Beaulieu 4008 Barney

[calgodot]

I'm thinking about having a Beaulieu 4008 barney constructed. I have a friend who can make castings of various kinds. I'm thinking of commissioning one from him. We've discussed it and he thinks it cane be done.

Once the mold is made, he can of course make others. So I'm curious how much interest 4008 owners would have in a fitted sound barney. (I have no idea about cost as yet.)

Of course, in light of the kibbitzing nature of this forum, I'd also love to hear from anyone who has tried this, as well as any recommendations or advice with regards to materials and design.

[paulcotto]

Are you talking about a hard blimp or a soft barney? If it's a hard blimp I would be interested.

Let me know,
Paul Cotto

I'm thinking about having a Beaulieu 4008 barney constructed. I have a friend who can make castings of various kinds. I'm thinking of commissioning one from him. We've discussed it and he thinks it cane be done.

Once the mold is made, he can of course make others. So I'm curious how much interest 4008 owners would have in a fitted sound barney. (I have no idea about cost as yet.)

Of course, in light of the kibbitzing nature of this forum, I'd also love to hear from anyone who has tried this, as well as any recommendations or advice with regards to materials and design.

[Lucas Lightfeat]

I strongly recommend that you are talking about a hard blimp, as a soft one won't be enough.

An air gap is vital. The best blimp I ever owned was called the UniBlimp, and was made here in London.

It was a hardboard, 5 sided box, lined in thick felt, covered in vinyl. It had perspex (glass would be much better) screens at each end, so only three sides were hardboard. It had a felt lined board underneath with a male tripod mount underneath and a female on top of it. The other 5 sides sat on this without any fastenning.

It worked amazingly!

The controls were unreachable, as was the lens, without removing the box from the base, but this could be made specificaly for a camera with great effect. With good measurements and a remote trigger wire to trigger shooting, the lens adjustments could be made with a device through a lined slot accross the width of the blimp. Try to leave an inch of air around the camera. This is a tripod only system, which can be a good thing.

That's my twopenneth anyway. I hope it's of use.

Oh, check these people out too:

http://www.filmtools.com/cup.html

They made me a barney for my Nizo 6080 which is good, but not amazing, and for a Beaulieu you need amazing!

Lucas

[calgodot]

I'm talking about a hard blimp, I guess. Sorry for crossing the terms. A barney is easy enough to make that it's a DIY project.

What I'm envisioning is something that will completely silence the camera, with doors that open and close. It will have at least one door to allow access to the film door. A door on the other side would allow access to the controls, as well as viewing the film and frame counters.

I am concerned about the lens. A lot of noise can be transmitted via the lens. The best solution I suppose would be to completey enclose the lens barrel with the blimp. But this would make follow-focus and zooming impossible.

How much noise am I really going to get off the lens?

[Basstruc]

I was thinking about it too but don't think design is such a problem, I just wonder what kind of material would be sound proof enough.

[Scotness]

I read in a book about sound - that to dampen effectively the thickness of the foam should be one quarter the wavelength of the sound -- I can't remember the logic behind it though - I think it's to do with sound waves cancelling each other out -- you should look into it though because there are certain specifications which can make a blimp work more effectively than others --- another thing in the book too was that double wall with an air gap in between will also dramatically reduce the transmission of sound - and this should be possible with a blimp made of hard sides

Anyway I want to make a blimp for my R16 -a nd will share ideas and info too when I get into it

Scot

[mattias]

I read in a book about sound - that to dampen effectively the thickness of the foam should be one quarter the wavelength of the sound -- I can't remember the logic behind it though - I think it's to do with sound waves cancelling each other out

exactly. the round trip through 1/4 wavelength thickness material is half the wavelength, which puts the echo at an exact opposite phase, which means it all cancels out on the foam surface, which means there's no sound that can be reflected off it, which is what you're after. this is for reflection of sound though, i.e. for studios and such. i'm not sure if it applies to sound passing through the foam.

/matt

[MusicAlly]

Please excuse my ignorance, but so many times I read articles and I don't have a clue what they are talking about. This time I have decided to take the plunge and ask the question: what is a blimp?

Thanks

[The Central Scrutinizer]

Blimp:

http://www.fujifilm.com/JSP/fuji/epartn ... pFacts.jsp

F1

[flatwood]

good point, matt, thats true and i wonder if its not possible to electronically phase cancel out camera noise. we do it all the time in the studio and on live gigs. also pilots wear noise cancelling headphones that throw loud engine noises 180 out thus cancelling. i bet it could be easitly done for cameras. i have a mic installed in the air space above the control room in my recording studio that i use to phase cancel outside noises when necessary.

mattias wrote:

exactly. the round trip through 1/4 wavelength thickness material is half the wavelength, which puts the echo at an exact opposite phase, which means it all cancels out on the foam surface

[calgodot]

My friend tells me the expensive part will be the initial mold. Once the mold is made, we can test different materials. We have some already lined up, and I am investigating other substances that may provide acoustic baffling. Of course, if anyone has any leads or ideas, yatta yatta....

It may be a few weeks before we can go to prototype, considering the costs of materials.

[Lucas Lightfeat]

I used to be a proffessional guitar maker, so I know a thing or two about acoustics, and the 1/4 wave thing is all well and true, but maybe not very practical to calculate, nor necessarily necessary.

For a hard material, you want something that is dead - what you don't want is wood. MDF is pretty dead. Various resins can be quite dead, acoustically speaking.

Thick and dense is good - aluminum would be perfect, as unlike steel it has no boing to it. (Very technical stuff this, I know).

Failing that, try liquid plastic resin, which is available in cans, and is the perfect moulding material. It is heavy, dense, strong and shiny. Dye can be added to it too. It's quite expensive, but so what? Line this stuff with a really thick (6-8mm) dense felt, and I think you're laughing.

The lens is the tricky part, you're right. You could do what ARRI did with the 16BL and make a rotating blimp for that too, but it would be a polava (a fish that is difficult to eat :? ) Hey, hold on, mould some tubes, line them with felt, so that they are snug with felt joints, and attach them to the various barrels - just an elaborate idea!

Lucas

[paulcotto]

What about a piece of PVC pipe lined with the acoustic stuff they line cars with? Cut it down the middle and hinge it. Then get some optical glass or a large ND filter for the lens end. I am sure you could find a piece of PVC pipe your camera would fit into. Heck cut a hole for your 4008 Beaulieu camera handle to stick out of. Or get that expanding foam stuff they put around exterior pipes to keep them from freezing, then put your beaulieu in thick plastic shrink wrap and then into the PVC pipe. Then put in the foam and let it set up. Then carefully cut around the camera with a utility knife to free it from the foam, Paint it black to make it look good. Total cost would be under $20.00. I bet it would work.

http://www.partsexpress.com/webpage.cfm ... roup_ID=37

http://www.partsexpress.com/pe/showdetl ... 5898&DID=7

Regards,
Paul Cotto

[mattias]

What about a piece of PVC pipe

might be a good idea, but if we're to take the dead material thought into account i don't think it is anymore. pvc pipes are more acoustic than trumpets. ;-)

/matt

[mattias]

good point, matt, thats true and i wonder if its not possible to electronically phase cancel out camera noise.

i did that for my latest short, as in recording the camera separately and subtracting this signal from the audio recording. the problem is that the camera noise interferes a lot with all other sonds, so it either can't be cancelled out altogether, or the dialog will get muffled. i still used this technique for two shots with great results. other than that maybe four or five didn't need treatment, and the rest were post synced with dialog taken from the rehearsals, reversed el mariachi style. see if you can tell which is which when you finally get to see it. ;-)

/matt