Suggestions on GoPro HD Hero2 or equivalent... - Page 3

Greg G · 01-11-2013, 03:27 PM

Unfortunately it doesn't do 60fps, just 30 fps in HD (720p) or STD (640x480). Plus the lens doesn't go wide enough to get a good view of the entire court from the back fence. But I'm pretty happy with it!

Tried filming a match indoors just now, auto exposure works OK, you just get a low shutter speed and resultant blurs on slow motion. Manual high speed was just barely enough with f3.6 and 1/800 shutter speed. Dark but useable video.

Chas Tennis · 01-13-2013, 09:41 AM

Greg G, you should also be able to easily get your serve velocity on your serve videos with the camera side view (perpendicular to the serve's trajectory). Most accurate if you can record a scale placed in the direction of the serve before or after the serve without moving the camera. In a pinch, use your tennis racket for a scale .

http://vimeo.com/49909907

It would be more accurate to measure over a longer distance, say, several frames at 240fps. With 1/1000 sec exposure time, the ball image will have motion blur. Just estimate location of the ball by the center of the blur or best guess front edge of the ball.

Not nearly as convenient as a radar gun but it could be very accurate if done properly.

(I was going to try it with my android smartphone, Samsung Galaxy SII, but I've read that some smartphones, including iPhones, might have variable frame rates under some circumstances.)

Greg G · 01-13-2013, 01:20 PM

Nice! Will try that one of these days.

Hey! I just pressed the HS continuous shutter button, and in this mode it allows manual exposure, up to 1/40000 shutter speed, 40 fps, maximum of 30 frames! With a 10 second delay timer, I can still manage to record my serve!

Addendum: the shutter speed in HS continuous shutter mode seems to carry over to video (!). The camera is allowing me to adjust the shutter speed all the way, and the video I take has the same exposure as the 1/40000 shutter speed still picture (at least by eyeballing the brightness of the picture and video). Will have to confirm this next time out. Crossing my fingers...

Greg G · 01-26-2013, 03:16 AM

Serve video using the FC-150, manual exposure, 1/40,000 shutter speed, f3.6, ISO 3200 on a overcast yet bright day.

http://youtu.be/OC4lfWM2k0w

Chas Tennis · 01-26-2013, 04:23 AM

Greg G, Looks as if you have done very well! For $90, super!

The motion blur on the ball and racket look very small. You can farther evaluate motion blur by taking close ups of the racket and ball.

Have you found anything in the user's manual (Casio 200 pages) that describes what you have found regarding the HS button and getting faster shutter speeds?

I like the behind view for showing the serve. You should see all the details and some important angles. Direct sunlight also shows the shadows, for example, shadows on the elbow bones that are helpful in analyzing the upper arm rotation on the serve. https://vimeo.com/21512296

I have just recently discovered that Youtube now will single frame using the forward and backward arrows. Before it didn't.

Greg G · 01-26-2013, 03:30 PM

Yes, very happy with it! Wish the lens was a bit wider and had a lower f stop, but for the price I got it for, no complaints!

Here's forehand footage showing the widest FOV. Not too bad, I still have about 5 feet of room to move the camera back before it hits the fence.

http://youtu.be/vPHKWH-V_dU

The FC-150 manual is the typical cryptic Casio manual- it does differentiate standard/HD movie mode and HS movie mode by saying that only auto exposure is avilable for standard mode video, while auto/shutter priority/manual exposure are available in HS movie mode. It also mentions that the range of the shutter speed depends on the current high speed recording speed (fps). The specifications do mention a 1/40000 shutter speed available in high speed CS mode/shutter speed priority AE, or manual mode.

Anyway, I believe it does work because when I try to force manual mode for standard video, I can set it up to high shutter speed but when you press record, automatic exposure settings override it. This is not the case when doing high speed video, it seems to accept the manual settings with nothing overriding the settings- the videos have an exposure equal to the high speed CS photos.

