The gigantic "which camera should I buy" thread!

Boyd Ostroff · July 13th, 2005, 11:37 AM

I really have no experience with cameras in this price range, but can help a little with the specs. All NTSC DV cameras, regardless of price, shoot at the same resolution which is 720 pixels wide by 480 high. Most in this price range will have a single CCD, or possibly 3 tiny ones. As long as you're going with good companies like Canon and Sony I don't think you'll see much of a difference in the amount of image detail. The 3 CCD cameras may render color better, probably not much of a factor in your application.

All NTSC DV cameras also capture 30 frames per second regardless of their cost. Each frame has two fields that contain the odd and even lines of the image. So the fields are 1/60 second apart and combine to represent a 1/30 second slice of time. With fast motion - like a tennis swing - the images in the odd and even fields won't quite match since they are captured 1/60 sec apart. When combined into the 480 line image you will see a jagged effect around the moving arm and racquet for example.

Yes, adjustable shutter speed can help, but only within these limits. The default would be to capture one of these video fields for 1/60 sec sixty times each second. Now you could increase the shutter speed to 1/1000 sec if you like, but you will end up exposing each filed for 1/1000 sec sixty times per second. This may give a little clearer image, although the odd and even lines in each of the 1/30 sec frames will look even more different (more of the jagged effect). In this example, picture the following timeline:

0.001 seconds: capture lines 1-3-5-7-9-11-13, etc in 1/1000 sec
0.016 seconds: wait
0.017 seconds: capture lines 2-4-6-8-10-12. etc in 1/1000 sec
0.033 seconds: wait
-------
0.033 seconds = 1/30 sec

Sorry, but spending more money won't really buy you any more frames per second if that's what you're after....

Tony Truong · July 13th, 2005, 02:37 PM

Thanks for the quick response.. Can you or anyone here tell me how expensive the camera that took this small video clip would cost?

http://advancedtennis.com/atrp/guga.htm

Boyd Ostroff · July 13th, 2005, 02:44 PM

I just don't know enough about tennis or sports photography to be much help. Just offhand that looks like it was shot faster than 30 fps however. Perhaps it was a Varicam which costs $$$$$ ? There are also special purpose cameras for shooting high speed video, I think they're expensive too.

K. Forman · July 13th, 2005, 02:48 PM

You might look into a film camera, possibly one that can be overcranked to more than 30 frames per second?

Tony Truong · July 13th, 2005, 03:24 PM

Thanks again for the help. One last question .. Hope I'm not bugging too much :)

Since you mentioned that all those standard NTSC camcorders are the same resolution 720x480.. If i purchased an 1080i HDV camcorder would the resolution be 1920x1080 once I download it onto the computer?

-Tony

Mike Teutsch · July 13th, 2005, 03:42 PM

Tony,

You did not say exactly how you were going to use it or how long.

I noticed that one of the cameras you were looking at was about $1,300.00. For that price you could probably pick up a used JVC JYHD-10U, or JVC GR-HD1US. Both of these are High Definition cameras and capable of shooting 720P, which is progressive. Progressive is full frame and not interlaced, making it much better for slow motion because each frame is full and not just half a frame, (non-interlaced). The JY-HD10U I know shoots SD in 1/60 fps progressive too, which may be easier for you to use without additional software. This would be 60 full frames per second, not 60 half frames per second, and you could use a higher shutter speed also to help even more.

Many many others on this forum are much more knowledgable on this subject than I, and I hope they respond to this too. But, shooting in progressive mode will help a lot.

If you want to try it out, maybe you could rent one!

I hope that I helped and did not give you any misinformation or confused even further. Anyone else?

Good Luck,

Mike

Mike Teutsch · July 13th, 2005, 03:50 PM

Tony,

I did not get my post in before your last one. 1080i is higher definition, but again interlaced, hence the i after the 1080i. I think most would agree that progressive would be better for slow motion. Just remember that any High Definition filming, 1080i or 720p would probably require you to spend much more on software to capture it to your computer. Your computer may already alow you to capture SD, but you should check.

Mike

Tony Truong · July 13th, 2005, 03:59 PM

Quote:

Originally Posted by Mike Teutsch

Tony,

I did not get my post in before your last one. 1080i is higher definition, but again interlaced, hence the i after the 1080i. I think most would agree that progressive would be better for slow motion. Just remember that any High Definition filming, 1080i or 720p would probably require you to spend much more on software to capture it to your computer. Your computer may already alow you to capture SD, but you should check.

