Maximum realistic Weight of glass on SI-2K PL mount? at DVinfo.net

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Old April 16th, 2010, 10:17 AM   #1
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Maximum realistic Weight of glass on SI-2K PL mount?

Say, this zoom lens is 4.5Lb:

Canon 8-64mm Super 16 Zoom #30528 :: Lenses :: Used Equipment :: Equipment Sales :: Abel Cine Tech

Would it be realistic to mount it on SI-2K? I'd imagine there's going to be a lot of strain on Mini's body/PL mount with such front heavy setup?

What is the maximum recommended weight of the glass on Mini, for practical shooting?
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Old April 16th, 2010, 10:35 AM   #2
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In still photography, larger lenses have tripod mounts directly on them for just this reason. It reduces strain on the lens mount if the body hangs off the tripod mounted lens.

In your case, it would be difficult to do, as it may interfere with follow focus & such. Still, it's worth looking into. If the front of the lens barrel doesn't rotate when you focus, there's probably a way to rig a clamp to the tripod.
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Old April 16th, 2010, 03:20 PM   #3
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The Canon zoom is a pretty standard lens to be used with a PL mount on a 16mm camera and they usually aren't supported by rails. This would common practise with the much heavier 35mm zoom lens on a PL mount. The Zeiss Digiprime combined with the adapter in this link weighs much the same as the Canon

Silicon Imaging

However, with the Mini on it's own (rather than the full camera as above) I suspect it'll be a case of mounting the camera to the lens and the balance for use would be under the lens, rather than camera body. You'd have make support rather like that used by TV cameras with large zooms or used by stills cameras with large telephoto lenses.

Perhaps not what you have in mind:

http://www.pstechnik.de/en/digitalfilm-si2k-minirig.php
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Old April 16th, 2010, 04:45 PM   #4
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The Canon lens you linked to has an Aanton mount but apart from that there should be no issue using this lens - I know of at least one person that has shot SI-2K with the 8-64 Canon.

The lens mount seems to be quite strong - here's a couple of pics with a Nikon 300mm hanging off the front of the Mini.
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Old April 16th, 2010, 04:52 PM   #5
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Whoa, Nelli! Now that's the lens :)

Cool tripod, too.

Hey, where's the computer?
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Old April 16th, 2010, 05:16 PM   #6
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These pics were taken just before I got the full body.
I had a Mac Book Pro sitting on a magliner trolley with a tangle of cables between - not the best way of working but doable.
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Old April 18th, 2010, 12:01 PM   #7
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Now wait a sec, how did you get that Nikon in PL mount?
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Old April 18th, 2010, 10:18 PM   #8
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I think a Nikon mount would break off the back of the lens before the IMS mount or the camera-to-body anchorage gives way.

With the full body and a Sigma-for-Nikon 50-500 zoom, I have used a set of rods and a bridgeplate from a cinecity mattbox bridge upside-down on the rods with the vertical sliding adjustment also mounted to the bridgeplate upsidedown ( which faces it rightway up ) as a prop under the lens barrel.

The Sigma is not the sharpest kid on the block for 2/3" sensors but is all I have to long reach aircraft in flight. I have also used the Nikon 200mm f2 which is a smaller brother to the one in Rowan Dadswell's image.

Some stills telephoto lens supports are a single pillar or pillar and handgrip and come too far down between the rods for a normal bridgeplate to work.

Last edited by Bob Hart; April 18th, 2010 at 10:20 PM. Reason: error
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Old April 18th, 2010, 10:30 PM   #9
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Bob, maybe I'm missing it - sorry - but still, how do you attach Nikon lenses to SI-2K?
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Old April 19th, 2010, 02:29 AM   #10
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Alex.


The IMS mount system by P+S also includes a Nikon to IMS adaptor which fits in place of the PL to IMS adaptor. The P+S mount on front of the IMS adaptor is quite robust. The Nikon lens is not offered up to the mount rotated about 60 degrees clockwise and twisted as usual.

The newer P+S Nikon to IMS mount that I have seen requires you to offer the lens up to the mount in the 12 O'clock position with the latch pin slot on the back of the lens over a fixed locating pin on the P+S Nikon mount. A rotating collar on the P+S Nikon mount is then rotated about 60 degrees clockwise to lock the lens in place. The older style was like the Letus with a small spring latch and conventional mount and twist technique.


They seem to be both listed here :-

Part No. 23499 and Part No. 18381 which is the conventional style Nikon mount with turning of lens and release latch..

http://www.pstechnik.de/en/optics-ims-mounts.php


Treat my comments above with a bit of caution as I am unlcear on whether the "professional" F Mount is the revised Nikon mount they developed. It is hard to see on the small image posted.


This mount, like Letus and a few others will not suit really older Nikons with the full overhanging shoulder which is part of the aperture (iris) ring.

If you are swapping mounts out and are careless, sometimes it gets tricky because the IMS end of the Nikon to IMS adaptor will also fit into a PL-Mount. You end up with a Nikon mount adaptor twinned up ion a PL mount adaptor and a Nikon lens about 30mm forward of where it should be and incapable of focusing on anything except maybe a gnat running around on front of the glass.

In the case of my rig, I made my own using a lathe and a Nikon mount ring and spring bought in as replacement parts. It is not quite as strong as the P+S because it uses the genuine Nikon parts.

Last edited by Bob Hart; April 19th, 2010 at 02:40 AM. Reason: error
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