On Apr 20, 2005, at 10:59 AM, Mitchell Conant wrote:
Anybody here using k-mount lenses on a D/DS? I'm interested in the pros and cons. I realize that I will lose the automatic features of the camera/lenses, but I am used to shooting with an MX. What are the thoughts from those of you who have been down this path.
As has been said, you lose some of the D/DS metering features but it works just fine. I find the DS' semi-automatic metering using the Manual exposure mode and AE-Lock button easy to deal with, and a CW Averaging or Spot meter pattern is enough.
The second question is on the flash systems. Will the D/DS control a Vivitar 285 flash unit; both with and without the remote sensor? Are there any issues with the triggering voltages required for the 285?
The Vivitar 285 is not a dedicated flash unit, it has its own sensor, and will work on the D/DS the same way it works on any other camera. The only issue is trigger voltage: I don't like to put anything greater than 10V trigger voltage on a digital camera's hotshoe, even though Pentax claims the D/DS can handle up to 400V or something like that.
It's easy to measure the trigger voltage... Just turn on the flash (off the camera) and use a Volt-Ohm-Meter set to DC current to measure the voltage across the center and side terminals in the hot shoe. If the voltage is greater than 10V, buy a Wein Safe Sync adapter to protect the camera's circuitry.
A flash question you didn't ask...
The DS built in flash supports only P-TTL or full power manual output. With older lenses on the DS, like the K-mounts you mention above, the built-in flash unit reverts to full output with no metering (it requires aperture information to support its normal P-TTL operation) and you set the exposure using a guide number provided in the manual. Dedicated external flash units for the DS can support P-TTL, TTL, external sensor automation as well as manual output control; for older K-bayonet lenses, you lose the P-TTL flash metering again but for many circumstances the TTL capability is useful.
Godfrey
