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360 Brain Teaser: how a Sony a6000 beat a Sony a7R for a virtual tour 360 photo

Sony a6000 vs Sony a7r for virtual tour
Sony a6000 vs Sony a7r for virtual tour

I took a 360 photo with 4 shots on the Sony a6000, and I took another 360 photo with 4 shots on the Sony a7R, but the 360 photo from the Sony a6000 has about 50% higher resolution.  How did that happen?  Try to figure it out before  I reveal the answer!

The Sony a6000 is a 24-megapixel mirrorless camera with an APS-C size sensor.  The a7R is a full frame camera with a 36-megapixel sensor.   I took a 360 photo with each of the cameras using a popular lens for 360 photos, the Sigma 8mm f/3.5 (using a Nikon to E-mount adapter).  In both cases, I used the Nodal Ninja 3 panohead (tutorial here), taking 4 HDR shots (3-shot bracket each) in a single row.  In each case, it took less than a minute to take the photo.  I stitched both panoramas on PTGui 11.

Here is the 360 photo with the a7R:

Here is the 360 photo with the a6000:

If you’re wondering why the a7R photo looks less detailed, that’s because it is in fact less detailed.

100% crops from Sony a7r 360 photo (left) vs Sony a6000 360 photo (right)
100% crops from Sony a7r 360 photo (left) vs Sony a6000 360 photo (right)

The a7R 360 photo resolution is 10546 x 5273 (55.6mp), while the a6000 360 photo’s resolution is 13,090 x 6545 (85.7 mp).  Can you figure out why?

HOW COULD THIS HAPPEN?

This is not a trick, and no I did not mix up the files. The Sony a6000 photo really is more detailed. The reason is because of the lens I used.  But didn’t I use the same lens?  Indeed I did, and that’s actually the reason for the discrepancy.

On the Sony a7R, the Sigma 8mm is a circular fisheye, while on the Sony a6000, the same Sigma 8mm is a cropped / partial circular fisheye.  For a 360 panorama, this works out to the a6000’s advantage because the Sigma 8mm uses a much larger portion of the a6000’s APS-C size sensor than on the full frame sensor of the a7R.  At the same time, because the Sigma still has a 180-degree field of view on the long edge of the sensor, it is still possible to capture a fully spherical 360 photo within a single row, with just 4 shots.

Sigma 8mm on a7R (left) vs. Sigma 8mm on a6000 (right)
Sigma 8mm on a7R (left) vs. Sigma 8mm on a6000 (right)

THE BOTTOM LINE

The point of this article is NOT that the Sony a6000 is better than the Sony a7R. Obviously the Sony a7R is better. However, to make the most of your camera, you need to use the RIGHT LENS for your camera body. In that regard, you can’t say whether a lens is good or bad without knowing which type of camera it will be used for. Therefore, when choosing a camera or lens for 360 photos or virtual tours, you really ought to consider the camera and lens as a pair, rather than individually. And if you care at all about resolution, circular fisheyes, no matter how sharp they may be, are actually not an ideal choice for 360 photos for virtual tours.  Cropped fisheye lenses can take photos that are much higher resolution, with the same number of shots.  For some suggested camera and lens pairs, check out this post.

About the author

Mic Ty

12 Comments

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  • That is exactly why one should invest in a good lens specific for the camera one is using. I use a Canon 8-15mm and shoot AP-C (crop sensor) at 8mm and Full frame at 12mm. Make sure you tape the zoom ring before shooting.

  • Another great post Mic. Confirms what we were talking about the other day. The Meike 6.5mm circular fisheye has the same effect on the a6000 reducing resolution as you pointed out.

    • Thanks Roland. Yes that’s why the Meik, is actually not so good for APS-C even though it is sharp and cheap. My 360 photo from the Meike on the a6000 is only about 30mp, whereas, I can get around 75mp from the Samyang 7.5mm, both of them with 4 shots.
      Best regards,
      Mic

  • Hi Mic
    We get over 128 megapixel native with a Sigma EX 10mm f/2,8 DC HSM Fisheye
    it is 180 degree in the cornor on a sony A77
    5-6 shot around and one up
    on a full frame we should use a Sigma EX 15mm f/2,8 DG Fisheye
    in the same way both lenses are pretty sharp and good
    PTGui 11.5 Pro has these Lenses in the Database
    and you can batch stitch the images out of the box

  • apart from the Sigma 8mm, have you come across any other lenses native to the Sony E-mount which has the same angle of view?

  • Hi:
    I notice you say the you are using a Nikon to Sony E mount adapter for you Samyang 8mm. Is there any reason why one can’t use the Samyang 8mm E Mount?