Originally posted by eddie1960 ok last time i reply
you aren't paying attention
Good since you're not being too polite.
Quote: he was talking a 200 2.8 on the small sensor (likely an affordable kit) which wuld have 35 mm FOV of about 1120mm. DOF was not a consideration as we all realise the bigger sensor has shallower DOF capability. This this though would be an unobtainable FOV with this light gathering ability on apsc (or 35mm or MF...) so i has it's uses as long as you aren't concerned about apparent DOF, and for some things people won't be
What was argued was that a small sensor has advantage when a large DOF is needed at certain FOV. I claimed that this is not true and provided practical evidence to support my case.
Quote: Re-read what has been written. no one denies the DOF will be better on the bigger sensor, thing is that wasn't what the discussion was pointing out. it was that you could have huge reach with a fast lens (as in lots of light therefore i can have a high shutter and lower iso), just no DOF
Please read the previous posts yourself. I simply stated that there is no image quality advantage for the small sensor camera under any circumstances.
You are also ignoring the fact that the f/2.8 number, thus the light collecting ability, is relative to the real focal length. A f/16 1120mmm lens would collect about the same amount of photons a f/2.8 200mm lens will.
When you talk about high shutter speeds due to the fast lens, you're forgetting that the 1120mm equivalent lens needs at least about 1/1000s, preferrably 1/2000s shutter speed. This means that only on good light one could use the base ISO. If the subject is in shade, one needs to up the ISO. A camera with a tiny sensor has quite bad image quality to start with - upping the ISO will not help things.
If we talk about the sizes of the lenses - a 200/2.8 lens would be quite a large lens regardless of the size of the sensor (a kilogram or so). Putting a 300/4 and a couple of TCs together would create a 1200/16 lens which would not be much bigger.
If one wants to find a sensible use for a tiny sensor interchangeable lens camera, it is special purpouses. It might be decent for budget astrophotography (with a slow and cheap telescope), hidden camera photography and for example aero-photography with radio controlled aircraft toys.
But this is not something Hoya could make money out of, but instead would lose quite a bit if tried to push such a product.