Photo quality from the W650 is very good for its class, but like most compact cameras, it still stumbles at higher ISOs. Photos at ISO 80 and 100 are relatively sharp with a decent amount of fine detail and low noise. At ISO 200, subjects soften some, losing sharpness and fine detail. At ISO 400, images get noticeably softer and there's an increase in noise in darker areas of images. If you're printing at and below 5x7 inches and are not doing heavy cropping, the results are usuable. Photos at ISO 800 and 1600 look painterly from noise reduction, so subjects will appear soft and smeary; it's even worse at ISO 3200, making it unusable.
Viewed larger, you can more easily see noise and loss of detail start at about ISO 200. Basically, any photo taken indoors without a flash or in low-light conditions will likely result in a soft and somewhat flat-looking photo.