interesting doubt: user interchangeable lens mounts

Jannard said:
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
Click to expand...

voice of reason :)
 
agreed.. i didn't lose you jarred.. :) i posted that because i agree with your words: «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»

that's why i'm worried.. i'd like a way to go with a quick change on set if possible.. we hope jim may get this feature.. we hope..

thx all for your help including you jim.. we'll be waiting..
 
thanks man.. yes, we dont know yet, and it could go either way.. It doesnt really matter to me.. if it is a quick release it better be damn good because i've seen PL mounts fail when they are locked down.. and every single quick release ive seen fail as well.. 2x the risk scares the hell out of me.
 
I’d think that it is simpler to create a match between the mount’s plane and the sensor’s plane if the base is machined flat. Any indentations and protrusions would need a more complex machining process to ensure a plane match without a commensurate benefit. At most I would look at guide rings around the screw holes with matching sockets on the mount. This is more than I would like but it would probably be worth it for guiding and holding the mount while putting it in place.

My take is that five high tensile screws would suffice to keep the mount firmly positioned even with a good sized unsupported lens hanging off the front. I would make the screw holes mildly asymmetrical so that the mount can only go on in one orientation... as well as machined in markings on the body and mount that can be visually lined up. Redundancy when it comes with no additional cost is something that I am fond of.

In the quick release vs. screwed down mount I come in on the side of screws. There will be a few times where it would be advantageous to be able to change lens systems in eight seconds rather than a minute and eight seconds but the problems that would ensue from having two quick releases behind the lens as well as the added complexity would probably induce far more problems than it would solve.

Then again, when I hand out my two cents I include a free grain of salt seein’ as how I am an unedumicated high school drop out.
 
Jarred Land said:
thanks man.. yes, we dont know yet, and it could go either way.. It doesnt really matter to me.. if it is a quick release it better be damn good because i've seen PL mounts fail when they are locked down.. and every single quick release ive seen fail as well.. 2x the risk scares the hell out of me.
Click to expand...

I've seen mounts of various kinds fail...with disastrous results at times. I once saw another shooter's brand new Fujinon 33x ($35k USD) zoom drop right off a Digital Betacam and bounced down a cliff in what seemed like slow motion as lens elements and barrel pieces sprayed out everywhere. A sickening sight! He then looked like he was about to jump over the same cliff and end it all! I've also seen other shooter's mounting plates fail and entire camera/lens rigs drop from the tripod to concrete below. Ooooooooops!

Whenever possible I use a "lens leash", a custom safety strap, that secures the lens to the camera body, and another safety leash that secures the camera body to the tripod head. These are quick-release velcro or pull-strap 1" black nylon straps that can be bought at any hardware store.

Better safe than sorry...

Maybe RED could design a "RED Leash" accessory strap for these uses?

Gibby
RED #8
www.cut4.tv
www.4umat.com
 
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Gibby said:
I've seen mounts of various kinds fail...with disastrous results at times. I once saw another shooter's brand new Fujinon 33x ($35k USD) zoom drop right off a Digital Betacam and bounced down a cliff in what seemed like slow motion as lens elements and barrel pieces sprayed out everywhere. A sickening sight! He then looked like he was about to jump over the same cliff and end it all! I've also seen other shooter's mounting plates fail and entire camera/lens rigs drop from the tripod to concrete below. Ooooooooops!

Whenever possible I use a "lens leash", a custom safety strap, that secures the lens to the camera body, and another safety leash that secures the camera body to the tripod head. These are quick-release velcro or pull-strap 1" black nylon straps that can be bought at any hardware store.

Better safe than sorry...

Maybe RED could design a "RED Leash" accessory strap for these uses?
http://www.4umat.com
Click to expand...



I saw Strap-ons and leashes and my mind wandered elsewhere.. :D
 
Gibby said:
I once saw another shooter's brand new Fujinon 33x ($35k USD) zoom drop right off a Digital Betacam and bounced down a cliff i
Click to expand...

Wholly crap gibby.. i would pay good money to be the bird in the tree watching that scene play out.. and i think i may of jumped down the cliff as well... back in the day when I used to race mountain bikes i remember half hazzardly chasing after my bike down a cliff a number of times.. and that was just a $3000 ride.. a $50,000 lens? forget the leash.. Red should make a Red Parachute for the poor camera assistant.
 
