Smartphone – Sensor Size Impact

In addition to fundamental differences between the lenses of smartphones and DSLRs, there is another performance-impacting element to consider, the camera’s sensor. All else being equal, bigger is better – and DSLR sensors are much bigger. What’s the potential impact? Side-by-side images at end tell the tale.

A small image sensor’s photosites (pixels) are smaller than those of a larger sensor if both sensors have the same number of megapixels. Duh…

  • A photosite’s size impacts image quality.
  • Larger sites result in the potential  (not a guarantee) for:
    • Less noise (mainly in shadows and at high ISOs)
      • See image at end of post full size (especially upper right)
    • Better dynamic range (range of tones which a sensor can capture)
    • Improved low light performance
    • Better overall image look and feel
      • If two sensors have the same apparent noise when viewed at 100%, the sensor with the higher pixel count will produce a cleaner looking print
  • The improvement over small sensors may be less than you think
  • Smartphones are getting better, but the laws of physics are fixed
  • The tradeoff is between image quality and convenience
  • If you’re happy with your camera’s image quality, that’s all that matters

For illustrative purposes here are the sensor size data for several cameras. They each have different sensor sizes (the D800E has 50X the area of the iPhone) and formats (full frame, APS-C & smartphone). If you shoot with another model/brand, your camera’s specifications will still be similar.

iPhone 6 Plus

  • ƒ/2.2 aperture, 35mm equivalent focal length of 29mm – both fixed
  • 4.8 x 3.6 mm (17.28
    • Full Frame DSLR is 49.9X larger in area
    • APS-C DSLR is 17.4X larger in area
  • 8 MP CMOS
  • 3280 x 2464, 1.5µ pixels (this is a pixel’s physical size)
  • 4:3 aspect ratio

Nikon D300

  • 24 x 15 mm APS-C format
  • 12.3 MP CMOS
  • 4,320 x 2,888, 5.49µ pixels
  • 3:2 aspect ratio

Nikon D800E

  • 35.9 × 24 mm Full Frame format
  • 36.3 MP CMOS
  • 7,360 × 4,912, 4.88µ pixels
  • 3:2 aspect ratio

Here are two images – one iPhone & one D800E (RAW) – with nearly equal settings:

  • Focal length: 29mm to match the iPhone’s fixed length
  • Aperture: f/2.2 (iPhone fixed value); f/2.8 (nearest D800E lens value I had)
  • ISO: 800 for both (to illustrate noise, if any is visible)
    • iPhone 645 camera app used so that ISO could be set
    • 645 has several B&W and color films; one must be selected
      • Selection affects the color & contrast “look”
  • Both shot on tripod with good natural light
  • Cropped in post-processing
    • No other alterations in post
    • D800E RAW to JPEG via Adobe Camera Raw in Lightroom
  • Can you tell which is which (I’m not telling)
    • 36.3 vs 8 MP, one sensor 50X larger than the other (pixel size 3X larger)
    • Either is fine for a Creaking Bones “Fridge-Photo” IMO

Click for full screen-plus; check the noise & dynamic range effects (upper right)


Books on Bookshelf

About 10% of my photo library

Did the full screen view show you which image was which?

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