Mike

Hmm I didn't know I needed software for the transfer. A friend just told me the firewire port transfers everything. What kind of software or hardware would I need?

Mike Teutsch · July 13th, 2005, 04:12 PM

Tony,

First, your computer will have to be pretty strong! Still firewire, but then you have to buy additional plug-ins, like Cineforms Aspect HD (what I bought for $500.00) or another program. Adobe Premiere and most other editing programs will not capture HD without these plug-ins.

Also, remember that there are no HD DVD players really available yet. That is why I was suggesting SD video. Others will know more.

Hang in there!

Mike

Glenn Chan · July 13th, 2005, 11:44 PM

You probably want to shoot interlaced (NTSC) so you capture 60 fields/second. If you shoot progressive, you only capture 30 frames/second (which would be really bad for slow motion).

In post, you want to look at slowing things down so that each field gets interlaced and becomes its own frame (instead of two fields getting deinterlaced into one frame). 1 second of 60i (29.97fps interlaced) would give you ~60 frames (at half the resolution of a progressive frame) per 2 seconds, at 50% speed.

I don't think Final Cut can do that (at least, it isn't immediately obvious to me). Haven't tried this in Vegas yet. Shake (a few thousand dollars) can do this. It's really quite simple, you shouldn't need a super expensive program to do it.

If you want the slow-motion to look slicker, there are techniques available to fake the in-between frames. Field blending is the simplest and works by dissolving between frames. The best and most expensive solution would be Boris' Optical Flow plug-in or the version of Optical Flow found in Shake 4 (very long render times!!).

2- If you shoot in high definition, it should make up for the resolution loss from shooting interlaced and de-interlacing as described above. Post production will be harder though.

3-

Quote:

All NTSC DV cameras, regardless of price, shoot at the same resolution which is 720 pixels wide by 480 high. Most in this price range will have a single CCD, or possibly 3 tiny ones. As long as you're going with good companies like Canon and Sony I don't think you'll see much of a difference in the amount of image detail.

In my experience, the Sony TRV22 is noticeably blurrier (lower resolution) than other consumer cameras. I think the higher-end models are what they're supposed to be.

Boyd Ostroff · July 14th, 2005, 06:36 AM

Quote:

Originally Posted by Mike Teutsch

The JY-HD10U I know shoots SD in 1/60 fps progressive too, which may be easier for you to use without additional software. This would be 60 full frames per second, not 60 half frames per second, and you could use a higher shutter speed also to help even more.

Is this true? I don't think so. AFAIK, it can shoot 30 frames per second in progressive mode, not 60.

I agree with Glenn about using interlaced for your application because there are 60 samples taken each second instead of only 30. For your application I'm assuming that you just want to clearly see what's happening in slow motion, and not create something "artsy." If so, then the plug-ins that Glenn mentions are probably not worth the investment.

Now theoretically, you could shoot with the Sony FX-1 in 1080i high definition mode and get a lot of motion data. Since the vertical resolution is more than twice that of SD DV, each 1/60 sec field could be downsampled to 720x480 and (theoretically) give you 60 progressive frames for each second. I say "theoretically" because I'm not sure how this would work from a software standpoint. The other problem is that the MPEG2 compression used by HDV is not supposed to be very good for fast motion.

Why don't you rent or borrow some of the cameras you're considering and do a few tests. I think this will be much more instructive for you than all the theories we're debating here :-)

Mike Teutsch · July 14th, 2005, 06:59 AM

Quote:

Originally Posted by Boyd Ostroff

Is this true? I don't think so. AFAIK, it can shoot 30 frames per second in progressive mode, not 60.

I am no expert on this and I may be wrong, but the owners manual for my JVC JY-HD10U, has the following information on page #21.

SUPPORTED FORMATS:

Horz. lines--704, Vert. lines--480, Aspect Ratio---16:9, Frames per Sec. (Rec)---60, Scan Mode---Progressive, Recording Mode---SD

HD is 30 fps, SD is 60 fps

Thanks,

Mike

Chris Hurd · July 14th, 2005, 07:15 AM

Anytime you see 60fps, be it in specs, product lit or wherever, they're referring to 60 fields per second interlaced (60i). It's definitely confusing.

