interesting doubt: user interchangeable lens mounts

I've been thinking about this issue for some time now. The PL mount has a flange focal distance of 52 mm. The Aaton 35mm handholdable camera's ff distance is 40 mm. Panavision, Arri PL or Aaton mounted lenses can be installed. The Aaton mount, because it has the shortest flange focal distance, can receive almost all the best still lenses, like the Leica R, Nicon and Canon. The newer Aaton cameras come with exchaneable lens mounts, but the co. recommends those be done at a service facility as lens seating errors of as little as 0.01 mm will cause focus problems. I'm hoping that Red will come up with an user friendly interchangeable lens mount system that would ensure a proper lens seating and would be durable enough for frequent use.
 
Here is the most popular mounts:
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From the pictures it seems that changing mounts comes down to unscrewing 8 long hex screws:
Picture2.png


Regarding the precision, I can't really see why there should be a difference between mounting the flange in a PL mount and changing the mount. Same problem with the precision and tolerances, and lenses are mounted many times a day.
 
evinsky said:
They will be available, how easy they interchange is another issue.
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Very easy. The Trick is to have the base to intermediate mount distance set at the factory and leave enough room for all possible mounts. More details pretty soon.

jim
 
Jim, I'm glad to hear that. Congratulations on the IBC screening. I'm hope you've enjoyed your stay in Prague, the city where I was born. I'm looking forward to the Red screening in the LA area.

Bea
 
Seems like 8 screws is overkill for the mount. Any chance it could be whittled down to only 4 or 6 screws?
 
Seems like 8 screws is overkill for the mount. Any chance it could be whittled down to only 4 or 6 screws?
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Ah the engineer in me says no. When you deal with fine tolerences such as a base plate flange (as an example) having four screws would probably be fine until one of those screws lets you down. When that happens your screwed so to speak. Red are becoming incredibly skilful at some of these finer points that make anything you build last longer than others. Eight screws might be a pain if you have to change mounts but if in your rush to change you crossthread one of the screws you have plenty to keep things tight and secure.

Michael
 
Lowkus said:
Seems like 8 screws is overkill for the mount. Any chance it could be whittled down to only 4 or 6 screws?
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ill take 8 thank you very much :) A lens mount needs to be completely solid, there can be a tremendous amount of pressure on that mount as well, along with temperature bulging etc. Since its not cast.. i dont want it to move around. at all.

Plus.. i dont expect to change my mount really that much anyways.
 
good advice jarred..

but i don't follow..



first, jim said
Jannard said:
Very easy. The Trick is to have the base to intermediate mount distance set at the factory and leave enough room for all possible mounts. More details pretty soon.

jim
Click to expand...
..it's easy.



however, lowkus returns back to the screws..
Lowkus said:
Seems like 8 screws is overkill for the mount. Any chance it could be whittled down to only 4 or 6 screws?
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..are they important in order to change the mounts?.. isn't there any other suitable method to the job during a shooting?.. easier?.. isn't it what jim is speaking about?



and both of you mike
mike the beginner said:
Ah the engineer in me says no. When you deal with fine tolerences such as a base plate flange (as an example) having four screws would probably be fine until one of those screws lets you down. When that happens your screwed so to speak. Red are becoming incredibly skilful at some of these finer points that make anything you build last longer than others. Eight screws might be a pain if you have to change mounts but if in your rush to change you crossthread one of the screws you have plenty to keep things tight and secure.

Michael
Click to expand...
and jarred
Jarred Land said:
ill take 8 thank you very much :) A lens mount needs to be completely solid, there can be a tremendous amount of pressure on that mount as well, along with temperature bulging etc. Since its not cast.. i dont want it to move around. at all.

Plus.. i dont expect to change my mount really that much anyways.
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..are you talking about like jim didn't post what he posted?



this is a sensitive point that we should enlight.. is it or not viable to change mounts between shots?




thx
 
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I think this says it all:
video.jpg

Might be 8 screws, might be some sort of universal bayonet.
Both are technically possible, but the latter much more expensive, and needs much more testing to prove it really is durable enough.
As soon as something like a bayonet is introduced more users will change mounts much more frequently and therefore accellerate the wear of the connection.

In a practical shooting situation I really don't think I would want to be changing mounts on set.
Until the Red zoom is released I think I'll rent a Zeiss prime kit for productions with a budget and, depending on the price of the mount, use my Nikon AI primes for productions without one.
 
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..are they important in order to change the mounts?.. isn't there any other suitable method to the job during a shooting?.. easier?.. isn't it what jim is speaking about?
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Hi Filmmaker, here is what i think, bearing in mind my very limited knowledge of cameras!

