Super easy / basic question about tripod load

[FlyingSquirrel]

I'm looking at buying a new tripod. My question is:

Why, when the manufacturer gives a max load capacity, do they also give a "up to xx mm lens"

For example, I am looking at the Gitzo GT1531 Tripod and it says it supports a max of 17.6 lbs. Then they proceed to say "for DSLRs with 135mm lenses (up to a 200mm maximum)"

That makes ZERO sense to me. There is absolutely no way a 200mm lens and DSLR body will weigh anywhere near 17.6 lbs, even "pro" models of said equipment. So, they must be blowing smoke up someone's skirt in one way or another.

The way I see it, max load is max load. If it can't support bigger than 200mm lens for some reason (off balance weight distribution?!) then they have no business claiming a 17.6lb load bearing spec.

If someone can solve this mystery, please enlighten me

[William W]

I'm looking at buying a new tripod. My question is: Why, when the manufacturer gives a max load capacity, do they also give a "up to xx mm lens" For example, I am looking at the Gitzo GT1531 Tripod and it says it supports a max of 17.6 lbs. Then they proceed to say "for DSLRs with 135mm lenses (up to a 200mm maximum)"

What is your source of those words I have underlined?


Here on the Gitzo site, it states the load capacity is 8kg (yes, about 17.6lbs)

– BUT-

also the site states:

“An excellent choice for […] DSLRs with 135mm lenses, up to a maximum of 200mm. Offers an excellent maximum load capacity and good torsion rigidity at a reduced weight. . . .”

NOTE the underlined words.

That whole sentence is saying the tripod is an “excellent choice” for the lenses and camera combinations it mentions.

It is clearly NOT saying that the tripod "cannot hold a lens longer than 200mm."

***

As a second point, there will be a moment of turning (a turning force) as the lens is longer, especially if there is not a tripod mount to mount the LENS and the camera is mounted to the tripod. I interpret the phrase ” good torsion rigidity” to refer to this factor: so I expect that the manufacturer is taking into account the physical LENGTH of the lens when they make the statement of what an "excellent choice" would be.

***

As a third point, a camera and lens on a tripod can damped, either by a central weight slung below or by a cover over the rig: this will add quite a deal of weight the “load”. So one does not necessarily account for only the Camera and Lens as being the total load.


WW

[Stagecoach]

Matt,

You are right in that the load quotes are confusing with tripods.

It's capacity is going to very much depend upon where the load is acting.

If the camera and lens have their centre of gravity acting downwards at the centre of the tripod that's the theoretical 'ideal' position.

If the centre of gravity of the camera plus lens are acting downwards away from the centre of the tripod the maximum safe weight of the load will also depend upon the weight and angle of the rear legs of the tripod which react/oppose against the camera/lens offset loading.

In other words a camera with a very long lens may be fine on a heavily constructed tripod but when put on a tripod of light construction, although rated for the weight if central, may topple over. Many variables here and not the easiest to provide straight forward simple specifications for.

[FlyingSquirrel]

Bill, thanks for your reply

also the site states:

“An excellent choice for […] DSLRs with 135mm lenses, up to a maximum of 200mm. Offers an excellent maximum load capacity and good torsion rigidity at a reduced weight. . . .”

NOTE the underlined words.

That whole sentence is saying the tripod is an “excellent choice” for the lenses and camera combinations it mentions.

It is clearly NOT saying that the tripod "cannot hold a lens longer than 200mm."

I understand exactly what you are saying. However, I only somewhat agree with you. The way I read it, when they say "up to a maximum of 200mm" they are implying that it would not be a good choice to use a longer lens. Just my opinion based on the wording. You could definitely be 100% correct though.

***

As a second point, there will be a moment of turning (a turning force) as the lens is longer, especially if there is not a tripod mount to mount the LENS and the camera is mounted to the tripod. I interpret the phrase ” good torsion rigidity” to refer to this factor: so I expect that the manufacturer is taking into account the physical LENGTH of the lens when they make the statement of what an "excellent choice" would be.

***

That is a good point, thanks for explaining it.

