Canon G5X Field Review | Autofocus & Depth of Field

In a previous article about the G5X I looked at the rationale behind choosing a compact camera and the reasons why I chose a Canon G5X.

Since then I’ve received several e-mails from readers who are still fairly fixated on the minutiae of resolution and sensor output. In order to ground this discussion again, we’re talking about compact cameras – cameras which we’ll use as small and convenient tools for recording personal outings and family gatherings. Therefore the watchwords are ‘fun’ and ‘portability’.

All of the photos below were shot in RAW since that’s where I spend my time. They’ve received exactly the same processing preset in LR, the same one I use on all of my bigger sensor images – a simple curve boost and a touch of vibrance.

Canon G5X Colour

Colour output is vitally important to me – and it’s one of the reasons I couldn,t warm to my Sony RX100ii, which seemed clinical and not that easy to process to a pleasing state (given that I’m a RAW shooter). This little G5X on the other hand outputs neutral but rich colours. Auto white balance is impressively accurate in almost every situation. Accurate WB (whether using auto or a fixed Kelvin value) saves me no end of time later on in postprocessing.

Canon G5X Autofocus DOF 1100px-1053.jpg
Canon G5X Autofocus DOF 1100px-1117.jpg
Canon G5X Autofocus DOF 1100px-1178.jpg

Canon G5X Focus

Fast and accurate focus was firmly on my wish list in Part I of this article. And I have found the focusing speeds to be snappy, even in quite low light. The G5X has a contrast detect autofocus system so it may struggle in dim light (or with heavily backlit subjects) over areas with insufficient detail – although plenty of other cameras do as well. Overall, don’t expect the focusing to be as accurate as a good system camera. At one stage I couldn’t get my new camera to focus on anything, until I discovered I’d accidentally left it on the macro setting.

Lastly, the size of the chosen focus box can be altered and it does have a small setting, but this is nowhere near as small a focusing point as you’ll find on a DSLR or similar (sometimes these things can be improved in later firmware updates). As such, the camera will lock focus on whatever it feels is an appropriately contrasty area within that focus box, which may not be the centre. Therefore you might occasionally find that the camera focuses behind your subject.

Continuous autofocus can be useful in some situations but all in all I found it a pain – with cameras like this zone focus can be much more reliable for moving targets.

Canon G5X Depth of Field

A Canon APS-C camera has a slightly smaller sensor than full frame and hence is designated a ‘crop factor’ (or focal length multiplier) of x1.6. Similarly, a Micro 4/3 camera has a sensor which is a little smaller than APS-C and has a crop factor of x2. A 1 inch sensor like that of the G5X has a crop factor of x2.7. With an increasing crop factor depth of field becomes less shallow, but you can still gain pleasing subject isolation.

To put things into perspective a Micro 4/3 camera at F1 .8 will give depth of field broadly equivalent to F3.5 on a full frame camera. A 1 inch sensor camera shot at F1.8 will look like F4.8 on full frame. Similarly, at F2.8 your 1 inch compact camera will exhibit depth of field equivalent to about F7.6 in full frame terms.

The images below were taken at 84mm (in FX terms), the target was about 3 feet from the background and I was about 3 feet from the target. The images were shot at f2.8, f4.0 and f5.6 respectively:

Since my pre-existing handbag camera was a GM1 with a small f3.5 to f5.6 pancake zoom, at the longer zoom ranges that combo will be broadly equivalent to f11.2 in 35mm terms (so it wasn’t that great for portraits). Therefore the G5X is a better prospect if shallower depth of field is important to you. In fact the G5X is very nice for half shots and head shots, giving a good degree of subject separation at f2.8 at longer focal lengths. You can enhance that separation even more if you place your subject further away from the background.

1/2000 f2.8 ISO125 36.8mm

1/2000 f2.8 ISO125 36.8mm


Canon G5X Close-up functionality

For close-up photography we need to be stopping down the lens a little since depth of field is minutely thin at wide apertures and close working distances – even on smallish sensor cameras. On the G5X f4 is broadly equivalent to f10.8 on a full frame camera.

If you’ve seen my previous article on this camera you’ll know that at very close focusing distances images become soft and hazy at f1.8 (you’ll be pleased to know that at normal working distances centre sharpness at f1.8 is pretty good). Stop down a bit like any normal person would (f4 to f5.6 appears to be optimal for sharpness and contrast) and your close-up images will look great.

The point of focus is the XI numeral. You’ve probably realised that I’m a watch enthusiast (a lot of photographers are, for some reason) and watch dials make perfect subjects for testing lens sharpness and close up capability. The lens was approximately 3 inches from the watch. The pictures below were all shot at ISO500 and the widest lens setting (24mm). The first image was shot at f1.8 (yuk), then f2.8, f4 and finally f5.6.

