Why (small-sensor) digital compact cameras suck

I don’t like small-sensor cameras and I’m sceptical of high pixel density sensors in general. I recently purchased a Canon A495 compact for a gift. It cost only A$89 and I was interested to evaluate its performance. I found the A495 can produce satisfactory results in good light. Most social photography is under low-light conditions however (especially indoors) and here compact digital cameras produce noisy images. I think this a general problem for cameras with small sensors and small aperture lenses. Even cameras three or four times the price of the Canon A495 have poor low light performance.

A confession

I must confess that I’m a “pixel peeper”. I evaluate my digital photos at 100% to check focus, sharpness and noise. I use digital SLRs and quality lenses. I aim to get a good results at capture and nowadays I rarely use software for correcting photos (except for white-balance adjustment in RAW).

Introduction

Most camera reviews provide excessive details on camera hardware and functions. What really matters in the end is whether the photos are any good. In this review I examine image quality only.
To start, here are some photos to illustrate typical performance of the Canon A495:

Wheelie bins. Photographed in sunlight and a good result. Aperture f/5.8, shutter 1/250 second, ISO80.

Bottle brush. Macro photograph in sunlight. Red and blue channels are clipping but there are no colour artefacts and the detail is good. A satisfactory result. Aperture f/5.8, shutter 1/320 second, ISO80.

Tin shed with harsh back-lighting. A bad result from a cheap and likely plastic lens. Aperture f/5.8, shutter 1/250 second, ISO100, exposure compensation +1.0.

Low-light performance

To examine low-light performance I photographed text and plates from a book. You’ll need a tripod for these tests to avoid camera shake and use the self-timer.

Low light test at 6 MP, high ISO. 100% crop. There was strong afternoon light coming through a window but the book was in the shade. Levels adjusted in software to increase brightness. Aperture f/4, shutter 1/60 second, ISO800.

Low light test at 10 MP, high ISO. 100% crop. Levels adjusted in software to increase brightness. Photo resized 77% to match the resolution of the 6MP image. Downscaling (averaging pixels) should reduce noise and not handicap the 10MP image. Aperture f/4, shutter 1/60 second, ISO800.

I found that 6 MP photos were cleaner than 10 MP (maximum resolution) at ISO 200, 400 and 800. The 10 MP photos showed more chromatic noise. At low ISO differences were not apparent. I recommend to use the Canon A495 on the 6MP setting where resolution is adequate and image quality is generally better.

Portrait tests

Here are some more low-light tests:

Indoor portrait test at low ISO. Colour balance adjusted in software (but skin tones are still not satisfactory). 10MP resized 25% and 100% crop. Aperture f/5, shutter 1/3 second, ISO80.

Indoor portrait test at high ISO. 10MP resized 25% and 100% crop. Colour balance adjusted in software. Aperture f/5, shutter 1/30 second, ISO800.

Indoor portrait test in Auto mode and Auto flash. 10MP resized 25% and 100% crop. Levels adjusted in software to reduce brightness. Aperture f/5, shutter 1/50 second, ISO640.

Even at 25% reduced size, the low ISO photo is clearly more detailed. I think you could even see a difference in 6 x 4 inch prints. Nobody is going to routinely use a tripod for taking photos indoors however.

The common solution for low light is to apply flash. This resulted in harsh lighting and a shadow. The camera has selected a high ISO for the flash to better illuminate the room and avoid the “rabbit in the headlights” look. Unfortunately, detail is lost at higher ISOs and the camera produces a rather noisy photo with harsh lighting. I’ve seen lots of garbage photos like this from compact digital cameras.

To get better flash photos indoors with the Canon A495 I would try Program mode, limit sensitivity to ISO400 and turn on Auto or Forced flash. Even better, ask you subject to stand in the window light (if it’s daytime) and shoot with flash off.

Conclusions

Consumer digital compact cameras deliver good results only in good light. Small-sensor cameras have poor low light performance and we often have to fix photos in software with additional noise reduction and other corrections. If you think I’m wrong and are confident that your new $300 dollar consumer pocket camera produces quality images under all conditions, I recommend to perform careful low-light evaluations for yourself.

Finally, it is possible to get pleasing images from digital compact cameras and here are some better results from my tests:

Washer woman. Here I forced the flash on which produced a pleasing contrast between the subject and the slightly underexposed background. Aperture f/3, shutter 1/800 second, ISO80.

Tin shed 2. Close focussing can be used for creative effect but most people shoot ordinary snaps and would not experiment with this capability. Aperture f/5, shutter 1/1500 second, ISO80.

Leaf detail. Some interesting macro photographs can be taken with the A495 although depth of field is rather shallow. Aperture f/4.5, shutter 1/800 second, ISO100.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: