All the current 1-chip Sony Mini-DV camcorders, as
far as I know, work the same way, and have the same
features, with the exception that at least on the
TRV30, portrait mode does not limit focus (and it
does appear to lower edge sharpening, reduce average
auto exposure a bit, force the lens to a wide stop
[for more limited DOF], and improve low light color,
all generally useful things with this camera...
BTW, selecting shutter speeds below 1/60th (NTSC)
dumps one field, reducing resolution somewhat, and
going below 1/15th produces excessive "trailing",
and can cause marginal pixels to show as white dots
in the picture if the gain is at +18db...


On Tue, 16 Jul 2002 08:37:49 -0700, "Luc" wrote:

>David,
>
>Thanks very much for the explanation. Reason I ask is that most people
>commented on the poor low-light performance. So I thought I could improve
>this by lowering the shutter speed (I assume digital effect slow shutter
>will enable this). Then if that's not enough increase gain (but as you said
>it would be selected anyway). I hope the TRV25 has the same adjustable slow
>shutter speed as TRV17 and others.
>
>Thanks for the portrait tip. Makes sense since it chooses lower F value (but
>may not work well with distant objects).
>
>Luc

>"Neuman - Ruether" wrote in message
>news:3d3517c0.2478959@newsstand.cit.cornell.edu...
>> On Mon, 15 Jul 2002 12:17:24 -0700, "Luc"
>> wrote:
>>
>> >I know I can adjust the exposure on most Sony mini-dv camcorders but is
>this
>> >simply achieved by changing the shutter speed? Is there also a way to
>> >increase the gain manually on TRV25/27 or TRV50? I.e. increase
>sensitivity
>> >of the CCD (with increase noise).

>> In auto mode, as light level falls, Sony camcorders
>> first drop the shutter speed to 1/60th (1/100th for
>> 1-chippers, with stabilizer engaged), then open the
>> aperture to maximum, then increase gain toward +18db.
>> When you use the "lock-and-shift" method of increasing
>> exposure, the same sequence is followed, but with manual
>> control over the effect, not the specific mode of achieving
>> it. With Sony 3-chippers, you can use AE-A and AE-S to
>> select the aperture or shutter speed to be fixed while
>> the others shift, or other modes to fix the shutter speed
>> (and with the VX2000/PD150, to limit gain rise) and
>> aperture. With 1-chippers, using different program
>> modes can give you slightly biased exposures, if desired.
>> Generally, it is less desirable to increase gain, rather
>> than using the slowest shutter speed and/or widest
>> aperture, so this option is rarely offered in small
>> camcorders - but if you are after the "look" (not sure
>> why...;-) of high-gain, you can use ND filters sufficient
>> to force maximum gain - otherwise, the picture will
>> look better even if the lens is wide open (I often prefer
>> using "portrait mode" [with the TRV30 only...] to force
>> the aperture wide and to reduce slightly the overall
>> auto exposure level [I use "spotlight mode" with
>> other Sony 1-chippers to do this for exteriors, since
>> "portrait mode" has undesirable effects with these]).
>> David Ruether