Introduction: DIY Follow Focus for DSLRs
With HD video being all the rage, I thought I'd share how I made a simple follow focus for my DSLR. There are several different ways to do this, I know I've seen a couple of other DIYs for the same thing on youtube (e.g. using rubber bands, jar openers), but I made mine with the materials I had lying around or nearby, in true MacGyver style :)
Enjoy!
Step 1: Materials
First of all, what is a follow focus?: A follow focus is a focus control mechanism used by videographers to be more precise in focusing on a subject while its moving, or to smoothly change focus from one object to another while filming. No one wants to see the camera shake when using the manual focus ring on your lens. A follow focus is a way to operate your focus more efficiently.
For materials, you will need:
1. a dslr camera
2. a cheap magnifying glass ($1)
3. A knife or sharp object with which to cut
4. One "m-wave" reflective leg band, that can be tightened and loosened (a set of two costs $5)
Step 2: Step 1
Pop the glass out of the cheap magnifier (you can use the left over glass to make a cool projector for your ipod or iphone: https://www.instructables.com/id/How-to-make-a-projector-for-your-iPodiPhone-for-a/)
Step 3: Step 2 Cut Magnifying Glass
Since the circumference of my lens is slightly too big for the magnifying glass, I had to cut the plastic. I did this by heating up the knife for a few seconds and sinking it into the plastic, making a clean cut.
Step 4: Step 3 Attach Magnifying Glass and Reflector
After wrapping the magnifying glass around the lens, I also attached the reflective leg band on top of the magnifying glass and tightened it to hold the magnifying glass plastic securely to the camera lens.
Using the handle of the magnifying glass you have a useful follow focus for your dlsr.
Depending on the size of your lens, the magnifying glass may be too small or large. If it's too small for your lens, you can still wrap it around part of the lens since the magnifying glass plastic is really flexible (if it's a cheap one!).
Please vote if you found this at all useful! Thanks :)

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46 Comments
8 years ago on Introduction
"Experienced still photographer" shooting for 50 years using AUTO FOCUS, that's hilarious.
8 years ago
As great as simple! Thanks
10 years ago on Introduction
Why bother when you can set the AUTO FOCUS and the ANTI VIBRATION controls so that you do a smoother and less geeky looking video anyhow.
Reply 10 years ago on Introduction
Whether it's good or bad, some dslr's disable the auto-focus when you are in video capture mode. There may be many reasons, such as the videoagrapher wants the subject to be in one of the 1/3 corners, and the auto-focus will insist on trying to focus on the background, which may very well not have any contrast for the AF to work with. You'd end up with a video where the focus goes in and out through the entire focus range of the lens, and you end up with video that's not of any use. You may also be working to capture video of a person in a crowd, and then need to switch to someone else in the crowd without actually moving the camera.
Reply 9 years ago on Introduction
A reasonably good DSLR has follow focus IN VIDEO MODE, and can be set with a field, spot or a adaptive intelligent 'follow' focus mode in Video mode. My Nikons have ALL had this feature, as does, I believe the Canon line.
With cameras, you get what you pay for. If you buy cheap cameras, you get the effects you've described. There are things I scrimp on, but my cameras aren't in that category.
Reply 9 years ago on Introduction
This also depends on the camera being able to recognize what it is you want it to maintain focus on. Some do a better job of this than others, and even with those that do a fairly decent job of this, there are likely to be situations where you want finer control than the camera will maintain. Keeping one person's face in a crowd in focus for example, while they are moving through that crowd.
Note that I'm not saying that a good camera can't maintain focus on a subject, just that this gives you control that may not otherwise be available.
Reply 10 years ago on Introduction
rusty0101, I may be mistaken, but I thought you could focus on the subject, hold the shutter button halfway down to hold that focal length, move the subject to "one of the 1/3 corners", and then push shutter button down.
Reply 10 years ago on Introduction
For a Photo yes. Not for video. The Instructible is related to taking video where you would not be moving the camera around for focus. In this case you want to be able to adjust the focus on the fly, with as little movement of the camera in the process.
