NikonGear'23
Gear Talk => Lens Talk => Topic started by: Michael Erlewine on September 14, 2015, 02:50:42
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I have a nice, but rather small, room in my house that I use for a studio. The light is perfect, with skylight, and large vertical windows, etc. What is not perfect is that the floor vibrates, ever so slightly, even if I am just standing there… trying to be still.
So, my question is. If, for example, I use a four-legged stool to set my subject on (a flower) and the camera is on a tripod. The tripod does not seem to vibrate, but he stool does.
What could I place under the four legs of the stool to dampen vibrations?
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Michael, the first things that comes to my mind are some concrete blocks. The same method for dampening the vibrations of the record players and speaker cabinets.
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I solved this once (in the case of a wooden floor, dancing, record player) by softly pumping the inner tupe of a bicycle and putting a marble slab on top, both of which I had in the closet by chance.
After that we could dance on the floor without the record jumping.
I guess though that the tripod might then be moving relatively to the Flower, so the construction might even be better if the tripod it on the mareble plate too.
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Mass alone is insufficient in the dampening of vibrations. What one needs is decoupling.
For speakers, standing them on spikes is a well known and recommendable practice. You can use a small metal piece underneath each spike to avoid marking the floor boards.
Alternatively, two heavy and torsionally rigid pieces of metal or stone, in between which an intermediate layer of hard rubber or similar pliant material is inserted, can be quite efficient. The shutter unit of the Nikon Multiphot follows this design principle.
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Thanks all. I had come up with the idea of the two (or so) cement blocks and I have ordered some rubber vibration-isolation pads, so I will combine the two. This phenomenon does not seem to affect the tripod, but only the stool I have the subject (flower) sitting on. Obviously I have to solve this, because it affects every stacked photo... a lot.
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Thanks all. I had come up with the idea of the two (or so) cement blocks and I have ordered some rubber vibration-isolation pads, so I will combine the two. This phenomenon does not seem to affect the tripod, but only the stool I have the subject (flower) sitting on. Obviously I have to solve this, because it affects every stacked photo... a lot.
The rubberpads I tried they do not dampen / absorb the movement enough, they just frequency-modulate them. The bicycle tube did work much better, like an extremly slow levelling balance absorbing all kinds of vibration of different wavelengths.
Show a making off. when your done and tell us what did work and whatnot
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So, my question is. If, for example, I use a four-legged stool to set my subject on (a flower) and the camera is on a tripod. The tripod does not seem to vibrate, but he stool does.
What could I place under the four legs of the stool to dampen vibrations?
Why not just put the flower pot on another tripod if the camera on the tripod is not vibrating?
If you put a weight on a spring, then stretch the spring, then let it go, the weight bounces up and down, a little less each time, and eventually stops. That is damping. The time it takes to stop is related to the mass (the heavier the quicker it stops) and the stiffness (= elastic modulus) of the spring (the stiffer the quicker it stops). So making the stool heavier or of stiffer material - steel rather than wood, eg - will damp the vibrations better.
But if the vibrations are, eg, from nearby trains or trucks and reaching your floor through the earth damping will help but is not enough, because the vibrations do not happen in an instant and then decay. You need uncoupling, as Bjorn says (which is probably why the tripod is not vibrating: it is very stiff and poorly coupled to the floor).
Uncoupling, however, is a bit counter-intuitive. It requires that the vibrations cross boundaries between materials of different density. It is not that soft material, such as rubber, "absorbs" the vibrations, it is that they are lost at the interfaces between the light and heavy materials. The loss depends on the difference in density, so steel on either side of rubber is much better than concrete either side of rubber, which is a poor choice because concrete is usually only a little denser than hard rubber. Steel either side of bubble wrap is excellent. Because only the interfaces matter it does not matter how thick the layers of material are: thin metal sheets are as good as thick ones and one layer of bubble wrap is as good as several - but many interfaces with different densities is many times better than one.
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Why not just put the flower pot on another tripod if the camera on the tripod is not vibrating?
good as several - but many interfaces with different densities is many times better than one.
Anyone know of a flat plate that we can mount at 90-degrees to the tripod head screw or quick-release clamp?
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How about sorbothane telescope vibration pads?
http://starizona.com/acb/Vibration-Suppression-Pads-P680C0.aspx (http://starizona.com/acb/Vibration-Suppression-Pads-P680C0.aspx)
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How about sorbothane telescope vibration pads?
http://starizona.com/acb/Vibration-Suppression-Pads-P680C0.aspx (http://starizona.com/acb/Vibration-Suppression-Pads-P680C0.aspx)
That's right. I have some already on order. These are the folks who really care about vibrations. I have checked it out.
