DV Info Net

DV Info Net (https://www.dvinfo.net/forum/)
-   Alternative Imaging Methods (https://www.dvinfo.net/forum/alternative-imaging-methods/)
-   -   What's so hard about a DIY Follow Focus? (https://www.dvinfo.net/forum/alternative-imaging-methods/40741-whats-so-hard-about-diy-follow-focus.html)

Daniel Skubal June 27th, 2005 10:25 AM

Oh wow! How is the motion on it? Pretty smooth? What about the strap gear? Where'd you find that at?

All-in-all, how much did the ff cost? I assume the machined alloy drove the cost up quite a bit

Robin Davies-Rollinson June 27th, 2005 10:40 AM

The motion is very very smooth - and makes finding focus a breeze. Especially as you can set up a mark and return to it (which after all is the point of the rig...)
It only really cost me 18GBP and a few bottles of wine, since I had it made up by a pal in the BBC mechanical workshops here in Cardiff. He takes a real delight in making up bits of gear like this. My next project is to try and interest him in a mini-35 adaptor .... ;-)


Robin

Aaron Shaw June 27th, 2005 02:19 PM

Very cool! Any chance you could post your design? I'm sure others would be quite interested.

Robin Davies-Rollinson June 27th, 2005 02:58 PM

Aaron,
I'll do my best.
There weren't any real drawn-up plans, merely a case of adapting bits and pieces that were available to us.
The hardest bit (at least, I thought it would be..) was to find the right-angle gear drive. I did a Google search and came up with : THIS

Once we had that, it was just a case of mounting it to the 15mm rods that I already had for the Arri matte box. We found a spare slider for the rods and machined a block to hold the gearbox, with slots to allow the gears to be moved up to the lens gear ring as required.
I'll take some more pix as soon as I get a chance to show the parts in more detail.
I'm very happy with it and have already been using it on some docs that I'm shooting for the BBC as well as for one of our commercial channels.

Robin.

Aaron Shaw June 27th, 2005 04:16 PM

Awesome :). I know how building things goes so no worries!

Eniola Akintoye September 8th, 2005 04:46 PM

So is it possible for you to make some for different camcorders and sell?????.

A lot of people can not afford $800 for a FF which I presume is the price for cheap ones.


With the enormous amount of Indie guys looking for cheap camera accessories, could you make some and sell?

With a price of like $70 or something, I think it would not be bad adding some 5 zeros to 6 zeros in your bank account....what do you think?

Also in regards to the adapter, what have you been able to come up with?

Dan Diaconu September 8th, 2005 06:15 PM

You may be interested to get a closer look at this items:
http://dandiaconu.com/available_products.htm

Leo Mandy September 15th, 2005 02:31 PM

I am also interested in the cheap design system. Going to look for the mitre joint tomorrow!

Also Dan, is there a reason you used the redish blossom knob for your kit?

Giroud Francois September 15th, 2005 04:02 PM

ok , lets be creative.
the problem: so many lenses, so many diameters.
forget about gears, too difficult to pruce, almost impossible to get one size fits all.
solution: Gear belt. just cut the length needed to wrap your lens.
need to fix it ? use velcro.
no need for a pulley yet. you just need a second gear belt that goes over the one on the lens. they are theeth over theet on a big length so no risk for slippage. the width of each belt can cover even the biggest displacement of lens.
now the pulley. Again for universal mount we will do it in a way it has an adjustable position so you can make the belt streched (tended ?) properly.

The rest is easy, you can use any right angle (but do we absolutely need right angled ?) device you will find to transmit the rotation to the button.
(i have seen really nice plastic gear for potentiometer).

some cheap plastic motor offers good source for right angle shaft
http://www.hobbyengineering.com/SectionM.html#IX1209

and Dremel has is own
http://www.hobbylinc.com/htm/dre/dre575.htm

if you relly wants gear, see alltronics
http://www.alltronics.com/images/23Z027.jpg
for 5$ this stuff is more than 3 inches diameter.

