Review – Canon S90, Part 2: Using the Camera

by Miserere

  

⇐ Part 1: First Impressions

Since I started writing my initial impressions I’ve continued playing around with settings and even read through the manual (gasp!); I’ve also got more comfortable with the camera, which gives me confidence when shooting. I’m still not at the point where the camera disappears in my hands, but I know that day is rapidly approaching.

Now let me address different aspects of shooting with the S90.

  

LCD Screen

When you have a camera that lacks a viewfinder, a good LCD is important, and in every respect the S90’s screen excels. It is crisp and bright; so much so that I have it set to its lowest brightness and have no problem using it in bright sunlight. The antireflective coating no doubt helps in this mission. I don’t know how resistant it is to scratches (I hope you’ll understand that I don’t take a nail to it to find out), all I know is that there are no marks on it yet after about 1 month of living in my pocket, often with my BlackBerry. For those of you who like to wear polarised sunglasses while shooting, here is the low-down: The LCD screen is horizontally polarised, so brightness is maintained while shooting in landscape format; if you rotate the camera to portrait, however, brightness decreases considerably

Photos displayed on the LCD look great, and you can cycle through them with either the left/right arrows (with each photo popping up immediately) or with the rear wheel (which shows the photo shrinking as the next one flies in). When you press the up arrow in playback mode, you access the playback menu that allows you to look at photos by date, by category (a type of tag you can set in-camera) or jump them by 10 or 100. Also in playback mode, you can press MENU to start a slideshow and access options for that photo (erase, protect, rotate, add category, crop, correct red eye, resize, etc, etc; all for JPEGs except ‘category’).

And speaking of playback, it can be used even when the camera is off. Just keep the play button pressed for 1s and you can browse your photos without the rest of the camera turning on or the lens extending.

And here is what the screen looks like while shooting. It appears cluttered, but for me most of it just goes away when I’m shooting; I only pay attention when I need to consult the histogram or know the value of a setting. Basically, I see through it unless I need to look at it.

Allow me to decipher the less-obvious features for you: The big M tells me I’m in Manual mode; the MF indicates Manual Focus; on the bottom, the green circle with holes next to the current shutter speed indicates the rear wheel is controlling it; the two green brackets to the right indicate the lens ring is controlling the aperture, currently set to f/2; the two square brackets in the lower-left corner tell me I’m metering in center-weighted average mode; finally, the scale running along the bottom half of the right side is the light meter, which in this case is telling me I’m 1 1/3 stops overexposed. The dark bars along the top and bottom delimit the 2:3 aspect ratio, and the grid is the famous rule of thirds, which I actually use to get straight lines straight. The center square is the area that gets blown up to roughly twice the size to aid in manual focusing. last of all, that little camera icon with the arrowhead on top tells me which way is “up”; turn the camera 90° in either direction and the icon will turn to point up. But if you turn the camera upside down, the arrow will point down.

  

Shooting Modes

Shooting modes available are the standard M, Av, Tv, P and AUTO, plus C (custom mode), low light and SCN (scene mode, with a hefty 17 settings: portrait, landscape, night snapshot, kids & pets, indoor, sunset, night scene, fireworks, beach, underwater, aquarium, foliage, snow, color accent, color swap, nostalgic and stitch assist). Movie recording is accessed as another mode on the dial.

Scene mode names should be self-explanatory. Some of them are quite pleasing, such as the nostalgic scene (which offers 5 different “nostalgic” looks), while others (such as snow, or fireworks) will be superfluous to any experienced shooter who understands camera settings. The real downside is shooting is completely automatic in SCN mode, so the photographer can only control the focal length, thus rendering this mode useless for RAW shooters.

Another interesting mode is Low Light. Again, all you can control is focal length, while ISO varies automatically between 320 and 12,800. That’s not a typo. What the camera does is bin up pixels 2×2, so the output image is only 2.5MP in size (1824×1368 pixels), or 1/4 the native resolution, thus gaining 2 stops in effective ISO range. Needless to say, the resulting image is a JPEG. This “gain” in ISO can also be achieved by downsampling a RAW file in postprocessing, and likely with better results.

As far as I can tell (because the manual doesn’t), the only modes that give you RAW output are Av, Tv, M and P.

Now for the modes I use the most: Av and M, the former for general shooting, the latter for low light shooting.

Av: I seem to have settled on using the lens ring for aperture, the rear wheel for EV comp., the shortcut key for AE-L, and I change ISO through the FUNC. SET key, who’s first item is ISO, thus acting like a shortcut key (see screen grab below).

