How can a tripod be unstable?

Question

This sounds like a fairly stupid question, but it is one that has arisen whilst I was looking for cheap (<£50) and lightweight (<1kg) DSLR tripods.

I understand there's a price difference because of material/build quality, weight, height, and load weight, but there's also people reviewing tripods describing how they're "unstable". May I ask how a tripod can be unstable?

Also, please apply the answer to my situation: they'll all be landscape photos where I have all the time in the world (so I'll be using a remote shutter/2 sec timer), and I will be shooting long exposures (5 to 20 secs). Plus the place I will be going will not be that windy.

So I don't really get how you can get camera shake from something that is on solid ground, no human interaction, and no wind - heck couldn't I just use a wooden board flat on the ground?!

So there's my situation - so how can a tripod be unstable?

Answer 1

A tripod can be unstable by:

Having cheap leg fasteners / too heavy a load for the legs

• My first tripod ever was a hand-me-down Velbon that had seen some abuse. Even sporting just a 20D and 70-200 f/4 (~3.2lbs) if left alone, the legs would begin to collapse. Slowly, sure, but enough to not want to walk away or be able to do a long exposure.

Poor Quality Feet

• A decent, sticky rubber is most often used, as it will work well on dirt, rock, decently in sand (might sink a bit), cement, etc. Cheap feet (or even old feet) will be less sticky, negating these benefits. And really cheap feet may even expose a screw head or some metal - causing real slipping issues when used on hard surfaces.

Height to Base ratio

• You’ll notice that you have a lot of stability when the distance between the legs is greater than the height of the tripod. As you increase the height in comparison to the distance between the legs, you lose stability.
• This is doubly true when extending the center column or when photographing in high wind.
• In public places, someone could knock into your tripod. Whether or not you have to dive for it is dependent on this stability.

Where is the Center of Mass?

• Top heavy things in general are less stable and are easier to get moving, whether by wind, vibration, or some other force.
• Actions can be taken to counter-act a heavy camera on a (especially) light tripod, such as attaching weights to the center column or using something like a sandbag over the legs.

Vibrations

• Different materials handle vibrations differently. That same Velbon aluminum tripod vibrated enough to ruin photos at 400mm if a car drove by within 20 yards. It also vibrated for every small gust of wind.
• Generally speaking, the more material there is, the more vibrations will be dampened. Thick aluminum will work better than thin. Different materials also behave differently – carbon fiber, steel, aluminum, etc.

Head Design

• Some cheaper tripods come with built-in heads, as it negates the buyer from having to find one and creates an all-in-one ticket item. These can suffer the same fate as the cheap legs – the build quality can be such that, even tightened down, they still move over time or if influenced by wind/vibration.

Assuming that your chosen tripod could withstand the weight of your equipment without collapsing, and if it were tested in a vacuum, I would expect it to be on par with every other tripod of similar or better build quality.

But the real world has wind. It has people moving about. You may not notice that something as benign as a small gust could shake your shot during a moderately slow exposure – but the problems will exacerbate as your exposure lengthens.

The sturdiest of all tripods will withstand a heavy load, wind, and vibration. It’ll also weigh an absolute ton. As you look into models that shave weight but still maintain overall sturdiness, you’ll notice that the price starts to go up. Finding the right one for you means weighing your use case against price, carry-ability, pack-ability, load bearing, stability in wind, and stability with vibrations. Hence, the many differing designs utilizing differing materials and head types, at all different qualities.

Answer 2

I have a nice heavy tripod and a cheap, light aluminum tripod. I hear a lot of people talking about wind and vibration, etc, and I think you're right - the environment makes a big difference. Landscapes with little to no wind are very forgiving. However, even little wind can go a long way and cause vibration and the type of vibration we're talking about here might not even be visible to you as you're standing there taking the picture.

One of the main "unstable" things I find about lightweight tripods is the heads don't lock up very well. There's a little bit of wobble in the head even when it's tight, and if the camera is at an angle, it can drift just from the weight of a zoom lens (assuming a nicer, heavy lens). If you have a light camera and a light lens, even these drawbacks might not be a big deal.

