[EsBee]

Will it work?

Thanks.

[SOldBear]

Will it work?

It will fire, but only in manual mode.

The AF400FTZ does not have its own light sensor, so it doesn't have flash-auto mode. It does TTL which the K20D does not have. The K20D has P-TTL but the AF400FTZ does not. So the AF400FTZ works with the K20D only in manual mode.

In manual mode, the AF400FTZ has 2 power settings: high and low. You will need to manually adjust the high/low setting on the flash, the ISO and aperture settings on the K20D depending on the distance to the subject.

It's clumsy, but doable.

Even if you plan to buy another flash that support P-TTL and/or auto flash, it doesn't hurt to learn to operate the flash manually.

But I know you'll buy another flash. If you do, don't buy one that does not have its own light sensor.

[EsBee]

Thanks, I thought the only way I might be able to use it was in manual mode but didn't know about the voltage compatibility but I am assuming that is not an issue.

[res3567]

It will fire, but only in manual mode.

The AF400FTZ does not have its own light sensor, so it doesn't have flash-auto mode. It does TTL which the K20D does not have. The K20D has P-TTL but the AF400FTZ does not. So the AF400FTZ works with the K20D only in manual mode.

In manual mode, the AF400FTZ has 2 power settings: high and low. You will need to manually adjust the high/low setting on the flash, the ISO and aperture settings on the K20D depending on the distance to the subject.

It's clumsy, but doable.

Even if you plan to buy another flash that support P-TTL and/or auto flash, it doesn't hurt to learn to operate the flash manually.

But I know you'll buy another flash. If you do, don't buy one that does not have its own light sensor.

You wonder why Pentax did not make their DSLR's backwards compatable with their flashes as well.

[SOldBear]

You wonder why Pentax did not make their DSLR's backwards compatable with their flashes as well.

In the name of progress.....

Actually, I think because P-TTL is cheaper, not necessarily better than TTL.

The pre-flash strobe is needed to support wireless. Except for some firmware code, it costs nothing to also use it for P-TTL. If Pentax had supported TTL too, they would have to install a light sensor in the mirror box. That would cost money and real estate inside the camera.

TTL, IMHO, is much better (for consumers) than P-TTL. There is no annoying pre-flash. More importantly, it works with anything that you can attached to the camera, including a pin-hole body cap. But when do manufacturers try to benefit consumers? Pentax would lose a reason for you to spend money on new lenses.