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Thread: Balance your gear with a rail.

  1. #41
    Glenn NK's Avatar
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    Re: Balance your gear with a rail.

    John:

    your point about the difference between aluminum and CF is well made I think.

    But what interests me is your finding that you get better results hand holding, and I think your point about the damping effect of one's hands is the key here. My hands don't vibrate at a high frequency and as you note, hand tissue deadens vibrations - this does not imply however that I'm not shaky. As they kindly say, I'm getting on in years.

    That's another reason for getting the Mark II version of this lens - it has Canon's so-called fourth generation IS which they claim up to four stops gain - real testing by Photozone indicates that three stops is quite safe.

    Glenn

  2. #42
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    Re: Balance your gear with a rail.

    Quote Originally Posted by Glenn NK View Post
    …But what interests me is your finding that you get better results hand holding, and I think your point about the damping effect of one's hands is the key here
    Hi Glenn,

    Under some conditions, better handheld results may be expected because:
    • the body and the lens are both supported and
    • the softer skin is indeed damping a lot…

    …that is if no other vibration is introduced in the equation.

  3. #43
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    Re: Balance your gear with a rail.

    Quote Originally Posted by Kodiak View Post
    Hi Glenn,

    Under some conditions, better handheld results may be expected because:
    • the body and the lens are both supported and
    • the softer skin is indeed damping a lot…

    …that is if no other vibration is introduced in the equation.
    Thanks Daniel:

    It's almost a mantra that images will be sharper using a tripod than hand-held, but apparently this is a bit false.

    Like so many "rules", this one should be viewed as a guideline.

    As I said, I don't vibrate so much as I wobble.

    It isn't visible in the second image I posted, but when the shutter activates, there are very small ripples on the surface of the water in the container I balanced on the hot shoe. As I recall, the wavelength of the ripples is in the order of 1/2 mm. Very tiny, but visible when viewed at the right angle.

    Glenn

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    Re: Balance your gear with a rail.

    Quote Originally Posted by Kodiak View Post
    Hi Glenn,

    Under some conditions, better handheld results may be expected because:
    • the body and the lens are both supported and
    • the softer skin is indeed damping a lot…

    …that is if no other vibration is introduced in the equation.
    Push the camera/lens ferm to a stone wall, and you will have no camerashake.

    George

  5. #45
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    Re: Balance your gear with a rail.

    Quote Originally Posted by george013 View Post
    Push the camera/lens ferm to a stone wall, and you will have no camera shake.
    Of course, being a tad resourceful helps in most cases. This old trick you
    mentioned is a must!

  6. #46

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    Re: Balance your gear with a rail.

    Quote Originally Posted by Kodiak View Post
    Of course, being a tad resourceful helps in most cases. This old trick you
    mentioned is a must!
    That's all after 3 weeks?

    I was referring to the statement below.
    Under some conditions, better handheld results may be expected because:
    • the body and the lens are both supported and
    the softer skin is indeed damping a lot…
    Damping is when you don't want a force/movement being passed to another subject, or with a less impact. Concerning the camera I'm interested how i can prevent a movement. No damping or vibration.
    The stiffer your tripod is, the less the camera will shake. Another old trick is hanging your camerabag on the middle leg of the tripod.

    I think balancing the camera is contra productive. The flexibility of the tripod is unused so the impulse given by the mirror has maximum possibility to shake the camera. That's why I asked you to experiment with the camera more to the back. The tripod is now under pressure and you moved the mirror away from the center of the tripod.
    I hope you understand my English.

    George

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    Re: Balance your gear with a rail.

    Years ago the chief film cameraman of my TV station commented that stability came from support under the nodel point of the lens rather than the balance point.
    I wonder if anybody has heard of that idea also or has any comment on it?

    The nearest I have got to the subject has been to make a collar to fit around a large and heavy tele-adaptor to mount the rig by rather than the camera. ... a very basic step I am afraid I never conducted tests ... just assumed it worked which it seemed to.

  8. #48
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    Re: Balance your gear with a rail.

    Quote Originally Posted by george013 View Post
    Damping is when you don't want a force/movement being passed to another subject, or with a less impact.
    That is an incorrect definition.

    From Wikipedia: "Damping is an influence within or upon an oscillatory system that has the effect of reducing, restricting or preventing its oscillations. In physical systems, damping is produced by processes that dissipate the energy stored in the oscillation."

    John

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    Re: Balance your gear with a rail.