M: I’m still battling for the best way to set up Manual mode for low light shooting. I am undecided between the method I described in part 1 of this review and the following: Lens ring for aperture, rear wheel for shutter speed, shortcut key for AE-L, and I change ISO as in Av above, through the FUNC. SET key. Neither are perfect, both have their drawbacks. For slow shooting, either works fine and I have no complaints, but for candid shots in low light where brightness changes quickly, I yearn for auto ISO in M mode. A quick way to set the correct exposure in M mode is to half press the shutter, then press the up key; the camera will set aperture and shutter speed to what it considers appropriate.

  

Focal Lengths and Maximum Aperture

I complained in part 1 about how slow this lens was towards the long end so I thought it would be useful to list here how the maximum aperture changes with focal length in order to help owners better choose what focal lengths to use if they want to maximise light gathering.

Canon S90 maximum aperture
for each focal length

F.L. (mm-equiv.)	Max. Aperture (f/)
28	2
32	2.2
35	2.5
40	2.8
50	3.2
60	3.5
70	4
85	4.5
105	4.9

One thing the LCD display does not tell you is what focal length you’re zoomed to. The zoom lever moves in fixed steps, each of which corresponds to the values in the table above, except there’s an extra step between 40mm and 50mm where the max. aperture does not vary and stays at f/2.8. If you are really fussy about what focal length you’re shooting, you can assign the lens ring to zooming. When doing this, each click of the ring corresponds to 28mm, 35mm, 50mm, 85mm and 105mm; these values show up on the LCD so you know which one you’re choosing.

  

Auto ISO

It would be so nice to have control over the ISO range available in auto ISO, or at least the maximum ISO; major blunder for Canon here. Furthermore, the S90 is rather quirky with respect to what ISO ceiling it chooses in each shooting mode. I’ve produced a table below listing what that ceiling is for every shooting and scene mode. This information is not given in the Canon S90 user manual and is not available anywhere else that I’m aware of.

Canon S90 maximum ISO in Auto ISO mode
for every shooting and scene mode

Scene Mode	Max. ISO	Shooting Mode	Max. ISO
Portrait	400	AUTO	1600
Landscape	400	P	1600
Night Snapshot	1600	Tv	800
Kids/Pets	800	Av	800
Indoor	1600	M	–
Sunset	400	Low Light	12,800*
Sunset	400
Night Scene	80
Fireworks	80
Beach	400
Underwater	800
Aquarium	1600
Foliage	400
Snow	400
Color Accent	800
Color Swap	800
Nostalgic	800

*: Images taken at lower resolution of 2.5MP.

  

White Balance

You can manually select from the typical list of white balance light sources (plus “underwater”, which is a first, for me), or custom set it using any white (or grey) surface in your scene. Each WB setting can then be warmed up or cooled down to taste.

So far I’ve just used auto WB because it just works. Even though I’ve shot in RAW, I’ve only had to reset the WB in postprocessing once when shooting indoors in low light, and with mixed lighting conditions.

  

The Flash

I’m finding the onboard flash quite neat, and given my expectations for it (quite low), I’m happy about it. In Av and Tv you can set it to fire always, never, or slow synchro (Which is Canon-speak for “fill flash”); in P mode you can also choose “Auto Flash”. In all 3 modes you can control the flash EV comp. with a range of ±2 EV, in 1/3 EV steps. When shooting Manual mode, you have the option for flash on, or off; when on, you can to choose between 3 power output settings (even photographing an average room, I just used medium power).

  

Focusing

Autofocus: So far so good; I haven’t used so many P&Ss that I can compare AF speed, so all I can say is it’s slower than my DSLR, but faster than a tortoise, and certainly adequate for my needs. Cool feature: You can set AF to face recognition and it will try to find a face anywhere in the frame in order to focus on it; if it doesn’t find it, it focuses on something else and shows a green square (or more) around that area. I can see this feature appealing to mums and dads trying to get their kids’ faces sharp. Combine this with servo focusing (Canon-speak for continuous focus) and you can at least stand a chance against any 5-year old.

Manual Focus: In part 1 I said I wasn’t happy with manual focusing but would wait to start complaining about it. Good job I waited. Even better job that I read the manual while I was waiting. My main issue with manual focusing was that it appeared to turn off after reviewing an image; turns out you need to press the up arrow in order to make the rear wheel control focus again. Once in manual focus, hit the up arrow again, and the rear wheel reverts to its assigned duty (EV comp. or whatever). Of course, some may like using the lens ring for manual focusing—I tried that but didn’t like it. Here’s a nice trick: When in autofocus, you can focus on your subject, then, if you press the left arrow (which is the shortcut to set focus mode) while keeping the shutter button half pressed, the camera goes directly to manual focus, with the focus distance set to your subject. You can also autofocus, lift your finger off the shutter button, and then press the left arrow to access the focus modes, then scroll through the 3 options (macro, auto and manual) to get to manual. Pressing the left arrow while half-pressing the shutter you bypass this last bit completely. You can choose to have the center portion of the scene magnified to aid with manual focus. Manual focusing is not sticky, so if you turn the camera off, you’ll be in autofocus mode when you turn it back on; same goes for Macro focusing. I’ve happily figured out a workaround for this: Save manual focus to the Custom mode. I’ve configured my Custom mode to Av with Auto ISO and manual focusing. When in Custom mode, turning the camera on and off doesn’t unstick the manual focus setting.

