Disc standards specify a humidity of 5% to 90% but also non-condensing. Any
moisture can harm the disc or can interfere with operation of the drive.
Your suspicion of condensation on the objective lens may be correct. Other
possibilities would be moisture in the suspension that radially and axially
positions the objective lens to maintain accurate tracking and focus or
moisture on the rails upon which the pickup sled travels.
Most sources recommend 5 to 25 degC (41 to 77 degF) and 8% to 60% relative
humidity. Cool (10 degC, 50 degF) and dry (20% to 50% humidity) are optimum
Media Sciences, Inc.
> -----Original Message-----
> From: Association for Recorded Sound Discussion List
> [mailto:[log in to unmask]] On Behalf Of [log in to unmask]
> Sent: Saturday, August 30, 2008 5:23 PM
> To: [log in to unmask]
> Subject: [ARSCLIST] ...CAN'T SEE FOR THE FOG...
> I was recently making a CD recording for a private collector, using a
> JVC deck, which has worked flawlessly many-a-time. Monitoring the tape
> playback, everything sounded just fine. In listening to the CD result,
> there was distortion, and generally lousy sound. I thought it might have
> been a plug making intermittent electrical contact, and checked this,
> along with every other connection. Round two of recording produced the
> same results. Since we just had a dehumidifier decide to die on us, I
> wondered if maybe the high humidity might be causing troubles...lately it
> has been raining a lot, with terrible humidity. Suicide weather...you
> could go outside and take a deep breath, and drown yourself. I put on our
> air conditioning for a while before attempting another session, and put in
> a laser cleaner disc, just prior to recording. This seems to have taken
> care of the problem. The next recording came out fine. Apparently, the
> laser was getting fogged from the humidity. Have any of you experienced
> this kind of problem? I'd be interested to hear what your remedies might
> have been. SS