Out of simple curiosity, do DSLR cameras produce an inverted image on the sensor, with the image being flipped by software?

 I've dabbled with astronomy prior to my current interest in photography and own a 3 inch refracting telescope. Here the object lens produces an inverted image. An extras lens could be introduced to provide an upright image but this would reduce the amount of light that could be captured.

I use a Panasonic Lumix GX80/GX85, but would assume all digital cameras would operate in a similar fashion?


Many DSLRs will work with lenses made for film cameras (my Pentax K10D does). That should tell you all that you need to know. Also, including image-erecting elements would be utterly pointless, since all that they do is (effectively) rotate the image by 180 degrees. So, yes, the image is inverted, just like in telescopes (and film cameras). Amateur astronomers sometimes use erecting prisms for convenience when observing, and accept the slight degradation in optical performance that they entail.

  • Unfortunately I don't have any alternate mounts for my micro four thirds, otherwise I would have tried this. Thanks – MiguelH Jul 1 '19 at 10:25

Yes, the image is inverted.

In case you wonder, the big protuberance at the top of SLRs (film or digital) is a pentaprism (a pentamirror in lesser cameras) that straightens up the image for the viewfinder.

But there is no explicit rotation by software, you just have to decide how you map the sensor to the final file.

  • The image is also flipped left-right, which the pentaprism/mirror also corrects. Maybe the left brain handles the right side because it also sees the right side. It would be too confusing to see the right side, but control the left (and vice versa). – xiota Jul 1 '19 at 10:35
  • @xiota We made do with waist level viewfinders for decades. – Michael C Jul 1 '19 at 15:00
  • There is a little more to it. The reflex mirror does invert the image to a waistlevel viewfinder, but it is still reversed left to right (like a right angle prism on a telescope). This often works well enough, but is a bit awkward to follow motion with it A regular pentaprism on a SLR reflects it twice more, remaining non-inversion at eye level, but it is still reversed left to right. So instead, the pointy roofprisims actually used on SLR also reverse it laterally once, so it becomes perfect. There is a lot going on up there. A mirrorless viewfinder must flip the image with software. – WayneF Jul 1 '19 at 20:07

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