Whatever focus mode you use, you can choose to bracket your focus automatically, whereby the camera will take 3 shots: one at the chosen focus distance, one slightly in front, one slightly behind. You can set 3 different interval sizes for the bracketed shots. This is a cool feature that I’ve heard many people ask for on DSLRs.

Now here comes a focusing gripe: Although the camera does remember what distance it was focused to when you turn it off, then on, it forgets if the LCD turns off automatically due to the powersave feature. Here’s the funny thing, if your camera is set to meters, it will revive focused to 5m; if it’s set to feet, it revives at 5 feet! There is some good news, the focus distance is one of the settings that is registered with the Custom mode, so make sure you focus to some useful distance before saving settings to Custom. I have the Custom focus set at 3m (or at least where I think 3m is) because that’s the hyperfocal for 28mm-equiv. f/2.

Canon S90 LCD in Manual Focus mode

Normal distance	Macro distance

As I’m interested in street photography, zone focusing is an important part of quick, unobtrusive shooting. A ‘Hyperfocal’ focusing mode would have been extremely useful, and I see its lack as a big hinderance, especially since it’s so easy to implement. Are you listening, Canon? The fact that the camera’s distance scale in MF only has marks at 1m, 2m, 5m and ∞ (10cm, 20cm and 50cm in macro) doesn’t help matters. In order to help all you zone focusing enthusiasts out there, I’ve created the following tables for you; I hope they’re useful. For your convenience, I created a PDF version of these tables, in both meters and feet: Canon S90 Depth of Field and Hyperfocal Tables. These tables will also be useful for any other camera with a 1/1.7″ sensor, such as the Canon G10 or G11; it will be approximately correct for the Panasonic LX3 and Leica D-Lux4.

Canon S90 hyperfocal distance for main
focal length and aperture combinations

	Hyperfocal Distance (m)
F.L.	f/2	f/2.8	f/4	f/5.6	f/8
28mm	3.01	2.13	1.51	1.07	0.76
35mm	–	3.32	2.35	1.66	1.18
40mm	–	4.37	3.09	2.19	1.55
50mm	–	–	4.78	3.38	2.40
85mm	–	–	–	9.78	6.92
105mm	–	–	–	14.9	10.6

  

Canon S90 Depth of Field for wide/normal focal lengths
at standard distances in Manual Focus mode

		Depth of Field (m)
F.L.	Dist.	f/2	f/2.8	f/4	f/5.6	f/8
28mm	1m	0.75 – 1.50	0.68 – 1.88	0.60 – 2.96	0.52 – 15.9	0.43 – ∞
	2m	1.20 – 5.96	1.03 – 33.3	0.86 – ∞	0.69 – ∞	0.55 – ∞
	5m	1.88 – ∞	1.49 – ∞	1.15 – ∞	0.88 – ∞	0.65 – ∞
35mm	1m	–	0.77 – 1.43	0.70 – 1.73	0.63 – 2.49	0.54 – 6.53
	2m	–	1.25 – 5.01	1.08 – 13.3	0.91 – ∞	0.74 – ∞
	5m	–	2.00 – ∞	1.60 – ∞	1.25 – ∞	0.95 – ∞
40mm	1m	–	0.81 – 1.30	0.76 – 1.48	0.69 – 1.85	0.61 – 2.84
	2m	–	1.37 – 3.70	1.21 – 5.73	1.04 – 25.1	0.87 – ∞
	5m	–	2.32 – ∞	1.90 – ∞	1.51 – ∞	1.17 – ∞
50mm	1m	–	–	0.83 – 1.26	0.77 – 1.41	0.71 – 1.71
	2m	–	–	1.41 – 3.43	1.26 – 4.86	1.09 – 11.9
	5m	–	–	2.45 – ∞	2.02 – ∞	1.62 – ∞

Now here are a couple of crazy ideas for camera manufacturers: First, give us a hyperfocal focus setting; second, give us a value of what distance the lens is focusing to in manual focusing, because a scale with 1m, 2m, 5m, and ∞ (or 2ft, 5ft, 10ft and ∞) just doesn’t cut it. Instead of a little bar going up and down, just give us the distance as a number, and while you’re at it, you could also give us the near and far focus limits of our DoF for the focal length and aperture we’re using. The maths aren’t difficult, and I’m sure the camera’s little brain can handle it.

