720p30 at DVinfo.net

Go Back   DV Info Net > JVC ProHD & MPEG2 Camera Systems > JVC GY-HD Series Camera Systems

JVC GY-HD Series Camera Systems
GY-HD 100 & 200 series ProHD HDV camcorders & decks.


Reply
 
Thread Tools Search this Thread
Old October 25th, 2008, 06:10 PM   #1
Trustee
 
Join Date: Sep 2007
Location: Newark, Delaware
Posts: 1,029
720p30

I do weddings and I just started shooting in HD with my GY-HD100. I realize I get a studder in the image which I am told is from the 30 fps of the 720p30. Is there any way to correct that or did I possibly make a bad choice of camera for weddings? Does anybody else use these cameras for weddings? Do people notice the studdering?

Randy
Randy Johnson is offline   Reply With Quote
Old October 25th, 2008, 06:33 PM   #2
Regular Crew
 
Join Date: Mar 2008
Location: Jurbise, Belgium
Posts: 29
I think you might have another problem that is causing the studder and it might not be on your original footage. Where do you see the studder? How often and under what conditions? What program are you using to edit the footage? What project settings? More info will help to diagnose the problem.
Taylor Brush is offline   Reply With Quote
Old October 26th, 2008, 01:57 AM   #3
Major Player
 
Join Date: Aug 2006
Location: Larkspur, CA
Posts: 378
I shoot 720p30 too. The stutter you are referring to is actually called judder. It's effects are even more pronounced at 24p.

You just have to change the way you shoot. Slower pans and tilts.

Honestly, I think 720p30 is beautiful, and so do my clients.

There is nothing wrong with your camera!
Justin Ferar is offline   Reply With Quote
Old October 26th, 2008, 07:42 AM   #4
 
Join Date: Nov 2001
Location: santa fe, nm
Posts: 3,264
Images: 10
Do you have SMOOTHING turned on? Turn it off, if you do.
Bill Ravens is offline   Reply With Quote
Old October 26th, 2008, 05:26 PM   #5
Trustee
 
Join Date: Sep 2007
Location: Newark, Delaware
Posts: 1,029
o.k. thanks guys. I know theres nothing "Wrong" with the camera I just thought I may have made a bad choice in camera for my applications(weddings). I dont do alot of pans but at the reception theres alot of dancing which I cant control. I will turn off "smooth motion" though.
Randy Johnson is offline   Reply With Quote
Old October 26th, 2008, 07:48 PM   #6
Inner Circle
 
Join Date: Dec 2005
Location: New York City
Posts: 2,615
Play around with 1/30 shutter. This introduces a film-like blur to motion.
__________________
William Hohauser - New York City
Edit/Camera/DCP production/Animation
William Hohauser is offline   Reply With Quote
Old October 26th, 2008, 08:40 PM   #7
Regular Crew
 
Join Date: Jul 2006
Location: NY NY USA
Posts: 95
Sounds like your shooting too low of a shutter speed, try 1/60 if the light permits.
Jamon Lewis is offline   Reply With Quote
Old October 27th, 2008, 02:28 AM   #8
Wrangler
 
Join Date: Aug 2005
Location: Toronto, ON, Canada
Posts: 3,637
Quote:
Originally Posted by William Hohauser View Post
Play around with 1/30 shutter. This introduces a film-like blur to motion.
Actually it introduces a very UN-filmlike motion blur.

Most film cameras are limited to a 180 shutter which means the exposure is equal to 1/frame rate x 2. In the case of 24fps each exposure at 180 is 1/48th of a second. 30 fps would be 1/60th of a second and so on. Exposure time is directly related to the amount of motion blur in the image.
Many film cameras have adjustable shutters that can be dialed down for "strobe" effects like in Saving Private Ryan or Gladiator.

Matching the exposure time to the frame rate is physically impossible with film cameras. It would be like using a 360 shutter (removing the shutter completely) which would mean you couldn't mask the movement of the film as it advanced in the gate. The long and flowing motion blurs of using 1/24th or 1/30th shutter speed on a video camera is a tell-tale sign that it wasn't shot on film. A recent example is the film 21 (less recent examples of 1/24th shutter are Collateral and 2007's Miami Vice.)

