Tripod/ Head Testing Parameters - Help!

[Chris Soucy]

The title says it all, really.

I am hoping that, some little way down the track, I MAY get an opportunity to do some direct, side by side comparison tests on some tripod/ head systems.

How many, what makes and what models I don't have a clue - yet.

The parameters I initially came up with to test are: actual readings of things like "wind up", "lateral displacement" and "warp".

The test procedure I have come up with so far involves an effective foot anchoring system, a strategically placed laser pointer, a weight/ pully system to apply the necessary loads and a distant wall with some sort of measurement device allowing deflection to be measured (sounds a bit crude but should be effective).

I'm aware that I will have to find a way of eliminating any movement in the head from the measurements (I think I have found a way) so that any figures refer to the tripod alone and not my choice of head.

I'm also aware that I need to be able to achieve total repeatability with any test so that I am actually comparing like with like (could be tricky but can't be impossible).

Now, the questions for the Forum are these:

1. Assuming for a moment this actually comes to pass, is there a consensus that members/ visitors would be interested in such info? (another assumption is that I can publish this data for tripod systems readers may actually want to buy, not fairy land stuff).

2. Are the three items I mentioned as far as I should go, and if not, what other physical test(s) would you like to see done?

3. Can anyone come up with a better testing procedure/ methodology for any tests?

3 (b). Any suggestions about the best format to display the figures.

4. What do YOU want to see in any tripod/ head review? I don't see the point going into excruciating detail on tiny issues if it's not relevant to the reader (bearing in mind some of the readers grasp of tripod/ heads basics will be slim indeed). Similarly, what I think is important and what YOU think important may well be quite different. What is it you all want to know about a system?

I really do want to get this right from the off and I'm going to need a lot of help from you guys (and gals) to do it.

All suggestions greatfully received.


Thank,


CS


PS. I'm really looking forward to this.

[Anthony Todd]

I did do some testing a few years ago when trying to find a light tripod for videoing birds with extreme focal length lenses.

The tripod had to be carried some distance, over difficult terrain, so had to be light, as did the head.

I bolted a 1.5 metre length of 25mm angle iron over the bowl and attached a spring balance to one end of the bar and set up a dial gauge at the other end.

By applying a force to the spring-balance I could measure the deflection on the dial gauge and the results plotted.

I was not interested in "stability" as this is really straight geometry and is a function of height against footprint. As long as the vertical CofG of the rig is within the footprint the rig will not fall over and the lower the CofG the more tip the rig will stand, nothing to do with weight or cost.

But I was focussed on what I call "micro-movement", the sort of flutter you see when in wind, or when the hand is on the handle. Also seen as "cardiac-footage", when the pulse-rate of the cameraman can be counted by the oscillation of the image. Often on tele, during sporting events, when the bored cameraman fills in with long shots of distant scenery.

The test results showed some surprises.

1. The weight of the tripod had no influence, some heavy and perceived as "stable" models fluttered in the breeze, until the slack in the leg locks was taken up, which often needed quite high loadings.
Giving this sort of result:

Load 50gm deflection 1cm
100g 2cm
200g 4cm
400g 8cm
1Kg 9cm

ie the deflection was linear until the “slack” was taken up then virtually nil.

2. Removing the rubber feet protecting the steel foot spikes made a big difference.

3. Centre columns often oscillated like a metronome!!

4. Jamming the leg locks and the hinge at the top of each leg could make a big, big difference. I formed the opinion that I would go for a single stage, if I could, as each stage lock was a source of movement.

5. The old trick of hanging a heavy camera bag under the tripod didn't help the deflections at all [but will lower the CofG so make the rig more stable].
Remebering though that when the bag swings it makes things worse!

6. Carbon fibre was stiffer than aluminium and lighter.

7. If you always take your hand off the handle results are spectacularly better!!

I ended up with a Vinten [forgotten the model] after testing various models at their factory. The heavy studio models did not deflect at all!!!

The tech staff were very very interested in what I did, and muttered amongst themselves and nodded...
I fondly dream that my visit was the start of the tests and charts now seen in their brochure.

There was an unfortunate sequel. The first carbon-fibre model collapsed in Peru, when one of the leg-locks didn't, smashing the camera and breaking a long lens in half.
The replacement, [Vinten said it had never happened before etc.etc.], fell apart in the Gambia, and I mean the leg joints just fell off, a problem with the adhesive Vinten said.
So I bought a Miller, good test results, slightly better than the Vinten, and it's been fine. And I got another one too, just as good.

I didn't do much with heads except to discover that the micromovement in a Cartoni head I bought, was due to the base’s not being tightened to the ball. Once that was adjusted the figures were virtually zero.

I just bolted the head to a heavy bench and fixed the bar to the camera mounting plate and measured as above, thus isolating the values between the two.

I think your testing should somehow incorporate a ratio between the deflections and the weight of the legs and/or head as, obviously, if you weld a tripod out of solid steel, or borrow a gun turret from an old battleship, there will be no deflection at all, but if you make one out of thin bamboo the reverse will be the case.

Carrying one might be easier than carrying the other though ;-)

Then it just comes down to a price comparison, certainly I found that the cheaper light-weight tripods gave very poor results; sometimes I could actually hear the tripod moving with the applied loads.

Without some quantitative measurement of deflection caused by small loads most of the recommendations in the forum should be discarded.
Everyone still confuses fall-over stability with resistance to deflection.

Roll on the testing, Chris, I’ll bet the results are eye-opening!

tt

[Chris Soucy]

Now, there is a man after my own heart.

I agree with just about everything you say, and it's bloody heartening to hear someone else say it.

I was starting to feel like a lone voice here.

I am now emboldened to persevere, despite the obvious underwhelming response to this particular post.

Now, all I need to do is persuade some very important manufacturers to entrust their latest and greatest to my tender care, and............rip 'em to shreds!

No hard sell there then!

Many thanks for your reply.


CS

PS. Stay tuned for my Vinten Vision 3 head reveiw, it's a real doozy.

PPS. Er, what, exactly, were you trying to say with that "Head Properties" post earlier? I keep re - reading it and am still not sure what you were saying.


PPPS. Whereabouts in London are you? Lived there for absolutely yonks. And no, wouldn't go back for the Queen, or all the Tea, quite frankly.

[Anthony Todd]

I just asked the shop or wholesaler if I could test their tripods, no probs., most were very interested.

tt