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-   -   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)

Dan Diaconu March 21st, 2005 02:00 PM

But I ain't got no fishing rods nor fish here (somthg's fishy though) ....always good for a laugh.... thanks guys. almost 4goat : *smile*
Now:
I'd still go with the CMOS thing (in your shoes) and a FF for one lens only. You'll make it somehow, I know.
Rafael, all you may need is da right (or the left?) gear to go on the lens (instead of the one mounted now) or you could engage that one to another one to go on the lens and you're there. What you have for 15mm rods might be the best thing you need to mount it. Good luck.

Daniel Skubal March 21st, 2005 02:07 PM

Has anyone considered a "strap on gear" for the lens ring?... something similar to a zip-tie but with larger teeth? I don't even know if they make them but it'd definitely be worth looking into. Just standardize the teeth, and then you can build an any-camera follow focus without having to worry about the lens ring.

Rafael Cruz March 21st, 2005 02:11 PM

great, thanks Dan, also i have canon ef and nikon still lenses to use with the mini35. is it better to fix some kind of gear ring to them? are this rings comercially available? what could i use for it ? what about plastic ones?

Daniel Skubal March 21st, 2005 02:30 PM

You can order these rings from the manufacturers of pre-existing products, but the rings sell for between 100-200 dollars. Plus, if add on a micro35 or any lens for that matter, the ring becomes useless and you have to buy another one to fit that specific lens. I would much rather have a disposable/adjustable strap to save me from that problem

Dan Diaconu March 24th, 2005 12:24 AM

Rafael,
the Nikons I have mod have four different dia (out of seven lens) so, I had to do custom fitting rings. However, the outer dia I made is the same for all. A pain, but awesome to work with now. I also had to take them apart (one by one) and re-do the greasing job which was good for still lens but not adequate for "in take" focus roll speed (they were stiff)
Now, they have the Zeiss moves....hehehe....
Same for a FF I played with today. Made in China, sold here for $ Can 1200 (about US$950) Stiff (well... compared to the one I made and the standard) and therefore solicitting in use. (small "details" that add up when one looks at a certain product and questions the price like I do) There were other two inconveniences but I would prefer to move on and follow Shannon's advice and make one (the way I would like to use it) available for a decent price that will address those issues as well. Working on it....

Matt Kelly March 27th, 2005 11:02 PM

<<<-- Originally posted by Daniel Skubal : Has anyone considered a "strap on gear" for the lens ring?... something similar to a zip-tie but with larger teeth? I don't even know if they make them but it'd definitely be worth looking into. Just standardize the teeth, and then you can build an any-camera follow focus without having to worry about the lens ring. -->>>

What about nylon or thin plastic rack (& pinion) gears? Do you think you could get one flexible enough that you can just bend it around the lens and you could either glue it or screw it in place? If there was anything like this, then you could probably make it into something that can be strapped onto any lens, like daniel's saying, but i'd think it would need some hella grip to keep from slipping around.

Daniel Skubal March 27th, 2005 11:39 PM

<<<-- Originally posted by Matt Kelly : <<<-- Originally posted by Daniel Skubal : Has anyone considered a "strap on gear" for the lens ring?... something similar to a zip-tie but with larger teeth? I don't even know if they make them but it'd definitely be worth looking into. Just standardize the teeth, and then you can build an any-camera follow focus without having to worry about the lens ring. -->>>

What about nylon or thin plastic rack (& pinion) gears? Do you think you could get one flexible enough that you can just bend it around the lens and you could either glue it or screw it in place? If there was anything like this, then you could probably make it into something that can be strapped onto any lens, like daniel's saying, but i'd think it would need some hella grip to keep from slipping around. -->>>

Do they make gears like that? For most lenses, the built-in focus ring is rubber, so if you could just make a locking mechanism like a watch (where it folds back and clips in), or maybe even just a pin system...

I'm no engineer but I believe standardizing the gear strap and making it adjustable would be optimal for making a DIY FF

Also, the gear strip wouldn't be required to go all the way around because most focus systems only have a 120-270 degree turn radius, so as long as the strap device was opposite to the ff gear, there would be no confrontation.

Matt Kelly March 27th, 2005 11:55 PM

This is the sort of thing i was thinking about http://www.machined-plastic.com/rack.htm The green gear isn't the best example, but i bet something similar to it could work.

Daniel Skubal March 28th, 2005 12:42 AM

Ohh! Yeah I think that would work... that was actually what I was "looking" for when I originally posted the idea. Hmm... I think this may be something worth pursuing. I mean... a 1$ piece of plastic versus a 350$ crafted product... I think it's worth a try.