Canon G5X Viewfinder and LCD

Many compact cameras have viewfinders and most of them are pretty useless – too small to give you anything but eyestrain. Fortunately the G5X has a very good quality and quite large EVF. A viewfinder is helpful on bright days when it’s difficult to see the rear LCD. More importantly perhaps, a viewfinder also acts as a stability aid since it helps you to brace the camera on your face when shooting in lowlight conditions. I tested both the LCD and EVF on a bright day and I found that the LCD (which is superb) performed well with the brightness turned up one notch from centre. The brightness of the G5X EVF can be adjusted independently but at its brightest setting there may be times when the LCD is more useful.

The tilt and turn articulated rear LCD screen pulls out to the side where it can be swivelled and turned – ideal for people who love doing selfies.

The viewfinder automatically turns itself on when you place your eye to it, or you can turn off the LCD completely in the menus.

Canon G5X Metering

Very accurate under pretty much every situation. I found I needed to use exposure compensation less with the G5X, versus a DSLR or other system. Compact cameras like the G5X are aimed at an enthusiast audience and hence tend to have higher levels of compensation built into the camera’s software engine.

Canon G5X Battery

Unlike the Sony RX100ii I used to own, the G5X comes with its own charger and also offers USB charging.

The battery is small and is rated to give around 230 photographs. Having said that, how much juice you get out of your battery will depend on how often you’re zooming your lens, how long the camera is turned on for, if you’re doing bits of video etc etc. Good third-party replacements are affordable from Amazon and it’s always worth having a couple of spares in your pocket.

Canon G5X Continuous Shooting

This is quite respectable when it comes to JPEGs (around 5.9 frames per second) but it’s a woeful one frame per second if shooting RAW.

Canon G5X Video

I’m ashamed to say I’ve never made a film – but the G5X is highly rated by vloggers and there are plenty of You Tube reviews to support this. I do in fact want to make a video – even if I never make one again. I’ll grit my teeth and try to do something at some point. If top quality video is a main priority for you, you may prefer a camera which offers 4K functionality.

Canon G5X Flash

The G5X has a small built-in flash which is surprisingly powerful for what it is. It isn’t tiltable like the flash on the Sony RX100 cameras or the Canon G7X, but there is a hot shoe on which you can mount a dedicated flashgun, Canon specific TTL trigger, or generic radio trigger. These days I can’t be doing with a camera which doesn’t have a hot shoe, or a slow x-sync speed.

Talking of X-Sync speeds, the G5X has a leaf shutter and can synchronise with flash up to 1/2000 second. That’s handy for fill using the built-in flash, and incredibly liberating when using small flashguns outdoors during the day (providing your triggers support a high sync speed). It also means you can use a wide aperture for shallower depth of field if you want to (traditional syc speeds of around 1/250 sec demand very tight apertures in bright daylight, and hence powerful flash units).

One restriction is the fact that when you set your ambient exposure, assuming you might be underexposing by a couple of stops for drama, the scene in the EVF or LCD is very dark and you can’t see to focus accurately. With a DSLR you won’t have this problem since you’ll be using an optical viewfinder rather than an electronic one.

Canon G5X Review Verdict

Overall I would give this camera a healthy 4/5 for its impressive combination of features and quality. Compact cameras like this are about smallness, convenience and fun, and in that regard the G5X doesn’t disappoint. But it’s also a sophisticated camera and it’s well-suited to very advanced users.

If you specifically want a larger sensor then there is the Panasonic LX100, but it’s a bit less pocketable. If absolute pocketability is your priority then the Canon G9X is the smallest of the lot, at the expense of lens speed. If small size and 4K video is on your list then the latest Sony RX100 will cover that.

One of my arguments for always carrying a small camera is that you won’t miss important picture opportunities. In fact that’s how I’ve gathered many of my award-winning images over the years. Would I enter the pictures taken with the G5X into top industry shootouts? Of course I would. My tests have shown that out and about in good light there is very little difference between the images my G5X generates and those from many larger sensor cameras (notwithstanding lens vagaries). But that is subject to the caveats of good technique, and output size.

As with most compact cameras there are some compromises – the lens is good but it’s soft around the edges at the widest settings, it’s also prone to flare and purple fringing. But otherwise, in the centre it’s as sharp as some of my best kit lenses. You can’t expect the close up or lowlight focusing to be as good as a quality system camera though. And the RAW burst speed is hopeless. But it has some fantastic features which are really useful for me – such as the high X-sync speed, the built-in ND filter, excellent dynamic range, the intuitive handling and the glorious colours. Thanks to the combination of sensor and lens, the pictures have a depth which you would normally only see from its larger sensor counterparts. But if you’re going to expect it to achieve all the things you can do on your DSLR, then I don’t think a small compact camera is for you.

So am I keeping the G5X? Definitely. My priority came down to handling – I can take the G5X out with me and I don’t even need to carry a pair of reading glasses, the process of changing settings is completely painless and very quick. It’s a joy to use. My GM1 always had a small kit lens on it in order to be compact enough to fit in my handbag. That means a slow aperture in all situations, and in low light correspondingly high ISO values. You can claw that back (and more) thanks to the G5X’s fast lens and excellent stabilisation. As an all-round personal use travel camera this little thing hits the mark very nicely and I’m pleased I bought it.