Most of the higher end prosumer rigs mount the camera on a shoulder rig that the videographer uses both hands to control for stability, and the follow-focus control is either a rotating handgrip (think motorcycle accelerator or bicycle gear shifter) or a thumbwheel on the rig. Either is going to control the focus for the lens through a cable system (like a bicycle's breaks.) Again this isn't all that helpful with single shot photography, but is not at all uncommon when it comes to video work. And DSLR's are very common these days in capturing videos.
9 years ago on Introduction
Wow, very usefull, thank you!
9 years ago on Introduction
Yup! A perfect solution for my manual focus lenses. Elegant, inexpensive, fast and easy to make - even on location. The clams were a great solution too. Other items I have seen use large hose clamps and such. This looks super easy, fast to install and can be carried in a vest pocket. Well done.
10 years ago on Step 4
i like the DIY but why no clothes? lol
10 years ago on Step 3
Heating a knife will undo the tempering, making the blade softer. Don't do that to a knife you like.
Reply 10 years ago on Step 3
not nessecarily. if you only heat it for a short time (the time needded to make it go through plastic) it may even temper it more
10 years ago on Introduction
I was originally going to add this defensive comment:
"I'm guessing the 'topless' comments would have been much different if the author had been female."
Until I went to the <TWOWEEKSOFF> website and saw the 'sweet' still photography there, read the bio, and then became enlightened.
Yeah.
Why as a society are we so hung up on clothing, or the lack thereof?
And hair length. What's that all about?
To tenzijth,
Nice job on this! Years ago, I used a similar technique on a video camera that had a one-speed zoom that was way too fast. I really appreciate the 'instructables' spirit and simplicity of this project. This is a project accessible to someone like me who doesn't happen to have a laser cutter, 3d printer and/or CNC machinery just laying around the house. Or the newest DSLR equipment, for that matter.
Good luck in all your endeavors, and keep capturing the moment.
10 years ago on Introduction
You've completely omitted the fact that many DSLRs that can do HD video, can do on-the-fly weighted auto-focus. For the type cameras being used by the inventor here, it's a good, and rather ingenious solution. I'm not being critical of it, but my camera obviates the need for such a device My camera was primarily designed for stills, professionally, and hasn't all the handles and such you describe either. And an experienced stills photographer can shift gears, brace his or her body, use a mono-pod or tripod and shift gears to film easily.. The 'lines' between still and motion picture are becoming smaller and soon will be non-existent. I've been photographing (still and film/video) for over 50 years, and I admire the inventiveness here. But sometimes there's no need to re-invent the wheel. AUTO-FOCUS....works quite well. And on the fly too.
10 years ago on Introduction
This has nothing to do with using auto focus - AF would be turned *off*. Please learn about video- or cinematography first and have a look at items like this US$15 device: http://www.b-hague.co.uk/hague_follow_focus_zoom_lever.htm or this one for $50: http://reviews.photographyreview.com/focus-shifter-affordable-follow-focus-digital-slr-video . The OP's solution isn't elegant, but it *would* work for the intended purpose.
10 years ago on Introduction
Awww! I think he's kind of cute w/o a shirt. But there aren't many other guys who can pull it off (so to speak), so I hope they don't try.
10 years ago on Introduction
My DSLR has a continuous duty auto focus ON while using to film, you can choose weighting before shooting, and then go. It's Nikon, and I highly recommend them. The newer D3200 has 24 MP and I'm shooting for that one next as I will share lenses I have already with my D5100. A great reason to research what you are about to buy first so you don't get stuck with clumsy work arounds. (Not that this work around isn't ingenious, it's just not necessary for some DSLRs.)
10 years ago on Step 4
Brilliant, I've got the 18-135mm looks like the grip area is about 73-75mm so a 2.5" or 2.75" would work. What size did you find? Dollar store or where? I'm surprised there isn't enough tension in the magnifier ring to use it as is, without the leg things.
thanks for the idea
10 years ago on Introduction
Weird how many people are snarky toward your build. I appreciate both your efforts and your diplomacy toward snarky folk.