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01-08-2011, 08:15 PM - 1 Like   #1
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Large Lens Support

I recently tested a Pentax A* 600/5.6 lens on the Pentax 645D. It worked well, but many images were blurred despite using MU and wireless remote (and a study tripod). I had an idea from the RRS (reallyrightstuff; http://reallyrightstuff.com/Items.aspx?code=LongLensPkgs&key=cat) catalog, where they describe a long lens support system. This provides a Y-support for the front of a lens.

However, the 600/5.6 has a very sturdy, and relatively short, front lens extension beyond the footplate. So I thought I'd flip the RRS design around and provide support for the body, as the body hanging off the lens can act as an oscillating mass.

I did a test with the single (standard) and the dual support setups. Items used: RRS TVC-24 Tripod, BH-40 head, CB-10 rail, B2-Duo clamp, MPR-ER (vertical bar), B2-mAS (clamp for MPR), B2-40LR (clamp for camera), and two B67 plates for the 645 body. In the upper right photo, you can see the CB-10 rail on the tripod head clamp; the B2-Duo clamp interfaces the CB-10 rail and the standard rail still on the lens's footplate (it has two nylon thumb screws). The B2-mAS is on the end of the CB-10 rail. Sliding up and down this clamp, is the MPR-ER with the B2-40LR on it's end. The 645D has two B67 plates, one seen on the side.

My readings on this forum seem to suggest that the 645 body is sensitive to vibrations in from 1/15 to 1/100 sec. I used 1/60 at f8 with MU and wireless release. I also observed a laser pointer on the set up. The dual support system had virtually no movement even when manually pressing the shutter release as the body and lens are rigidly connected.

The photos in the top row show the single support (a laser finder/pointer is resting on the handle) and the dual support setup. The bottom row shows 100% sized images taken at 7m with above setup. Not to be misleading, the single support setup did have the occasional sharp image; the dual setup was sharp every time.

This is not the first time someone has provided support for the body. The Manfrotto #359 system (reviewed here: 359) ties the body to the tripod. However, this design prevents easy re-positioning as the body is not fixed to different location than the lens. The RRS CB-10 based system is easy to re-position via the ball head (or a geared head).

This dual support setup would also work well with the Pentax 67 system. Due to the larger lenses, front lens support would be best, along with the longer CB-18 rail (8" longer than the CB-10). This front support would require adding parts at the lens end of the CB-18 rail: one CB-EC connector, one CB-YS and another B2-mAS clamp.

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Last edited by rlj; 01-09-2011 at 04:33 PM.
01-08-2011, 09:25 PM   #2
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very nice setup...including the tripod and head :-)
01-08-2011, 09:36 PM   #3
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I didn't get some of the specifics but I think I understood the key points. I think I've got an ok set-up for my long lenses but I'm convinced a two point arrangement would be significantly better.
01-09-2011, 12:14 AM   #4
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Fancy setup and it looks like it works really well. In a pinch, and in the absence of that setup, you could also put a monopod on the camera and even that helps at least on a 6x7 it does using a 67 M* 300mm ED IF lens.

01-09-2011, 02:00 AM   #5
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Early on, I started to use a rail mount, or two point mount, as you call it, attaching both the lens mount and the camera to it, as shown in the photo betow. It was at first to compensate for the flimsy lens mounts on Carl Zeiss Jena lenses that I adapted to the 67, but eventually I have come to use it for all my long lenses.

I use a Series 5 Gitzo hydrostatic head that mounts into my Gitzo G1500 three section tripod. The head has two advantages: the vertical distance from the top of the tripod to the mounting plate is small, and the central shaft is thick steel, both of which reduce the amplitude of torsional vibrations. The tripod itself is made of aluminium and weighs just short of 5kg, with main tube diameter of 37mm. This tripod is very stiff torsionally, but even so, I rarely extend the second tubes more than 250mm, and I almost never extend the third tubes.

I have found that it is simply not sufficient to just hang mass from the hook beneath the head. Such mass mounting does not help at all to resist torsion within the system as it is mounted on-axis, although it does help to prevent the tripod falling over if mass is to be added elsewhere. As I do - I take a divers weight belt with about 14 kg of lead shot in it and drape it over the lens - this puts mass on the lens where it is most needed.