The last piece to consider is vibration damping. There are vibrations from wind, other people walking on the same ground, and even the mirror flipping up in the camera. Certain materials do a great job at damping, but the mass of a heavier tripod can also help. Again, if you're in a field with no other people, and you lock the mirror up before shooting, vibration is minimal.

What it comes down to is flexibility. The cheapest tripod that doesn't buckle under the weight of your camera will work fine in perfect conditions, but if you spend a little more on something nicer, you can deal with a lot of variables much more smoothly.

Answer 3

May I ask how a tripod can be unstable?

Unstable might be the wrong word to describe the major problem with tripods; unsteady might be a better choice. Tripods are quite stable in the sense that, absent a really strong wind or careless photographer, all three feet will generally stay on the ground. They don't rock like a four-legged table on uneven ground.

However, all tripods are unsteady to some degree. Much of that unsteadiness comes from the legs, which are generally made of several sections of some sort of tubing that telescope inside one another. If you looked at just one section, even the smallest one, it'd seem very rigid on its own. When the leg is extended to four or five feet, though, there can be enough flex in the whole leg to be a problem.

How much flex are we talking about? If you set the tripod up with the legs extended all the way, it's not uncommon for the legs on a cheap tripod to deflect a centimeter or more if you apply some force near the middle of the leg's length.

The three legs are joined at the top to a bracket called a spider, and those joints are another source of shake. On some (usually more expensive) tripods those joints lock in position; on others, they don't lock at all, but cross braces limit the distance the legs can spread.

Tripods typically also have a center column that extends through the spider. Since the tripod head, and ultimately the camera, are mounted to the top of the center column, any play in the connection between the column and the spider creates some potential for movement.

One way that photographers try to eliminate shake and dampen vibration is to preload the tripod with some weight. Good tripods often have a hook on the lower end of the center column for just that purpose -- you can hang your camera bag, a bucket of sand, or any heavy thing you have handy from that hook, and that adds a lot of stability to the tripod. Of course, that can backfire, too -- if a weight suspended from one end of the center column starts swinging, the camera at the other end is going to see some movement. Rock bags are less prone to this problem because they attach at three points.

Finally, the head is one more source for unsteadiness. Cheap tripods generally come with cheap heads, and cheap heads are less likely to be as rigid or to lock down as tightly as better heads do.

Also, please apply the answer to my situation: they'll all be landscape photos where I have all the time in the world (so I'll be using a remote shutter/2 sec timer), and I will be shooting long exposures (5 to 20 secs). Plus the place I will be going will not be that windy.

The reason that people get worked up about the stability of a tripod is that even very small movements have a noticeable impact when using a long lens and/or making a long exposure. People spend a lot of money to buy very sharp lenses, so it doesn't make much sense to then use a cheap tripod that'll introduce a lot of motion blur. Even the tiny force of a DSLR's mirror flipping out of the way can create an unwanted vibration for an astrophotographer.

If you're shooting landscapes with a wide angle lens, for example, you might not be quite as concerned about absolute steadiness. More steady is always better, but steady enough for your purposes may well be attainable without spending a big pile of dough.

Answer 4

You are severely underestimating both the effect of wind, and how quickly vibration is damped. Even on days you'd now classify as perfectly still the small wind will still shake unstable tripods. And vibration from camera/ground doesn't necessarily dampen in two seconds.

That being said, very lightweight tripods can still be very useful.

Personally, I find a GorillaPod more useful than a cheap regular tripod, but I prefer a more sturdy (and heavier) tripod to both.

Answer 5

Lots of great answers, just one point to stress out: tripod stability has very little to do with price.

An old wooden geodetic tripod (provided you rig its head to fit a modern camera screw) will be much more stable and will dampen vibrations much better than a brand new tripod from a top brand built from cosmic materials.

