Why do my photos have such poor quality?

Question

I've been using my camera Sony DSC HX100v for years. Lately, some photos have really poor quality (photos taken before and after on the same day look fine). I usually use automatic mode only, so I am wondering if that is a sign for my camera not working properly anymore?

Edit

Here's the details from exif.regex.info:

EXIF — this group of metadata is encoded in 152 bytes (0.1k)

Exposure Time 1/2000
F Number 5.60
Exposure Program Program AE
ISO 3,200 Sensitivity Type
Recommended Exposure Index
Recommended Exposure Index 3,200
Exif Version 0230
Components Configuration Y, Cb, Cr, -
Compressed Bits Per Pixel 2
Brightness Value 9.73984375
Exif Image Size 4,608 × 3,456
Exposure Compensation 0
Max Aperture Value 2.8
Metering Mode Multi-segment
Light Source Unknown
Flash Off, Did not fire
Focal Length 4.8 mm
Contrast Normal
Exposure Mode Auto
Maker Note Sony (12,324 bytes binary data)
User Comment
Flashpix Version 0100
Color Space sRGB
Interoperability Index R98 - DCF basic file (sRGB)
Interoperability Version 0100
File Source Digital Camera
Scene Type Directly photographed
Custom Rendered Normal
White Balance Auto
Digital Zoom Ratio 1
Scene Capture Type Standard
Saturation Normal
Sharpness Normal
Lens Info 4.8-144mm f/2.8-5.6
Print Image Matching (28 bytes binary data)
Compression JPEG (old-style)
Image Description
Make SONY
Camera Model Name DSC-HX100V
Orientation Horizontal (normal)
Resolution 72 pixels/inch
Thumbnail Length 11,261
Y Cb Cr Positioning Co-sited
Exif Image Width 1,440
Exif Image Height 1,080
Thumbnail Image (11,261 bytes binary data)

Answer 1

I think the issue is explained by the first four lines of the EXIF information:

Exposure Time 1/2000
F Number 5.60
Exposure Program Program AE
ISO 3,200 Sensitivity Type

For this particular photo you used the P, or Program, mode of your camera.
The actual behaviour varies between cameras, but the baseline is that you let the camera decide what shutter speed (exposure time), aperture (F number) and sensor sensitivity (ISO) to use to get a properly exposed photo (see this previous question on their relation to each other).

The camera chose to use a very short exposure time, which required a higher sensor sensitivity (an ISO of 3200). A higher ISO often correlates to more noise in the photo, which the camera tries to correct with noise reduction technology.

As your camera is quite old, the sensor is not very developed, high ISO results in relatively high noise, which in turn requires a lot of correction.

This correction is probably causing the "really poor quality".
I don't think this is a sign of camera failure, just a sub-optimal choice of exposure settings.

To prevent this in the future try to limit the maximum ISO the camera can choose, especially when you know you will be shooting in broad daylight.
The camera will then choose a longer exposure time, requiring a lower ISO and less noise reduction.

Answer 2

It's both the gear and your (lack of) technique.

First off, your camera is a 10-year-old model superzoom bridge camera that uses a small 1/2.3"-format sensor. The smudging and color blocks you see when you magnify your file are basically due to having such a high ISO (3200) setting with such a small/old sensor. You probably don't want to go much above ISO 800 unless there's a good reason. If you have the image quality set to higher compression on the JPEGs that might be exacerbating the issue.

But your technique of simply putting the camera on an automated exposure mode (programmable auto) and handholding are also at fault. Your camera's auto-exposure system chose a very high ISO (3200) and shutter speed (1/2000s) combination possibly assuming you'd be using the superzoom lens at its supertelephoto end, or as if it were set for a low-light (e.g., night time) scene. If you're using a scene mode, you might want to check that it's on landscape for landscape shots like this.

And your camera has the PSAM modes and a tripole mount hole. You can put the camera on a tripod to hold it steady, and explicitly set the camera to use a much slower shutter speed and ISO, while still using a smaller aperture for deep depth of field without getting any camera shake blur from handholding.

See also:

• What is the "exposure triangle"?
• Why are my photos not crisp?