Optimize Fotga’s DP500IIS Follow Focus for Fly-by-Wire Lenses

A Simple Fix
By Sol March in Resources

The adjustable hard stops on Fotga’s DP500IIS follow focus are mighty useful, but things can get a bit noisy when you’re not using them. There’s a fix for that.

Fotga’s DP500IIS follow focus is a gem. Quick-release 15mm rod mounting, adjustable dampening, and buttery smooth performance all for under $200 make this follow focus tough to beat. In fact, the DP500IIS is my preferred follow focus over other more expensive units that I’ve used in the past.

Fotga DP500IIS Follow Focus

Another one of the DP500IIS’ useful features are its pair of adjustable hard stops. These hard stops can be positioned at any point around the follow focus to mark specific focus points– such as the start point and end point of a focus pull– making it easy to consistently hit those marks take after take.

Adjustable hard stops

Changing the position of each hard stop is quick and simple as well. Just loosen the knob, rotate the ring to set its new position, and tighten the knob back down to lock it in place.

However, there are situations where hard stops may not be necessary or even desirable. For example, the hard stops can prevent the follow focus from making a full rotation, which can be a problem when using lenses with electronic fly-by-wire focus rings and non-linear focus adjustment such as native Sony E-mount and Micro Four Thirds lenses. The focus rings on such lenses may need to turned more than 360° to reach the desired focus point, so a hard stop on the follow focus can get in the way.

Fortunately, the DP500IIS’ hard stops can be easily removed simply by unscrewing them all the way. Once they are removed, the follow focus can turn the focus ring as far as necessary.

Hard stop bolts removed from DP500IIS

The only problem is that without the hard stops screwed in, the DP500IIS’ inner rings are no longer locked down and can rotate from the inertia of your focus pulls. This can create a metal-on-metal scraping sound, especially when making fast pulls.

The good news is that there’s a fix that allows you to silence the DP500IIS when you’re not using the hard stops. The even better news is that the fix is dead simple and costs you less than $2.

Let’s do this.

Step 1: Pick Up a Pair of Set Screws

The DP500IIS’ hard stops lock the follow focus’ inner rings in place when tightened down. Therefore, when you need to shoot without hard stops, you need to use something else to keep the inner rings from spinning freely.

Set screws to the rescue!

Set screws are basically screws without heads, so they can be screwed in flush without any external protrusions that could block the follow focus from making a full rotation.

Set Screws

The DP500IIS’ inner rings have M3 (3mm) threaded holes for the hard stops, so you’ll need a pair of M3 set screws. Additionally, the threaded holes are 7mm deep, so you want to make sure that the set screws are shorter than this to avoid any clearance issues. To be safe, I recommend M3 set screws that are 5mm long.

A good place to find short set screws like this are in hobby shops that sell parts for small remote controlled cars and the like. I found a packet of 4 M3 set screws for $1.50 at a local hobby shop, but if you cannot find any nearby, you can always pick up some set screws online.

Get it: M3 x 5mm set screws

Note: If you don’t already have one, you may also want to pick up a 1.5mm Allen wrench for loosening and tightening the set screw.

Allen wrench

Step 2: Lock Down Inner Rings with Set Screws

Remove the DP500IIS’ hard stop knobs and use a 1.5mm Allen wrench to screw one M3 set screw into each of the inner ring’s threaded holes.

Install set screws into DP500IIS with 1.5mm hex key

Once the set screw is fully tightened, the inner ring will be locked and will no longer spin freely when you turn the follow focus’ knob.

DP500IIS inner rings locked in place with set screws

Step 3: Take that Knob for a Spin!

Now that the DP500IIS’ inner rings are locked down, you can spin the follow focus with abandon without worrying about making any extra noise!

A Cheap & Easy Fix

Shooting with highly-adaptable cameras like the Panasonic GH4 and Sony a7S II means that you can use a wide variety of lenses. As a result, the DP500IIS’ hard stops may be extremely useful with some lenses, while they might just get in the way with others.

Thankfully, with this cheap and easy fix, you can use this smooth follow focus silently with any lens, including ones with fly-by-wire focus rings and non-linear focus control.

Happy shooting!