Jarred Land said:
Wholly crap gibby.. i would pay good money to be the bird in the tree watching that scene play out.. and i think i may of jumped down the cliff as well... back in the day when I used to race mountain bikes i remember half hazzardly chasing after my bike down a cliff a number of times.. and that was just a $3000 ride.. a $50,000 lens? forget the leash.. Red should make a Red Parachute for the poor camera assistant.
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Yeah man...it would be tempting to just do a nice cannonball or one and a half and follow the lens down...bungee jumping without a bungee!!!

Gibby
RED #8
www.cut4.tv
www.4umat.com
 
We had a shooter doing a clifftop piece. Wind took the Chrosziel Sunshade and ND Grad straight off the lens and made a $4000 jigsaw puzzle.

Insurance claim wasn't a problem as the shooter caught it on tape!
 
Ouch!!!! All these stories are a good reminder to keep your insurance up to date. It's not that expensive compared to losing your whole rig and starting over...

Gibby
RED #8
www.cut4.tv
www.4umat.com
 
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filmmaker1977 said:
steve, how much is it?.. can you give an idea over your own?.. insurance is a good subject to our knowledge.. thx
Click to expand...

I'm sure that the cost will vary from in different parts of the world, but in the USA, a $1,000,000 USD All-Risk liability insurance policy, with equipment replacement coverage for maybe $50,000 worth of equipment ranges from maybe $1,600 to $2,500 per year. If you're going to get permits to shoot at any public places, most government agencies require a copy of a $1,000,000 All-Rick insurance policy. If your crew or equipment injures someone, and they bring a lawsuit against you, having All-Risk insurance can mean the difference between keeping yourself in business, or going bankrupt.

I also travel with an International Carnet, where I sign my equipment into and out of each country with Customs. That way if the equipment is stolen or destroyed while you travel, I have a way to prove to the insurance company that I took it with me on the trip.

Getting into business is one thing...but staying in business may hinge on your wise choices about things like insurance and Carnet use.

Gibby
RED #8
www.cut4.tv
www.4umat.com
 
Clint Johnson said:
I’d think that it is simpler to create a match between the mount’s plane and the sensor’s plane if the base is machined flat. Any indentations and protrusions would need a more complex machining process to ensure a plane match without a commensurate benefit. At most I would look at guide rings around the screw holes with matching sockets on the mount. This is more than I would like but it would probably be worth it for guiding and holding the mount while putting it in place.

My take is that five high tensile screws would suffice to keep the mount firmly positioned even with a good sized unsupported lens hanging off the front. I would make the screw holes mildly asymmetrical so that the mount can only go on in one orientation... as well as machined in markings on the body and mount that can be visually lined up. Redundancy when it comes with no additional cost is something that I am fond of.

In the quick release vs. screwed down mount I come in on the side of screws. There will be a few times where it would be advantageous to be able to change lens systems in eight seconds rather than a minute and eight seconds but the problems that would ensue from having two quick releases behind the lens as well as the added complexity would probably induce far more problems than it would solve.

Then again, when I hand out my two cents I include a free grain of salt seein’ as how I am an unedumicated high school drop out.
Click to expand...
Most modern machining plants use CNC milling machines and the precision involved is as high for oddly shaped parts as for flat planes.

One of the best reasons for a quick-change of lenses and lens mounts is to protect the sensor from getting dusty. One minute of exposure to environmental air can put a lot of dust particles onto the imaging chip, even in what appears to be a clean environment. You could argue that the chip could be cleaned after changing lens mounts, but many situations don't provide an easy opportunity to clean the sensor. Even with time to clean the sensor, there's always a risk when physical contact has to be with it (scratching the surface, pressing too hard on the sensor, etc). If it comes down to extra lens mount screws or a speckle-free image, I'll choose the speckle-free image.
 
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Gibby said:
I'm sure that the cost will vary from in different parts of the world, but in the USA, a $1,000,000 USD All-Risk liability insurance policy, with equipment replacement coverage for maybe $50,000 worth of equipment ranges from maybe $1,600 to $2,500 per year. If you're going to get permits to shoot at any public places, most government agencies require a copy of a $1,000,000 All-Rick insurance policy. If your crew or equipment injures someone, and they bring a lawsuit against you, having All-Risk insurance can mean the difference between keeping yourself in business, or going bankrupt.

I also travel with an International Carnet, where I sign my equipment into and out of each country with Customs. That way if the equipment is stolen or destroyed while you travel, I have a way to prove to the insurance company that I took it with me on the trip.