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Check out this set up:
http://nikongear.net/revival/index.php/topic,1570.msg16565.html#msg16565
Then there is no issue re camera and subject, unless you have other vibration issues in the house...
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Check out this set up:
http://nikongear.net/revival/index.php/topic,1570.msg16565.html#msg16565
Then there is no issue re camera and subject, unless you have other vibration issues in the house...
Well, as mentioned, the vibration issue I am look for a solution to is not related to camera and lens, but to vibrations in the floor itself. I am working on some possible solutions, which I will document here if they are successful.
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........ The tripod does not seem to vibrate, but he stool does.
What could I place under the four legs of the stool to dampen vibrations?
Remove the stool from the set up!
Put the flower and camera on the same platform and put the platform onto the tripod.
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Uncoupling, however, is a bit counter-intuitive. It requires that the vibrations cross boundaries between materials of different density. It is not that soft material, such as rubber, "absorbs" the vibrations, it is that they are lost at the interfaces between the light and heavy materials. The loss depends on the difference in density, so steel on either side of rubber is much better than concrete either side of rubber, which is a poor choice because concrete is usually only a little denser than hard rubber. Steel either side of bubble wrap is excellent. Because only the interfaces matter it does not matter how thick the layers of material are: thin metal sheets are as good as thick ones and one layer of bubble wrap is as good as several - but many interfaces with different densities is many times better than one.
Les,
Very usefull, I didn't know about this density variation impact.
In a sandwich, is it better to vary densities accross layers or will it not be significally different from a repeat of layers? In other words, would steel/bubblewrap/steel/bubblewrap/steel be equivalent to steel/rubber/lead/bubblewrap/aluminium?
Thanks.
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Remove the stool from the set up!
Put the flower and camera on the same platform and put the platform onto the tripod.
+1
Recording and sample on the same platform AND decouple the platform
from the house vibration.
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Well, as mentioned, the vibration issue I am look for a solution to is not related to camera and lens, but to vibrations in the floor itself.
When they moved the research lab that I worked in from the ground floor to the second floor , we ran into an almost incurable vibration issue especially for photomicrography. After trying several methods we basically ended up with a sandwich of a 80lb granite block and insulating pads for the microscopes, and the table legs were also on individual insulating pads. Even then, there were still times when this was insufficient.
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Les,
In a sandwich, is it better to vary densities accross layers or will it not be significally different from a repeat of layers? In other words, would steel/bubblewrap/steel/bubblewrap/steel be equivalent to steel/rubber/lead/bubblewrap/aluminium?
I am sorry, I have been careless. The issue is actually impedance matching. Impedance is the medium's density (ie, mass/volume) x speed of sound in the medium. The speed of sound in a material is the square root of (stiffness divided by density). Broadly, denser materials are stiffer (steel is denser and stiffer than wood, eg), but relatively dense but very un-stiff materials, such as rubber, or sorbothane, can have much lower impedance than somewhat denser materials that are much stiffer.
The principle, however, is the same for electricity and sound, eg: where you want to minimise interface losses, as with power transmission or telephone lines, you match impedances on either side of a junction. Another example of matching is when you have an ultrasound examination and they put jelly on your skin: the jelly has impedance similar to tissue, so it eliminates what would otherwise be a severe mismatch at the probe/air and air/skin interfaces. And you have those little bones in your ear to impedance match the eardrum to the fluid-filled inner ear, because if there were two air-tissue interfaces you would hear poorly.
To maximise losses you want the biggest possible difference between impedances, and you want as many interfaces as possible. Because air is so light its impedance is very low, so a lot of air to something else interfaces is good.
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Shaky Floors
The worst problem I’ve encountered is the fact that the floor of the room is not well-enough supported, with the result that the floor vibrates enough to cause stemmed flowers (and even whole vases) to shake, even when I am standing still. The vibration in my own body, the tension, is enough to ever-so-slightly move the plant or flower, making very exact photos difficult.
I have found ways of lessening this vibration, but the saving grace is that the walls and verticals do not shake, so I devised a way to hang wide (22-inch) shelf brackets upon which to place plants, flowers, vases, and so on. This works well. The shelf is easily movable (up and down) and can support up to 300 pounds, they tell me. (PHOTO E)
As for the tripod, which does sit on the floor, I have tried out different vibration buffers under the tips of the three tripod legs. I have tried the Celestron Vibration Suppression Pads and Sorbothane Vibration Isolation Square Pad (1/2” thick). Of the two, its seems that the Sorbothane pads work better
More small-studio ideas in this companion post:
http://nikongear.net/revival/index.php/topic,1674.0.html