As a third point, a camera and lens on a tripod can damped, either by a central weight slung below or by a cover over the rig: this will add quite a deal of weight the “load”. So one does not necessarily account for only the Camera and Lens as being the total load.

That is something I had not considered, and it reminds me that the tripod head must also be figured in.

[FlyingSquirrel]

Grahame, thanks for the reply. You make excellent points and it makes a lot of sense.

I appreciate your reply and also Bill's reply. I need to think about this. It might be worth it to for me to get a "sturdier" tripod that is rated at a higher load, just to be on the safe side...

I'm considering the Sigma 500mm f4.5 lens and a Wimberly gimbal, plus my canon 7D body. Should amount to around 13 lbs of weight for those 3 items. It's not likely that I would damp things with extra weight, but then again, I can't rule that out 100%. Also, with a 500mm it might be wise to have a beefier base based on the length of the lens? It's 13" long and 7lbs. I would have it mounted on the gimbal using the lens collar, with the weight centered.

[William W]

. . . it reminds me that the tripod head must also be figured in.

Yes.

***

Also the centre of gravity (as mentioned) is related to the moment of turning: if the rig is perfectly balanced the centre of gravity is over the centre stick and there is no moment of turning . . .

And if the legs are not even, (that is to say if the tripod and rig are slanted off the vertical) there is another moment of turning to consider.

WW

[FlyingSquirrel]

Thanks again, Bill.

[William W]

Thanks again, Bill.

Thank you too: I should have designated the "head" as being another separate load in my answer.

The Head, can be quite heavy.

WW

[NorthernFocus]

Matt, others have already mentioned the potential for torsional effects. With the rig you mentioned that's not an issue because by design the load will be balanced. However, if you use good technique you will likely put addtional load on the tripod either by hanging weight under it or with your hands. For the rig you described I would recommend looking at tripods designed for at least 30 lbs or so. Another consideration is handling. Larger leg diameters are easier to handle and carry when moving around.

[Manfred M]

You would like a simple answer for a complex question.

First of all, there are two parts to this question; the absolute load that the legs can take. This would be total force applied directly on the centre column before the tripod “fails”. Failure could be a simple as the friction lock on the legs failing or as serious as a catastrophic failure of a part (i.e. a part actually breaking). The problem, of course, is that no tripod manufacturer actually seems to state as to how this force is measured. At a minimum, it should include the camera, with lens, the head and any weight you put on the tripod hook. My tripods have two positions; the normal “high” position where the legs lock and also a second “low” setting that allows me to splay out the legs to get close to the ground. I’m fairly certain that on my tripods, the maximum stated weight is likely not for the lower position. The other unknown is whether or not the manufacturer has applied a “factor of safety” in the stated maximum load. Back in the old days, it was fairly common to assume a factor of safety of 2 on the published data, but I would expect that this might still be the case with premium gear, while lower end equipment might not have any at all.

The second issue is what is referred to as static or dynamic loading. I assume that the weight limits are likely based on static loading. A dynamic load would be encountered if you put the tripod down on the ground or have your equipment mounted on the back of a moving truck that is bouncing up and down. If you put your tripod down hard or the truck bounces with a force of 2G (i.e. twice the force of gravity), the load on the tripod would be doubled.

I quite agree that there is a second issue related to the torque applied to the head by the weight being off centre. Torque is measured in foot-pounds or inch-pounds or in metric, N-m (Newton-meters) and is the twisting force on the tripod head. This has absolutely no impact on the weight capacity of the tripod, but obviously affects your head choice. Again, tripod collars on large lenses help here, but I don’t see any published information on the amount of torque various camera / lens combinations put on the tripod head. As well, the recommended maximum ratings on the various heads are not often clear. Testing your head is really the only way to go here. I find that a proper lens collar with mounting foot for larger lenses is the only way to ensure a reasonably steady shot with a longer lens.

The third issue is the amount of off-centre weight a tripod can support. The issue here is how “tippy” the lens / tripod combination are. Again, there are a number of variables and work-arounds. If the tripod with a long lens or a camera mounted in a portrait position are unstable, hanging an appropriate amount of weight on the hook will help. I personally prefer shooting portrait mode using an L-bracket” that lens me mount the lens directly over the column, but these devices are not inexpensive. Again, trial and error will help here; dropping the tripod / camera while testing is not a good idea. Don’t forget that a strong wind can knock over your setup too.

