Sep 16, 2008

My Sound Blimp Tutorial




*UPDATE: This blimp is Version 1.0. I built a new and improved version for a D3 that includes a viewfinder for the LCD screen.

I was the set photographer for My Name Is Jerry, a feature length film shot in Muncie, IN this summer. It was filmed over 3 weeks, and I wanted to be able to take pictures during takes. because sound equipment is so sensitive, a naked SLR makes too much noise while they're filming. People would kill me after I ruin a few takes.

So, I set out on my quest to silence my camera. After my first google search I found a Jacobson Sound Blimp. This would cost me $900 to purchase or $25/day to rent. I thought, no way am I paying $900 for an oversized box that makes my camera look like it was made in the 1800s and offers me no controls. But I might spend $100. I found a "DIY guide" by Dave Buzzard. However, it is kind of rough around the edges and left a lot up to the imagination. So I am writing this to go into further detail and explain how I expanded on his initial design.

I built my blimp around a Nikon D300, which is a pretty large body. Going into the project I knew I wanted to be able to switch lenses while keeping the same box. One solution to use different lenses is to build a second blimp, but I wanted to save money by using one case and changing the lens tube. I think this is how the Jacobson blimp works, so I thought it'd be neat if I could do it too.

List of Equipment:
The case is going to be the most expensive part. A case that is waterproof works best. Why you ask? Because being waterproof, it creates a vacuum. Since there is no gaps, there is nowhere for the sound wave to exit, which significantly reduces transmitted noise. I used a Pelican 1150 case , just like Buzzard. Be sure the case you get includes a foam insert. The Pelican 1200 Case is the size you need for a large camera body like the D3.

I raided Home Depot's Plumbing section for the lens tube. I used a 4" diameter Female Adapter as my main lens tube. The 4" tube snugly fits both my Tokina 12-24mm and Nikon 80-200 AF-S lenses. If you are only shooting with prime lenses, you may be able to use a smaller diameter. You will also need a 4" screw-on Cap. I also picked up a second 4" female adapter and 4" Male Adapter to build the extension tube.  $20

Also need a shutter release. I found one from Gadget Infinity, here. Note there are two different lengths of cable releases sold by Gadget Infinity, I opted for the short one so there wouldn't be excess cable spaghetti inside the case. $15
(Update: I would recommend buying a Wireless Shutter Release instead. It's one less hole to drill and not much more expensive)

Instead of buying a pre-made 4" glass filter (which cost $125!), I had a custom piece of glass made by a local glass company for $15.

All that's left is some strong adhesive to hold everything together. I used some weld adhesive from Wal-Mart that said it worked great on glass, pvc, and plastics! Perfect! $5



Onto construction!


The first step is to determine the placement of your camera. Optimally, there is equal padding on all sides. No part of the camera should touch the edges of the case. If part of your camera is touching the case, sound will be transmitted. Bad. The case comes with soft foam padding that can be plucked out. I used toothpicks to make sure it was the right place before I started plucking. But afterwards I realized the camera was a bit off-center still, so I shifted it over a bit by cutting off one row from the right and moving it to the left. Once I was satisfied that my camera was sitting snugly in the correct place, it was time to cut the holes.

There are a total of 3 holes in the case, one for the lens, a second for the eyepiece, and a third for the shutter release. The placement of the lens and eyepiece hole must be precise, otherwise you won't be able to see through the lens, or put any lenses on the front. This is the part where you check thrice, cut once. If you screw this up, there's no remedy except buying another $30 case. That being said - my method of make sure I was drilling in the right place is rather barbaric. The process involves a lot of guessing and second guessing. Alignment and re-alignment.

*Side note: I decided not to make a hole for my LCD because I was afraid the large space with no padding might compromise the sound proofing. *UPDATE: NOT TRUE!



The Eyepiece


I used an old replacement eyepiece for a Nikon FE. It was nice because it had some threading, so I could screw it into the hole that I drilled and it would hold without any glue. I know most people wouldn't have a spare eyepiece from a 20 year old camera lying around, but a small piece of plexiglass will work just the same.

I placed my D300 in the foam and measured to the center of the eyepiece. Then I copied those measurements over to the lid.

After a few eyeballs gauging it from several angles, I made the incision.

When I was threading the eyepiece in, the hole was too tight and a little oblong, and I ended up cracking the glass. Oops. I used some adhesive to fill in gaps around the eyepiece. (the crack hasn't been an issue thus far.)



The Lens!

This was the trickiest hole to drill, because I don't have a large enough drill bit to drill a 4" hole (but they do exist), so I had to use a dremel. Also, there was not really a surefire way of making sure I was lining it up perfectly. What I ended up doing was using the lid from a can of spray paint. This perfectly fit over my lens mount. I placed the camera inside the case with the foam around it. Then I carefully removed the foam. That allowed me to have enough room to trace around the camera body while maintaining the correct positioning. I guess I could have used a lens on the camera to do the same thing. Now you have to turn that smaller circle into the outer diameter of the PVC pipe.

Then it's just a matter of slowly dremeling away until the the PVC fits snug.

Cut a piece of plexiglass and cut it to fit the bottom. Then drem
el a hole that is the inner diameter of the PVC pipe. By gluing the extra layer of plexiglass to the bottom, it creates a lip that creates more support and surface area for the pipe. Once the plexiglass glue is set, you can attach the PVC to the body. Put a bead of glue on the lip of plexiglass as well as the edge of the case. This will ensure a secure bond.

I put a layer of foam around the inside of the PVC pipe to act as a noise dampener. The foam also doubles as snug padding for my lenses.


The Shutter!

(pictured with optional extension tube used with telephoto lenses)

The shutter was purchased through gadgetinfinity.com, and only set me back $15. I dremeled one of the ridges off the outside of the Pelican case. Then I drilled a hole and used a strain relief bushing to secure it in place. I used a piece of velcro to secure the shutter release to the outside of the body.




The Lens Tube!

This picture shows the extension tube and the front glass filter. Instead of buying a pre-made 4" glass filter (which cost $125!), I had a custom piece of glass made by a local glass company for only $15. The screw-on attachment I glued it to was a 4" Cap with Threaded Plug  which I dremeled a hole into. I left a 1/8" lip that the glass will rest on.
Here you can see the glass fitted into the cut-out plug. I spray-painted the entire plug black before I glued it on, but as you can see, the adhesive ate through the paint around the lip. That's okay. I shouldn't have painted that portion.

The only downside to the custom piece of glass is that there isn't an anti-reflective coating, I've had a couple images where ghosting was an issue. I put a piece of extra foam around the inside of this PVC pipe as well.




And Finally!

This video is a little test I made.

Sound Blimp Test from Kyle Peters on Vimeo.

I used this blimp for the entire shoot, and found it to work very well. It wasn't too heavy or cumbersome. And as far as performance goes, Blair Scheller, the sound mixer, told me that it was almost as quiet as the Jacobson Blimps he's worked alongside! Not bad, for 1/10th the price!

I used the blimp for over half of the shots here.

25 comments:

Joe said...

This is awesome

brad crawford said...

made a very similar one myself.

http://www.vimeo.com/2198713

Works very well though I won't have room for super telephotos i figure i'll just use a simpler cloth-based blimp when using my 80-200 as i'll probably be further away from actors/mics at that point.

Kelly Kruschel said...

I wish I saw your blog last month!
I'm working on a movie production right now with no blimp and its very limiting.

I've ordered everything you listed in your blog to make the blimp and I'm going to try it out for the next project I work on.

Thanks for the details and pictures!!

Kaustav said...

would you make one for me, for a price ofcourse?

Jim Newberry said...

Well done! Last May I made a blimp from a Pelican case loosely based on Buzzard's idea as well, and posted instructions on my blog: http://www.picturedujour.com/?p=67

Your lens tube is much better...

Joe said...

Do you think the sheet of plexi in the front reduces sound significantly? I'm thinking of trying this with the threaded adapter (lens mount) cut down in the back, so the lip of the threaded portion would sit flush with the Pelican case. This would give it more surface area to bind to without using the extra sheet of Plexi, and allow me to use smaller prime lenses without vignetting. I'd be grateful for your thoughts.

Kyle Peters said...

Joe,

The plexiglass sheet is really only there to add more surface area for the glue to adhere to. I do not think it contributes to dampening the sound. I found that the key to keeping the blimp quiet was to ensure that there was no gaps or leakage. In other words, make it waterproof! No gaps. It's just like a door to a room: if the door is just a little bit cracked sound gets through, but if you shut the door all the way it is much quieter!

I like your idea, although I didn't use any wide prime lenses in my case. I mainly used my 50mm, 85mm, or my wide 12-24 which fit snugly to the front of the tube. If you have a full frame sensor or a wider prime then making the attached barrel shorter is a great idea!

Hope this helps!
-Kyle

Joe said...

Hi Kyle. Thanks for the quick response. I'm adapting your design for use with a D700, so the full frame sensor is my motivation for shortening the tube. I have another DIY blimp I made years ago (and recently remade) that's very quiet (competitive with the Jacobson), but it's as big as a house. I'm hoping your design might be a little smaller and quieter. I've used the Jacobson for years at my regular job, but buying a new one every time I get a new camera has become daunting for the small amount of freelance work I use it for. Thanks much for posting these directions on your blog.

mikehedge.com said...

thank you!

Anonymous said...

Have you tried modifying your lens tube so you can focus manully or use telephotos in the way Jacobson's do?

Kyle Peters said...

In my original design I wanted to be able to manually focus and zoom, but doing so would add a lot of complexity to the otherwise simple design. Another thing: creating a mechanism to adjust zoom and focus might allow for sound reverberations to reach the outside. Right now the entire camera has a layer of foam cushioning it from touching the outer case. But since a part would have to touch the camera it might allow more vibrations to travel outside the camera case.

That's just my theory, I'm not entirely sure if it is right or not.

Anonymous said...

Hi, I'm working on my blimp right now, and was hoping someone would come up with a simple, soundproof way to manually focus! Someone should be able to figure it out, I've got some rough ideas but nothing simple or concrete yet. Any ideas,suggestions? Thanks for your step by step instructions! JF

Kyle Peters said...
This comment has been removed by the author.
Kyle Peters said...

@JF No easy way of doing manual focus that I have found. Each lens is unique, so you would have to have a different tube for each lens. It takes some getting used to, but I found that the D300 did a great job of tracking focus. I was able to adjust my shooting style around the blimp and it worked well. By the end of the show, I was rarely missing focus. It just takes some getting used to.

Erdumrunder. Ein Jahr Sabatical mit Fotomission... said...

Great work, could use one on my journey around the world. Might also work pretty good as protection case against sand, dust, water, drop...

Tom White said...

I just made a blimp in pretty much the same way - http://photographylot.blogspot.com/2010/02/diy-sound-blimp.html - , though I like the way you made the lens tube. I was toying with the idea of removable tubes but didn't bother. Nice job.

jUUggernaut said...

I got a hole saw that fits perfectly and a hole saw mandrel at HomeDespot.
The size you need for the socalled 4" pvc pipe is actually 4 1/2" aka 114mm because the 4" refers to the inside.
Cost: $35 hole saw, $17 mandrel.
Fast work and precise fit.
Had to be fast because I want to photograph a children's musical at my Unitarian Universalist church this weekend without being a nuisance.

Rusty said...

A friend of mine in the Hollywood film industry commented that some directors might actually require a Jacobson blimp, since that's what they know and trust. Has anyone here ever run up against that?

Filmo said...

Had a question about the custom built glass for front of the tube. Did they build the whole thing for you for $15 or did they just give you the piece of cut class.

Can't tell from the picture, but it looks like the glass is sandwiched inside of a treaded cap and there's some sort of retaining ring that is then alan wrenched down onto the glass to hold it into place ???

Any more details you can share on building out the front lens glass cover would be appreciated. Thanks.

Kyle Peters said...

@Filmo sorry for lack of picture. they just gave me the cut piece of glass. I meticulously cut the hole in the threaded cap. It originally looked like this: http://bit.ly/99BTcJ

Once the hole was cut, I glued in the piece of glass! Hope that clears things up!

Andre Cherri said...

Hi Kyle! I'm Andre, from Brazil.

Can't find those 4" Male Adapters neither Female ones... I was wondering if you mind buying them for me and I pay you... pay pal, western union...

Thanks!

Creative19 said...

I'd possibly be interested in getting you to make one of these for me if you're interested. What would the cost be?

湯舜 said...

Thanks for the awesome post, Peter. Based on your design I constructed my blimp. I glued a 4″ PVC tube-lid onto the box, allowing us to screw mount the lens tube. Moreover, the twist-able part of the lens tube will be in contact with the lens, which give us the possibility to zoom a lens without taking the camera out of the box, adjust the zoom range and put it back again.

I put it on this bi-lingual post.

http://workandworkshop.com/blogs/2010/12/homemade-sound-blimp/

Mark Chilvers said...

great post and I have tried to follow your instruction but having a little trouble working out the lens tube set up. I am trying to find the pipes and caps to make the tube interchangeable. Any further details or advice would be cool. Need to get it worked out in the next week or so for a job. Thanks

Foam-By-Mail said...

One good rule of thumb when dealing with pick and pluck foam, is to always err on the side of too tight. For one, foam is really compressible, so a tight fit will keep contents more secure. Two, it leaves a little wiggle room, because you can't really put foam back in the same way (glue free)once its taken off. Lastly, if it's just a little too tight, you can even carefully cut away just a piece of a cube with a sharp serrated blade, for the best fit.