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lyonfilms
04-17-2009, 07:59 AM
A few questions for those who understand camera chip architecture. We own a 300 and have posted a fair number of observations and videos on other posts, especially in regard to the rather terrible skew present specifically in 1080 24PN.

My questions are:

1. Why is the skew so significantly reduced when the camera is in the 720 settings?
2. Why is the mosquito noise noticeably less in the 720 modes? ( in -3 gain).
3. Any news on firmware, if any, for the 1080 issues?
4. Is it certain that all the production cameras that shipped have the latest firmware update? We received one of the first in Oregon and I would like to know how exactly I can tell. Jan?

Thanks!

Jan_Crittenden
04-17-2009, 12:29 PM
The latest firmware is 9.19. Look under the diagnostics menu.

As an interim on the skew, slow down your pans to the recommeded speeds for the 24P stuttering, in the ASC manual. It seems to work well at slower speeds.

Keep in mind by going to -3 you are also taking 3 dB off the top.

Hope this helps,

Jan

lyonfilms
04-19-2009, 12:02 PM
The firmware is the latest update you mentioned. Thanks for providing the number.

Jan, I understand your point regarding the rate at which a pan should occur based on the ASC guidelines. In fact, I've made a similar point in a few of my other posts about how to mitigate the skew at the 1080 24p setting. The problem is that one cannot always control the environment in such a way. What about shoulder-mounted shots where you are following an unpredictable subject? In our test the skew is unavoidable in those situations. If Panasonic's position is "don't use 1080 24p except in very controlled situations" and it was marketed as such I would have no problem. People could then make a choice. But it isn't marketed that way. If it wasn't for these types of forums how would a end user or company know of the problem? Especially if they lived in a city where there were no demo units.

There is a lot to like about this camera. But what we have a problem with is that we own a 300 but are very limited in how we can use the camera in that 1080 24p setting (which is the one setting we would like to use the most). That is why we are holding out hope that the company engineers can do something to make it better.

We are big Panny fans. That's why we bought the camera. We also appreciate your willingness to be very responsive in people's concerns. I just hope the engineers are actively working on the issue.

Jan_Crittenden
04-19-2009, 09:00 PM
Jan, I understand your point regarding the rate at which a pan should occur based on the ASC guidelines. In fact, I've made a similar point in a few of my other posts about how to mitigate the skew at the 1080 24p setting. The problem is that one cannot always control the environment in such a way. What about shoulder-mounted shots where you are following an unpredictable subject?

Hi,

I think the one thing that needs to be said in all of this. is that is the wildly moving camera shots that were performed in thes test, neither one was a take home winner. I wouldn't have hired either camera person to shoot. Part of the job that comes with a MOS based camera is the fact that you have to learn how to control the skew. If you don't want to do that you need to find another camera to use.


In our test the skew is unavoidable in those situations. If Panasonic's position is "don't use 1080 24p except in very controlled situations" and it was marketed as such I would have no problem. People could then make a choice. But it isn't marketed that way. If it wasn't for these types of forums how would a end user or company know of the problem? Especially if they lived in a city where there were no demo units.

I think our position is that any customer that buys a MOS based camera and does not know its limitations at this point of almost 2 years into the delivery of MOS based cameras and is able to spend $10,000 sight unseen, well God Bless Them. They should be quick about testing their commodity product. But I don't think this is a commodity product but any one that is not searching it out because they need or want to buy from a vendor several hundred or thougsand miles away, well I don't know how to help them. There certainly is many, many articles about the differences between MOS based imagers and CCDs, one of the earier and more clear ones to read on this very site.

What is marketed is a 2.2M progressive 3MOS imager that has the ability to record in 4:2:2 AVC-Intra.


There is a lot to like about this camera. But what we have a problem with is that we own a 300 but are very limited in how we can use the camera in that 1080 24p setting (which is the one setting we would like to use the most). That is why we are holding out hope that the company engineers can do something to make it better.

I think you need to work with it more. I am watching concert footage that was shot with it, Drivebys with tracking on cars and motorcycles, all done on AVC-Intra at 1080P/24PN
]


We are big Panny fans. That's why we bought the camera. We also appreciate your willingness to be very responsive in people's concerns. I just hope the engineers are actively working on the issue.

In the mean time, try finnessing the camera, I do believe you will be a little surprised on how and what you can shot. Keep in mind, I would not have hire eiter camera based on the Skew Off, the point is no one gets paid for footage like that.

What we did announce today was a flashband compensation for auto correcting of the partial exposure that also is cause by the MOS imagers. This firmware download will be available this summer.

Hope this helps,

Jan

G.P.
04-20-2009, 12:27 AM
2. Why is the mosquito noise noticeably less in the 720 modes? ( in -3 gain).

Thanks!

Just out of curiosity when you say "mosquito noise" do you mean the little black dots that are much darker than the noise we are used to seeing, or are you referring to the speed at which the noise seems to move at?

thanks!

puredrifting
04-20-2009, 08:36 AM
Giuseppe:

You may find this helpful.

http://www.adamwilt.com/pix-artifacts.html

Mosquito Noise (a.k.a. feathering, scatter, "critters", "gribblies") results from high-frequency data lost in the compression/decompression process. It's always within 8 pixels of a hard-to-compress edge or detail, and a common artifact in any DCT based compressions such as DV, JPEG, or MPEG. Unfiltered titles (here, from Premiere 4.2's title generator) on plain blue backgrounds make the clearest demo images, but these artifacts are also frequently found in DV pix of dense clusters of leaves, sharp diagonal details, and the like, especially where the background image is itself quiescent and bright enough so that the noise isn't lost in the shadows.

Dan

lyonfilms
04-21-2009, 02:13 PM
Great news on the flashband compensation firmware update. Very cool. Also, good interview of Jan at FRESHDV (http://provideocoalition.com/index.php/freshdv/story/nab_2009_panasonic_hpx300/)where she shows the update in use.