Dan Diaconu September 15th, 2005 05:53 PM

[QUOTE=Mandy Leo Also Dan, is there a reason you used the redish blossom knob for your kit?[/QUOTE]
http://www.speedtv.com/_assets/libra...terior.web.jpg
http://www.cars.com/features/2001ove...or_292x178.jpg
http://www.rodmillen.com/images/Conc...s_interior.jpg
http://www.aaton.com/galbums/cameras...prod_front.jpg
http://www.filmcamerakit.com/Picture...20LTR%2032.jpg

http://www.dvinfo.net/sony/images/ci.../cinetech3.jpg
http://www.dvinfo.net/canon/images/cinetech4.jpg
http://www.dvinfo.net/canon/images/cinetech7.jpg
http://www.dvinfo.net/sony/images/ci.../cinetech1.jpg

'nough?
I guess is only a matter of taste. I like wood (blasphemy in a plastic and Al world, I guess...) but plastic and Al knobs are almost finished.

Noah Yuan-Vogel September 15th, 2005 09:26 PM

for those of us looking for a really cheap solution, I was at the hardware store today and noticed a $15 hand drill that transfers rotational motion like a bevel gearbox would. I'd imagine there is a way to mount it and attach a gear to go together with some kind of gear band on a lens.

Just an idea.

Anyone know where to get some kind of strap with gear teeth on it? Plastic ties like the ones that you slide through a hole on one end and have to be cut off have some notches in them, so maybe something like that could be strapped to a lens? Someone mentioned such a thing, but I am not sure where to get them. If they are cheap you could just attach one to each lens and leave them on.

Wayne Morellini September 16th, 2005 03:04 AM

Good thinking, when ever it breaks, throw it away and put another on for a few cents. That would make it cheap to do for zoom and iris as well on a SLR lens.

The ring tie straps should be in office stores, and various trades stores that use them, I forget where I got mine from.

The nob on the strap could also be used as a leaver that could hit stops for direct hand control. For instance, mount one main strap and cut to knob, mount another secondary strap next to it with some sort of attachments (even more micro ring tie loops) sticking out over the main strap, that the knob will hit for a stop. You could even use ring tie loops as adjustable stops. But it would depend on the lens configuration allowing it.

Diagram top view (laid out flat, because of no curves in text graphics):

Secondary strap with main stops "()" and adjustable stops "(o)" over lapping main strap

(),,,,,,,(o),,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,(o),,,,,,,,,,,,,,,,,,,,,()
(),,,,,,,(o),,,,,,,,,,,,,,,,,,,,,,,@,,,,,,,(o),,,,,,,,,,,,,,,,,,,,,()


Main strap with "@" knob.

You could make the adjustable stops by tyeing two straps on top of each other on the secondary strap, one tight on lens and the other loss to allow the stop rings to slide, both firmly tied to each other by loops used as the main stops. Like this

(side view of secondary strap)

(),,,,,,,(o),,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,(o),,,,,,,,,,,,,,,,,,,,,()
(),,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,()

Leo Mandy September 16th, 2005 07:28 AM

Isn't there a worry about using electronic and battery powered motors (dremels or otherwise), that you are going to strip the gears in the SLR or the gears that are purchased?

Oscar Spierenburg September 16th, 2005 07:53 AM

Just a thought I had some time ago:
If you put a flexible axes (from a dremel or another drill) on one side through a ring that mounts on the non moving part of the lens, so it is parallel to the lens, and you put a gear on that end of the axes that touches the lens (with a strap on it), so if you turn the other end of the axes, the lens would move with it. Because the thing is flexible you can mount the other end ( with a knob and markers) anywhere you want, like on the tripod or in the hands of a focus puller.
If this is not clear at all, I'll draw it.

Giroud Francois September 16th, 2005 09:02 AM

i found it back...
http://www1.conrad.de/xl/1000_1999/1..._00_FB.EPS.jpg
about 20$ but goes around 10$ if you order at least 20

more info at the bottom of this PDF
http://www.produktinfo.conrad.com/da...9_66_de-en.pdf


All times are GMT -6. The time now is 09:08 AM.

DV Info Net -- Real Names, Real People, Real Info!
1998-2024 The Digital Video Information Network