pgk Posted March 12, 2012 Share #21 Posted March 12, 2012 Advertisement (gone after registration) I am not following you. I said the main causes of blurry photos are: 1) Too much of a jab on the shutter release, a high velocity movement. 2) Gripping the camera too tightly, which causes tremors, which are high in velocity too. Those are simply two causes, but not the main causes when a camera is being used by an experienced photographer. Inexperienced photographers can be brutal on the shutter release and can grip cameras both too tightly and incorrectly, none of which helps stability. Lindolfi I have taken surprisingly sharp photographs from boats by attempting to move my body to counteract the inherent motions - there is no other way of shooting at low shutter speeds from a boat unless I suppose some form of gyro assistance was to be used (outside my finances I suspect). The failure rate is extremely high though. Underwater is easier - the damping effect from the water is helpful here. Link to post Share on other sites More sharing options...
Advertisement Posted March 12, 2012 Posted March 12, 2012 Hi pgk, Take a look here Taking pictures handheld; some neuromechanical aspects. I'm sure you'll find what you were looking for!
Lindolfi Posted March 12, 2012 Author Share #22 Posted March 12, 2012 Ornello, If you can not see the action of the shutter in the movements (in the acceleration curves or motion of the laser pointer), the movements dominate the unsharpness and not the shutter action. Thanks Paul, interesting addition! Link to post Share on other sites More sharing options...
Guest Ornello Posted March 12, 2012 Share #23 Posted March 12, 2012 Those are simply two causes, but not the main causes when a camera is being used by an experienced photographer. Inexperienced photographers can be brutal on the shutter release and can grip cameras both too tightly and incorrectly, none of which helps stability. Yes, I agree, but my point was that the velocity of movement is the key issue. You can be very steady on your feet and so forth, but have taut muscles causing tremor. Experience is in itself not the issue. I was always good at holding the camera steady, as far back as I can remember, and I started at age 14. Link to post Share on other sites More sharing options...
Lindolfi Posted March 12, 2012 Author Share #24 Posted March 12, 2012 Ornello, velocity is not the issue. The surface covered in the image (in number of pixels) by a steady point target is the issue during the time the shutter is opened. That is what ruins an image.You can have very high velocity, but when the frequency content is also high, the surface covered can still be very small, due the the complex curved trajectory of the point target. We measure motion with 3D linear acceleration transducers and 3D angular velocity transducers of handheld devices. Link to post Share on other sites More sharing options...
Jeff S Posted March 12, 2012 Share #25 Posted March 12, 2012 Jeff S. Indeed the shutter release action is important, but only beginners tend to not only press the button but also the whole camera down. The control of your finger and the sensory interplay with the steel and springiness of the button is remarkable. The test whether you do it right is just attach a small laserpointer to your camera and see wether the wanderings of the dot does anything special at the release of the button. If you do it right, you see nothing happening. Well, lots of discussion on this forum about thumb rests, soft release buttons, M9 soft release setting, grips, etc, for various kinds and methods of stabilization, not just because they're beginners or don't understand the principle of camera steadiness. I prefer my camera 'naked,' but thought all these discussions by others somehow might fit into your neuromechanical framework. Jeff Link to post Share on other sites More sharing options...
Guest Ornello Posted March 12, 2012 Share #26 Posted March 12, 2012 Ornello, velocity is not the issue. The surface covered in the image (in number of pixels) by a steady point target is the issue during the time the shutter is opened. That is what ruins an image.You can have very high velocity, but when the frequency content is high, the surface covered can still be very small, due the the complex curved trajectory of the point target. It depends on the shutter speed, of course, too, but at any given shutter speed, high velocity movement will cause more blur than low velocity movement of the same amplitude. Link to post Share on other sites More sharing options...
Lindolfi Posted March 12, 2012 Author Share #27 Posted March 12, 2012 Advertisement (gone after registration) It depends on the shutter speed, of course, too, but at any given shutter speed, high velocity movement will cause more blur than low velocity movement of the same amplitude. No, it does not as I have explained. You forget frequency content. If you think of human motion as a 1 dimensional thing during a quarter of a period of a sinusoidal movement, you would be right, but the trajectory is curved and complex (look at my image of 3 attempts) Jeff, your finger has some wonderful padding and control. If people are happy with a soft release addition then that fits the way they work. Personally I also very much like the design of the M button with its depression without an addition: nice direct contact and precise action. The padding inside my finger smooths it out. Link to post Share on other sites More sharing options...
pico Posted March 12, 2012 Share #28 Posted March 12, 2012 Favourable postures and relaxed concentration ('flow') can improve, but the 'engines' of tremor and postural plus aiming control can not be trained. Those engines can be negatively influenced by things like alcohol, however. I appreciated your generous and informative earlier article, Doctor, but I do not understand your last sentence above. Would you agree that there is a case where a little alcohol actually helps one who has familial (essential) tremor? The tremor diminishes significantly after a couple ounces of alcohol, but the remedy doesn't last long enough to carry out a long assignment. It makes me feel poorly later, and if I were a career photographer I'd be a wreck with such treatment. (I had it as a young man and it went away then resumed about ten years before I retired.) Link to post Share on other sites More sharing options...