Mike Teutsch · July 14th, 2005, 08:35 AM

I still am confused, so help me out.

Book says:

HD 30fps/prog.
SD 60 fps/prog.
DV 60fps/Inter.

DV it says is, "The camera records signals in the interlace scan mode(half of 525 scanning lines at 1/60th of a second)

SD, it say is, "The camcorder records signals in the progressive scan mode, (525 scanning lines at 1/60th of a second at one time......The SD mode reduces flickering more effectively than recording in DV mode."

HD, it says is, "the camcorder records signals at 1/30th of a second for playback at one time."

What is it really?

thanks,

Mike

Christopher Lefchik · July 14th, 2005, 10:47 AM

According to the Videomaker review of the JVC GR-HD1 (the consumer version of the JY-HD10U), it does shoot 60p SD:

"In SD mode, the camera shoots at the same resolution (480 lines), but shoots 60 progressive fps (60p) at a true 16:9 widescreen aspect ratio."

and

"We also shot some fast action video at 60 progressive fps in the SD mode. This video looked spectacular on the computer and gave us much more room to create dramatic super-slow motion effects that would not be possible at 60i (or even 30p)."

Basic editing software that can handle the footage the camera produces is also included.

(Videomaker Test Bench: JVC GR-HD1 Mini DV and HD Camcorder)

July 13th, 2005, 02:48 PM	#829
K. Forman Capt. Quirk Join Date: Apr 2002 Location: Middle of the woods in Georgia Posts: 3,596	You might look into a film camera, possibly one that can be overcranked to more than 30 frames per second? __________________ www.SmokeWagonLeather.us

July 13th, 2005, 03:42 PM	#831
Mike Teutsch Inner Circle Join Date: Oct 2004 Location: Port St. Lucie, Florida Posts: 2,614	How long do you need it? Tony, You did not say exactly how you were going to use it or how long. I noticed that one of the cameras you were looking at was about $1,300.00. For that price you could probably pick up a used JVC JYHD-10U, or JVC GR-HD1US. Both of these are High Definition cameras and capable of shooting 720P, which is progressive. Progressive is full frame and not interlaced, making it much better for slow motion because each frame is full and not just half a frame, (non-interlaced). The JY-HD10U I know shoots SD in 1/60 fps progressive too, which may be easier for you to use without additional software. This would be 60 full frames per second, not 60 half frames per second, and you could use a higher shutter speed also to help even more. Many many others on this forum are much more knowledgable on this subject than I, and I hope they respond to this too. But, shooting in progressive mode will help a lot. If you want to try it out, maybe you could rent one! I hope that I helped and did not give you any misinformation or confused even further. Anyone else? Good Luck, Mike

July 14th, 2005, 07:15 AM	#838
Chris Hurd Obstreperous Rex Join Date: Jan 2001 Location: San Marcos, TX Posts: 27,368 Images: 513	Anytime you see 60fps, be it in specs, product lit or wherever, they're referring to 60 fields per second interlaced (60i). It's definitely confusing. __________________ CH Search DV Info Net \| 20 years of DVi \| ...Tuesday is Soylent Green Day!

July 14th, 2005, 08:35 AM	#839
Mike Teutsch Inner Circle Join Date: Oct 2004 Location: Port St. Lucie, Florida Posts: 2,614	Thanks Chris! I still am confused, so help me out. Book says: HD 30fps/prog. SD 60 fps/prog. DV 60fps/Inter. DV it says is, "The camera records signals in the interlace scan mode(half of 525 scanning lines at 1/60th of a second) SD, it say is, "The camcorder records signals in the progressive scan mode, (525 scanning lines at 1/60th of a second at one time......The SD mode reduces flickering more effectively than recording in DV mode." HD, it says is, "the camcorder records signals at 1/30th of a second for playback at one time." What is it really? thanks, Mike

