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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 :)

Mounting Long/Heavy lenses

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Dave Blackham

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I guess this is a question for the lens tech's.

With the newer 19mm support bar standard that's mounted to the Arri/ET 19mm plate is it acceptable to use a lens support direct to the 19mm bars with out problems, or is it thought best to use a long (say 500mm) support plate and mount the lens directly to that.

thanks,

Dave
 
The standard is to mount a lens support to the 19mm rods. That's what they're there for.
 
I suggest this for maximum safety and solidity. There is a long plate that supports the camera AS WELL as the rods, with an extra support bracket at the end of the rods:

1406_1227711337.jpg
 
Example- 24-290 Angie on 15mm Arri rods

Example- 24-290 Angie on 15mm Arri rods

The combination of the lens weight and the support foot distance from the base plate flexes the rods too much so they do not offer adequate support. Los Angeles Rental houses use 18" sliding plate and a special bracket(I think that's what Lewis's pic shows above) The bracket fits both onto the rods and the dovetail effectively binding them together. If you place it immediately behind the support bridge it will solidyfy the support so the lens sits on the plate now rather then the rods.
Good, solid, safe setup used by rental facilities.
Jacek Zakowicz, OptiTek.
 
Thanks for the replies, they are very helpful.

Dave
 
OptiTek said:
The combination of the lens weight and the support foot distance from the base plate flexes the rods too much so they do not offer adequate support. Los Angeles Rental houses use 18" sliding plate and a special bracket(I think that's what Lewis's pic shows above) The bracket fits both onto the rods and the dovetail effectively binding them together. If you place it immediately behind the support bridge it will solidyfy the support so the lens sits on the plate now rather then the rods.
Good, solid, safe setup used by rental facilities.
Jacek Zakowicz, OptiTek.
Click to expand...

To clarify what Jacek is saying, the problem is 15mm rods, which Los Angeles companies insist on continuing to use even though Arri introduced the 19mm standard 20 years ago. That's because those LA rental houses had invested hundreds of thousands of dollars each in 15mm gear that could not be switched over to 19mm.

With 19mm steel rods a huge lens like the Optimo 24-290 will not flex the rods and it will be fully supported. With 15mm steel rods there will be flex and the lens will typically deflect about 30 microns in the mount -- enough to loose focus and possibly cause lasting damage to the camera or lens or both. To help alleviate this the LA rental houses add a small wedge that fits between the rods and the dovetail plate, to be placed near the front of the rods, essentially supporting them from both ends. These small plates must be custom manufactured to fit to specific dovetail plates. There is enough variation in design of dovetails that they could easily never work with anything other than a signle manufacturer's dovetail.
 
Mitch knows his shit!!!!!!
 
Mitch thats interesting. Thanks for the advice. Our problem here is we shoot a good deal of Wildlife and adventure programmes, we have standardised on 19mm for Red. For our work in the field we need to keep the weight and general parafinalia down to a minimum but keep the rig reasnobly light and workable. We had thought to use light weight weight bars such as the ET nickle plated alumuninium ones or perhaps CF bars but dont know if these are rigid enough. We use the ET bars on the top mount which are fine but am still unsure if they are suitable for some of the long lenses we use with out a plate alone. We have a tame machine shop who do excelent work so making a few brackets is possible for us. Where I think we will end up is either light weight bars and a plate or stainless bars and no plate. Finding 19mm accessories is not as easy as 15mm.

thanks again for the advice,

Dave
 
The ET nickel plated rods will not support large lenses. I believe ET even says so on their website. I tested this myself and it was extremely obvious -- deflection could be measured in inches. I have not tested any carbon fibre rods but I am told they are extremely rigid -- my fear being that with CF, failure with the extreme rigidity leads to explosive shattering force. But I understand that this is the purpose for which they were designed, so perhaps they would work for you. At Abel we use nothing but stainless steel for 19mm rods, but things are different when you're a rental house.

Abel would be happy to assist you in finding appropriate 19mm accessories.
 
Dave,

Me and my crews do a lot of long lens work for my wildlife, nature, alternative sports, and adventure travel productions.

