the link posted by larry is easier to understand.
ok, here's my query.given a scene of mount fuji and a fore ground of flowers.
before i put my dslr to my eye, is it possible to SET the hyperfocal distance right away on the lens?
OR do i have to focus on mount fuji(infinity), then adjust back to the hyperfocal distance, then find out how many feet/meters(let's say,distance A) in front of me will be sharp TO infinity and focus on that?(distance A)
i apologise if my ques sounds stupid.:dunno:
Strictly speaking no.
There is one component that you need to take into consideration: print size and view distance.
Let me explain DOF first.
In a photo, there is only 1 plane that will be in focus. Moving away from this plane, the blurness will increase with the distance from this plane of focus. Human eye has limited resolution. When the blurness is very small, our eye will still register this small blurness as in focus. Therefore, when the print is big or distance is close, our eyes can detect more blurness. (Think big poster appearing focus when far, but blur when close.) This range of distance from the plane of focus where object appear focused to our eyes is the DOF.
Therefore, factors affecting DOF is:
1. Final pictue - print size & view distance (in calculators that doesn't require you to input this, they already made an assumption on the print size and viewing distance, usually 8x10in print at 1ft viewing distance)
2. Sensor or film size
3. Aperture
4. Lens focal length
5. Distance of subject
Now, back to your question "is it possible to SET the hyperfocal distance right away on the lens?"
The answer is no, unless you have already in your mind the the print size/viewing distance, and you can do a mental DOF/hyperfocal distance calculations.
My suggestion is to use the link I posted to make the calculations and print a copy of the hyperfocal distance chart and keep it with you.