    Quote Originally Posted by jcuknz View Post
    Years ago the chief film cameraman of my TV station commented that stability came from support under the nodel point of the lens rather than the balance point.
    I wonder if anybody has heard of that idea also or has any comment on it?
    The idea is that in panning, there shall be no parallax movement, another kind of stability than the one we are discussing here. TV cameras have no moving parts, so there is nothing to induce vibration.

    The problem we want to solve is that some cameras have considerable vibration-inducing movements inside. The camera industry has known this for a century, and in the early times of focal plane shutters, it was an argument against them. Imagine a curtain that is 7" wide, which when it starts rolling upsets the camera and causes it to dip.

    In the fifties and sixties, some manufacturers went to great length to dampen the impact of the mirror, with sliding, rather than clapping mirror systems (Canon RM, Zenza Bronica). The different mirror movement also permitted a shorter flange distance, which is the reason why Canon's is shorter than in other SLR:s, and Bronica got room for a focusing tube within the camera. Also later, Bronica has made an advanced mirror system with a split mirror moving in two directions, where upslap is complimented with downslap.

    We cannot influence the design of the camera, so there are mainly three ways we can control movement induced by mirror slap. Either, we can try to hold the camera as rigidly as possible (pressing it against a rock, or using a very heavy tripod), which makes the oscillation system a lot heavier, thereby decreasing the actual movement induced, or we can try to damp the oscillation as fast as possible, hoping that it will be sufficiently small when the shutter opens, or third case, we can release the mirror first and then wait till oscillation has ceased before releasing the shutter. As the tripod with camera mounted is an oscillating system per se, other oscillation than the one induced by the camera and operator, as wind, also might need attention.

    The most efficient way to increase rigidity of a tripod is to have the camera as close to the joint of the legs as possible. Any extension, as a centre column, or even the tripod head, can aggravate vibration problems. Therefore, there is no centre column on many of the better tripods. The TV pods never had them, neither tripods for measuring instruments (theodolites). The latter were almost always made of wood, until composite materials came in use. Wood dissipates vibration rapidly.

  10. #50

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    Re: Balance your gear with a rail.

    Quote Originally Posted by PhotomanJohn View Post
    That is an incorrect definition.

    From Wikipedia: "Damping is an influence within or upon an oscillatory system that has the effect of reducing, restricting or preventing its oscillations. In physical systems, damping is produced by processes that dissipate the energy stored in the oscillation."

    John
    You are right.
    But I'm not interested in vibration. Vibration, oscillation, implies that there is a movement allready. For that situation you have the mirror-up trick. Miror goes up, camera waits for a second and than opens the curtains.
    But if you don't want to use the mirror-up trick, you will have to prevent the camera to shake from the beginning.
    The impuls given by the mirror is a constant factor. So I think that the attention should be there to reduce that influence as much as possible. Hanging a weight under the centre colom has the advance that it's using the flexibility in the tripod system so leaving less room to camerashake. Or place the camera in unbalance, the mirror further from the tripodconnection. The flexibility in the system is used now for a part too.

    But going back to the balancing idea, I still think that balancing is working contra productive. You are giving the impuls maximal room to cause a camera shake.

    And about shooting handheld: you use two hands, two fixed points. The right hand on the camera and the left hand under the lens, as much as posible to the front. And the elbows against the body, your legs wide. Now you have something similar as shown in post 20.

    George

  11. #51
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    Re: Balance your gear with a rail.

    George - you assume that there is no movement when you hand hold, which is of course not correct. Relying on muscles tohold a camera perfectly still is simply not going to happen. You are trying to balance the forces provided by offsetting muscle pairs; muscles work by contracting; so there are so many different factors in play that getting perfect control in a handheld shot simply cannot happen.

    Secondly, there is no alternative to the mirror up "trick", as you put it. Any camera movement, whether it be due to external forces (hand holding, for instance), the forces from either the mirror slap or the shutter movement, will all introduce minute amounts of motion within the camera. With mirror up, we do rely on damping to reduce the impacts of mirror slap quickly.

    As for adding mass; well yes and no. Hanging a weight from the tripod hook is definitely one way of increasing the system mass, but the relative impact is likely going to be less than you think. There are all kinds of other variables in play, including how well the camera and lens are isolated from the tripod body. The rubber gasket in a lower end tripod or the spring in the clamping mechanism that holds onto the mounting plate in a higher end model are both going to end up decoupling the camera from the tripod legs to some degree. This means mirror slap is still going to influence your shot to some extent, even with a weighted tripod.