Chas Tennis · 01-26-2013, 05:13 PM

Quote:

Originally Posted by Greg G

........................., I still have about 5 feet of room to move the camera back before it hits the fence.

http://youtu.be/vPHKWH-V_dU

Again, the video looks great with small motion blur. The shot from behind will produce less motion blur because the fastest part of the swing near impact is moving away from the camera.

There is a risk of hitting the camera or, more likely, the tripod. I would never put my camera behind me except when practicing the serve. I put it to the side for forehand or outside the fence, protected from ball impact.

Doesn't the sun ever shine there?

Greg G · 01-26-2013, 05:40 PM

Quote:

Originally Posted by Chas Tennis

Again, the video looks great with small motion blur. The shot from behind will produce less motion blur because the fastest part of the swing near impact is moving away from the camera.

There is a risk of hitting the camera or, more likely, the tripod. I would never put my camera behind me except when practicing the serve. I put it to the side for forehand or outside the fence, protected from ball impact.

Doesn't the sun ever shine there?

Well this was a practice session, I would probably not put the camera there during an actual match! I am trying to figure out how to add some protection for the camera...

Oh we get a lot of sunshine here in Manila. It's probably Murphy's Law at work..yup, clear skies out now, when I'm not scheduled to play...

I'm not complaining though, the weather is pretty nice now, 15-20 degrees C vs the usual 26-30!

Chas Tennis · 01-26-2013, 05:57 PM

Wrap a tripod in some soft sponge for shock protection and bungee cord it to the fence outside?

Use a tripod with a geared elevator and bungie cord it to the fence with the sponge between the fence and tripod. Use the geared tripod elevator to raise the camera to look through a hole in the fence. Make something to block the fence hole so that a ball can't get through - a piece of plywood with a hole in it that the ball can't get through.

If a ball hits the fence and there is no sponge/shock absorber the shock might cause damage.

Someone mentioned that possible theft might be an issue with a camera outside the fence.........

Some other ideas in an earlier reply on camera protection.

Greg G · 01-27-2013, 03:25 AM

Perhaps an underwater housing would keep it safe? Though in my case, the housing would cost more than the camera!

http://www.shootingunderwater.com/se...a-housing.html

Chas Tennis · 01-27-2013, 04:27 AM

That box has no shock absorption so when it gets hit or falls to the ground it still might damage the camera inside. ?

If your camera has a zoom lens take care especially that dirt & sand don't get on and inside the lens tubes.

See replies #12 & 13.
http://tt.tennis-warehouse.com/showt...era+protection

Greg G · 01-27-2013, 01:31 PM

BTW, Youtube seems to randomly skip frames when doing frame by frame with the left-right arrow. Plus video is always worse after uploading. Is Vimeo any better?

Chas Tennis · 01-27-2013, 04:21 PM

Sometimes YT stop-action single-frame works better with the arrows than at other times. Maybe? it works better when there is a longer time, a pause , between pressing the arrows. ?

Both YT & Vimeo (free) apply compression before they store the videos. I believe that the video is also already compressed when it comes from the Casio cameras. Compression can lose quality with the degree of loss depending on the nature of the compression. Vimeo has a paid service that gives the option to not compress the video and save it just as it was uploaded.

You can also use dropbox to upload and store files including video files for other people to download. Those files are not farther compressed after uploading. Another person can download and play on Quicktime using the arrows with the same quality as you have.

Check out Kinovea for comparing and analyzing videos.

01-11-2013, 03:27 PM	#41
Greg G Semi-Pro Join Date: May 2012 Posts: 589	Unfortunately it doesn't do 60fps, just 30 fps in HD (720p) or STD (640x480). Plus the lens doesn't go wide enough to get a good view of the entire court from the back fence. But I'm pretty happy with it! Tried filming a match indoors just now, auto exposure works OK, you just get a low shutter speed and resultant blurs on slow motion. Manual high speed was just barely enough with f3.6 and 1/800 shutter speed. Dark but useable video. Last edited by Greg G : 01-11-2013 at 06:36 PM.