Lindolfi Posted March 12, 2012 Author Share #29 Posted March 12, 2012 Well, Pico, there are several kinds of tremor, so the story is complex. There is a 10 Hz tremor that is called "essential tremor". Everybody has it, it does not come from feedback, but from random processes in the motor neurons, enhanced by descending pathways from the cortex. Then there is a slower tremor, like you see in Parkinsons', which has a frequency content of 4 to 5 Hz and involves feedback from the muscle receptors. The problem (as you said) is that alcohol can have both a benificial and a negative effect on a steady hand. The cross over point is hard to predict. Link to post Share on other sites More sharing options...
jaapv Posted March 12, 2012 Share #30 Posted March 12, 2012 No, it does not as I have explained. You forget frequency content. If you think of human motion as a 1 dimensional thing during a quarter of a period of a sinusoidal movement, you would be right, but the trajectory is curved and complex (look at my image of 3 attempts) . In that case, if I understand you correctly, the "soft" option of Leica and my method of resting the finger on the collar and just "rolling" it should reduce shake by reducing the length and complexity of the movement. Is that correct? Link to post Share on other sites More sharing options...
Lindolfi Posted March 12, 2012 Author Share #31 Posted March 12, 2012 Yes, since you are creating a "joint" very close to the point of action. You see the same in artists using tiny brushes or in the technique of watch makers. Link to post Share on other sites More sharing options...
spydrxx Posted March 12, 2012 Share #32 Posted March 12, 2012 I might have missed it in your original premises, but the actual effect of a circulatory pulse (forgetting for a minute the muscle tremors) can have an effect on motion, a strong pulse can often be seen in people's hands and faces, particularly when under stress. Link to post Share on other sites More sharing options...
Guest Ornello Posted March 12, 2012 Share #33 Posted March 12, 2012 No, it does not as I have explained. You forget frequency content. If you think of human motion as a 1 dimensional thing during a quarter of a period of a sinusoidal movement, you would be right, but the trajectory is curved and complex (look at my image of 3 attempts) Jeff, your finger has some wonderful padding and control. If people are happy with a soft release addition then that fits the way they work. Personally I also very much like the design of the M button with its depression without an addition: nice direct contact and precise action. The padding inside my finger smooths it out. Let's talk about displacement then. If you move the camera rapidly, the loci of the image points trace a path which can be measured. I am not talking about 10 second exposures or something like that. During 1/100 second, you can't draw circles with the image points' paths. The displacement will be approximately linear. Link to post Share on other sites More sharing options...
giordano Posted March 12, 2012 Share #34 Posted March 12, 2012 I have taken surprisingly sharp photographs from boats by attempting to move my body to counteract the inherent motions Did you think of it in those terms at the time was it more like "move the camera to keep the horizon level and 1/3 of the way up the frame"? Like an old-time naval gunner I used to "fire at the top of the roll" - i.e. time the shutter press to shoot at a moment where the motion is at a temporary minimum. (More recent naval gunners used expensive gyroscopic stabilisers.) One destabilising factor that caught me stupidly by surprise: MBT shoes. They neatly decouple your feet from even firm ground, adding wobbles in (I guess) the 2-5Hz range If you haven't tried them, it's not totally unlike standing on a trampoline. Link to post Share on other sites More sharing options...
Washington Posted March 12, 2012 Share #35 Posted March 12, 2012 Lindofi, Something tells me you went to College…. nice work!!!!! Link to post Share on other sites More sharing options...
Lindolfi Posted March 12, 2012 Author Share #36 Posted March 12, 2012 spydrxx, I know what you mean. Especially people with a slow pulse and large heart experience mechanical events. Now please do the following experiment: repeat the experiment with the tiny disk on a black surface I described in my first post, while you slowly pan the camera and an exposure time of 8 seconds. With my pulserate, you would expect 7 disturbances over the track. As you can see in the image, you can't see them. So most likely, pulse is not that important. Now that applies for me in this situation, but it may differ for others or for me in another situation (for instance when I stop during my training ride for a picture). Link to post Share on other sites More sharing options...
Bobitybob Posted March 12, 2012 Share #37 Posted March 12, 2012 Very interesting article. What about the effects of age with associated loss of myelin sheath. Didn't they ban the use of beta blockers in some sports eg shooting, snooker etc as these reduce anxiety and natural tremor. I like the alcohol idea the best, seems like another excuse to go to the pub! Link to post Share on other sites More sharing options...
pico Posted March 12, 2012 Share #38 Posted March 12, 2012 Thank you for that, Doctor. I can appreciate how very complex medicine can be. I will use fast shutter speeds when I can. Link to post Share on other sites More sharing options...
k-hawinkler Posted March 12, 2012 Share #39 Posted March 12, 2012 Thank you for that, Doctor. I can appreciate how very complex medicine can be. I will use fast shutter speeds when I can. And I am using my tripod with cable release. Now, if someone could switch off the wind around here, especially in the spring! Bert, Many thanks for your contributions to this forum. I always find them most illuminating, indeed. Link to post Share on other sites More sharing options...
pico Posted March 12, 2012 Share #40 Posted March 12, 2012 Yes, since you are creating a "joint" very close to the point of action. You see the same in artists using tiny brushes or in the technique of watch makers. And dentists as they use finger-rest techniques. (I've waxed up some crowns as a kid for my grandfather who was a prosthodontist in the Fifties. One was "almost acceptable", but he rejected them all. What a patient man he was.) Those techniques come in handy now as I work on camera parts. Link to post Share on other sites More sharing options...
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