Hi,
Your arithmetic is wrong.
The easiest way to see it is that the 600 mm lens projects an image twice the size the image projected by the 300 mm lens.
Let's assume the you shoot a lion so it fills the image with the 600 mm. So, it projects an 24x36 mm image. On the Nikon D850 that gives you 45.7 million usable pixels.
Now, you take the 300 mm, it will project an 12x18 mm image, regardless if you use 4/3, APS, 24x36 mm or 54x40 mm. So, on the Nikon D850 it will give 45.7 / 4 -> 11.4 million usable pixels.
Would you use it on a Panasonic G9, it would yield 20.3 million usable pixels.
If we shoot with a 100 MP digital back with 54x40 mm sensor size, the pixel size would be 4.6 microns, with the pixel area being 2.16e-5 square millimeter. That would give you 12x18/2.16e-5 -> 10 MP.
So, with a 300 mm lens, the best option would be the Panasonic G9. The reason for that is that with the 100MP back you would throw away 90% of the pixels and also 90% of the photons collected.
To add insult to injury, the 300 mm lens on that Panasonic would be optimized for the 12x18 mm format and be very sharp. The Hasselblad lens is optimized for a much larger format and it will not be very sharp.
But, you can zoom with your feet, that will change perspective, though and may also feed the lion.
Best regards
Erik
Pardon my ignorance, but assuming the Nikon has 50MP sensor, don’t you get similar images using a 600mm lens on the Nikon and using a 300mm lens on the Hasselblad 100MP sensor and cropping by 50%?
You would also have the advantage of the larger sensors and viewfinder on the Hasselblad setup and a nicer sounding mirror thump?
Roger