    Balancing the camera is not going to have any influence one way or the other, so long as the clamp is strong enough to hold the camera,other than ease of handling. This assumes that the beam is suitably rigid (which is certainly the case in Kodiak's design).

    I would suggest that you get a better understanding of basic mechanics (try any second year mechanical engineering textbook dealing with the mechanics of solids) and human physiology. Based on what you have written, I don't think you have a clear understanding of either field.

  12. #52

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    Re: Balance your gear with a rail.

    Quote Originally Posted by GrumpyDiver View Post
    George - you assume that there is no movement when you hand hold, which is of course not correct. Relying on muscles tohold a camera perfectly still is simply not going to happen. You are trying to balance the forces provided by offsetting muscle pairs; muscles work by contracting; so there are so many different factors in play that getting perfect control in a handheld shot simply cannot happen.
    I just react on the statements made that sometime they get a better result handheld and that was partly due to a softer skin that's damping a lot. Handheld you have mostly two points to hold the camera. If you want to try out the difference with a one point hold, just keep only the camera in your hand. You may even use two hands to do that. The results will be less.
    Well, I still think that holding the lens also, reduces the impact of the mirror slam.


    Secondly, there is no alternative to the mirror up "trick", as you put it. Any camera movement, whether it be due to external forces (hand holding, for instance), the forces from either the mirror slap or the shutter movement, will all introduce minute amounts of motion within the camera. With mirror up, we do rely on damping to reduce the impacts of mirror slap quickly.
    We are discussing the camera movement due to the mirror slap. So I will stick to that. The mirror slap creates an impuls, a force in the camera in a certain direction and is a constant factor. The mass and speed of the mirror doesn't change. You can accept that impact on camera and tripod and use the mirror-up trick or you can try to reduce that impact as much as possible.

    As for adding mass; well yes and no. Hanging a weight from the tripod hook is definitely one way of increasing the system mass, but the relative impact is likely going to be less than you think. There are all kinds of other variables in play, including how well the camera and lens are isolated from the tripod body. The rubber gasket in a lower end tripod or the spring in the clamping mechanism that holds onto the mounting plate in a higher end model are both going to end up decoupling the camera from the tripod legs to some degree. This means mirror slap is still going to influence your shot to some extent, even with a weighted tripod.
    Well, some agreement. But the idea behind this is not just increasing the system mass but to put the tripod under pressure so the flexibilty of it is gone. I think a elastic or rope around the legs as mentioned before will also give a positive result.

    Balancing the camera is not going to have any influence one way or the other, so long as the clamp is strong enough to hold the camera,other than ease of handling. This assumes that the beam is suitably rigid (which is certainly the case in Kodiak's design).
    What I asked was to unbalance that system with the weight more to the back. In that case you would keep the tripod under a certain pressure and you would get rid of the leeway in the clamp you mentioned. As you might know the flexibility of a system is not a lineair function. By consuming the first part, the mirror slam will also get less impact.


    It's all second years mechanical.

    George

  13. #53
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    Re: Balance your gear with a rail.

    Quote Originally Posted by george013 View Post
    I just react on the statements made that sometime they get a better result handheld and that was partly due to a softer skin that's damping a lot. Handheld you have mostly two points to hold the camera. If you want to try out the difference with a one point hold, just keep only the camera in your hand. You may even use two hands to do that. The results will be less.
    Well, I still think that holding the lens also, reduces the impact of the mirror slam.
    Only if everything else is equal, but then it's not. If someone is getting better results handheld than with a tripod, its either time to buy a better (sturdier) tripod or fix the tripod shooting technique. Unless the ground is vibrating and that impact is amplified though the tripod there is no way that I can see a handheld shot being sharper than one using a tripod.

    Carefully said, chosing the right tripod for the right purpose is important here. I own four tripods and use them in different shooting situations. I am traveling right now and have my smallest, lightest tripod along. If I am planning to take exposures that run into multiple minutes, I have a heavy duty tripod that is extremely rigid. I can replace the centre column with a fixed plate and heavy duty ball head and I can take extremely long exposures without any motion issues creeping into my shots.