Bottom line; it is always safer to use a large and sturdy tripod and a ball head whose capacity exceeds the maximum total weight you are planning to mount on the tripod. The downside is of course, that weight and cost go up with beefier gear.

[Glenn NK]

As Manfred notes, it's not a simple answer - the question is more complex.

1) A tripod will rarely fail under load - one of the mods here posted a pic a while back with the tripod holding up his weight. Strength is not the issue or is rarely the issue. The absolute load capacity is irrelevant.

2) What is important is stiffness. Stiffness and strength are not the same thing. A rubber surgical tube can be very strong (can hold up quite a bit of weight without breaking), but is not very stiff (it will stretch to at least twice its original length without breaking).

3) Stiffness varies with the type of material, and the shape/size of the members. Tripod legs are hollow tube because this type of cross section provides maximum stiffness with minimum weight.

4) Stiffness decreases with length. When the legs aren't extended, only the larger legs carry the weight - it will be very stiff because the larger and shorter sections are stiffer.

5) Stiffness is what keeps a tripod from vibrating in the wind, or deflecting under the load of the camera and lens.

6) I've never seen a tripod rated for stiffness - manufacturers don't get into this - it might be too revealing.

Glenn

[FlyingSquirrel]

Thank you to everyone who responded, again.

For the rig you described I would recommend looking at tripods designed for at least 30 lbs or so.

Bottom line; it is always safer to use a large and sturdy tripod and a ball head whose capacity exceeds the maximum total weight you are planning to mount on the tripod.

Thanks, guys. After coming to the realization that the answer to my question was far more complex and technical than I originally thought (and want to think about ).....the two quotes above are really the kind of take-away info that I think I need.

In essence, I need to suck it up and deal with the extra beefiness and weight, for the safety and stability I really need. Realizing the potential issues that I could encounter, I think it's best not to skimp on the tripod if I'm going to have $7K + of gear supported on it.

After dumping the idea of the 17lb load tripod, I am now looking at another gitzo that is up a few notches...

- the Gitzo GT2541 which is rated for 26.4 lbs (that would be 2x the weight of the heaviest body, lens, and head that I'd be supporting, allowing for extra weight to be hung on the tripod and basically more strength/sturdiness compared to the other tripod I was looking at) Do you think that would be enough? Or should I go even more beefy?

- next Gitzo up in the mountaineer series is GT3541, rated for nearly 40lbs. The tripod itself, however, weighs 46% more. I wonder if, for the base 13lb rig I mentioned, this would be overkill?

An added comment: I think it is somewhat realistic to expect that sometimes I will not be able to get the tripod 100% even / perpendicular to the ground. That is because, obviously, in nature, the landscape and conditions don't always cooperate. Granted I can change the leg angles and heights individually, but if I'm shooting wildlife and things are happening fast before I can set up properly, or the ground angles are just plain crazy, or I'm in mud, or whatever, the load could be slightly off the center of gravity. Hopefully a sturdier tripod could offset some of the issues due to the slightly off balance load. Obviously I'll be careful and not let it go if it seems tippy.

p.s. 1 - I am now in somewhat of a mad dash to choose a tripod since Gitzo (and a few other manufacturers) are having a rebate promo right now that ends in two days, and if I make it in on that I could save $150 or so.

p.s. 2 - Thanks for any additional help on this

[William W]

An added comment: I think it is somewhat realistic to expect that sometimes I will not be able to get the tripod 100% even / perpendicular to the ground. That is because, obviously, in nature, the landscape and conditions don't always cooperate. Granted I can change the leg angles and heights individually, but if I'm shooting wildlife and things are happening fast before I can set up properly, or the ground angles are just plain crazy, or I'm in mud, or whatever, the load could be slightly off the center of gravity. Hopefully a sturdier tripod could offset some of the issues due to the slightly off balance load. Obviously I'll be careful and not let it go if it seems tippy.

In adverse terrain - splay the legs wider and keep the tripod short.

Carry a lot of big green garbage bin liners - they are very good ground sheets that you can sit on.