01-13-2013, 09:41 AM	#42
Chas Tennis Professional Join Date: Feb 2011 Location: Baltimore, MD Posts: 1,312	Greg G, you should also be able to easily get your serve velocity on your serve videos with the camera side view (perpendicular to the serve's trajectory). Most accurate if you can record a scale placed in the direction of the serve before or after the serve without moving the camera. In a pinch, use your tennis racket for a scale . http://vimeo.com/49909907 It would be more accurate to measure over a longer distance, say, several frames at 240fps. With 1/1000 sec exposure time, the ball image will have motion blur. Just estimate location of the ball by the center of the blur or best guess front edge of the ball. Not nearly as convenient as a radar gun but it could be very accurate if done properly. (I was going to try it with my android smartphone, Samsung Galaxy SII, but I've read that some smartphones, including iPhones, might have variable frame rates under some circumstances.) Last edited by Chas Tennis : 01-13-2013 at 09:44 AM.

01-13-2013, 01:20 PM	#43
Greg G Semi-Pro Join Date: May 2012 Posts: 589	Nice! Will try that one of these days. Hey! I just pressed the HS continuous shutter button, and in this mode it allows manual exposure, up to 1/40000 shutter speed, 40 fps, maximum of 30 frames! With a 10 second delay timer, I can still manage to record my serve! Addendum: the shutter speed in HS continuous shutter mode seems to carry over to video (!). The camera is allowing me to adjust the shutter speed all the way, and the video I take has the same exposure as the 1/40000 shutter speed still picture (at least by eyeballing the brightness of the picture and video). Will have to confirm this next time out. Crossing my fingers... Last edited by Greg G : 01-13-2013 at 10:52 PM.

01-26-2013, 04:23 AM	#45
Chas Tennis Professional Join Date: Feb 2011 Location: Baltimore, MD Posts: 1,312	Greg G, Looks as if you have done very well! For $90, super! The motion blur on the ball and racket look very small. You can farther evaluate motion blur by taking close ups of the racket and ball. Have you found anything in the user's manual (Casio 200 pages) that describes what you have found regarding the HS button and getting faster shutter speeds? I like the behind view for showing the serve. You should see all the details and some important angles. Direct sunlight also shows the shadows, for example, shadows on the elbow bones that are helpful in analyzing the upper arm rotation on the serve. https://vimeo.com/21512296 I have just recently discovered that Youtube now will single frame using the forward and backward arrows. Before it didn't. Last edited by Chas Tennis : 01-26-2013 at 04:29 AM.

01-26-2013, 03:30 PM	#46
Greg G Semi-Pro Join Date: May 2012 Posts: 589	Yes, very happy with it! Wish the lens was a bit wider and had a lower f stop, but for the price I got it for, no complaints! Here's forehand footage showing the widest FOV. Not too bad, I still have about 5 feet of room to move the camera back before it hits the fence. http://youtu.be/vPHKWH-V_dU The FC-150 manual is the typical cryptic Casio manual- it does differentiate standard/HD movie mode and HS movie mode by saying that only auto exposure is avilable for standard mode video, while auto/shutter priority/manual exposure are available in HS movie mode. It also mentions that the range of the shutter speed depends on the current high speed recording speed (fps). The specifications do mention a 1/40000 shutter speed available in high speed CS mode/shutter speed priority AE, or manual mode. Anyway, I believe it does work because when I try to force manual mode for standard video, I can set it up to high shutter speed but when you press record, automatic exposure settings override it. This is not the case when doing high speed video, it seems to accept the manual settings with nothing overriding the settings- the videos have an exposure equal to the high speed CS photos. Last edited by Greg G : 01-26-2013 at 05:16 PM.