Getting into business is one thing...but staying in business may hinge on your wise choices about things like insurance and Carnet use.

Gibby
RED #8
www.cut4.tv
www.4umat.com
Click to expand...
thx v much..

international carnet.. how does it work?
 
Lowkus said:
Most modern machining plants use CNC milling machines and the precision involved is as high for oddly shaped parts as for flat planes.

One of the best reasons for a quick-change of lenses and lens mounts is to protect the sensor from getting dusty. One minute of exposure to environmental air can put a lot of dust particles onto the imaging chip, even in what appears to be a clean environment. You could argue that the chip could be cleaned after changing lens mounts, but many situations don't provide an easy opportunity to clean the sensor. Even with time to clean the sensor, there's always a risk when physical contact has to be with it (scratching the surface, pressing too hard on the sensor, etc). If it comes down to extra lens mount screws or a speckle-free image, I'll choose the speckle-free image.
Click to expand...

Cutting edges wear and it is easier to adjust for that on simpler surfaces- but money can be spent to compensate for that... just tryin’ to save Jim some expenses.

Your reasons for wanting a quick change are sound. I have to clean the sensor on my still camera a couple times a year and that is with a nice quick bayonet mount.

But I think that the time it will take to move the mount away from the body and have the replacement mount sitting in its place, ready to be screwed down, should actually leave the sensor exposed for roughly the same amount of time as a quick release mount. Most of the extra time would be removing and installing the screws while the mount is sitting in place.

My thinking is that the view inside the camera with the mount removed will show a shallow cylinder with a protective (and optically clear) glass at the back that covers the actual sensor. This area would be tightly sealed from the rest of the camera and clear of any protrusions so that a quick blast of compressed air would clear any dust out of it and not further into it like too many other cameras.
 
Clint Johnson said:
Cutting edges wear and it is easier to adjust for that on simpler surfaces- but money can be spent to compensate for that... just tryin’ to save Jim some expenses.

Your reasons for wanting a quick change are sound. I have to clean the sensor on my still camera a couple times a year and that is with a nice quick bayonet mount.

But I think that the time it will take to move the mount away from the body and have the replacement mount sitting in its place, ready to be screwed down, should actually leave the sensor exposed for roughly the same amount of time as a quick release mount. Most of the extra time would be removing and installing the screws while the mount is sitting in place.

My thinking is that the view inside the camera with the mount removed will show a shallow cylinder with a protective (and optically clear) glass at the back that covers the actual sensor. This area would be tightly sealed from the rest of the camera and clear of any protrusions so that a quick blast of compressed air would clear any dust out of it and not further into it like too many other cameras.
Click to expand...
I like the glass over the sensor idea, but I'm not sure about using the compressed air. I've heard it can leave a filmy substance that hurts the optical quality of the glass.

Another thing that concerns me about the screw-mount is the hassle of keeping track of the screws while trying to handle the mount. One hand for the camera, one for the mount, one for the hex-wrench, one for the screw being loosened/tightened, and another hand for the loose screws. It doesn't add up to a situation that can easily be performed by a person born with only two hands, especially in an uncontrolled environment.
 
Lowkus said:
I like the glass over the sensor idea
Click to expand...
me too

but I'm not sure about using the compressed air. I've heard it can leave a filmy substance that hurts the optical quality of the glass.
Click to expand...
careful warning

Another thing that concerns me about the screw-mount is the hassle of keeping track of the screws while trying to handle the mount. One hand for the camera, one for the mount, one for the hex-wrench, one for the screw being loosened/tightened, and another hand for the loose screws. It doesn't add up to a situation that can easily be performed by a person born with only two hands, especially in an uncontrolled environment.
Click to expand...
agreed.. the screw-mount isn't a good idea.. i hope for an easier method really run and gun.. the most part of us will be at a EFP/ENG-style environment, that's for sure.
 
Sorry if this is repeating stuff that's already been said, or if I've misunderstood. There seems to be some confusion between changing lens mounts (which needs screws) and changing lenses (which doesn't).

Surely there woluld be very few projects for which you would use a selection of lenses all with different mounts. If you were doing an ENG style shoot, all your lenses might be B4, but for a cine style shoot you might have a set of PL mount primes. Therefore you would attach the approprate mount at the start of the shoot, not on location.
 
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