Hey Walt,
I may have missed an earlier explanation, but I'll ask anyway....
What were the acoustic characteristics of the room? And how close to the
camera was the meter. And one more, did you have a lens on the body (if so,
which one)? I seem to remember that speakers are measured at one meter in an
anechoic chamber. This is probably good for comparisons, but not so great
for listening... My OM4 sounded quiet at home, but oh so intrusive in Notre
Dame, Paris. That church had a very 'live' environment.
One more comment. 2 different sounds at equal dB may be more or less
pleasing. Perhaps even though the OMs registered slightly louder than the
other cameras, they may have a less offensive sound. Could you comment on
that?
-Mickey
----- Original Message -----
From: "Walt Wayman" <hiwayman@xxxxxxxxx>
To: <olympus@xxxxxxxxxxxxxxx>
Sent: Wednesday, November 28, 2001 10:24 AM
Subject: Re: [OM] OM clunks, clanks and doinks
---------- Original Message ----------------------------------
From: Jim Brokaw <jbrokaw@xxxxxxxxxxx>
Reply-To: olympus@xxxxxxxxxxxxxxx
Date: Tue, 27 Nov 2001 21:52:08 -0800
>on 11/27/01 12:19 PM, Walt Wayman at hiwayman@xxxxxxxxx wrote:
>
>
>snipped Walt's highly scientific description
>
>>The results:
>>
>> OM-1: 59 dB
>> OM-4: 59 dB
>> OM-4Ti: 58 dB
>> OM-1 with mirror locked up: 57 dB
>> OM-4 with mirror and aperture prefire: 57 dB
>> OM-4Ti with mirror and aperture prefire: 57 dB
>> Self-timer beep: 20 beeps @ 56 dB, last 4 @ 60 dB
>> Any OM with Winder 2: 67 dB
>> Any OM with Motor Drive 2: 62 dB
>>
>
>Walt, I think 3db represents a *doubling* of the sound level. So
>1db would be a noticable and significant difference... but how
>repeatable are your measurements? Did you try each one many
>times, or just once/a few times?
>
>I think your results would be more statistically valid if you
>tested more OM bodies in each configuration... which means you
>need to buy more OM's -- all in the interest of science, of
>course!
>
>;-)
>--
>
>Jim Brokaw
>OM-1's, -2's, -4's, (no -3's yet) and no OM-oney...
>
I repeated each measurement 10 times, and in every case only one
or two readings showed a 1 dB difference, so I just accepted the 8
or 9 readings that were the same and threw out the odd one or two.
As far as decibels and what they really represent, I won't try to
explain something I'm not sure I fully understand. I lifted this
from the Howitworks web site:
The decibel (abbreviated dB) is the unit used to measure the
intensity of a sound. The decibel scale is a little odd because
the human ear is incredibly sensitive. Your ears can hear
everything from your fingertip brushing lightly over your skin to
a loud jet engine. In terms of power, the sound of the jet engine
is about 1,000,000,000,000 times more powerful than the smallest
audible sound. That's a big difference!
On the decibel scale, the smallest audible sound (near total
silence) is 0 dB. A sound 10 times more powerful is 10 dB. A sound
100 times more powerful than near total silence is 20 dB. A sound
1,000 times more powerful than near total silence is 30 dB. And so
on. Here are some common sounds and their decibel ratings:
Near total silence - 0 dB
A whisper - 15 dB
Normal conversation - 60 dB
Lawnmower - 90 dB
A car horn - 110 dB
A rock concert or a jet engine - 120 dB
Gunshot, firecracker - 140 dB
End of quoted stuff.
For those interested in more examples, try this link:
http://www.coolmath.com/decibels1.htm
And I'll be happy to test other equipment. I'm especially curious
about the sound level of an OM-3Ti, and I think some long-term
examination of the effects on camera sounds of certain lenses,
particularly the 180/2, 250/2 and the 350/2.8, etc., would benefit
mankind in many ways. Those of you who have any of these may
contact me off list for details on where to send them. This
project could take a long time, but consider it your contribution
to the furtherance of human knowledge.
Walt Wayman
< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >
< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >
|