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Faster burst mode?

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Faster burst mode?
« on: 12 / July / 2008, 01:22:43 »
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I've done a bit of searching and reading and what I've gleaned doesn't seem hopeful, but I couldn't find much on the topic that wasn't cursory so I'll just come right out and ask:

Is there any way, by use of CHDK, to increase the fps of the burst mode?

I ask because I'd like to be able to take photos of golf swings, which are very quick and the more fps the better. I've seen some people saying that the burst mode is limited by the write speed to the card, but if that were true I assume one would notice a marked increase if you were to shoot on a low resolution with noise reduction et al. turned off -- which isn't the case as far as I can tell.

It also surprises me that you can get such high framerates in video on a camera but not not for photos, but I admit I'm a novice to all of this.


Regards,
XDZT

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Offline fudgey

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Re: Faster burst mode?
« Reply #1 on: 12 / July / 2008, 02:31:13 »
See here: http://chdk.setepontos.com/index.php/topic,1864.0.html.

I.e. you can do some optimization by selecting optimal settings, but CHDK won't be of much help.

Card speed is a slowdown, but it's not the only one. If you shoot to low resolution jpegs and want more speed, you must choose a shooting mode which actually SHOOTS at low resolution instead of just shooting at a high resolution and then downscaling. The digital zoom features do that. Just select the modes in a way that doesn't result in scaling.

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Offline brainwash

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Re: Faster burst mode?
« Reply #2 on: 17 / July / 2008, 08:22:35 »
Make sure you select the high-speed burst mode (my S2 IS has normal burst and H-burst).
Manual focus should be selected, although I don't think it matters for burst.
You can use high-resolution and low-quality jpeg, it saves quite a bit of time.
However, the most important factor is to set the exposure time to the shortest value you can (perhaps underexpose and then correct later).
Having a small aperture also helps since the shutter doesn't have to move so much. It does help from my experience.
Card speed is important, but not by that much, the camera has its own internal buffer which at the settings presented above stores about 5-12 pictures.

Re: Faster burst mode?
« Reply #3 on: 17 / July / 2008, 11:26:00 »
On my TX-1, I shoot 1280x720p video which gives me a "burst" speed of 30 frames per second. I can use Zoombrowser EX to pick out any frame I want, if I need a still image. 8)
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Offline LjL

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Re: Faster burst mode?
« Reply #4 on: 17 / July / 2008, 11:30:57 »
Video is an option, for sure, but for us unlucky owners of cameras with PAL quality video, not one with an incredibly high number of applications :P

It's shouldn't necessarily be disregarded for simulating long exposures or shooting moving subjects, though.

Re: Faster burst mode?
« Reply #5 on: 17 / July / 2008, 21:36:48 »
I forgot to mention that the TX-1 will shoot either NTSC or PAL as well. :D
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Offline LjL

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Re: Faster burst mode?
« Reply #6 on: 18 / July / 2008, 07:04:31 »
Well, I guess I should really say that my A720 is "NTSC only", for that matter, since the vertical resolution is 480 and not 512...

Re: Faster burst mode?
« Reply #7 on: 18 / July / 2008, 23:21:17 »
I'm not sure what the 512 refers to.

NTSC Digital SD resolution is 648x486 @ 30 fps while PAL Digital SD resolution is 720x486 @ 25 fps.
The frame rates are based on the frequency of the ac current of the electrical systems in use - 60Hz and 50Hz.

There are also the TV resolutions of 525 lines @ 60Hz and 625 lines @ 50Hz, not to mention square vs. non-square pixels.

And we haven't even started talking about HD resolutions!

However, I was simply suggesting that, whatever the resolution, using video mode and then extracting a lovely image or two from the video is a way to get a faster burst mode when there is no time to futz with settings. Better than missing the opportunity completely. :(
« Last Edit: 19 / July / 2008, 08:39:31 by cybercom »
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Offline LjL

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Re: Faster burst mode?
« Reply #8 on: 19 / July / 2008, 07:47:05 »
Typical PAL has 576 usable lines, while NTSC has 486.

640x480 is a typical home computer (and later VGA) resolution on NTSC, while 640x512 is on PAL.

So, while there's no way to really say that my camera is either "PAL" or "NTSC" because it's neither and couldn't ever be, it's certainly closer to NTSC standards than PAL.

Also, I'm not sure you've got your DV resolutions right... see Wikipedia.

 

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