    Quote Originally Posted by george013 View Post
    We are discussing the camera movement due to the mirror slap. So I will stick to that. The mirror slap creates an impuls, a force in the camera in a certain direction and is a constant factor. The mass and speed of the mirror doesn't change. You can accept that impact on camera and tripod and use the mirror-up trick or you can try to reduce that impact as much as possible.
    I agree with your first two sentences, but not your last. There are two ways to deal with mirror slap; the first is to shoot in mirror up mode, having allowed enough time for any internal vibratations related to triggering the mirror and bringing it to a stop to damp out. The second is to shoot at a suitable shutter speed so that mirror slap does not affect the image; as a guess any exposure shorter than around 1/15 s or longer than 10 s would work.

    Quote Originally Posted by george013 View Post
    Well, some agreement. But the idea behind this is not just increasing the system mass but to put the tripod under pressure so the flexibilty of it is gone. I think a elastic or rope around the legs as mentioned before will also give a positive result.
    I'm not sure that you have identified the mechanism that causes this to work. A loosly applied elastic or rope won't change the flexibility of the setup, but rather change (increase) the natural harmonic frequency that the tripod legs will vibrate at. Lower amplitude would result and this show up as less vibration in the legs. At a high level, if the elastic / rope were applied half way along the legs, you would get a similar impact by setting up the tripod legs half way. If you look at commercial video tripods, this is effectively what a mid-spreader does.


    Quote Originally Posted by george013 View Post
    What I asked was to unbalance that system with the weight more to the back. In that case you would keep the tripod under a certain pressure and you would get rid of the leeway in the clamp you mentioned. As you might know the flexibility of a system is not a lineair function. By consuming the first part, the mirror slam will also get less impact.
    I have no idea what you are saying here. An "unbalanced" load to me suggests all three tripod legs will not be carrying the same load. There is a theoretical advantage of having an equal load, but unless the load is quite unbalanced, practically I see no significant advantage or disadvantage of a perfectly balanced load from a stability standpoint.

    Likewise, an unbalanced load would result in one or two of the tripod legs carrying a slightly higher load than the other leg(s), but again, this will has little real world impact unless the offset is significant.

  14. #54

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    Re: Balance your gear with a rail.

    Quote Originally Posted by GrumpyDiver View Post

    I have no idea what you are saying here. An "unbalanced" load to me suggests all three tripod legs will not be carrying the same load. There is a theoretical advantage of having an equal load, but unless the load is quite unbalanced, practically I see no significant advantage or disadvantage of a perfectly balanced load from a stability standpoint.

    Likewise, an unbalanced load would result in one or two of the tripod legs carrying a slightly higher load than the other leg(s), but again, this will has little real world impact unless the offset is significant.
    It's the name of this thread: "Balance your gear with a rail"

    I'll quote myself.
    What I asked was to unbalance that system with the weight more to the back. In that case you would keep the tripod under a certain pressure and you would get rid of the leeway in the clamp you mentioned. As you might know the flexibility of a system is not a lineair function. By consuming the first part, the mirror slam will also get less impact.



    I agree with your first two sentences, but not your last. There are two ways to deal with mirror slap; the first is to shoot in mirror up mode, having allowed enough time for any internal vibratations related to triggering the mirror and bringing it to a stop to damp out. The second is to shoot at a suitable shutter speed so that mirror slap does not affect the image; as a guess any exposure shorter than around 1/15 s or longer than 10 s would work.
    I read this several times and I don't get it. I hope I don't make a mistake but what's wrong with a shutterspeed between 1/15s and 10s?
    Since the curtain opens directly after the mirror slam, exposure starts directly with the maximal motion of the camera

    I believe the intention of this thread was how get better results with the gear you have.

    George

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    Re: Balance your gear with a rail.

    Quote Originally Posted by george013 View Post
    I read this several times and I don't get it. I hope I don't make a mistake but what's wrong with a shutterspeed between 1/15s and 10s?
    Since the curtain opens directly after the mirror slam, exposure starts directly with the maximal motion of the camera
    These is nothing wrong with those shutter speeds; its just that mirror slap will only impact a small subset of exposures. If your shutter speed is sufficiently fast, you'll never notice an impact of shutter slap as the exposure will have been completed before the vibrations have any noticeable impact on the image.

    The same thing goes at the other end of the scale. If the exposure is sufficiently long, the amount of light that hits the sensor while the shutter slap is damping down is so minimal that it will not have any noticeable impact on your exposure. Simply said, there is a range of exposures where you will notice this and this will be to some degree depend on your camera and your gear setup.

