Thanks to you guys, I have a much better understanding of why a bigger sensor is better, and also why we donâ€™t see super-zoom cameras with large sensors (because the lenses would have to be impractically large).
However, I have another sensor-related question or two:
I see a lot of complaining about the megapixel count being too high on some of the small-sensor cameras. I can see why, as I have downloaded full resolution samples from say a 16 MP super-zoom, and the image is quite fuzzy at full resolution. But the same picture looks quite good at my monitorâ€™s resolution (1920 x 1080) and even zooming in a few levels.
Question 1: If I were to set the resolution to a lower setting in the camera, would that solve the issue? In other words would setting a 16MP camera to 10MP output produce the same image quality of a camera with a 10MP sensor assuming all other variables were the same? (yes, this is hypothetical since there probably are not two matching cameras with only the sensor pixel density being different)
Question 2: If the answer above is "no", would it be better or worse to reduce the image size in software on the computer? (I know jpeg is destructive compression, so assuming you are not working with RAW images, I would think reducing the size on the computer would be worse since it would be going through Jpeg compression twice)
Thanks in advance for your insight.
Given that the 10MP would use the entire sensor vs a 15mp (50D) or 18mp (60D/7D) shot at a medium setting, You wouldn't get the entire goodness of the sensor... so the 10MP, in this example, would be optimum. On a disclaimer, as far as raw sharpness goes, the 18mp 7d is not any softer than a 12mp 40D when using good lenses... The higher the MP, the more demanding it will be on the lenses, and quite frankly, it will expose the flaws and softness on cheaper/consumer grade lenses than the lower MP... The only part where the lower MP really becomes an advantage is diffraction on the lens, however between these two cameras you are looking at less than a stop difference.
Now if you were going to shoot 18MP and downsample to the same dimensions as the 10/12MP camera... the 18MP may be as good if not better because if you set photoshop to bicubic, it will come out quite nice and naturally sharpen... On tests vs the 7D and the nikon D300s, many reviews did the same thing (downsampled the 7D to match and then on the flip side up-sampled the nikon to match the 7D...) It's not a real fair matchup but it is what it is...
What to take from this, dont fear the higher MP cameras if you can afford nice glass... Remember to invest more in your glass than your cameras and you should be fine.