[Lord Lucan]

Others have cautioned you against getting that flash [Pentax AF400FTZ] as it does not have enough power. .... I received, several years ago, a Pentax AF160Sa flash which I have used for close shots, up to about 10 feet, and as a fill flash in a few instances. .... it may suffice in a few circumstances.

With a Guide Number of 40 metres @ ISO100 and standard beam angle, the Pentax AF400FTZ is a powerful flash. I believe the others were making the point that in the manual mode it has only two levels (for comparison, my Sunpak 4205G with a GN of 42 has seven manual levels). The Pentax AF160S is a basic compact flash with a GN of only 16, and only one manual level, and is not comparable.

[Photos-by-Chas]

With a Guide Number of 40 metres @ ISO100 and standard beam angle, the Pentax AF400FTZ is a powerful flash. I believe the others were making the point that in the manual mode it has only two levels (for comparison, my Sunpak 4205G with a GN of 42 has seven manual levels). The Pentax AF160S is a basic compact flash with a GN of only 16, and only one manual level, and is not comparable.

AS has been said, it should only be used with the camera in M mode, I usually shoot only M so should be okay. I will however, use it cautiously.

[Lord Lucan]

AS has been said, it should only be used with the camera in M mode

On a K70 or any other modern DSLR, the AF400FTZ should only be used in its manual modes (all two of them), because its TTL mode is only suitable for certain later Pentax film SLRs and a couple of early digital ones.

It is very unfortunate that the third flash unit mode, which was generally called Auto and was provided on all but the most basic units around 1975-2000, has been dropped from modern flash units (entirely? IDK). The latter have only manual and TTL modes (and sometimes only manual), and as TTL has always differed between brands and even models, the choice of recent third party flash units compatible with the Pentax DSLR version of TTL (ie P-TTL) is poor.

The old Auto mode was controlled by a photocell on the flash unit and did not require electrical inter-action with the camera, other than the trigger which was common to all brands (except Minolta/Sony). For this reason you can find a much wider range of useful flash units by looking for ones over 20 years old with both Auto and Manual modes, and which are brand agnostic and/or offered Pentax dedication to varios degrees, which was more common back then. Examples with good reputations are the Pentax AF280T, the Sunpak 383, 30DX and 36DX and the Vivitar 285HV. Some of these offered film era TTL as well. As I said in an earlier comment, the safety of the flash trigger voltage needs to be checked in all cases.

[Rickoutwest]

Merry Christmas and thanks to all for the input regarding flash units. I now know a lot more about flash photography than before. My needs are simple, mostly family gatherings and occasionally fill flash. So, I have ordered a Yongnuo 585 EX, which seems to fit my needs and is in my price range.


Rick