[pathdoc]

How well do owners of non TTL cameras find that the thyristor compensates for the altered light saturation in bounce mode? Intended applications are ME, MX and Spotmatic F.

[Tonytee]

How well do owners of non TTL cameras find that the thyristor compensates for the altered light saturation in bounce mode? Intended applications are ME, MX and Spotmatic F.

I for one liked the AF280T Flash Unit for fill flash for outdoor portraits and even for a small group of people. Before using it for bouncing off of the ceiling, I painted the ceiling with ceiling white. Unfortunately, the flash output was still inadequate. I found the unit to be very reliable and rugged, however it lasted approximately three years and then gave up the ghost. My release was purchased brand new, but then again, and Here it comes: You get what you pay for. Hope this helps. I used it on my Pentax ME Super and Pentax ME cameras.

Tonytee

[tibbitts]

How well do owners of non TTL cameras find that the thyristor compensates for the altered light saturation in bounce mode? Intended applications are ME, MX and Spotmatic F.

I'm not sure what you mean by "altered light saturation", but the flash (when set on auto) works just like an averaging reflective light meter whether the head is set to bounce or not. Which means it's usually close in terms of exposure, but rarely optimal. Accuracy in bounce mode seems to me to be the same as in direct mode. You can't see exactly what area the light sensor in the flash is measuring, and you can't "lock" the exposure by measuring a non-central portion of the scene, like you sometimes can with a camera's built-in meter (depending on model.) If you're using ISO 10 or something, you're going to have issues with power. ISO 100-200 seems to be okay for a residential (8ft) ceiling.

[pentaxus]

I found that it is best to use ISO 400 film for bounce use. If the room has off-white walls I found that using a wall directly behind you can give a pleasing result ( rotating the head so that it hits behind and above you, turning the wall into a giant umbrella ). Shooting a test roll is important. I have also used a Sto-Fen omni bounce on the 280T with nice results.

[pathdoc]

Accuracy in bounce mode seems to me to be the same as in direct mode.

This is what I was getting at - how well it meters when the thing is set to some arbitrary degree of tilt and swivel.

Which means it's usually close in terms of exposure, but rarely optimal.

Ultimately I'll be dealing with home-developed black and white film, so I can correct either in development or in the post-processing phase that follows digitisation.

If you're using ISO 10 or something, you're going to have issues with power.

LOL no. Not going there.

If the room has off-white walls I found that using a wall directly behind you can give a pleasing result ( rotating the head so that it hits behind and above you, turning the wall into a giant umbrella ).

I must give that a shot with my AF540FGZ-II and K-5. (Yes, the original FGZ had a thyristor function and would have made getting the 280T unnecessary - but it also had battery door issues, was significantly bigger, and wasn't WR, all of which counted against it for the intended use.)

Shooting a test roll is important.

Always willing to have an excuse to shoot and develop film. Come to think of it, why don't I shoot a test roll with my 540FGZ-II at various manual power levels on the Spotmatic? I've just loaded a 36-shot roll of 100 ASA film and will be looking for something to do (develop the film) at the end of this week. The results of that might be very interesting to see. Must go off and work out a test sequence.

[stevebrot]

How well do owners of non TTL cameras find that the thyristor compensates for the altered light saturation in bounce mode? Intended applications are ME, MX and Spotmatic F.

Sorry to be a little late to this discussion, but figured there is no harm adding my piece. I bought a AF280T as a companion to my Super Program. After all, why not own a TTL flash to go with my only TTL body? The flash works as expected as a TTL flash on the Super Program and also works great in auto mode on my other bodies. It is good to remember that the AF280T was top of the line for hot-shoe mounted models in 1981 was very full-featured for the time and intentionally compatible with all Pentax hot-shoe bodies produced up to that time with dedicated, TTL, and program functionality for bodies supporting those features.

Now back to your question...

Short answer? The auto-thyristor functionality is superb for both normal and bounce/swivel. Exposure is consistent and reliable within the flash range and when in doubt, test flash will confirm whether there is a subject within range. Range is modest by today's standards (guide number of 28 (meters)) but adequate for most rooms. I have used mine with bounce and 12' ceilings, but 20' is not a good idea.

The longer answer? Truth be told, I prefer the AF280T in auto-thyristor mode on my K-3 over both the built-in P-TTL flash and my Sigma EF 610 DG Super. When P-TTL falters, auto-thyristor comes through. What is doubly cool is that the modern bodies support the analogue flash control protocol meaning that the there is a surprising degree of flash automation available including the flash setting both aperture and shutter speed and the body setting power level on the flash

My September 2014 review has a full feature matrix for dSLRs:

PENTAX AF 280T reviews - Pentax Camera Accessory Review Database


Steve