Why I love this lens

The 4.35mm f2.8 lens mod for GoPro cameras absolutely transforms this action sports camera into a truly professional piece of kit.

The fish eye effect, while being quite fun at times, can totally destroy your aerial footage, doing all sorts of crazy things to your horizons while panning and tilting the camera. This rectilinear lens produces perfectly flat horizons at a much more comfortable focal length than the original GoPro lens. As well  benefiting from the as the straight horizons most people, including me, find the 4.35mm focal to be a MUCH more natural and usable focal length than the original gopro lens. I used to shoot with my GoPro FOV set to Medium, which means that I was unable to make use of the full 4K sensor. My video shooting capabilities were therefore limited to 2.7K and noise was more of an issue when only using a small part of the sensor. With the new lens, I can shoot in Wide mode, using the whole sensor, resulting in higher quality footage with less noise. This, coupled with the fact that there is no need to stretch the corners of the image to remove the fish eye distortion in post, means that you're resulting footage is significantly more usable than what was previously achievable with the original lens.


Test Footage (Graded)


Things to Consider Before buying

1. Compatibility

This lens is not compatible with all models of GoPro camera. The following models definitely are. If you don't see your model listed here then you'll need to do a bit of research but as far as I know it won't be compatible if it's not listed here:

  • Gopro hero 4 black
  • Gopro hero 4 silver
  • Hero3 black+ plus (note, the lens works with the + models, but not the standard hero 3 models)
  • Hero3 silver+ plus (note, the lens works with the + models, but not the standard hero 3 models)
  • Hero3 white
  • Hero1
  • Hero 960

2. Camera Shake

The 4.35mm lens gives you a tigher crop that what you might be used to with the original GoPro lens. It's more like shooting in Medium or Narrow Fields of view. What this means is that any camera shake that you already get in your footage is likely to be exacerbated (you are basically zooming in on the shake). If you are concerned about how this might affect you, then try flying with your field of view set to Narrow and see what kind of shake you are getting. This will give you an idea of what to expect if using the new lens in Wide mode. 

Now, just to be super-duper-mega helpful to you folk who are experiencing camera shake, here are some tips that I've picked up from experimenting and researching, which all work very well in eliminating camera shake, and hopefully make this lens more usable for you!

  1. Balance your props and motor hubs. First things first, you want to eliminate any vibrations from unbalanced props or motor hubs as early as possible in this process. Not only is it totally uneconomical to fly with unbalanced props, but it will also kill your footage. You can buy prop balancers online for very cheap and there are countless videos on YouTube showing you how to use them, so I won't go into detail here. This should be the first thing you do in your efforts to eliminate vibrations!

  2. Fly in Atti Mode. GPS mode is great, it really is. But if  you're priority is keeping your aircraft as geographically static as possible, you are potentially sacrificing smoothness in your video because of all of the correction that's going in in your flight controller. The micro-corrections that you're aircraft is doing to try to stay level is not going to be good for your footage at the best of times, even less so when using a tighter lens.

  3. Limit your ISO to 400 (Available in later GoPro models). By limiting your ISO, you're preventing your camera from reaching stupidly high shutter speeds (which is one of the most contributing factors to jello vibrations. For smooth aerial footage, your priority should be a low ISO and slow shutter speed. As your GoPro does not have manual exposure control, limiting your ISO is the only real in camera step that you can take to achieve this goal.

  4. Use ND Filters. ND filters are a very effective way to control the shutter speed of your camera. Putting ND filters in front of your lens will force your shutter speed to slow down. Slowing down your shutter speed means that the camera doesn't show the micro vibrations as much, as these tiny movements are all merged into a longer exposure. As a general rule of thumb, a ND8 works well in bright sunshine, an ND4 works in overcast daylight, and using no ND filter at all works best as it gets darker in an overcast evening. This will help HUGELY if you are still suffering from vibrations.

  5. Where possible, fly in the direction of the wind. This is not always possible, but more often than you might think, it is!! Use the wind to your advantage. If you can plan a flight path which follows the direction of the wind, and then stick your aircraft in Atti mode, you can literally allow it to drift the flight path in the wind. This negates not only any jerkiness from control inputs, but also any vibrations from wind. Ever been up in a hot air balloon? If so, you'll know that it's almost spooky how calm it is. That's because you're drifting with the wind. Let your craft do the same on a shoot and you'll be staggered by how much of a difference this makes to how stable your footage is!

  6. Choosing the correct rubber dampers. There are a couple of different directions you can go in with the way you dampen your gimbal mount. In my experience there are two main factors at play when looking at what creates vibrations. The first is wind, the second is aircraft inbalance. If you've done everything that you can to balance your aircraft and as far as you can tell, it's all in check and perfectly smooth, but you're still getting excessive vibrations, the chances are that the dampers you're using are too flimsy. If you're aircraft is smooth, there is no need for the extra give that the thin dampers provide (they are really more suitable for aircraft which are not very well balanced or smooth), all these things do is allow the wind to move the camera around more than you might like. So get yourself some stronger, mode solid dampers with less give in them instead.

