I wrote this in response to a question on the Pentax mailing list:

> In message "Pentax MZ-5N + 28-200mm", you write:
> 
> > Am still getting to know my 3 months old Pentax
> > MZ(X)-5N body and Pentax FA Zoom 28-200mm and:
> > 
> > 1) It says in the manual (p.36) that this camera has
> > a predictive autofocus
> > function which I can't find and am doubting I will
> > ever find. Can anybody confirm please?
> 
> Predictive autofocus means that the camera will sense
> movement and compensate by adjusting the focus for the delay
> between pressing the shutter and the picture being taken.
> This is automatic.  You can test this by taking a picture of
> something moving.  If it is sharp the predictive auto-focus
> is working.
> 
> > 2) Is the lens not compatible with this body's
> > built-in flash within a
> > certain range? The flash indicator blinks like crazy
> > when I use the
> > built-in flash and am at focal lengths between say
> > 28-70mm. There are no
> > vignetting in the photographs but they ARE
> > underexposed (programmed AE
> > mode). Is there a way to bypass this problem other
> > than use longer focal
> > lengths (strenuous), an external flash (bulky) and/or
> > change the lens
> > (bulky and defeats the purpose of this choice of lens)?
> 
> Unfortunately no, the lens physically blocks the flash.  The
> problem might be remedied somewhat by removing the hood
> indoors if you haven't already but the real solution is as
> you have described above.
> 
> Personally I would recommend getting a small external TTL
> flash like the AF200T or the AF220T for the following
> reasons:
> 
> 1)  Doesn't use your expensive lithium camera batteries like
>     the RTF.
> 2)  Gives at least twice the power of the RTF.
> 3)  Reduces "red-eye" by moving the flash away from the lens.
> 4)  Relatively small and compact, does not unbalance the
>     MZ-5n.
> 5)  Available cheaply used in many places, check pawn shops
>     and camera stores.
> 
> 
> > 3) Very silly question but here goes: when does one
> > use spot, multi-segment
> > and center-weighted metering?
> 
> Well, I don't use centre weighted very often but some people
> on the list recommend it for slide film.
> 
> Matrix I use for point and shoot.  Works pretty well but is
> fooled by backlit situations sometimes.
> 
> Spot I use when I need to carefully control the exposure,
> see below.
> 
> > 4) Very very silly question but here goes again: how
> > do you expose a scene
> > which is ½ brightly lit and ½ dimly lit?
> 
> This is one of the the toughest situations in photography
> and the one that is hardest for your camera to handle.  This
> is where your spot-metering comes in handy in conjunction
> with the exposure lock (ML) button.
> 
> There is a quick and easy way to do this and a more
> difficult and time consuming method.  Of course the harder
> method is more likely to give you the picture you want.
> 
> 1)  Easy - Put camera on spot mode, focus on most important
>     part of the picture you want properly exposed, push ML,
>     recompose and shoot.
> 
> 2)  Harder - Spot meter the various areas of the picture,
>     with negative film you have about 3 stops of latitude to
>     work with.  Make sure the brightest areas are not more
>     than 3 to 4 stops brighter than the darkest areas.  If
>     they are you must decide whether you want the detail in
>     the bright areas of the dark areas and set your exposure
>     accordingly.
> 
> Keep in mind that a silhouette can be very dramatic (ie.
> you've lost the dark areas) but for most photos you want to
> see the faces (losing the bright areas).  When in doubt try
> it both ways and don't be afraid to bracket up and down a
> stop as well.
> 
> If you're really keen you may want to check out a book on
> the Zone system, also check:
> 
> 
> > Thanks :-)))
> > 
> > Deana
> 
> Those are not silly questions, they are very important to
> good picture taking.  I hope this explanation helps you.
> 
> 
> Have fun,
> 
> Jim Little