Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
02-18-2010, 07:03 AM   #1
Site Supporter
Site Supporter




Join Date: Sep 2006
Location: Mississippi, USA
Photos: Gallery
Posts: 853
Question on Kx or K7 video

Is video captured at full sensor size and mega pixel count ?

02-18-2010, 08:29 AM   #2
Veteran Member




Join Date: Jan 2008
Location: Ste-Anne des Plaines, Qc., Canada
Posts: 2,013
No. It just uses what is needed to have the definition posted in the manual .
02-18-2010, 01:39 PM   #3
Site Supporter
Site Supporter




Join Date: Sep 2006
Location: Mississippi, USA
Photos: Gallery
Posts: 853
Original Poster
Thanks for the info.
02-18-2010, 02:52 PM   #4
Senior Member
netrex's Avatar

Join Date: Apr 2009
Location: Alta
Photos: Gallery | Albums
Posts: 279
QuoteOriginally posted by flyer Quote
No. It just uses what is needed to have the definition posted in the manual .
I'm pretty sure it uses the whole sensor, well, what it needs to cover the aspect ratio, but as much as possible without changing the ratio.

02-19-2010, 04:09 AM   #5
Senior Member




Join Date: Feb 2010
Photos: Albums
Posts: 264
not at 12 or 14 mega pixels that for sure

I think some guy here named "falconeye" has explained it in some thread already. It's called "downsampling" if I remember correctly.

though i won't be surprised that someday, videos can use the full resolution (say, 12 megapixels) for video at a decent framerate (like 25fps perhaps. maybe 60!). And 12 megapixels at 60fps will effectively make mirrored-SLR cameras obsolute right? But sadly, today is not that day. Hehe
02-19-2010, 06:27 AM   #6
Site Supporter
Site Supporter




Join Date: Sep 2006
Location: Mississippi, USA
Photos: Gallery
Posts: 853
Original Poster
Thanks for all the replies.
I'm a still image shooter and I also own a video camera. At times I've pulled images out of the video's for small prints. Mostly horrible quality. After reading a lot of talk about the cameras shooting the video, the thought crossed my mind about sensor usage and MP count. Woulda been nice to have full sensor size images......
02-19-2010, 02:13 PM   #7
Senior Member
netrex's Avatar

Join Date: Apr 2009
Location: Alta
Photos: Gallery | Albums
Posts: 279
QuoteOriginally posted by thazooo Quote
Thanks for all the replies.
I'm a still image shooter and I also own a video camera. At times I've pulled images out of the video's for small prints. Mostly horrible quality. After reading a lot of talk about the cameras shooting the video, the thought crossed my mind about sensor usage and MP count. Woulda been nice to have full sensor size images......
It records video with the whole sensor (as much as covered by the aspect ratio at least), but it's not 12 megapixles, it's resized (resampled down) to fit the 720p resolution. There is a function to extract images from video in the camera, but it's still just 1280x720 I believe.

02-22-2010, 06:45 AM   #8
Senior Member




Join Date: Feb 2009
Location: SLovakia
Photos: Gallery
Posts: 141
I think K-X and K-7 doesn´t record video with all sensor cells, but only with that cells needed for selected resolution.

Some machines do it in other way - recording full resolution and than software resizing to selected resolution.
02-22-2010, 12:36 PM   #9
Inactive Account




Join Date: Nov 2009
Location: Former capitol of Germany
Posts: 63
QuoteOriginally posted by therion Quote
I think K-X and K-7 doesn´t record video with all sensor cells, but only with that cells needed for selected resolution.
What makes you think so?

It would cause a lot of aliasing and increased noise because only a fraction of the light that reaches the sensor would be used. I don't think Pentax engineers are that stupid.

Stefan
02-22-2010, 02:03 PM   #10
osv
Veteran Member




Join Date: Mar 2007
Location: So Cal
Photos: Gallery
Posts: 2,080
QuoteOriginally posted by 16N64 Quote
What makes you think so?

It would cause a lot of aliasing and increased noise because only a fraction of the light that reaches the sensor would be used. I don't think Pentax engineers are that stupid.
yes, there is a lot of aliasing, and it's not just pentax, canon has the same problems.

in three years you'll look back on this immature technology and laugh, because the pentax you'll be shooting video with then will be quite different than what you have now.



http://prolost.com/blog/2009/12/3/you-didnt-believe-me.html

Last edited by osv; 02-22-2010 at 02:10 PM.
02-25-2010, 02:01 PM   #11
Junior Member




Join Date: Mar 2007
Photos: Gallery
Posts: 41
That doesnt make sense.

Does that mean when you switch to video mode, the Live view display suddenly changes to a cropped image?

I think its close to full sensor size and down-sampled
02-26-2010, 08:06 AM   #12
Banned




Join Date: Sep 2006
Location: Millstone,NJ
Posts: 6,491
QuoteQuote:
in three years you'll look back on this immature technology and laugh, because the pentax you'll be shooting video with then will be quite different than what you have now.
Every product using microchips will be much more advanced in three years.
[yt]http://www.youtube.com/watch?v=f7EoAE14Z9k[/yt]
02-26-2010, 11:28 AM   #13
Forum Member




Join Date: May 2009
Posts: 91
QuoteOriginally posted by 16N64 Quote
What makes you think so?

It would cause a lot of aliasing and increased noise because only a fraction of the light that reaches the sensor would be used. I don't think Pentax engineers are that stupid.

Stefan
No current video DSLR reads out the whole sensor for video and they all suffer from aliasing
02-27-2010, 11:48 AM   #14
Inactive Account




Join Date: Nov 2009
Location: Former capitol of Germany
Posts: 63
QuoteOriginally posted by karl79 Quote
No current video DSLR reads out the whole sensor for video and they all suffer from aliasing
Why do you think so?

Maybe they use a fraction of the sensor surface, but I am certain that they use all pixels from that area and downsample digitally. As the process has to be fast and is very likely done in hardware, it sure has some imperfection that causes aliasing. Worse, there will be some nonlinear processing for enhancing sharpness on edges that will also result in visible artifacts, especially if subjected to some test chart. But when shooting real world scenes, I am still very happy with the video quality of the K-x. Some 50 years ago, filmmakers would have given their right arm for the image quality and possibilities of current DSLR video.

Stefan
02-27-2010, 12:00 PM   #15
Inactive Account




Join Date: Nov 2009
Location: Former capitol of Germany
Posts: 63
QuoteOriginally posted by osv Quote
in three years you'll look back on this immature technology and laugh, because the pentax you'll be shooting video with then will be quite different than what you have now.
I assume this is a crop of some video, it shows a certain lack of detail, but surprisingly little aliasing. Some chroma aliasing, but the lines are perfectly merged into gray as they should.

Of course everything will be better some time in the future, but instead of complaining about current shortcomings, we should hold our breath and worship what amazing technology Pentax engineers have achieved for us so far:

Hail Pentax engineers!!!

Stefan
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
hdslr, kx or k7, video
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
KX Video Transfer Question Zulu209 Troubleshooting and Beginner Help 2 10-14-2010 03:30 PM
Pentax K-X video question Nflguy33 Video and Pentax HDSLRs 6 04-14-2010 02:34 PM
question K7 vs. Kx video Mystic Video and Pentax HDSLRs 7 01-04-2010 09:14 PM
k7 video question, a/v not in sync on pc allill Pentax DSLR Discussion 7 12-24-2009 05:30 PM
Pentax K7 Video Question Spock Pentax DSLR Discussion 3 08-10-2009 05:37 AM



All times are GMT -7. The time now is 04:01 PM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top