Tony Northrup - The TRUTH: Hi Megapixels + BIG Prints are a WASTE?

Started 2 months ago | Discussions thread
Erik Kaffehr
Erik Kaffehr Senior Member • Posts: 3,034
Apples to oranges...

Hi,

Tony Northrup's comparison is interesting. But, there are some issues with the method used.

One issue is that it is not just about pixels, Bob Atkins's write up on MTF and SQF is worth reading.

Now, let's assume that we compare the A7III, A7rIV. Tony is correct in the A7III having an OLP filter (AKA antialiasing filter). So the A7III needs more sharpening than the A7rIV. But, once you change sharpening you tilt the playing field. If you don't sharpen you are still tilting the playing field.

Now, reducing pixel size also affects sharpness. After all any information delivered by the lens will be smeared out over the pixel, so smaller pixels are inherently sharper. Proper downscaling is also quite complicated. Downscaling needs some blurring the image before size change, followed by some sharpening after resize.

Finally, going to the 240 MP mode on the A7rIV requires processing the image in some special software by Sony and that software will apply some significant sharpness adjustment, I would guess.

So I think the observations are correct, but there is a lot of room for experimental error making the images.

Best regards

Erik

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Erik Kaffehr
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