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11/09/2005 10:54:12 AM · #26 |
Originally posted by KiwiChris:
A 6mp camera has 2000 or so pixels vertically, so to get pixel perfect sharpness you'd need to have less than 3/2000 degrees of movement while the shutter is open! That's 0.0015 degrees. Dosn't take much imagination to see that a small movement will result in a large blur in the image!
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Continuing the equation, you get 1/666 seconds or faster shutter speed to assure no movement is visible, so the 1/800 i find to work best for me is true, mathemetically validated even!
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11/09/2005 10:58:04 AM · #27 |
Originally posted by deapee:
Originally posted by mavrik:
Originally posted by deapee:
It's a 1.5 crop factor... |
Damned Nikon. |
heh...damned Canon and their goofy 1.6 and 1.3 heh...1.5 is so much easier ;-) |
haha you forgot FF too.
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11/09/2005 11:20:42 AM · #28 |
Originally posted by Prof_Fate:
Originally posted by KiwiChris:
A 6mp camera has 2000 or so pixels vertically, so to get pixel perfect sharpness you'd need to have less than 3/2000 degrees of movement while the shutter is open! That's 0.0015 degrees. Dosn't take much imagination to see that a small movement will result in a large blur in the image!
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Continuing the equation, you get 1/666 seconds or faster shutter speed to assure no movement is visible, so the 1/800 i find to work best for me is true, mathemetically validated even! |
That bit of mathematics makes no sense to me i'm afraid. 0.0015 is approximately 1/666, so i take it that's what you did? Well as i understand the equation we're using, that would be the shutter speed needed to eliminate rotation of 0.0015 degrees over the course of 1 second. At that angular velocity it would take over 16 hours just to turn the lens 90 degrees, so i think it's a rather unrealistic figure for hand-held vibration.
I would suggest that to actually mathematically eliminate all detectable shake, you'd need a shutter speed in the millionths of a second - completely impractical - however, the contents of a pixel don't have to remain entirely still for the duration of the exposure to attain a sharp shot. I would suppose that the vibration of your hands would change direction quickly and often during the exposure, providing an averagely still image, assuming there are no larger or less random movements.
I think it would be very difficult indeed to try and mathematically calculate a guide rule for a shutter speed, and impossible without knowing the exact amplitudes and frequencies of vibrations around the lens - you'd have to take into account the lens' length, and mass distribution, and how it interrelates with the particular shakeyness parameters of the holder's hands... just too many variables.
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11/09/2005 11:38:26 AM · #29 |
To add to the mathmatics here are some biometrics to confuse you.
Think of the body (main or beast) as a motor. Go up to any motor..say your refrigerator, and feel the hum..the pulse. Biological creatures have a similar "pulse". Some are faster, some are slower.
Nobody can be perfectly still (unless you are dead). Hold your breath, lay on the ground, brace yourself...doesn't matter..your motor is still going.
The best nature photographers use rock solid supports, have fast glass of 2.8 or faster to allow for as fast a shutter as possible, remove themselves from the camera ala remote shutter release, use mirror locks, and shoot in bursts.
Do all that and your keepers will rise dramatically.
And the rule of "shutter speed=lens length" is a good rule of thumb but a lot of the above variables can affect this. PLUS>>>>>>>Don't forget your subject is a motor too, wind, rotation of the planet....hehehe :-D
Now you get why those national geographic photogs get such respect..and their subjects can even eat them! |
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11/09/2005 02:47:38 PM · #30 |
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11/09/2005 03:07:25 PM · #31 |
wow just looked at your images, I shoot with my 70-300 sigma lens and I never have that problem that you have.
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11/09/2005 04:57:18 PM · #32 |
One other thing to consider is the sharpness of the lens at an aperature of 5.6 Many consumer level lenses- particularly those with large zoom ranges like 70-300mm are very soft when shooting wide open at 300mm. Unfortunately, to get a fast shutterspeed you are usually at the widest aperature. So my advice for the sharpest picture possible is use a tripod and shoot with an aperature a couple of stops down from wide open.
Message edited by author 2005-11-09 16:58:29. |
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11/09/2005 05:53:02 PM · #33 |
If that lens is the same as the Nikkor AF 70-300/4-5,6D ED then I think you can blame the lens.
According to photodo it's a really poor performer and is at it's worst when wide open at the tele end.
bazz. |
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11/09/2005 06:03:15 PM · #34 |
Originally posted by sir_bazz:
If that lens is the same as the Nikkor AF 70-300/4-5,6D ED then I think you can blame the lens.
According to photodo it's a really poor performer and is at it's worst when wide open at the tele end.
bazz. |
I use the Sigma 70-300 APO DG Macro and have no problems. I shoot in P mode and go for it. I shoot a lot and select the best, never had that much blur or camera shake. Guess kpriest is right, lay off the coffee.
Steve |
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11/09/2005 06:14:47 PM · #35 |
This was shot at 300mm with a Sigma 70-300mm f4-5.6!Snow reflection helps provide more light though.
Neil
Message edited by author 2005-11-09 18:15:19. |
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11/09/2005 07:02:27 PM · #36 |
Originally posted by Dim7:
This was shot at 300mm with a Sigma 70-300mm f4-5.6!Snow reflection helps provide more light though.
Neil |
Must have been a fast shutter speed to freeze the wings like that though, even at the bottom of their arc - i'm guessing 1/1000 of a second at least?
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11/10/2005 03:01:18 AM · #37 |
Okay, I think I'm gettin' better:
1/1000th sec, f/5.6, 300mm, 1000 ISO
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11/11/2005 02:37:25 PM · #38 |
Originally posted by riot:
Originally posted by Dim7:
This was shot at 300mm with a Sigma 70-300mm f4-5.6!Snow reflection helps provide more light though.
Neil |
Must have been a fast shutter speed to freeze the wings like that though, even at the bottom of their arc - i'm guessing 1/1000 of a second at least? |
Yes you are correct 1/2000! |
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11/12/2005 07:30:57 AM · #39 |
Originally posted by Dim7:
Originally posted by riot:
Originally posted by Dim7:
This was shot at 300mm with a Sigma 70-300mm f4-5.6!Snow reflection helps provide more light though.
Neil |
Must have been a fast shutter speed to freeze the wings like that though, even at the bottom of their arc - i'm guessing 1/1000 of a second at least? |
Yes you are correct 1/2000! |
Well above the "rule of thumb" 1/300th then :)
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11/12/2005 08:43:29 AM · #40 |
It's ALL a question of camera shake and shutter speed. At the long end of any telephoto, you need shutter speeds at least 1/focal length, faster if possible.
 200mm 1/1250s
 420mm 1/500s
 420mm 1/1600s
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