Panasonic's Marketing Division
Click to expand...
Is that really what it's saying? Or is that perhaps a bit of an exaggeration?

Where does Mr. Green get his information?
Click to expand...
From the product managers and the engineers, who I get to see at trade shows and at speaking events. I try to talk to the folks who actually design and build the products. N.A.B. is a fantastic opportunity because I've had the chance to sit with the actual engineers who designed the P2 card and the original DVX100 and pick their brains, as much as the language barrier would allow.

This little issue is actually rather significant.
Click to expand...
How so? There are two possible interpretations: either A: it generates all images off a 1080/60p scan, as the brochure stated, which leaves the only possible option for 24p to be some bogus field-squashing time-shifting bullcrap, or B: the marketing page left out the words "up to", but the camera actually performs in the ideal fashion, reclocking the chip and delivering perfect frame accuracy, yielding ideal footage.

Like I say, if they had claimed something better than what was happening, I'd see your point. But they made an error TO THEIR DETRIMENT, so -- why is it such a big deal?

If I had any contact with the people who write the brochures I would have pointed this out to them, they would have said "thanks" and corrected it, and there'd be not even a tempest in a teapot.

So please -- what's the problem here?

Semantics? Do we all just throw our hands up in the air and laugh off any claim made by any company as some marketing mistake?
Click to expand...
Any false or bogus claim should be called out, obviously. If someone is trying to mislead you through marketing, that should be called into question and people held accountable. But in this case they ended up making themselves look worse, not better. So it's really, really, really hard to attribute any sort of nefarious motive to it. Therefore, what is it, other than a simple mistake?
 
You must log in or register to reply here.
Back
Top