  

Shutter Lag

Shutter lag is one of the most important properties for a P&S, because historically we’ve been given P&Ss that allow us to make coffee during the time it takes them to take the shot after pressing the shutter release. Not so with the S90, not even The Flash could get away with making coffee. There is clearly some lag when using autofocus, which is no worse than other P&Ss I have tried (not that many, to be honest) and is due to the focusing action, but when shooting in manual focus there is no perceptible lag.

In order to prove to myself that there really was no lag, I set a stopwatch running and took a photograph of it every 10s for 100s, measuring the delay between me pressing the button as the stopwatch hit 10s, 20s, 30s, and the time shown in each photo. The lag I measured is 160ms, which is in the same league as some DSLRs (high end DSLRs are in the 50ms range, while middle tier models are around 100ms). In real life, 160ms is just as good as instantaneous. Another gold star for Canon.

  

Shooting Speed

I don’t use the camera in servo mode (Canon-speak for continuous shooting), but I performed a quick test to see how quick it would shoot continuously, in both RAW and JPEG (but not RAW+JPEG—sorry, I have a life). I used a Kodak 4GB SDHC Class 2 card. I might redo the test with a 133x card to see if there is a bottleneck (because Class 2 isn’t very fast for an SD card) but I think the results will be the same because the shooting speed remained constant during the 10 consecutive shots I took for each test, meaning the camera’s buffer wasn’t getting filled up, meaning data was being written to the card efficiently. Or…the camera has no buffer and shooting speed depends only on the card speed (until the camera’s maximum processing speed is reached). I have not found any numbers for the buffer size on the internet, so can’t comment right now. What I can say is the JPEG shooting speed I tested is in line with Canon’s 0.9 fps claim.

One thing that hasn’t been stated anywhere is how ISO affects fps. If you shoot RAW, there is no appreciable difference; however, if you shoot JPEGs, you will get faster fps below ISO 800, while shooting at ISO 800 and above the camera slows down by around 40%. I assume this is because of the extra number crunching required to clean up noise at ISO 800 and beyond.

I also tested the time it takes for an image to pop up for review after the shot is taken. I’ve condensed all the results in the tables below.

Canon S90 FPS for various shooting modes

File Type	Focus Mode	FPS
		ISO < 800	ISO 800+
RAW	AF	0.5fps	0.5fps
RAW	MF	0.7fps	0.7fps
JPEG	AF	0.8fps	0.6fps
JPEG	MF	1.0fps	0.6fps

  

Canon S90 delay time between shot and review

File Type	ISO	Delay Time (s)
JPEG	<800	1.5
JPEG	800+	2.1
RAW	all	2.5

  

Taking Photographs

Let’s not lose sight of what this little black box was designed to do: Take photographs. How is this experience? For me, enjoyable. As I figure out how to best set up the camera for my type of shooting I also try to find workarounds for those things I don’t like. The unstickiness of manual focus was circumvented via the Custom mode, but other gripes cannot be avoided, such as not being able to zoom into the image preview that shows up after taking a shot. [UPDATE: Thanks to reader Thorsboe, we now know this isn’t quite true. In the setup menu one can choose the length of time the review stays up: never, 2-10s, and ‘hold’. ‘Hold’ basically means “forever”, and in this setting you can zoom in all you want. Just hit playback or half-press the shutter button to exit review mode.] [UPDATE 2: An anonymous tip in the comments tells us that pressing the FUNC. SET key during the review will “hold” the image, thus allowing you to zoom in. This seems like a better solution than the previous one.] But all in all, I’m finding it easy to take photographs the way I want to, and in general the camera manages to stay out of the way. It is also very responsive in MF mode, as evidenced by the short shutter lag, which allows you to photograph the decisive moment, not the decisive aftermath.

I could complain about its small size making it awkward to hold at times, but then I wanted a small camera to carry in my pocket always, so I’m still experimenting with different grips. In truth, shooting with one hand is very easy, it’s when I want to shoot at slow shutter speeds and hold the camera steady with two hands that I run into problems placing my left hand.

Can I use this camera to make Art, or will it be relegated to snapshot duties only? The answer to this question depends in part on the camera’s IQ, which I will address in part 3 of this review, but as far as controls and functions are concerned, the S90 is most definitely a camera to take real Photographs with, not just snapshots. Canon have to be commended for having catered to us photographers; while the camera does have plenty of gimmicky, newbie-friendly features, they are neatly hidden in the Scene mode and one never need encounter them unless one looks for them. Ridding menus of cute functions leaves them barren, with only the essential settings remaining. Furthermore, those intricately related to shooting can be controlled with a wheel or dial; yet those that are secondary are still only 1 click away.

Part 3: Image Quality ⇒