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Old Feb 18, 2003, 1:30 PM   #1
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Default Sony DSC-F717 Question

Hello all, I am looking into purchasing a Sony DSC-F717 for my second camera. My question is will I be able to take shots like this one...
http://www.steves-digicams.com/dpotd...3/02152003.jpg

with the moving lights of traffic without this camera having a bulb setting?
Thanks.
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Old Feb 20, 2003, 1:27 AM   #2
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Many cameras can have the lens open for upto 16 seconds, and that's more than enough time. The problem is, the longer the lens is open the hotter the CCD gets and the more noise you get...it's even noticable at shots of a few seconds on most digitals.

I don't know the Sony camera, so can't answer anything about its capabilities.
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Old Feb 20, 2003, 9:23 AM   #3
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Default Re: Sony DSC-F717 Question

Quote:
Originally Posted by scrid
Hello all, I am looking into purchasing a Sony DSC-F717 for my second camera. My question is will I be able to take shots like this one...
http://www.steves-digicams.com/dpotd...3/02152003.jpg

with the moving lights of traffic without this camera having a bulb setting?
Thanks.
My guess is you should be able to since it's based on the same flavor of the Sony CCD sensor used in the D7 as well as the CP5700 and the E20. http://www.pbase.com/nhl/daynight_comparison


At time longer than 4s (or in bulb), at least in the D7, the camera takes two shots: the first shot is taken for example @ 15s and the 2nd shot is done automatically by the camera again with an indentical 15s exposure with the shutter close to subtract out the 'dark current' noise!
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Old Feb 20, 2003, 9:56 AM   #4
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Hey that's pretty clever, so why can't you cap the lens of your cam, shoot the same exposure, temperature and all things staying equal and do the subtraction afterwards in editing? I don't use PS, but isn't this something you can do with layers and masks?
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Old Feb 20, 2003, 1:37 PM   #5
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Vox

Good idea, but I guess it also depends on the camera temperature @ that very moment, and you'll then have to keep an index of the different exposure times (very much like the ECU mapping of combustion engines), a pain in the behind for most folks... but possible :lol: :lol: :lol:

Regardless and believe it or not, some cameras using the Sony sensor like the D7's have already put this mechanical shutter to good use even during regular exposures:
Quote:
It reduced smear by 30 dB to a level of approximately 116dB by performing the following sequence:

Vertical register high-speed transfer -> Readout -> Mechanical shutter close -> signal output.
check note 5, page 9, and the various timing waveforms on the following page 19...
http://products.sel.sony.com/semi/PDF/ICX282AQF.pdf

Basically this shutter works in reverse. ie it stays open (how else can it updates its LCD, or EVF?), and closes briefly right after the shot while the data is being read to reduce smear. 8) 8) 8)
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