Matt Kelly March 28th, 2005 12:53 AM

Well if you want to try it, go for it. I'm definitely going to try my hand at building a set of rails for a follow focus, but at the moment i'm working on a mini35 adapter first... so it'll probably be weeks before i plan out measurements and gear ratios for the follow focus. Lemme know if you have any progress.

Also... any tips on making a follow focus? I've seen some homemade ones involving miter gears, but i have no idea if they work anything like the real thing. i.e., one hand turn of the follow focus should pretty much give you full range of focus turn on the lens. don't know much about gearing either, other than what i've done with legos. :)

Oscar Spierenburg March 28th, 2005 05:42 PM

<<I also had to take them apart (one by one) and re-do the greasing job which was good for still lens but not adequate for "in take" focus roll speed (they were stiff)>>>

Dan, is any normal grease fast enough for an FF. I wonder if it is grease in (slow) lenses. I searched a long time for the right grease to redo my arri tripod head. When I put sticky resin instead of grease, it gave exactly the slow moves it needs. Is it resin they put in there originally?

Dan Diaconu March 28th, 2005 10:20 PM

The "ideal" FF (as well as the "blamed" as expensive ones) should not have any more friction than required in the bearings (not much) The Cavision that I have looked at was stiff (when compared to "normal") That alone (aside from stiff lens) can make the difference between being "soft" or slow to reach focus and "right on" during a "fight scene" or fast moving objects in and out (towards and away) from the lens.
The resin in the head is OK (for a while) as the closest to original.
In the lens, there is "normal grease" for the job they were meant to do. However, that makes them "slow" compared to the way the cine lens turn.
I had to clean them all with WD40 and replace it with some stuff I saved from other mechanisms I had worked with. I am sure there is commercially available somewhere, but I did not need, so I do not know. End result is what matters and they turn EASY.

Brian Valente May 19th, 2005 10:49 PM

Hi Everyone,

I am adding to this post to inform you Redrock Micro (the micro35) is intending to build a low-cost, high quality follow focus.

We are soliciting input from you on what you want in this product. We have already started a thread on input that can be found here:

http://redrockmicro.com/forum/viewforum.php?f=15

We hope you will visit and tell us what you want. Redrock's intention is to offer this to digital filmmakers everywhere with the philosophy of high quality products at revolutionary prices. Those of you who are familiar with the (soon to be released) micro35 can fully appreciate what this means.

Thanks

Brian

Courtney Lana May 20th, 2005 02:51 AM

Quote:

Originally Posted by Shannon Rawls
Alls i'm sayin' is dis..........If someone comes up with a DIY way to make a follow focus that FUNCTIONS the way a follow focus should, and makes the plans availbale........they will be sittin' pretty. And I don't understand why nobody has not done this yet. People always complain about wanting an Internet Business and don't know what to do?? Well here it is...here's your opportunity. Shannon put it out there for you. That's alls i'm sayin' *smile*

- Shannon W. Rawls

Most of the problem comes to the fact that most people of here don't know how to machine. So they have to take their design ideas to someone and let them create it. Machinist charge, I'm sure, alot. I don't know exactly, but I'd guess at least $60/hour.

Fortunately for myself, I've got many years experience in machining. This past week I've been buying metal and various other things to do a few projects, one of them a 35mm adapter. Another one is a rail system - no big deal there. Another is a matte box with barn doors and a filter holder. Another is a follow focus and yesterday I picked up 50 bright white LEDs (at 15000 mcd a piece) to make one of those LED cam-lights....kinda like the light rings that are made now.

I was surprised at what aluminum costs. My first outting I picked up some at a scrap yard for kinda cheap. About $0.70 a pound. Two days ago I picked up some for $0.35 a pound and I'm going back for more. Also picked up some stainless rod, 1/2" dia., for $1 a pound. So far I've spent under $20 for material and I've got enough to do most of these projects. Now I just have to sit down, plan, and start machining.

Like I said, lucky for me I know how to do all this stuff. But if you were to pay someone to machine it for you, I can see very quickly how the price skyrockets in no time flat.

Court

Robin Davies-Rollinson June 27th, 2005 08:51 AM

These are a couple of pix of the follow-focus rig that we made up for the FX1.
It uses a "strap" gear mounted on a specially machined alloy holder.
The right-angle gear drive was purchased from Maplin UK for only 17 GBP!!!

http://img.photobucket.com/albums/v1...llowfocus1.jpg

http://img.photobucket.com/albums/v1...llowfocus2.jpg

Robin


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