> On 10 May 2001, at 11:13, Ayash Kanto Mukherjee wrote:
>
> > My next experiment was to decrease the aperture by 5 stops, i.e., f/22 and
> > therefore the exposure has to be increased by 5 stops, i.e., 64 sec. I got
> > a very horrible result. It was severely underexposed.
Decreasing the aperture and increasing the time accordingly will NORMALLY
produce a picture with the same brightness. You have to EITHER close the
aperture OR decrease the time.
Now, why didn't this happen with your second shot? First, the MZ-M like
99,9% of all cameras meter on automatic only up to 30 seconds, so you
didn't get your 64 seconds. Second and more important, when a film
receives very little light, then the trick with doubling the time does not
really work. You have to tripple or even quadrupple the time for one
f-stop difference.
Anyhow, try your shot again, with the same lighting. Set the camera to
manual operation, and take several shots: f/5,6 and 4 seconds and f/8 and 4
seconds. This should give you two pics with -1 and -2 stop exposure. In
other words, 1 stop and 2 stop darker than your initial photo.
NOW; BIG WARNING. Even if this yields correct exposure on the negatives,
the lab that makes the prints will automatically apply +1 and +2 stop
correction in order to "correct" your underexposed pictures. You need to
tell them NOT to do that automatic correction.
Cheers,
Boz
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