It will also weight a ton and look butt ugly, but none of this will affect your pictures (with the possible exception of weight, if you are into the hike-in kind of landscape photography; for the drive-in kind this of course does not apply).

Answer 6

A light tripod with a heavy camera on top is rather top heavy. This makes it more inclined to wobble from the slightest side force. I have a rather heavy lens and walk quite long distances with camera gear plus day-hiking stuff, so my tripod has to be light.

Don't neglect the benefit of good feet on your tripod. My spare is ancient (1970s) and the rubber feet are rock hard so they don't grip very well. On an uneven surface they slip easily.

If you're trying to keep the weight down and you don't need to pan smoothly (as you imply in one of your comments) a simple ball head locks off very nicely (this is the new version of one I've got; the other is an even smaller Slik which is just as solid but less easy to use in gloves). I assume that with a long/heavy lens you'll use the tripod mount on the lens itself so the net torque on the mount is low.

Carbon fibre can be very good against vibration and is light (and not too expensive).

It's almost always worth adding weight to the bottom of your centre column though I don't like to use a bag of delicate camera gear for this as the hooks often aren't very good. The camera bag can weight down the upwind leg instead.

Answer 7

With an inexpensive tripod the locking mechanisms may not clamp as firmly, and with long exposures a small amount of vibration will blur the image especially with a long lens.

When you are shielded from the wind it can change direction, especially with a long exposure: https://youtu.be/F025lg1rU6U?t=21s - it can cost you a lens.

When shooting the unexpected or unpredicted can happen: https://youtu.be/HGNQXXuMrEI?t=40s - a bird can send everything flying.

You can buy an inexpensive tripod, weights are inexpensive compared with the price of a good camera and lens, even with a better tripod some people use weights.

An expensive tripod might save all the grief of an inexpensive one and an inexpensive tripod might save some money, weight, and the risk of damaging an expensive tripod.

It's all about budget. Allocate a majority of your money towards lenses and next towards the camera body. Perhaps 10% of your money would go towards the tripod based on the camera and lens in use. A $750 camera and lens would probably be OK on a $75 tripod but I wouldn't want to put $7500 worth of equipment on one.

If you have an inexpensive tripod, all locked down, on the lookout for everything, you can use your unwavering hand to prevent vibration.

Just spend enough so it's useful and not junk. Read reviews on "inexpensive tripod" there's as many opinions as tripods.

Answer 8

Short answer: Easily.

Much longer answer:

With some engineering background one can see that all rigid bodies are not as rigid as expected. In the first estimation they all follow Hooke's law - defformation is proportional to the applied load. In this case the load is the sum of tripod weight, the gear attached, wind, reaction forces from your hands, shutter/mirror/lens operation and vibration from the ground.

If the defformation of all parts is constant in time, your camera is steady but it never happens. Wind and noise generates random changes in the actual load applied to the tripod body and cause random displacement of the camera.

The real question is "What displacement matters?"

You can project the sensor grid on the scene and when the shaking camera causes blurring the sharp grid to blurry but clearly distinguishable grid you can consider the camera "stable". If it blurs more your camera is not "stable" enough.

Answer 9

The lighter it is , the more useless it will be , wrt height. All connectors on telescopic extensions must be strong or the connection point becomes a fulcrum.

Answer 10

A lightweight tripod is a compromise. But everything in photography is a compromise. Will a lightweight tripod be unstable? The answer includes "unstable compared to what?" It will be more stable than hand holding. It will be less stable than a large wooden tripod.

When a reviewer says the tripod is unstable, the judgment is made relative to their expectations. The judgement is not relative to yours. If you practice with the lightweight tripod, you can maximize its benefits and get a feel for its limitations. Maybe vibrations ruin four out of five shots. Maybe that is acceptable to you. Maybe it isn't.

Your situation is typical when it comes to equipment. The choice is not between cheap and expensive. It is not between mediocrity and high quality. It is between cheap and none. It is between taking long exposures with a mediocre tripod and not taking long exposures at all. It is between a possibility of capturing certain types of images and no image.