http://www.nuocsong.com/nhatho/adapter/moon.mpg
The video was captured using Letus35 with 500mm FD lens at f32. under 2 seconds of video. Motor noise is improved. Thanks.

Quyen

So you are shooting at f32. Means that the LETUS has no restriction on the Aperture? Am I correct?

Yes, the test video with Canon FD 1.4 go to the minimum aperture of 16, with FD 500mm it can go to 32, so I can say it has no restriction. Thanks.

Quyen

Hey Quyen,

Can you change the GG you supply with your unit with a Nikon D focusing screen? That might really increase the image brightness if it were possible!

shooting at f32 directly aiming at the moon is like shooting at f32 directly aiming a ligthbulb.
It gives no information about the quality/limits of the gg, since there is a lot of light involved there.

Mandy Leo,

I can change the GG to Nikon screen but I doubt that it will be brighter since my setup has very little light loss.

Giroud Francois,

The purpose of the moon shot is for checking motor noise only, not to show any performance there. You are right about this. Thank you for pointing this out.

In my test video shows some shot at f16 without any vignetting (minimum on FD 50mm f1.4) so I think I can refer to this to say that my adapter has no aperture limitation or restriction. Thanks.

Quyen

Quyen, Your adapter as you shipped it to me is absolutely silent. I can only hear the motor when it's six inches from my ear, and even then it's a quiet noise. I have to feel it to determine if it's on or not.

that is really nice but 6 inches is probably twice the distance from the adapter to the camera microphone (and unfortunately, this one is pointed just right over the adapter).
So we really need a total silence.
i am just asking myself if some trick with magnet could make a really cool system.
just imagine a ring with 4 magnets (noon,three, six and nine hours.) with the positive (or neg) polarity pointed to the center of the ring.
now you put infront of each magnet, another one with same polarity, so they repulse each. this would be a perfect way to suspend something inside a force field, allowing very easy vibration and then quiet system.
gluing the motor with soft silicon should help too keep noise down.

Magnets have to be so exactly placed so they exert force directly in the center of the opposing magnet, otherwise they'll slip off in a perpendicular axis.

Magnets would be a very fishy way to go and I can see it being (1) difficult to set up and (2) difficult to keep in place.

Don't be fooled by the apparent simplicity and powerful force of magnets. Their application has to be extremely precise. Also, the force of magnets follows a logarithmic scale, so as you get closer to the magnet its power increases exponentially instead of in a linear pattern.

Actually I find the idea of magnets to be a brilliant one. There are some elegant and simple solutions to the stumbling blocks you (Ben) mention.

The "keeping in place" would be the easy part. For me the question comes down to, is it worth the trouble?

If you use external mic, this discussion is not for you. If you use internal mic, I can challenge all the units that using motor to do side by side to compare noise with my unit, this challenge includes mini35 of any generations.

My unit's noise is less than the noise of the camera itself (tape compartment's noise). Giroud Francois made the point there. This unit is right at the mic. In most cases, I found that motor's noise cannot be heard unless there is completely no other noise at all like the moon shooting scene.

Most of the noise come from the motor itself, not the hardware that mounting the GG. I wish you luck trying to use magnet to reduce noise.

When I saw and heard about the mini35, I said to myself, I can beat mini35 by 2 points: motor noise and hand held. I actually did it and offer very affordable price for my unit.

I have a plan to build supporting rods and of course it's steady and affordable. This one is built with light weight aluminum. I don't think that many people here are interested on building this. Tell me if you are interested then I will post the plan, thanks.

Quyen

I think the supporting rods would be a great idea for those that plan on using a Matte box in the future.

Or a zoom lens, lol. Those things can get pretty massive.

Putting an adaptor in front of the lens to get the film look and recording sound using the built in mike?. What a contrast?

Quyen,

Does your adaptor has interchangable lens mounts?

Please give me time to put together a plan, it's harder than actually build one. I am working to resolve my website problem to post pictures.

Maheel

My adapter has FD Canon lens mount now and cannot be interchanged. I can make Nikon lens mount too if you prefer. Thanks.

Quyen

at surplussched they sell adapter mount for M42 (T-mount) to most mount (about 15$ each)
http://www.surplusshed.com/pages/item/m1610d.html
unfortunately this is not usefull for us as we are looking for the reverse.
But i got some of these and there is an interesting thing in them.
the adapter is made from two part.the one emulating the mount (nikon,canon, pentax) and a ring that goes inside the adapter with the M42 thread.
If you can build the same kind of adapter but in reverse.
a M42 (or any other specs.) adapter that can receive a ring with all the differents mount, you could sale a one-for-all adapter.
the user would just need to change the ring according his needs.
these adapter are still usefull if you want to mold the shape of the mount without using expensive lenses.

For the magnet stuff, i think the fact that the power of magnet is not linear is an advantage. the closer they are the strong the force is, so there is no risk of "bumping" the two piece.
for the alignement, i do not think this is a problem , since you can find "levitation" gadget using the same principle and they do not look like hi-tech tool machining.
and finally it is ok the have the center pice trying to escape the force field, since that is helping the gg to stay into the focal plane..
a solution for controlling the stuff would be to have magnet on one side (the center ring) and electro-magnet (coil) on the outer ring, so you can even modulate the voltage to create the vibration. This way you can even generate a patterned movement (circle, flower square).

"and electro-magnet (coil) on the outer ring, so you can even modulate the voltage to create the vibration."

That will only move it on the Z axis or whatever plane you guys call the one that goes through the lens. Electromagnetic force acts perpendicular, not parallel. We just worked with exactly what you're talking about in physics class.

I don't know, the whole magnet thing seems extremely difficult to pull off. I've worked with magnets a lot lately and really don't see this working.

I encourage you all to prove me wrong though! :) lol.