Quick releases for LF cameras

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Originally Posted by Oren Grad

Three things I most worry about with QR's:
1) How secure is attachment of plate to camera? Will the plate tend to twist or otherwise loosen, without warning, under routine handling?

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My is secured by screw, it's never coming off unless I decide to remove it.

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Originally Posted by Oren Grad

2) How easy is it to attach camera-with-plate securely to the QR base on the tripod head while on the go? How easy is it to get it wrong, and thus end up with an insecure mount?

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Depends on the system used. I like the FLM clamp because I can put the camera in from the top, not from the side, where you have to wiggle it around to get it to fit in just so.
Once I drop the camera in from the top, it's mated to the clamp, but can still slide back and forth along the clamp. Tightening it securely means flipping the lever. The lever has a spring so it can be pulled out of the way of all the action.
Removing the camera/plate is done only by having the lever in its neutral position and pressing a button.

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Originally Posted by Oren Grad

3) How vulnerable is the clamp to unintended loosening?

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As I said above, the plate will not come off the clamp unless both the lever is in neutral position and a button is pressed.
When in use, there are two safety catches in case the lever gets bumped back and forth, but even then, the plate will stay on the clamp.

Different manufacturers use different systems of tightening/safety/release; it's worth looking into those differences if you ever decide to opt for this kind of system.
I find this system to be great for LF as there's no screw to tighten, making it faster to operate, and placing the camera in from above is faster and much safer to use.

That's a great setup, Ari.

Thanks, Peter. It's proven to be a very tough and reliable setup.
I really like Sal's large QR plates; they really add a lot of stability to LF cameras.

The only QR I own and like is Horseman, made for their Field cameras, which were 2x3 or 4x5 and it is plenty heavy duty for that purpose. They are heavy cameras.

It allows nearly sightless connection of camera to tripod, using a angled launch strip and ball detents that click when used when camera is safe. The lever tightens it down. Linhof copycat.

It works well with my 5X7 Linhof Standard weighing 7 lbs with lens.

It is NOT good enough for Horseman monorails of any size. Those are studio cameras. I tested.

I also like how it allows the camera to stand securely on a table when not on a tripod, some QR do not do that.

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Originally Posted by Oren Grad

...Seems that the most secure connection for a large flatbed camera ought to be a plate that screws into two sockets. I guess that might require a custom-made plate in many instances...

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Sometimes. Even when it doesn't, there are situations where custom work is better. For example, the standard, titanium bottom plates on my Ebonies, despite including two sockets, were problematic. Turns out titanium is extremely strong in shear, but can be made to flex with relative ease. Even attaching fairly large plates to them didn't eliminate their propensity to vibrate. Thus the Grimes replacements.

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Originally Posted by Oren Grad

...Some of my big wooden cameras have two tripod sockets, but I'm reluctant to do surgery to add a second one to those that don't...

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Aw, go ahead, dive in. Unless you're referring to a museum piece, and I seem to recall most of your cameras are users. :)

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Originally Posted by Oren Grad

...Just took a peek at the RRS website. I was aware of the many plates they have tailored to the shapes of specific small-format cameras, but was not aware of their somewhat more limited LF line, including their generic, somewhat adaptable two-screw B35 plate...

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Having learned a lot between 1998, when my Compact II was purchased, and placing the order for my second Phillips 4x5, I coordinated with Dick to address this by having him send me the double-socket assembly he planned to use. I confirmed its two sockets weren't too close together for a B35, then returned it to him for installation in the camera. Each combination requires detailed investigation to ensure system compatibility.

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Originally Posted by Oren Grad

...I guess a fourth consideration is how secure is the attachment of the clamp unit to the tripod head or legset.

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That's something one must address too. I've modified several heads to ensure rigidity and security of this connection. On the Linhof 3663, I replaced Linhof's fluted camera screw assembly with a hex wrench-driven stainless steel screw that mates with a brass bushing in the clamp, tightening that using a small Chapman ratchet driver. Once the brass deforms slightly, nothing loosens, and the Linhof's textured rubber sheet is fully compressed so the clamp makes metal-to-metal contact with the platform's raised circumference edge.

On an FLM CB-48 FT, I unscrewed the platform, installed a 3/8-16 male to M6-1.0 female bushing (that came pre-coated with Loctite) in the inside-threaded stud, waited 24 hours, then used a stainless steel M6 X 1.00 flat head socket head screw to attach an older, small Really Right Stuff lever release clamp. The last step included application of Loctite 242 ("Blue") to the screw's threads.

On the Burzynski, I simply applied Loctite 242 to the brass stud before screwing it into the head and screwing the clamp to it.

In addition to use of Loctite on most of them, all these clamp attachments were performed during the warmest part of the year. That's when metal connections become loosest as the parts expand. Thus, in colder weather, even if the Loctite doesn't do its job, things will remain secure. :)

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Originally Posted by Oren Grad

. . . I guess a fourth consideration is how secure is the attachment of the clamp unit to the tripod head or legset.

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That is a concern. I have had the clamp twist on the head once or twice when using the Seneca. If I remember to check it and make sure it is tight this should not be a problem. The riskiest behavior in this regard is hiking with the camera on the tripod and the tripod over the shoulder.

I have two of these clamps, one on a Manfrotto head, the other on a Gitzo. One of the clamps is from RRS, the other is a Desmond that I picked up on EBay out of curiosity. The Desmond is very well made, machined from high quality aluminum. I use each one with equal confidence. The Desmond has a slot on the tightening knob that allows you to use a screwdriver or other device to really tighten things down. I don't recall whether the RRS has this feature (it is out in the garage, so I will check later). As I think about it, the only problems I have had with untwisting is with the RRS clamp attached to the Gitzo head clamped to the Seneca. This is not to say anything negative about the RRS clamp. It could just be due to the larger size of the WP Seneca, or the different mounting surfaces on the two heads.

Probably not a practical suggestion but I have been fortunate to find some very early mounts for the Manfrotto hex plates that use a screw actuated clamp instead of the spring driven cam on the newer ones. Turn the knob on the screw actuator to clamp the hexplate and there is no camera that's releasing before you want it to. I use it for 8x10 and my 8x20.

Sal,

Good idea on the Loctite. I can't believe that I did not think of that!

Oren,

A plate like this should work pretty well if the tripod socket spacing is right: http://www.ebay.com/itm/Desmond-DPC-...item541cd13234. Nothing against RRS or the others, but these simple machined plates are not rocket science and do not have to be super costly.

I'd like to interject a comment here that may or may not be relative to the topic. I don't use QR plates, simply because I don't feel the need to attach my cameras to the tripod very quickly/conveniently for MY purposes. But if I were to start researching QRs, my engineering experiences with metals would cause me to dismiss out-of-hand any products made by casting the metals (I've only seen one such QR product). Often metal products with shape challenges are designed to be cast in order to avoid expensive machining of intricate shapes. The strength of a QR system is obviously important, but so is its toughness. Cast materials usually lack decent toughness (a measure of its ability to deform significantly before rupturing. The engineering term for this material property is its "elongation" (i.e., like a strong taffy). Castings exhibit brittle behavior, are very sensitive to knicks/notches/dings and can rupture suddenly without warning (think of breaking a soda cracker). I hope I've made my point clearly.

I'm just trying to grasp the idea of seeing the words quick and LF Cameras being used in the same sentence :rolleyes: