DIY rod system and 35mm adapter

F

fr3d

Member
I'm not a DVX user (though I certainly wish I was) and had to borrow the GL2 for this shoot, but I thought I would share some photos of the rod system and 35mm adapter I have been working on. This forum has been an awesome resource for getting this thing together.

The 35mm adapter is nothing too different from many of the other ones seen around this forum - standard ABS plumbing fittings cut in various ways. It's built for Minolta lenses - because the mount was available and my friend has an awesome 50mm f1.2 as well as many other lenses. It uses a Nikon focusing screen as the projection surface. Experimenting with 9 and 5 micron aluminum oxide compounds, I couldn't produce a ground UV filter that didn't have a horrible hotspot.

One thing that the 35mm adapter does do is use ABS fittings that screw into each other to give the ability to perfectly calibrate the mount-to-screen distance. Infinity focus on the lens is true infinity focus on the screen.

The rods are 5/8" stainless steel. 15mm stock seems impossible to find in North America and I didn't want to buy something ready made. It also means that I could find a corresponding 5/8" drill bit to make the aluminum clamping blocks. It was all pretty straightforward to do with a drill press, a bench-top bandsaw and a tapping set. The lens support is based on the design posted by Edweirdo (in the sticky thread at the top of the forum) whose generosity in sharing his work is much appreciated. One rod is left long as a handle for the camera on a tripod - no fluid head for us!

We went straight from putting the contraption on the camera into shooting. Luckily the whole thing held together.

Rough edit of preliminary footage can be seen here:
http://www.anaesthetic.ca/movies/turbo_train.mov

more pictures:
http://www.anaesthetic.ca/journal/2006/09/17/

cheers!

Tony
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Your footage looks pretty good. Seems like you're getting quite a hotspot (see the shot at 0:08 for a good example) and the right side of the frame is a bit dark but in a vertical manner. The build quality looks decent, especially the rods. :D Nicely done. How much did the rods cost you to make?
 
it's not perfect by any means - the hotspot seems to be a problem despite the Nikon screen. A friend speculated that it's because the GG needs to be millimetres away from the front of the GL2 lens for proper framing (GL2 lens can't be removed). Tests on his consumer cam with the GG further away weren't as bad. all things considered, I don't mind the vignetting in this case.

The rods cost $30-40 (CAN) in metal and about $5 in screws. It needs more work to be universal - i.e. for other cameras.
 
Fr3d,

Your rod support system looks great. Any way you could post a more detailed materials list and step by step directions for making it so I could take a crack at building one?

Thanks,

Mike
 
I love the rods. Any thoughts of selling them? I'd definitely pay for something like that. Seems to be cheaper than commercial rods, yet still sturdy and professional looking.
 
The images look great and really sharp! But i think i notice some sort of vignetting?

EDIT: Lots of vignetting it looks like
 
yeah. your camera is too close to the GG and im also guessing you cant zoom in enough to get rid of the vignetting before the GG is no longer in proper focus?

you need a diopter lens or some macros and a bit more space between the GG and your camera.
 
i can post more info about building the support system - just give me some time to get some drawings together. i'm happy to share. there is nothing innovative or proprietary about it at all.

as far as selling the support, i don't think it's really feasible. while the material is cheap, the time to machine the parts would make it too expensive for me to make. certainly more than a mass produced unit. another thing is that it's GL2 specific right now. (though it could be adapted for other cameras). now f i could just get my hands on a dvx....


re the vignetting - i know it's a problem. PaPa is exactly right. it was a problem to get the GG framed properly and in focus. a bit of a pain actually. i have some 58mm macro filters to play with so i'll see what effect they have.

thanks for the feedback!

tony
 
looks really nice!

dumb question: after looking at your clip, the purpose of the 35mm adapter is to achieve a film-like DOF, correct?
 
Hey Tony,

Are you still planning on posting some more info on how to build the support rods?

Thanks,

Mike
 
Hi Mike,

i am still planning to post a drawing of the clamping blocks in the support systemif there are people interested. the past couple weeks have been busy.

keep in mind that i built it for a GL2 so it may need some adjsutment to work for a DVX. i don't have access to a DVX to see if it would work as-is.

in the meantime, i can say that you will need access to:
- a good drill press with a vise
- set of drill bits including 15mm (or 5/8" depending on what size rods you can get)
- threading set - i used 10-24 and standard 1/4" (tripod mount thread) screws.
- unless you're good with a hacksaw, a bandsaw that will cut aluminum is nice. i used a little bench-top bandsaw by delta and it was fine.

i'll see what i can do about getting together a dimensioned drawing and step-by-step instructions.

tony
 
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