A big rig on uneven ground is more stable with the tripod splayed and close to the ground - even if you are sitting in mud, rather than standing in it.


As you seem to now be investing more money into your tripod, you might think about other qualities your tripod might have and what functions you might use:

As well as for reasons other than I just outlined, my tripods have legs that will splay to 90 degrees.

Also, a tripod with a centre stick which can be removed is very flexible.

I am not intimately familiar with the Gitzo range.




WW

[NorthernFocus]

Hey, Matt. I don't use a Gitzo but am using a carbon fiber tripod rated for 27 lbs. with a full size Wimberly (not a sidekick), a pro body, and 500mm f4 lens and it is plenty stout. I used with a rented 600mm for a week too and was perfectly comfortable. With a big telephoto rig I highly recommend getting one that is tall enough to stand comfortably behind without needing a center post. Another advantage to the long legs is for when you do need to deploy on uneven ground you have more room to work with. Without a post there are simpler and more stable. Another thing to think about is having the twist style locks on the joints rather than cam or thumb screw style. The twist style don't catch on things when walking or moving around with the tripod deployed. If you want to save a few dollars you may want to check out Feisol as an alternative to Gitzo. Personally I would not spend money on a self leveling base. If you are using a ball head or Wimberly self leveling is a moot point anyway. Keeping it as simple as possible with as few moving parts as you can will be more stable and less problems in the long run.

Bill, I think I have the same tripod and head as in your photo for my landscape rig. Though I have switched to a standard ball head now.

[William W]

That is a Manfrotto 055ProB Tripod with a Manfrotto 222 Quick Release Pistol Grip Head on it.
I use that Tripod and Head for most of my location Portraiture work – and I usually use it “normally”.

I just assembled it that way (and other odd ways too), so I have a set of photographs to use as examples of several aspects of use: including the angle finder and the splayed legs and the removable centre stick.

WW

[NorthernFocus]

Nope, I have a 190MF4. But the same head and same center post configuration. The center post that can be repositioned comes in handy once in a while. And as I said I use a different head now.

[FlyingSquirrel]

Bill, thanks for the extra tips!

Dan, thank you very much for your helpful reply. Basically everything you mentioned confirms most of what I was thinking about. So, since you have heavier gear than I will on about the same load bearing tripod (26.4 vs 27 lbs load bearing), I think the 2541 I am looking at might be the ticket.

I have always despised center columns; in my old aluminum bogen I took a hacksaw to it, leaving just a few inches for the legs to clamp onto so I can mount the head. For the Gitzo I am looking at, after some research, I'm considering replacing the center column with a Markins base- basically a more stable, wider base to replace the center column. This will be better for mounting the wimberly and RRS ballhead heads that I would be using.

Gitzo with center column removed and set up in the "ground set" configuration:
http://photos.pixel4.net/img/v26/p264440893-4.jpg

Gitzo with a Markins base instead of the default ground set above (visualize it without the ballhead) :
http://www.markinsamerica.com/MA5/images/TB_feature.jpg

The twist locks were a tough decision but the benefit you mentioned is among several that have convinced me to at least try it and see (I don't like the lever locks on my bogen)

I'm about to compare some other gitzos and see if there is something comparable in features that does not have a center column by default to avoid having to do the Markins base swap. Otherwise, I think I have found the model I want. If I need to return it or try some other tripods, it's not the end of the world.

[FlyingSquirrel]

Quick update...

Well, I found a Gitzo that I like even more than the 2541 I was looking at. The GT3541LS, but of course, it costs 2x as much and is not available through the typical reputable dealers I usually go through. Such is life.

Looks like the 2541 + Markins base is the set up.

Thanks for the help, guys.

[FlyingSquirrel]

Just purchased the Gitzo 2541. Was about to order the Markin's base and realized there is an issue. Posted new thread here Gitzo center column replacement (with Markin's or other base, need help)

[Bill Yeung]

I got the GT 2541 too.
match it with Manfrotto ball head MH054MO-Q5
good enough for video cam, 7D + 70-200 + flash + flash bracket...... while you will get all the attention around you wherever you shot!!!
you will like the twist lock too, it is so smooth yet strong.