    Quote Originally Posted by george013 View Post
    I believe the intention of this thread was how get better results with the gear you have.
    I wouldn't read it that way. I find I will invest in new gear when my existing gear limits my work. Sometimes you simply cannot use your existing gear and get acceptable results. Tripods are one place many photographers try to skimp on and it never works out well. As I said before, I own four different tripods and each one was bought for a very specific purpose and to a great extent, these are not interchangable.

    1. Small ultra light-weight travel tripod. I wouldn't want to take a long exposure (more than a few seconds) with it, but have no hesitation dragging it half way around the world to use with a small camera (mFT or APS-C). I would never use it with my full-frame of still cameras. I'm in South Asia right now and I am shooting with it.

    2. Medium tripod - my go-to tripod for shorter hikes and trips. I will use it with my larger cameras, but do understand its limitations.

    3. Large heavy duty tripod - studio work or travel by car. It is sturdy, rock solid and expensive. I can take a 30 minute exposure without worrying about vibrations or movement.

    4. Video tripod - heavy duty beast that is rock solid. Great zooming and panning with its fluid head. I have travelled to very remote places with it as it holds my relatively large video camera quite still.

    Just like there are tradeoffs with lenses and camera bodies, there are tradeoffs with tripods. Right now I am travelling with a mFT camera and two lenses simply because I am backpacking for two months and am not able to bring my full-frame body and pro glass along. Size and weight were more important that quality on this trip.

  16. #56

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    Re: Balance your gear with a rail.

    Quote Originally Posted by GrumpyDiver View Post
    These is nothing wrong with those shutter speeds; its just that mirror slap will only impact a small subset of exposures. If your shutter speed is sufficiently fast, you'll never notice an impact of shutter slap as the exposure will have been completed before the vibrations have any noticeable impact on the image.

    The same thing goes at the other end of the scale. If the exposure is sufficiently long, the amount of light that hits the sensor while the shutter slap is damping down is so minimal that it will not have any noticeable impact on your exposure. Simply said, there is a range of exposures where you will notice this and this will be to some degree depend on your camera and your gear setup.
    The delay with mirror-up is about 1s. So Nikon counts on the fact that on a normal tripod the vibration is over within 1s.
    With no mirror up the exposure starts right after the mirror slam. The camera gets an impuls of the slam and shakes. At this moment the impact of the mirror slam is maximal. Only when the shock is going through the tripod and being returned, then there is a wave, vibration.
    So what I would like to do is reducing the impact of the mirror slam. At this moment I don't care about the vibration. And that could be done by making it all stiffer. Hanging some weight so you use the first part of the flexibility, or "unbalancing" the camera by moving it back with the rail Kodiac made. In that case you are using also some of the first part of the flexibility.
    And not everybody has the money to buy the best tripods for different occasions.

    George

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    Re: Balance your gear with a rail.

    With this pre-occupation with mirror slap I see two solutions 1] shoot with short or long exposures as Manfred suggested [ thanks for pointing out the logic of this ] and 2] buy a camera without a mirror to slap.[ as Manfred tells us he is using currently ]

    As for tripods, I have/had about five or six so far ranging from the solid seven foot Debrie for 35mm motion picture use down to my Slick 8555 currently occasionally used. My most used tripod is over 40 years old from when I bought it on a special, also a Slick, a Master from the 1960's ....somewhere around is the theodelite tripod, war surplus following WWII when I was a struggling student.
    Depending on the tripod being used one adjusts ones technique to suit, as with cameras.
    If I was on Manfred's trip it would be the 8555 I'd be carrying. Very versatile.

    But as I suggested to my son last week .... don't forget the burst option ... first frame NBG but subsequent ones AOK ... something relatively new to me in the digital age.

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    Re: Balance your gear with a rail.

    Kodiak, you are truly a Renaissance man, an artist and an inventor combined!

  19. #59
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    Re: Balance your gear with a rail.

    Quote Originally Posted by rpcrowe View Post
    Kodiak, you are truly a Renaissance man, an artist and an inventor combined!
    Thanks Richard… I don't know what to add!

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    Re: Balance your gear with a rail.

    Quote Originally Posted by Inkanyezi View Post
    The idea is that in panning, there shall be no parallax movement, another kind of stability than the one we are discussing here. TV cameras have no moving parts, so there is nothing to induce vibration.

    .
    We were talking about film cameras not TV cameras .. but of course the solution is to dump the DSLR for a modern camera type which meets that requirement .... MFT

    But I'm biased of course

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