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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Lens support needed for EPIC?

As long as the P/L mount on the Epic is securely mounted to the body (which I expect it will be) there should be no difference at all!

From time to time I get a lens without rod support, and if I am uncertain if it will be safe to place it on the camera, I just simply hold it between my fingers (as my fingers were the P/L mount), and if I can hold it for a while I am quite sure the P/L mount on the camera can too. Example: the Angeniux optimo 24-290 fails this test, and needs support.
 
Jochen Schmidt-Hambrock said:
...
Now, with the EPIC being a lot shorter, the force from large lenses on the camera housing will be a lot bigger.
...
Cheers,
Jochen
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Not sure why this would be true... :confused5:

It might feel more unbalanced if you are handholding it but the force on the housing should be the same, no?
 
Terry VerHaar said:
Not sure why this would be true... :confused5:

It might feel more unbalanced if you are handholding it but the force on the housing should be the same, no?
Click to expand...

Actually, I think he's partly right.

Based on my understanding of physics (forgive me, it's been a while since my college class) ... the fact that there's less counter balance weight/length from the Epic body will mean that there's more torque pressure at the fulcrum going in the direction of the lens -- which in this case, means more pressure at the point of lens mount.

Now imagine a long heavy lens mounted on the Epic in a should mount configuration. Imagine holding it and feeling the intense weight of the front pulling down ... now, on the other hand, imagine the R1 with more length and weight going in the opposite direction. To me, it's intuitively clear (and we could probably crunch some numbers on this) that the torque at the mounting point would be more intense in the case of the Epic because of this weight/length imbalance.

However, it's mostly a moot point, as he mentioned RPP's and I don't actually think this will be a practical problem on the Epic ... because even though they are heavier, the torque issue has as much to do with the length of the lens as the weight.

Again, long lenses could and would create more pressure on the lens mount -- perhaps even more than they would on the Red One -- but again, in practice you'd still have to use a lens support on say an Optimo 24-290mm zoom on the Red One, because the torque level would still be quite high.

Also, this discussion -- from a physics sense -- is skewed when you consider the camera being mounted on a tripod, which would typically be the only way for it to be done on a lens big enough to make a real difference in torque. (I don't think many people shoulder mount the 24-290 zoom!) ... Because then, in this case, the weight and length of the tripod factor into the physical equation and makes the Epic's light weight and short length a less significant part of the calculation.

I know it probably sounds like mumbo jumbo, but if we really wanted to take out physics formulas and a calculator, I'd feel confident this could all be proven.

I'm just a bit too lazy for that right now :)

Anthony
 
AnthonyFlores said:
Actually, I think he's partly right.

Based on my understanding of physics (forgive me, it's been a while since my college class) ... the fact that there's less counter balance weight/length from the Epic body will mean that there's more torque pressure at the fulcrum going in the direction of the lens -- which in this case, means more pressure at the point of lens mount.
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All due respect here, but you might want to go back to physics class. :beer:

Simple fact of the matter is, when the camera body is the actuator of force, the force exerted on the lens mount is the same as the force that would be exerted on the lens mount of the RED One or any other camera, assuming the same mount and lens combo. The only time the camera is going to make a difference is if you go all "SLR" on the rig and start toting around the camera by the lens. In that situation, the Epic is going to exert far less inertia and force upon the lens/mount than more massive RED One would.

One thing I do see happening with the Epic is that it's smaller and I think we're going to see a LOT more hand-held use of the Epic. A LOT more whipping the camera around. That can indeed put additional stress on the lens mount. With any situation where external force may act upon the lens or camera system as a whole, use supports where necessary. If in doubt, secure it...

Matt Duclos has a very conservative approach to deciding to use a lens support. Gripping the lens mounting section in with the ends of your fingers, if your hand can't support the lens outward as the camera would, then you probably want a support on it. Like I said, it's very conservative as most people would have trouble doing this with any moderate sized prime or larger unless they have uncommonly large and strong hands. I tend to follow this rule for the flimsier SLR mounts, especially when mounting bulkier lenses like putting a PL lens via an adapter onto a Canon or m4/3 camera. For a PL mount, I don't concern myself too much. I use supports with larger zooms and with my RED 300. IMO, the 18mm RPP could use it just as much as the RED 300, but I don't use a support with it.
 
Thanks for the physics lesson Jeff :001_tongue:.

The main thing I foresee is a bunch of scenarios where the setup looks just plain ridiculous (or awesome, depending on how you look at it), with the lens being much longer than the camera.

Exhibit A...


Mark L. Pederson said:
IMG_6605.jpg
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I am not talking about the pressure on the lens mount, that would of course be equal on both the R1 and the EPIC.

My point is basic lever arm principle (sorry, english = 2nd language)

The lever is between where the camera is bolted to the plate (force vector = up), the front of the housing (pivot point, force vector = down) and the lens (force vector down).
The heavier and longer the lens, the greater the forces.
The shorter the lever, the greater the forces.
Hence my question about the EPIC, where the lever arm seems to be about a third of the R1.

If I remember my physics that relation is inverse proportional, meaning a force three times as large on the EPIC housing as on the R1 for the same lense.

Thank you all for your input.

All the best,

Jochen
 
Jochen, you're right, there is less mass in an Epic brain than a RED One. So that indeed does not counter-balance a large lens as well. It can put more strain on the base mounting points of the camera. Don't worry about it though. I'm willing to bet you could use the Epic housing or base portion of the housing to hang a car if you wanted. The lens mount will fail long before the aluminum block in which the brain resides.
 
As we have Epic M8 with the Super strong Titanium PL mount we fill we don't even need any support for any lens, but nonetheless
we did use support on the RPP 300mm, as I firmly believe that no matter how strong the PL mount can be it is always a good thing
to give support to longer lenses.
 
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