Therefore if you do want to match the temporal image of a typical film camera shoot 24p at 1/48th of a second.
__________________
Tim Dashwood
Tim Dashwood is offline   Reply With Quote
Old October 27th, 2008, 10:35 AM   #9
Major Player
 
Join Date: Mar 2004
Location: Perth, Australia
Posts: 250
Quote:
Originally Posted by Justin Ferar View Post
I shoot 720p30 too. The stutter you are referring to is actually called judder. It's effects are even more pronounced at 24p.

You just have to change the way you shoot. Slower pans and tilts.

Honestly, I think 720p30 is beautiful, and so do my clients.

There is nothing wrong with your camera!
Yes, I agree. You have to learn to shoot progressive. It's a different ball game altogether.
__________________
Dennis Robinson
G5, , 30 inch display, FCP6 Studio 2, JVC-GYHD111
Dennis Robinson is offline   Reply With Quote
Old October 27th, 2008, 12:45 PM   #10
Inner Circle
 
Join Date: Dec 2005
Location: New York City
Posts: 2,615
Quote:
Originally Posted by Tim Dashwood View Post
Actually it introduces a very UN-filmlike motion blur.

Most film cameras are limited to a 180 shutter which means the exposure is equal to 1/frame rate x 2. In the case of 24fps each exposure at 180 is 1/48th of a second. 30 fps would be 1/60th of a second and so on. Exposure time is directly related to the amount of motion blur in the image.
Many film cameras have adjustable shutters that can be dialed down for "strobe" effects like in Saving Private Ryan or Gladiator.

Matching the exposure time to the frame rate is physically impossible with film cameras. It would be like using a 360 shutter (removing the shutter completely) which would mean you couldn't mask the movement of the film as it advanced in the gate. The long and flowing motion blurs of using 1/24th or 1/30th shutter speed on a video camera is a tell-tale sign that it wasn't shot on film. A recent example is the film 21 (less recent examples of 1/24th shutter are Collateral and 2007's Miami Vice.)

Therefore if you do want to match the temporal image of a typical film camera shoot 24p at 1/48th of a second.
All in agreement here. However, "film-like" is how many non-technical clients experience 1/30th shutter. It gives them a "film-like" feel unlike 1/60th which is the normal shutter on the GY-HD series. 1/60th in 30p is not the same as 1/60th in 60i. A slower shutter elicits a "that looks like film!" comment from clients I have worked with. That might be a telling commentary on my clients but I don't really think so. The past two multi-camera jazz concerts I have directed and shot were in 30p at 1/30th shutter and they look great. A hyperactive rock concert might cause me to reevaluate this shooting style.

As longtime professionals we gain the ability to see behind the images on the screen, theater or television. Often I can clearly see the difference between 35mm and many HD 24p productions. I am nearly always able to see SD video that had been given the "film-look" treatment. And yes, 1/30th is more "smudged" then 1/48th. Very fast motion gets a little odd looking at 1/30th.

Tthere are issues that make 30p an easier format for many projects. A HD "film" I shot this year was in 24p 1/48th shutter since the producer is intending a movie theater future. 30p would be a terrible, project ruining, choice. The Jazz concerts have a direct to DVD future.

My suggestion was to help the poster to cut down on the "judder" he is experiencing with a technique that might also give his work something that will impress the clients. If he was shooting a film, not a wedding video, then my advice would be the same as earlier posters.

In the end, a good result is the point and a good result is achievable by many different methods.
__________________
William Hohauser - New York City
Edit/Camera/DCP production/Animation
William Hohauser is offline   Reply With Quote
Old October 29th, 2008, 12:51 PM   #11
Major Player
 
Join Date: Apr 2006
Location: Pacific NW
Posts: 431
Quote:
Originally Posted by Randy Johnson View Post
I will turn off "smooth motion" though.
most definitely. That will only make it worse.
Mark Silva is offline   Reply With Quote
Old November 1st, 2008, 05:29 PM   #12
Major Player
 
Join Date: Mar 2006
Location: Dallas, TX
Posts: 346
I never go less than double the frame rate, unless I'm going for a special effect of some kind. Stick with 30p with the shutter at 1/60 or faster. If it's dark, try some gain. I hate the idea of gain, but sometimes it is just what you need in a dark, dark room.

I've shot about 20+ weddings with this camera and it has been great.
__________________
David Chapman
www.davechapfilms.com
David Chapman is offline   Reply With Quote
Old November 1st, 2008, 09:37 PM   #13
Major Player
 
Join Date: Apr 2006
Location: Melbourne, Australia
Posts: 786
Quote:
Originally Posted by William Hohauser View Post
However, "film-like" is how many non-technical clients experience ... shutter. It gives them a "film-like" feel ...

... A slower shutter elicits a "that looks like film!" comment from clients I have worked with. That might be a telling commentary on my clients but I don't really think so.

... In the end, a good result is the point and a good result is achievable by many different methods.
You've brought up a very important point, William.

Tim is 100% correct (as is Stu Maschwitz) about the motion rendition of the "360 shutter" (such as 24p at 1/24th shutter) and how the pro can spot it as a dead give-away that it was originated on video (even if transferred to film later).

But what does your average, non-technical audience member perceive as "film-like" when viewing digital cinema at the local multiplex?

With the JVC ProHD camera, I'm finding (so far) that audiences - non-technical ones - definitely seem to regard the 24fps at 1/24th shutter (360) as being "film-like", much in the same way that William is finding with a 360 shutter for his non-technical clients.

I actually don't know why this is so. I've heard various opinions and summations about what makes video footage "look just like film" such as progressive scan, 24 fps, shutter angle, shallow depth of field, gamma handling, crushing the blacks, grain, etc.

But 24 fps at 1/24th, for some reason unknown to me, seems to give the non-industry audience member a significant impression of "film-like". Go figure.

While I always shoot corporate video with a 180 shutter (25 fps at 1/50th) I'm not convinced that 180 is the best way to go using a ProHD camera for a specific Digital Cinema project. (I intend to do future testing of shutter angles with a PMW-EX1 and a RED camera to see whether this audience perception holds true beyond the ProHD camera.)

And while Stu considers the 360 shutter angle as "a choice that sets back the progress of digital cinema", I'm not so sure.

ProLost: Reverie

However, I reserve the right to completely change my opinion about this depending on the results of larger audience screenings later this month!
David Knaggs is offline   Reply With Quote
Old November 2nd, 2008, 12:38 AM   #14
Inner Circle
 
Join Date: Dec 2005
Location: New York City
Posts: 2,615
I've posted it elsewhere here years ago but here's the summary.

The faster the frame rate the more "realistic" the image seems to the viewer. Special effect wizard Douglas Trumbell did many tests when developing his ShowScan system for amusements park rides that used projection. He preferred 120fps but had to settle with 60fps 70mm film as that was the fastest the film could physically handle repeated projections.

The slower the frame rate the more fantastic or dream-like the image seems to the viewer. Of course the shutter changes with the different frame rates (although this doesn't have to be with slower frame rates). 24fps is the compromise that film-makers came up with to conserve film yet have decent audio fidelity. 24 also has the advantage of introducing a slight reduction in visual motion information that is advantageous to story telling that 30fps starts to lose and is nearly lost in 60fps. Plus, action seems faster in 24fps.

Before sound, film-makers used various frame rates has they found that different moods could be attained by adjusting the rate. Silent films often came with frame rate instructions for the projectionists. Later many silent film frame rates were changed when they were transfered to sound films for re-issue. Comedies suffered especially.

Below 18fps increased motion blur and loss of visual information starts to create a dream-like pattern. This is used to advantage by film-makers trying to introduce an abstract or nightmare like situation. Peter Jackson used slow frame rates in King Kong and Lord of the Rings to make the rampaging villains scarier. Music videos frequently use below normal frame rates.

One day we might be able to have a wider selection of shutter speed on our digital video cameras instead of even increments of the frame rate. Why not 1/45 in 30p?
__________________
William Hohauser - New York City
Edit/Camera/DCP production/Animation
William Hohauser is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

Professional Video
(800) 833-4801
Portland, OR

B&H Photo Video
(866) 521-7381
New York, NY

Z.G.C.
(973) 335-4460
Mountain Lakes, NJ

Abel Cine Tech
(888) 700-4416
N.Y. NY & L.A. CA

Precision Camera
(800) 677-1023
Austin, TX

DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > JVC ProHD & MPEG2 Camera Systems > JVC GY-HD Series Camera Systems

Thread Tools Search this Thread
Search this Thread:

Advanced Search

 



Google
 

All times are GMT -6. The time now is 05:52 PM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2017 The Digital Video Information Network