Finally, I hold the tripod firmly just below the head with one hand to dampen torsion in the tripod and hold the camera with the other hand to dampen torsion at the camera/lens level.

If I do all of these things, I can get very sharp shots using my 400 Takumar and a 2X converter."

Best, Alan





QuoteOriginally posted by rlj Quote
I recently tested a Pentax A* 600/5.6 lens on the Pentax 645D. It worked well, but many images were blurred despite using MU and wireless remote (and a study tripod). I had an idea from the RRS (reallyrightstuff) catalog, where they describe a long lens support system. This provides a Y-support for the front of a lens.

However, the 600/5.6 has a very sturdy, and relatively short, front lens extension beyond the footplate. So I thought I'd flip the RRS design around and provide support for the body, as the body hanging off the lens can act as an oscillating mass.

I did a test with the single (standard) and the dual support setups. Items used: RRS TVC-24 Tripod, BH-40 head, CB-10 rail, B2-Duo clamp, MPR-ER (vertical bar), B2-mAS (clamp for MPR), B2-40LR (clamp for camera), and two B67 plates for the 645 body. In the upper right photo, you can see the CB-10 rail on the tripod head clamp; the B2-Duo clamp interfaces the CB-10 rail and the standard rail still on the lens's footplate (it has two nylon thumb screws). The B2-mAS is on the end of the CB-10 rail. Sliding up and down this clamp, is the MPR-ER with the B2-40LR on it's end. The 645D has two B67 plates, one seen on the side.

My readings on this forum seem to suggest that the 645 body is sensitive to vibrations in from 1/15 to 1/100 sec. I used 1/60 at f8 with MU and wireless release. I also observed a laser pointer on the set up. The dual support system had virtually no movement even when manually pressing the shutter release as the body and lens are rigidly connected.

The photos in the top row show the single support (a laser finder/pointer is resting on the handle) and the dual support setup. The bottom row shows 100% sized images taken at 7m with above setup. Not to be misleading, the single support setup did have the occasional sharp image; the dual setup was sharp every time.

This is not the first time someone has provided support for the body. The Manfrotto #359 system (reviewed here: 359) ties the body to the tripod. However, this design prevents easy re-positioning as the body is not fixed to different location than the lens. The RRS CB-10 based system is easy to re-position via the ball head (or a geared head).

This dual support setup would also work well with the Pentax 67 system. Due to the larger lenses, front lens support would be best, along with the longer CB-18 rail (8" longer than the CB-10). This front support would require adding parts at the lens end of the CB-18 rail: one CB-EC connector, one CB-YS and another B2-mAS clamp.
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01-09-2011, 03:59 AM   #6
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Cheap alternate within physical costraints of adjustment points by Velbon
Velbon Telephoto Lens Support #SPT-1 - Digital Camera Warehouse Australia
01-15-2011, 05:11 PM   #7
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Lots of possibilities prove the value of extra support for tele shots.

The RRS Long Lens Support works great reversed so that the Y brace with rubber rollers contacts the lens near the lens mount. This set up allows you to rotate the lens as needed. I've used it this way with the FA*250-600/5.6 which is "butt heavy" and the long barrel allows the RRS unit to bridge nicely from the collar to the contact point near the lens mount.

The RRS Long Lens Support unit works really nicely with the M*400/4 for 67 too. On this lens, the Y brace is positioned forward and contacts the lens shade. When the camera is rotated, the lens turns in the barrel so the front elements and shade don't move.

I've also had great results with the above lenses and teleconverters with the Bogen Super Clamp and arm with a tripod mount screw that I twist into the camera body (or QR plate) and then connect the clamp to the leg of the tripod and adjust a bit of tension or push by overextending the arm just a bit.

Bracing on the body like the Super Clamp or other similar options reduces your ability to vary the set up or use it to follow wildlife, but works fine for landscapes.

I recommend the RRS Long Lens Support System for it's ability to support without adjustment when rotating the lens in it's collar (or in the barrel). I'm guessing the rubber rollers contacting the lens also dampen vibration like rubber motor mounts in a car?

Add a weighted bag on top on windy days and it all shoots sharp
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