Typha latifolia -- broad-leaved cattail, South Boulder Creek trail, 2015. The upper picture was taken with a Sony α6000 camera and a 310-mm (35-mm equivalent) lens; the lower with a Canon SX280 point-and-shoot camera and a 600-mm (equivalent) lens. Consumer Reports rated the image quality of both cameras "Very Good," but they cautioned that you cannot compare ratings across camera types.
So I decided to compare the 2 cameras myself. The 2 images are cropped to show the same areas and reveal individual pixels. The SX280 image shows some electronic noise and a bit of chromatic aberration. The α6000 image, though taken at half the focal length, is far better. The α6000 may show better gray scale, but that may be an artifact of the exposure, which I have not compared. Nevertheless, if you do not want to push the limit, the SX280 image is very serviceable indeed.
3 Comments
Roger Lambert · 11 November 2015
dpreview watch out!
fusilier · 11 November 2015
Somewhat off topic but.... I'm an old chemistry guy (No, not THAT troll) so I still have problems getting my head around digital specs. I still think in terms of Plus-X in Dektol as better resolution than Tri-X pushed to ASA 800.
Is there any place to get a handle on how it comes about that 24 MPixels with a 55-210 mm zoom from Brand C at $800 is not better than 16.3 Mpixels with a 40-150 zoom from Brand O at $1200?
fusilier
James 2:24
Matt Young · 11 November 2015
Is there any place to get a handle on how it comes about that 24 MPixels with a 55-210 mm zoom from Brand C at $800 is not better than 16.3 Mpixels with a 40-150 zoom from Brand O at $1200?
Depends on the width of the sensor and therefore on the width of the pixel. For example, project the pixel through the lens at its longest focal length. Calculate width of a single pixel in object space at some arbitrary object distance such as 10 m. To do so, you will have to know the width of the sensor and the number of horizontal pixels. In the absence of noise and lens aberrations, the one with the smaller pixel (in object space) will have the better resolution.
You will see in my 2 pictures that the pixels have about the same width, even though one camera has a substantially longer (35-mm equivalent) focal length. But the less expensive camera has a smaller sensor, so more electronic noise. Pixel width is not all to consider, but perhaps it explains how 2 very different cameras, such as your C and O, can arrive at roughly similar image quality.
Is that what you were asking, or am I being too simplistic?
3 Comments
Roger Lambert · 11 November 2015
dpreview watch out!
fusilier · 11 November 2015
Somewhat off topic but.... I'm an old chemistry guy (No, not THAT troll) so I still have problems getting my head around digital specs. I still think in terms of Plus-X in Dektol as better resolution than Tri-X pushed to ASA 800.
Is there any place to get a handle on how it comes about that 24 MPixels with a 55-210 mm zoom from Brand C at $800 is not better than 16.3 Mpixels with a 40-150 zoom from Brand O at $1200?
fusilier
James 2:24
Matt Young · 11 November 2015