I use the ET nickel plated 15mm aluminum rods (18") with my stock (except Century PL mount conversion) Canon FD 150-600L zoom for wildlife and sports production, with no bending or mount problems. I have a 15mm slide on universal mount that slides onto the end of the rods and screws into the screw receptacle on the bottom of the lens. No problems whatsoever with that setup. The stock Canon 150-600 weighs nine pounds. I also use the same ET 15mm rods to support all of my Nikon long lenses - 400 f3.5 AIS (6 pounds) and 50-300 f4.5 AIS (4 pounds). I also use that 15mm setup with my RED 300 (6 pounds). My guess is that you won't be using any lenses heavier than the ones I use for your mobile wildlife and adventure work, so yes, the 15mm ET aluminum rods should be fine for you.

When mounting these lenses on RED, I put the camera on tripod, put the rods in, tilt the camera way back so the mount is facing upward, and mount the lens. This way the downward pressure of the lens is squarely on the mount while I attach the rod support bracket and screw it into the bottom of the lens collar. Once that is done, I simply tilt the camera back to level. I do this in reverse when I de-mount a lens. This keeps me from putting undue strain on the mount when I mount/de-mount heavy lenses.

When I use a lens heavier than the 150-600, especially an Optimo 24-290 (24 pounds), I use the 19mm steel rods and a long plate with dual support brackets as Lewis previously posted on this thread. I have both ET Arri bridge plates - 15mm and 19mm. But then again, since you do wildlife and adventure, both of which require mobility (thus keeping weight down), then I highly doubt you will be using an Optimo 12x or any lens heavier than a Canon 150-600, so IMO 19mm steel rods are not necessary in your field workflow - 15mm ET aluminum should be just fine.

Hope this helps...
 
Steve, thanks for the advice. Its very helpful.

Dave
 
If you already own 15mm or ET 19mm rods you might want to take a look at Colin Colberg's 24" base plate. They have very simple but elegant rod support ears at the front end. Weve been using them with Optimo's for years. No deflection issues.
He's the owner/machinist and can be a bit difficult to track down at times.
Makes nice handgrips too.

http://www.cameraaccessorysolutions.com/

John
Chater Camera Inc
 
That long base plate with ears looks perfect to me.

thanks for the link.

Dave
 
Those ears are precisely aligned to the thickness of particular Arri-manufactured bridge plates. Don't know if it would work with the RED bridge.
 
Mitch Gross said:
Those ears are precisely aligned to the thickness of particular Arri-manufactured bridge plates. Don't know if it would work with the RED bridge.
Click to expand...

Any one know for definite if the Bars to bridge plate top is the same on the Red/ET and Arri plates.

Also is the camera base to lens centre a standard measurement for most camera systems, I had always assumed it was so accesories would work between set ups.

Dave
 
Base plate hights

Base plate hights

Dave Blackham said:
Any one know for definite if the Bars to bridge plate top is the same on the Red/ET and Arri plates.

Also is the camera base to lens centre a standard measurement for most camera systems, I had always assumed it was so accesories would work between set ups.

Dave
Click to expand...

Hi Dave,
I know that the base plates for Arri 435 and 535 are different. When I designed and made the above mentioned rod support brackets I had to make two- one for 435 cam and one- slightly different- for the rest.
The distance between the rods and the dovetail was different enough so one plate wouldn't work for both. If I recall correctly it was about .050"-about 1.25mm
I hope it helps- although it may make things more complicated.
Jacek Zakowicz, OptiTek
 
Thank you all for a great thread. I have one question.

How heavy may a lens be without the need of lens support?

For instance; will I need lense support on a Nikkor 28-70mm F2.8D AF-S IF-ED Zoom, weight: ca 2 lb?
 
Still (heavier zooms)lenses without support

Still (heavier zooms)lenses without support

are said:
Thank you all for a great thread. I have one question.

How heavy may a lens be without the need of lens support?

For instance; will I need lense support on a Nikkor 28-70mm F2.8D AF-S IF-ED Zoom, weight: ca 2 lb?
Click to expand...

I'd say @ 2lbs it's not that heavy. Definitely wouldn't need support if it was PL mounted. Still mounts however depend on little sheet metal springs to keep the mounts properly seating. 2lbs may be enough to compress them and your lens will not be sitting properly- it may end up cocked and the top of frame may get a bit blurry. But it realy depends on your setup. Just mount each lens and carefully check all that during prep.
Jacek Zakowicz, OptiTek
 
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