A55 vs A900 resoolution test

Started Jun 1, 2011 | Discussions thread
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Nordstjernen
Nordstjernen Veteran Member • Posts: 6,876
A55 vs A900 resoolution test

Here is a small resolution test with the A55 versus the A900. I used my excellent Sony G 70-200 mm f:2.8 zoom lens at f:8 and ISO 200. The cameras were mounted on a very sturdy Gitzo tripod. For the A900 I had to use a 2 x loupe viewfinder and a cable release, and also mirror lock-up drive mode. For the A55 I just used the 10 sec self timer and pushed the release button with my index finger.

Focusing the A55 was like a breeze with the 7.5 x and 15 x loupe view. Focusing the A900 is a bit more challenging, but the 2 x loupe finder helped a lot.

First I took some images with the same focal length, to compare resolution side by side. The A900 FF sensor gives a wider view, but for photographing animals, birds etc. the zoom is mostly used at the long end.

Then I took some images at 160 mm focal length for the A900 and 110 mm for the A55, so that both cameras captured the same scene and same crop. Then I upsampled the A55 image with Photoshop so that both images were identical in size and scale. The result of the upsampling is a bit muddier/grainier look, which probably could be almost smoothed out with gentle noise reduction.

The results:

  • Using the same focal length (160 mm), the A55 is the clear winner

  • Upsampling the A55 image (110 mm) to match the A900 size (160 mm), the A900 is the winner (a little bit more detail and a cleaner look)

I think you need large prints to pick which is which from the A900 sv the upsampled A55 image. I will make some test prints within a few days.

Totally I am impressed with how well the A55 stands up against the A900. I would not be surprised if the new A55 matches--or even outperforms the A900.

The full scene as captured with 160 mm and 110 mm focal length:

100 % crops from my test images:

Here is the A55 file at 110 mm focal length (100 % crop):

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