[bobore]

Part two question regarding my daughter’s K-1(II): Can anyone definitively tell me if the good old AF-280T flash unit is safe to use (re voltage) on a K-1(II)?

A recent post of mine re her camera resulted from reading about possible damage to modern dslr cameras via older flash units. I assumed I should get her a newer unit, but last night I read reviews that indicate the AF-280T can be used in Auto & Manual modes with modern dslr cameras.

I gave her a AF-280T a number of years ago. Has anyone safely & successfully used it first-hand in combination with the K-1(II)?

[jbinpg]

I use the AF280T on my K-1 all the time with no ill effects.

[Church Key]

It's not shown at all in the K1-ii manual where compatible flashes are listed. I'd be extra cautious.

[K-Three]

here is a very detailed listing, with lots of discussion,
https://www.botzilla.com/photo/strobeVolts.html
The information suggests that the 280T may be safe?
Read through it and make your own conclusions for your case,

[OldChE]

It was my understanding that all of the film era Pentax flashes had low enough trigger voltages so that they are safe for Pentax DSLRs. Now, the TTL feature of the AF280T will not work on the K-1M2 DSLR, since the DSLR uses P-TTL (with a preflash) and the AF280T doesn't support that. However, you can use the AF280T in auto mode (using the sensor built into the flash unit) or use the flash on manual.

Added comment: I'm not sure about the earliest Pentax flashes, like the Autorobo. If anyone is curious about that one, I can measure the trigger voltage on mine and let you know. But hardly anyone has an Autorobo.

[stevebrot]

I use mine all the time with my K-3.

The AF280T is a popular option for Pentax dSLR owners interested in a voltage-safe flash with a usable dedication on both current and vintage cameras.

PENTAX AF 280T reviews - Pentax Camera Accessory Review Database

My exhaustive review may be viewed HERE

Added: As noted above, rule of thumb is that film-era Pentax-brand flash are voltage safe on Pentax-brand cameras. Note: There is some question regarding whether the Autorobo is safe on all Pentax dSLRs.


Steve

[mikesbike]

It was my understanding that all of the film era Pentax flashes had low enough trigger voltages so that they are safe for Pentax DSLRs. Now, the TTL feature of the AF280T will not work on the K-1M2 DSLR, since the DSLR uses P-TTL (with a preflash) and the AF280T doesn't support that. However, you can use the AF280T in auto mode (using the sensor built into the flash unit) or use the flash on manual.

I haven't had it on my K-1 II yet, but have used it with other modern Pentax DSLR models, which cannot function using TTL, only P-TTL. But in this case, as stated here^ the unit's own "Auto mode" which I believe has two power settings, does a good job. And this is quite a compact flash but with very good features- tilt, swivel, and even a downward tilt for close work.

[OldChE]

This link gives the most pertinent information I've found on this topic. The answer is that all legacy Pentax flash units (I'd leave the Autorobo for the moment out of this) are safe for Pentax DSLRs (see the comments section). We don't know for sure the maximum safe trigger voltage on the DSLRs, but I suspect they are compliant with the ISO standard so should be good up to 24V, but, for me, I wouldn't just go by that assumption. For me, I would go by the assumption that I can use any of the Pentax AF-XX flashes on my K-1M2, since we know that Pentax literature and tech support have indicated you can do so. I've used the AF160SA in auto mode quite successfully on my K-1M2, in auto mode.

https://ricehigh.blogspot.com/2007/03/which-flash-units-are-safe-for-pentax.html

[OldChE]

OK, being an engineer, I just had to know the trigger voltage on my Pentax Autorobo. While I was at it, I measured the trigger voltage on several others that I have. I used relatively fresh batteries (each alkaline AA cell was 1.48V +/- 0.02V), and I fired each flash using the "test" button (or shorted the PC terminal) three times before measuring the voltage, to form the capacitor, and set them on full output, auto mode (though I doubt that would change the trigger voltage, but we want to control variables). I used a Craftsman AutoRanging Digital Multimeter Model 82175. I give the date of first release for each Pentax model, as far as I know it (from copyright dates on manuals).

Pentax flashes:
1973 Autorobo 21 V
1983 AF200T 2.65 V
1986 AF160sa 2.6 V
1988 AF280T 2.65 V
2003 AF360FGZ 3.1 V

Modern, Pentax-compatible flashes:
Metz 26AF-2 4.57 V
Godox TT350P 3.08 V

So, I think you are pretty safe using the Pentax AFxxx flashes on any camera, including digital, and of course the modern third-party flashes made for P-TTL are fine. The Autorobo has a low trigger voltage for flashes of that era (21 volts), but that voltage is about 8X higher than the later Pentax AF flashes. The 21V of the Autorobo might be safe on a DSLR (if they comply with the ISO standard of up to 24V), but personally I'm not going to risk my $2000+ K-1M2 on that assumption, especially as I have many other auto thyristor flashes I can use that are better and more compact. My Autorobo is for when I want to be period correct for my Spotmatic or K1000, just for fun.

Some old non-Pentax flashes below. No years here, but I'll look them all up later. My Vivitar Auto 252 (non-thyristor) I've had since the mid 1980s, and it is a great little flash, though not thyristor. Where I list the voltage with a +, that means it was slowly rising as I took the measurement. I think some of the old circuitry doesn't have much control. As you can see, most of these are not for modern cameras.
Vivitar 102 180+ V
Vivitar Auto 252 179+ V
Vivitar Auto Thyristor 225 190+ V
Sunpak Auto 140 180+ V
Sunpak Auto 322 170+ V
Sunpak Auto 322S 170+ V
Sunpak Auto DX-8R 2.72 V (good thing it is low, because I've used this ring flash on my K-70 already. Great little flash. I used it in Pentax TTL mode on my 645n, works great.)
Morris Maxi Slave 11.5 V (probably could use this on a DSLR, but why bother. It is meant for slave operation, but can use a sync cord as a manual flash).

Just a side note: When I've used the Autorobo, it seems to recycle very fast when flash distances are short. I wonder if it has thyristor circuitry? The battery life given in the manual (150 flashes in manual, approx. 2000 flashes in auto) to me implies that it uses some type of power saving circuit like a thyristor.

That's it! - Richard.

[jopenmx]

I have used my old AF-280 T safely with K 10D , K-3 and K-1 cameras , without problems , except for the limitations of the own flash, since the better option is to use it in the auto modes of the flash ( green and red ) or manual. Of course, the AF-280 T is not a p-TTL .
Enclosed a link where some advices about the use of the AF-280T on a Pentax K-5 are described . Among them , the better modes to fix in the camera .

Pentax AF-280T Use and Settings Suggestions – PhotographyBanzai.com

[stevebrot]

I suspect they are compliant with the ISO standard so should be good up to 24V, but, for me, I wouldn't just go by that assumption.

That last is a wise decision. Anecdotal word is that at least some Pentax dSLR bodies will tolerate 24V, but that the accepted "safe" zone is <=10V.

Pentax flashes:
1973 Autorobo 21 V

Thank you for checking the Autorobo.


Steve

[TwoUptons]

As others have mentioned, I've used my AF280 plenty with the K1(ii), K-01, and K10.
I have some Metz flashes that are a little grumpy on the K1, and the 280 always works...

That said, I prefer the AF360 I bought a few years ago, since it does P-TTL and HSS, which is handy.
It also will drive the Metz flashes using the wireless.

-Eric

[bobore]

Thanks everyone - Very much appreciate any & all info!