The reason we need different mounts in the first place is to do with the distance from the lens to the sensor of each different mount. A few mounts might share the same distance required for the lens to operate properly. I think the easy part Red was talking about is to make the distance between the actual red body and where the sensor is positioned a specific distance that allows as much variance in the different mounts so as they all work properly. Some of the mounts are as i understand very close indeed to the sensor. I am not sure if the lenses for that particular lens mount matter or if it is a combination of the mount and lens. Anyway as i see it red have to make sure the body relative to the sensor is set at a suitable distance that gives plenty of leeway for different mounts with different distances to the sensor all fit.

As for the mounts themselves, that is what i was refering to with the eight screws. When you deal with tolerances of .0001" you have to make sure each mount is properly aligned and seating properly as well as being tight. With just four screws if one of them gets crossthreaded you may have a problem that requires fixing. With eight screws there is plenty of leeway, we can all make mistakes when under pressure. I dont know anything about mounts myself but there are materials that should fit the bill nicely and i have no doubt red will have that sourced already.

Some mounts may have to be inverted inwards towards the sensor which could pose a problem. The optional mounts might well vary in price depending on the work involved in making them work properly. It is remarkable that red are even considering doing the mounts themselves. This is far better for all of us as the mounts will be made with the right material and machined exactly to do the job. That man Jannard does not do things in half measures, the mounts from red WILL be excellent.

I could be talking absolute rubbish, no doubt someone either from red or wherever will put me right.

Michael
 
Micheal you did a nice job of suming some points up there.. you got the right idea. Since a PL mount is in a way a bayonet itself it may be risky putting two rotating mounting systems together on the same plane.
 
and filmmaker.. sorry man once again you lost me...

changing mounts is as easy as changing the screws... so you could do it on set if you really wanted too... but its not a quick release and nor do i think it should be.
 
The front mount is a representation. Not what the finished part will be... we aren't showing anything yet that is what the finished camera is. Don't look too close to the pics. You'll get confused.

Jim
 
Less is More

Less is More

Laco said:
And what about changing sensor position?
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With the sensor fixed at the point where the Aaton Universal Mount’s focal plane falls on the sensor (is that the closest?), the other adaptors simply have to vary in thickness to position the other mounts at the proper distances from the sensor depending on where the particular focal plane falls.

If it is the sensor that moves, I’d start worrying about someone accidentally changing the settings from the Mitchell BNCR to the Aaton Universal and have the sensor try and position itself 28mm inside the lens. Built in adaptor and/or proximity sensing could take most of the worry out of that but I kind of like the simplicity of an extra 28mm of solid metal holding the lens that much further out. As long as you aren’t giving up functionality, fewer parts, fewer moving parts and fewer electronics makes for a more reliable and robust product.

Then the only worry is someone trying to mount a lens with a different mount that is both smaller in diameter and deeper... I can just hear the CRACK as the rear of the lens makes contact with the sensor. A ruined sensor and a scratched rear element on the lens would make me sad.

I’m supposing that this has already been discussed and that there will be an intermediate piece of optically clear glass placed a few millimeters ahead of the sensor- so I’ll just suggest that it be easy to remove for when we need to clean the sensor and when it needs to be replaced.
 
Personally, I'd like to see a quick-release mount. However, if I had to build the mount and was incorporating screws, I'd take it down to just three screws. The fit and tightness would be more efficient if made by using indentations and protrusions between the body and lens mount metals, fitting together like a jigsaw (or like two gears pressed together). The only function of the screws should be to keep the lens mount pressed against the camera, and since the indentations/protrusions would provide the primary structural support for the lens, the quantity of screws becomes somewhat irrelevant; the lens mount could remain solidly affixed using just one screw. The reason for three screws... it leaves two screws as a backup in case one gets lost or stripped.
 
Lowkus said:
Personally, I'd like to see a quick-release mount. However, if I had to build the mount and was incorporating screws, I'd take it down to just three screws. The fit and tightness would be more efficient if made by using indentations and protrusions between the body and lens mount metals, fitting together like a jigsaw (or like two gears pressed together). The only function of the screws should be to keep the lens mount pressed against the camera, and since the indentations/protrusions would provide the primary structural support for the lens, the quantity of screws becomes somewhat irrelevant; the lens mount could remain solidly affixed using just one screw. The reason for three screws... it leaves two screws as a backup in case one gets lost or stripped.
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this actually might work lowkus..
 
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