Car rig, step 3 of 1?

Speedy Supra? It was actually only moving at a walking pace.

Hello friends!

Today I used my newly built car rig for the first time. What’s a car rig you ask? It’s basically a jig that allows me to rigidly attach my camera to a car, so that I can take motion shots.

To capture motion, there are essentially two options – either drive really fast and pan the camera while using a fast enough shutter speed to avoid camera bounce, or use a really long exposure with slow subject speed, and a rigidly mounted camera. For example, a 1/50th exposure of a car travelling at 250km/h will look exactly the same as a 1 second exposure of a car travelling at only 5km/h. Choosing the second option is much more controllable, practical, and repeatable in my opinion – it would be next to impossible to correctly track a subject going 100km/h, turning a corner 2 meters in front of you, using a 17mm lens. It’s much more practical to have the car drive (or be pushed) at only walking pace, after setting up the exact composure and exposure in advance.

This is where the car rig comes into play. It allows you to mount the camera to the car, compose your photo, set your exposure, and then take a nice long exposure while still keeping the car nice and sharp.

It’s quite simple really, but there are three tricky parts:

1. Building the rig
2. Mounting the rig
3. Removing the rig from the photo (using Photoshop)

I intend to post about the first two issues at a later date, but for now I’m going to give a really quick crash course of what step three looks like in my workflow. This isn’t a photoshop tutorial, so people unfamiliar with the clone tool, adjustment layers, and blending will have to look elsewhere. But I do show each step I take during my post-production stage.

The original photo

The car rig I use consists of two suction cups that hold an aluminium pole on the car. The camera mounts on the other end of this pole. This design allows for quick set-up and removal, and a decent range amount of flexibility of placement. One of the major downsides is that it’s highly visible in the photos. This means I have to Photoshop out the rig during post processing. To minimise the complexity of the editing I’ve positioned the rig such that it obscures as little of the car as possible – sky suddenly seems easy to Photoshop when the alternative is compound reflective curves on a car’s fender!

As it was out of the camera

This is how it all starts. I open the file in photoshop – not much to explain about this step…

After removing the rig from the photo

This is the only difficult step, and unfortunately a full tutorial is beyond the scope of this post. Using a combination of the clone tool, and slicing and shaping other areas of the car, I remove the rig from the photo. So I’ll start by cloning out the easy parts – sky, constant gradients, etc. Always working on a new layer – I’m a huge believer in non-destructive editing.
Sometimes cloning is enough, but often there will be tricky parts that are almost impossible to replace by cloning alone. These will require you to reconstruct the image – I will take slices from the background image of similar sections (such a the carbon-fibre texture on the wing), and move them into position, then using the free-transform tool I’ll resize, rotate, and skew the slice until it fits where I want, then use a layer mask to blend it back in to the background layer. Using a combination of these techniques I’ve removed the car-rig from the shot.

Bluring out the reflections of the rig

We could stop there, and to be honest most people probably wouldn’t notice what’s wrong with the image…. but if you look carefully, you’ll see that the reflection form the rig is still on the car, which ruins the illusion of speed. Removing this reflection is easier than you’d think – I duplicated the background layer, applied a motion blur in the same direction as the real motion blur, and blended this back in over the reflections. The blur does a convincing job of hiding the reflection, while still retaining the shape and gradients of colour on the car. -Another tip: Any time I add blur to an image I also add a tiny bit of random noise over the blur – this gets rid of the overly smooth effect the blur creates, and helps to seamlessly blend it back in the with the ‘grain’ of the original photo… it has the added bonus of also preventing banding when you save as a JPEG!

Using the curves too to selectively darken the photo

Now the image is at the same stage where most photos start – your standard post workflow would start from here. For me, that means tweaking the exposure. Being digital, I’ve exposed to the right (as bright as possible without blowing out important highlights – in this case I’ve probably overexposed a little too far). So I use the curves tool with a layer mask to bring the brightness back down. I pull the mid-tones and shadows down, then use the layer mask to restore areas that have gone too dark.

Two coloured tints are added

At this stage the image feels a little flat to me, so I use two photo-filters (basically coloured tints) to add some depth. I use a bronze-coloured tint on the right side of the photo (the rear of the car), to heighten the glow from the sun, and make it seem more like sunset. I then add a blue tint to the left side of the car, to bring out more of it’s natural colour. I use layer masks on both of these layers to control the areas that get tinted. This stage gives the exact same result as adding coloured gels before taking the photo would have, only much more controllable.

Finished off with an artificial vignette

I’m nearly done now. My final step is to add a vignette (darkened corners). This helps to draw the viewer’s eye into the middle of the frame, and also exaggerates the brightness and colours of the car. I always find it amusing that Canon invested a lot of money to design lenses that minimise vignetting, and I nearly always add some back into my photos…

So, there you have it, a high-level overview of the post-production of my latest photo. I hope someone finds it useful! I’d welcome any questions and appreciate any feedback or suggestions you might have in the comments.

Cheers