John Sheehy
Forum Pro
It seems? I did not claim in this current thread to be talking about practical choices. I did that in the thread which this one spun off of, and have done so in many threads at this website. I've written many times of empirical aspects of the choices:
A larger sensor, with the same lens and subject distance, allows more room for tracking a moving subject which might work its way out of the frame with a smaller sensor. Unless the larger sensor has a higher pixel density, however, it will capture less detail of the subject than the smaller sensor.
The metering and AF may be more relevant with a smaller sensor (and with a crop mode using the LCD and on-sensor AF).
The amount of light you get from the subject (exposure times area) for any given shutter speed has no relation to the sensor size, but rather, to the size of your effective physical aperture. IOW, a FF sensor does NOT work like a bigger antenna that is more sensitive to weak signals; only the lens does that.
Etc.
People do a lot of things that I wouldn't do. My goal is to help people be aware of the difference between scaling and proximity, real or apparent, and hope that at least a few people might adopt what I think is better terminology.
Well, none of this is as important as good health, finding sustainable energy and food sources, or Peace on Earth.
However, what I was talking about is the choice of the term "reach"; it is not used consistently with a single meaning among the people who use it, and it has implications which are not a good representation of what is happening.
Yes, long arms have more reach, because they get your hands closer to what you are interested in. Longer arms give you true reach for photographing flowers on the other side of the fence, or the interesting insect on your ceiling. So can a monopod and a remote release. For a bird 100 feet away, your arms are irrelevant and what matters is how big the subject is on your sensor, combined with how many pixels it falls on (both are desirable, but just one is still a plus). That is due to pixel density and magnification; not to anything that resembles actually reaching something. I don't use a longer lens or a TC or smaller pixels or any combination thereof to make it look like I am closer to, or "reached" the subject. I do it so as to get more resolution of the subject, and the idea of the subject "looking closer" plays no role; only literally getting closer does that.
Scaling and proximity are independent things.
People who don't understand what "reach" means in this context likely don't understand the advantage of higher pixel densities on smaller sensors in the first place.
