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Rig Shots 8: Do Vacuum Cups damage paint or panels?


John Jovic

The simple answer is yes, they can!

Damage from vacuum cups can be as extreme as a shattered window, windscreen or dented panel. Often this kind of damage is the result of poor judgment when fitting the cups or rig in the first place as no car panel, window or windscreen is designed to hold a large heavy rig. Other times the rig may move or fall on the car because one or more suction cups have lost grip. You need to exercise as much care and judgment as you can whenever you fit a rig. Never fit a rig onto a flimsy or weak panel. Look for the stiffest parts of a panel, usually near a crease or fold, and try to use larger vacuum cups if possible as this will spread the load better than small vacuum cups. Some panels are so weak that they can actually be deformed by the vacuum of the cup itself, but this is not common. Modern windscreens are made from laminated glass and are generally quite strong whilst old windscreens are made from tempered glass which can shatter under extreme loads.

  This tripod based rig is mounted in such a way that even if one of the upper 2 vacuum cups did let go it would be unlikely that the rig would fall. If the lower vacuum cup let go then it is unlikely that anything would happen except for the rig loosing some rigidity. However if both upper vacuum cups did let go then the rig would fall towards the ground and if the lower cup held firmly then the panel it's mounted to could be dented/damaged. Although this is a relatively safe setup you must always expect the worst and keep checking the vacuum indicators on the cups regularly. Most of the weight of the rig is applied to the lower vacuum cup so a larger cup is recommended so as to spread the load as much as possible.
  This tripod based rig is mounted precariously (although it is very rigid) in that it is completely dependant upon the upper vacuum cup mounted on the bonnet. If this cup lets go then the rig will certainly fall, possibly damaging any part of the car it is still mounted on as it rotates around the remaining mounting points. The lower 2 cups (6" x 3" Oval Suction Cups), although ideal for use on such narrow panel sections or bumper bars, simply act as supports for the tripod and would not keep the tripod mounted to the car on their own. This kind of configuration is intrinsically less safe than the previous setup. Knowing this, it would be unwise to walk away from the car for any period and ideally the camera/rig should be supported at all times whilst shooting and either buy yourself, the owner, assistant, anyone at all, at all other times
  This bonnet mounted full car rig is different to most in that there are two vacuum cups opposite the camera and one in the centre of the boom whilst some shooters use two vacuum cups in total. The problem with using a single vacuum cup at the 'end of the boom opposite the camera is that if it does let go then the boom will fall, rotating around the centre vacuum cup, assuming it is still holding, and possibly denting both the panel under the cup and anything else the boom hits on it's way down. Using 2 vacuum cups at this end gives you some redundancy so that if one cup does let go then it is unlikely that the boom will fall. The centre cup (centre of the boom) is not as critical as the cups at the end of the boom. Using 2 cups opposite the camera is about redundancy, not rigidity. If you wanted to you could add a counter weight at this end, balancing the boom around the centre cup, and this would prevent the boom toppling forward if the cup let go however the added weight may be unacceptable.

Some vacuum cups have a tendency to mark or scuff (lightly scratch) paint surfaces whilst others can leave a short term imprint of themselves in the paint surface. Always make sure vacuum cups and the surfaces they are attached to are as clean as possible. Protect the vacuum cups with their protective pads, if supplied, and store and transport them carefully to ensure they are not deformed or damaged.

It's not a good idea to apply a vacuum cup to the interior of windows which are tinted with a film as the film will be deformed, probably permanently, by the vacuum cup. Adhesive films or stickers on the exterior of the car should not have vacuum cups applied because they may be damaged or deformed and they are often a cause of air leaks causing the vacuum in the cup to weaken or let go altogether.

Vacuum cups behave differently depending on their design and the material they are made from. Some of the effects you might expect from a few commonly used vacuum cups are described below.

These cups are made from a relatively soft rubber. They have a series of fairly deep ridges so this vacuum cup can leave an impression of the ridges in some paint surfaces. It seems that the 'clear' which is applied to most paint surfaces can be quite soft, even after many years, and it is this 'clear' which takes the impression. It is most visible with dark colours and is often very difficult to detect with light colours. It doesn't happen with all paints and it is very difficult to judge when it will happen, if at all. The impression usually disappears after a period of several hours.
Woods 4.5" Suction Cup  


Same as above.

Woods 6" Suction Cup  


The Avenger/Manfrotto vacuum cups are made from a relatively stiff rubber which can mark or scuff (lightly scratch) paint surfaces. The cup is quite stiff so as the vacuum increases the cup is pressed down against the paint and this stretches the cup slightly outwards, which is when the scuffing or marking occurs. It doesn't always happen but sometimes a dark rubber ring, which can easily be cleaned off, is left around the edge of the cup. Sometimes the light scuff mark may need to be buffed out but it is generally quite minor. 
Avenger F1000, Pump Cup with Swivel Pin (shown above). All Avenger/Manfrotto Pump Cups use the same rubber pad.  


Vacuum cups simply can not be trusted to keep their vacuum and therefore keep a rig mounted to a car indefinitely. All vacuum cup manufactures warn users to regularly check vacuum indicators, where fitted, and to re pump regularly. It's safest to always assume that a rig will fall off and act accordingly, ie keep it supported whenever possible, before, during  and after the shoot.

The simple fact is that if you are confronted with a car where you can not afford to take any risks then do not apply any vacuum cups to any of the paint surfaces at all.

The above is by no means a comprehensive list, it's just food for thought.

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