  7. Foam Ear-plugs! Now we're starting to get stuck into actual modifications to your gimbal mounting system. If you've got a lot of confidence in how smooth your aircraft is and you want to make your dampers even more robust and resistant to wind movement, get yourself some of these bad-boys! They cost almost nothing and I've found that stuffing one of them inside each of the rubber mounts is extremely effective in eliminating wind vibrations!

  8. Stabilisation in Post. This point is last for a reason, because you shouldn't need it. Or at least not for everything you're shooting! But I'll mention it anyway. Personally I've found that the best results come from Adobe's Warp Stabiliser but use it sparingly! The most straight forward way to control the effect is simply to turn the "amount" slider down and step it up by 5% at a time until it looks about right. The other thing I'd recommend is changing the warp mode from "subspace warp" to either "Postion only" or "Position-Scale-Rotate". The reason for this is that your camera is not moving around by huge amounts and so subspace warp is massive overkill. That said, the software will look for opportunities to warp the hell out of your footage if there are any, which can result in all sorts of crazyness! The other peice of software which people rave about is Mercalli. I've only used is a couple of times and personally have not found it to give as good results as Warp Stabiliser but others have said the oposite so give it a try and see what you think. Version 4.0 offers huge improvements over the previous versions and there is a free trial available from their website at www.prodad.com.

These points, coupled with general common sense and smooth flying, as well as knowing the limits of your aircraft in terms of wind speed and maneuverability etc, should help you with your vibration issues and allow you to use these tighter lenses on your machines with no problems at all.

3. Pink corners

The original GoPro lens exhibits various optical artefacts which are corrected by the GoPro software in camera with a "Lens Correction Profile" which is specific to GoPro's standard fisheye lens. These corrections are hard-coded into the firmware and without some seriously hardcore hacking and breaching GoPro's terms of use, you can't very easily remove or replace this lens correction profile with something else. Incidentally, there is a company which does offer this service but it's expensive and I would not recommend it at all!! One of the artefacts that the firmware lens correction profile has to overcome is a green tint to the edges of the frame. This is fixed in camera by overlaying a pink vingette to counteract the green tint. What this means though is that when you replace the lens with any other aftermarket lens, you can visibly see the pink vingette that the camera's software overlays. It's not very obvious at all and can be corrected easily in post. But it's something to bare in mind.

Again, just to be super-duper-mega helpful to you folk who are interested in buying one of these lenses, I've made a solution for you! I've created an overlay which reverses the effect of GoPro's lens correction profile, restoring the corners of your footage to the correct colour and luminosity!

Here's a link to download the overlay:

Download GoPro Lens Correction Overlay

And here are some instructions on how to use it:

  1. Make sure the footage was shot in Wide mode.
  2. Load the JPG into a new track in your video software's timeline (or a new layer in your photo editing software if it's a still image)
  3. Resize the overlay so the width is the same as the width of your footage, preserving the original aspect ratio of the overlay. Please note that the overlay is designed to cover the whole sensor, which is a 4:3 aspect ratio. When shooting video you are most likely using a 16:9 aspect ratio, so you will be clipping the top and bottom off the overlay when using it on your video clips. Don't try to resize the height and width independently of each other to stretch the overlay over your wide-screen footage, otherwise your corrections won't be quite right.
  4. Change the blend mode to "Overlay". This can be done from within the "Opacity" effect in premiere or under the blend modes dropbown box in Photoshop
  5. Enjoy your fixed footage with no pink corners!

Installation

Please see this video on how to replace your GoPro lens. This video shows a different lens being installed but the process is identical:

If you have any questions regarding installation, please feel free to contact me.


Ungraded test footage

What I've tried to do with this clip is fully demonstrate what you might expect to see straight out of the camera when using this lens for aerial applications. The first 3 clips are from the video that I posted up there ^, but ungraded and unstabilised. These were shot using the considerations that I made above. The last clip shows some footage that I shot in GPS mode, in turbulent windy conditions between some bushes and without appropriate dampners installed. I've also demonstrated how the overlay can be used to correct the pink corners so that you can see what it looks like before and after this has been applied. Hopefully this little clip should give you an idea of what to expect in terms of vibrations in a worst case scenario. Rather than upload to youtube, here is a link to the full quality file so that you can judge for yourself:

Ungraded, Unstabilised Footage


Purchasing this lens

I've had such a huge amount of interest in this lens after posting videos online and talking to people in forums, that I've decided it might make sense for me to start selling them. So you can now buy one directly from this page using the link below:


4.35MM f2.8 10MP Rectilinear Non-Distortion Lens Replacement for Gopro Cameras

 

£79.95