Archived from groups: rec.photo.digital.slr-systems (More info?)
On Mon, 02 May 2005 17:00:30 -0700, Stefan Patric
<writeme@addressbelow.com> wrote:
>On Monday 02 May 2005 07:58, Alan Browne wrote:
>
>> DelphiCoder wrote:
>>
>>> "Stefan Patric" <writeme@addressbelow.com> wrote in message
>>> news:2xhde.10104$_K.5452@fed1read03...
>>>
>>>> What are you planning on photographing at those speeds? Bullets in
>>>> flight?
>>>
>>>
>>> Actually, I did want to try that.
>>
>> The shutter speed has nothing to do with it. Even at 1/8,000, a high
>> powered bullet (3000 fps) will travel over 4 inches over that time. A
>> more common speed bullet will travel 1.5 inches.
>
>Okay. Bullets are out. All the shooting required to calibrate
>everything would probably scare the hell of neighbors anyway. But how
>far would a starship traveling at, say, Warp 3 go in 1/8000 sec?
>Inquiring minds want to know. ;-)
>
>> Further, don't forget that at high shutter speeds a "slit" is
>> travelling across the frame.
>
>Actually, with these types of high speed shutters, the slit travels
>vertically from the bottom of the frame (the top of the picture. It's
>upside down, remember.) to the top.
>
>> You need a specialty strobe with high power and very short cycle at a
>> high ISO.
>
>Yes, a special strobe, but it doesn't need to recycle fast. It just
>must have a very, and I mean VERY, short flash duration like on the
>order of one millionth of a second.
Most highspeed photography now doesn't depend on the strobe
speed of a light. I've seen it. The light comes on for a couple
seconds, the speed of the camera is accomplished by a ultra high
speed motor spinning a cylindrical mirror (polygonal?) that provides
the "strobe" across a film plane. It's used in conjunction with a
shutter.
If you want to capture a bullet in flight and aren't interested
in things like capturing a supersonic shock wave, you can detune the
bullet speed by reducing the powder charge. Some .45 cal. ammo fps is
well under 1000.
-Rich
On Mon, 02 May 2005 17:00:30 -0700, Stefan Patric
<writeme@addressbelow.com> wrote:
>On Monday 02 May 2005 07:58, Alan Browne wrote:
>
>> DelphiCoder wrote:
>>
>>> "Stefan Patric" <writeme@addressbelow.com> wrote in message
>>> news:2xhde.10104$_K.5452@fed1read03...
>>>
>>>> What are you planning on photographing at those speeds? Bullets in
>>>> flight?
>>>
>>>
>>> Actually, I did want to try that.
>>
>> The shutter speed has nothing to do with it. Even at 1/8,000, a high
>> powered bullet (3000 fps) will travel over 4 inches over that time. A
>> more common speed bullet will travel 1.5 inches.
>
>Okay. Bullets are out. All the shooting required to calibrate
>everything would probably scare the hell of neighbors anyway. But how
>far would a starship traveling at, say, Warp 3 go in 1/8000 sec?
>Inquiring minds want to know. ;-)
>
>> Further, don't forget that at high shutter speeds a "slit" is
>> travelling across the frame.
>
>Actually, with these types of high speed shutters, the slit travels
>vertically from the bottom of the frame (the top of the picture. It's
>upside down, remember.) to the top.
>
>> You need a specialty strobe with high power and very short cycle at a
>> high ISO.
>
>Yes, a special strobe, but it doesn't need to recycle fast. It just
>must have a very, and I mean VERY, short flash duration like on the
>order of one millionth of a second.
Most highspeed photography now doesn't depend on the strobe
speed of a light. I've seen it. The light comes on for a couple
seconds, the speed of the camera is accomplished by a ultra high
speed motor spinning a cylindrical mirror (polygonal?) that provides
the "strobe" across a film plane. It's used in conjunction with a
shutter.
If you want to capture a bullet in flight and aren't interested
in things like capturing a supersonic shock wave, you can detune the
bullet speed by reducing the powder charge. Some .45 cal. ammo fps is
well under 1000.
-Rich
/www.star-fleet.com/ed/warp-chart.html
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