July 13th, 2005, 11:37 AM	#826
Boyd Ostroff Wrangler Join Date: Dec 2002 Location: Mays Landing, NJ Posts: 11,801	I really have no experience with cameras in this price range, but can help a little with the specs. All NTSC DV cameras, regardless of price, shoot at the same resolution which is 720 pixels wide by 480 high. Most in this price range will have a single CCD, or possibly 3 tiny ones. As long as you're going with good companies like Canon and Sony I don't think you'll see much of a difference in the amount of image detail. The 3 CCD cameras may render color better, probably not much of a factor in your application. All NTSC DV cameras also capture 30 frames per second regardless of their cost. Each frame has two fields that contain the odd and even lines of the image. So the fields are 1/60 second apart and combine to represent a 1/30 second slice of time. With fast motion - like a tennis swing - the images in the odd and even fields won't quite match since they are captured 1/60 sec apart. When combined into the 480 line image you will see a jagged effect around the moving arm and racquet for example. Yes, adjustable shutter speed can help, but only within these limits. The default would be to capture one of these video fields for 1/60 sec sixty times each second. Now you could increase the shutter speed to 1/1000 sec if you like, but you will end up exposing each filed for 1/1000 sec sixty times per second. This may give a little clearer image, although the odd and even lines in each of the 1/30 sec frames will look even more different (more of the jagged effect). In this example, picture the following timeline: 0.001 seconds: capture lines 1-3-5-7-9-11-13, etc in 1/1000 sec 0.016 seconds: wait 0.017 seconds: capture lines 2-4-6-8-10-12. etc in 1/1000 sec 0.033 seconds: wait ------- 0.033 seconds = 1/30 sec Sorry, but spending more money won't really buy you any more frames per second if that's what you're after....

July 13th, 2005, 02:37 PM	#827
Tony Truong New Boot Join Date: Jul 2005 Posts: 7	Thanks for the quick response.. Can you or anyone here tell me how expensive the camera that took this small video clip would cost? http://advancedtennis.com/atrp/guga.htm

July 13th, 2005, 02:44 PM	#828
Boyd Ostroff Wrangler Join Date: Dec 2002 Location: Mays Landing, NJ Posts: 11,801	I just don't know enough about tennis or sports photography to be much help. Just offhand that looks like it was shot faster than 30 fps however. Perhaps it was a Varicam which costs $$$$$ ? There are also special purpose cameras for shooting high speed video, I think they're expensive too.

July 13th, 2005, 03:24 PM	#830
Tony Truong New Boot Join Date: Jul 2005 Posts: 7	Thanks again for the help. One last question .. Hope I'm not bugging too much :) Since you mentioned that all those standard NTSC camcorders are the same resolution 720x480.. If i purchased an 1080i HDV camcorder would the resolution be 1920x1080 once I download it onto the computer? -Tony

July 13th, 2005, 03:50 PM	#832
Mike Teutsch Inner Circle Join Date: Oct 2004 Location: Port St. Lucie, Florida Posts: 2,614	Tony, I did not get my post in before your last one. 1080i is higher definition, but again interlaced, hence the i after the 1080i. I think most would agree that progressive would be better for slow motion. Just remember that any High Definition filming, 1080i or 720p would probably require you to spend much more on software to capture it to your computer. Your computer may already alow you to capture SD, but you should check. Mike

July 13th, 2005, 04:12 PM	#834
Mike Teutsch Inner Circle Join Date: Oct 2004 Location: Port St. Lucie, Florida Posts: 2,614	Tony, First, your computer will have to be pretty strong! Still firewire, but then you have to buy additional plug-ins, like Cineforms Aspect HD (what I bought for $500.00) or another program. Adobe Premiere and most other editing programs will not capture HD without these plug-ins. Also, remember that there are no HD DVD players really available yet. That is why I was suggesting SD video. Others will know more. Hang in there! Mike

July 14th, 2005, 10:47 AM	#840
Christopher Lefchik Trustee Join Date: Jul 2003 Location: US Posts: 1,152	According to the Videomaker review of the JVC GR-HD1 (the consumer version of the JY-HD10U), it does shoot 60p SD: "In SD mode, the camera shoots at the same resolution (480 lines), but shoots 60 progressive fps (60p) at a true 16:9 widescreen aspect ratio." and "We also shot some fast action video at 60 progressive fps in the SD mode. This video looked spectacular on the computer and gave us much more room to create dramatic super-slow motion effects that would not be possible at 60i (or even 30p)." Basic editing software that can handle the footage the camera produces is also included. (Videomaker Test Bench: JVC GR-HD1 Mini DV and HD Camcorder)