Mark, You can quote the manual all you want. The manual is not correct in that it doesn't specify the "A" series manual focus lenses' operation properly.
I tested flash behavior using a Pentax-A 50mm f/1.7 lens on my DS body and what I reported is how it behaves. The flash does P-TTL in all exposure modes with these lenses: Av mode locks the shutter speed at 1/180, P, Tv and M modes operate as you would expect. It also supports P-TTL using lenses without electrical aperture coupling in Av mode at full aperture (or manually stopped down, in the case of screw mount/mirror lenses and the like), I believe, although I did not test this explicitly. The DS' built-in flash only reverts to full output, non-metered mode when a lens that has no aperture information electical couplings (M and K bayonet; A lenses with the lens taken off the 'A' setting) is fitted and Manual exposure mode is selected. Godfrey --- Mark Erickson <[EMAIL PROTECTED]> wrote: > > Godfrey DiGiorgi wrote: > > Mark Erickson wrote: > > > I took a look at the *ist-Ds manual, and it appears that > if an > > > older lens (i.e., not an FA, FAJ, D FA or DA) is mounted > and > > > the built-in flash is used, the shutter speed is fixed at > 1/180 > > > and the flash always fires at full power (see page 147 of > the > > > manual). Yikes! Seems like a little bit of a limitation, > > > doesn't it? > > > > Not quite correct. An A manual focus lens works the same as > an > > FA/DA/D-FA/FA-J lens in P, Tv and M modes; in Av mode, > shutter > > speed is fixed at 1/180 second. > > Let me quote from page 147 of the manual: > > Using the Flash in Tv (Shutter Priority) Mode > ... > The shutter speed is fixed at 1/180 sec. when lens other > than > DA, D FA, FA J, FA, or F is used. (The built-in flash always > discharges fully.) > > ... > > Using the Flash in Av (Aperture Priority) Mode > ... > The shutter speed is fixed at 1/180 sec. when lens other > than > DA, D FA, FA J, FA, or F is used. (The built-in flash always > discharges fully.) > > My reading of this is that the *ist-Ds does not in fact treat > SMC-A lenses the same as DA, D FA, FA J, FA, or F lenses in > Av or Tv mode. Also, the fact that the built-in flash always > discharges fully seems to be a little limiting, as well. > > --Mark > > __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
