[Ash]

EXIF is stripped on these images.

If the AF540 is firing a pre-flash but not main flash make sure it is not set to Wireless "Controller" mode. The flash on off button should be firmly in the on position, not at the halfway Wireless position. What does the panel say the mode is ?

i don't know if your Sigma is compatible with the K1. it is quite an old model so possibly not. If it should be compatible and is also not working then perhaps the fault lies with the K1 hotshoe/electronics.

Can you find another Pentax flash to test on your K1

Sorry about the EXIF data loss. Must have been in the upload as the images are directly from the camera. Flash is definitely in on position only in these test shots. Panel says P-TTL on the FGZ and TTL on the Sigma. The hotshoe was my next thought but I will test both on a K-5 and check.

[Ash]

Maybe not too much help in it, but I just tested my K-1 (original) with a Metz 58 AF-1 (w/updated FW) with the settings you describe above, flash in P-TTL mode, bounced off the roof. All the exposures were spot on. The in-camera lightmeter says 1.5-2 seconds without flash, with flash I get 1/60th.

That’s the way a flash should work. I’ll keep investigating into this.

[Ash]

I apologise if this presents a red herring, but I mentioned inconsistent P-TTL flash metering with the FGZ-540 to a Ricoh Pentax rep at a recent trade show. The specific issue here was occasional random over-exposure (especially with daylight fill).



He indicated that the firmware in the FGZ-540II is better in this regard. But I’ve not got hold of one to try it yet. Are you using the older flash model too?

I wonder whether the rep just wanted you to buy a new flash. But the original (first version) 540 that I have has served me well on all my other cameras. I don’t really want to buy another flashgun until I’m certain what I have won’t work. Thanks for the tip, though. I’m still looking for answers through more tests.

[Ash]

But you must appreciate that you had to understand you were not necessarily conveying that impression ....

The only way to test P-TTL working, by isolating the flash exposure from all other possible influences, is to set M camera mode, set a fixed ISO, a fixed aperture, and a fixed shutter speed, and report exactly what these are. These settings should be such that they completely eliminate all ambient exposure. We still don't have this assurance from your tests so far, as they have been in Av mode with who knows what Flash Sync mode setting, and what ambient exposure level is mixed in there.

I do of course accept that you appear to be dealing with some sort of flash contact or communication issue through the hotshoe, but that's still not absolutely proven by your reporting so far.


The other good thing to try is to use M flash mode on your flashes (again of course with every camera settings fixed to eliminate ambient light), in order to check if your flashes are syncing correctly. You can assess the flash exposure level on a series of shots in M mode as you progressively increase the power, say from 1/32th through to 1/2. At least this would prove whether its a flash contact issue, or if its likely to reside in software, ie the camera is not telling the flash what to output properly in P-TTL mode.

I appreciate all your advice here, but the report from my side is that I did test the exact parameters above on M and X modes (31mm f/5.6 ISO 200-400, in camera shutter speeds of 1/180) with all exposure compensation figures at 0, and found it made no difference to the results. With the FGZ, the pre-flash fires, but not the exposure flash. With the Sigma, pre-flash doesn’t fire, but the exposure flash does though only at full power. I am looking for P-TTL functionality so it is not my intent to test the flash in its manual mode, although that does work for the Sigma.

I will report back after I have tested both flashes on my K-5, which may change the scenario but I can say there is at least odd behaviour coming from the AF540FGZ. I cannot be sure that the Sigma will be fully compatible with the K-1. But I can’t see why not, since it is a P-TTL flashgun.

[Ash]

Okay. Update.

Af540 only fires pre-flash on the K-5 as well. It has been a stellar performance from this flash but it appears there is a loose connection within the gun that will need surgery. I will be performing it over the next week or so.

The Sigma flashgun works flawlessly on the K-5. I see two scenarios here. One is the flash is not able to communicate metering with the K-1, and this just firing at full power each time (more likely) or the K-1 hotshoe is faulty (less likely, since the AF540 was working fine on it about a fortnight ago).

[pschlute]

I will be performing it over the next week or so

Anaesthetic, gloves, scalpel.....good luck.

[Ash]

Anaesthetic, gloves, scalpel.....good luck.

Thanks.
Operation report.
Patient anaesthetised by batteries taken out of battery compartment.
Preparation with patient in head down position.
Inferior approach with size 2 Phillips screwdriver.
Removed footplate.
Inspection of footplate wiring connections, no defects in wiring noted.
Cleaned connections with 70% alcohol wipes.
Secured all fastened connection adapters.
Reapplied footplate.
Tested flash with K-1 II + DA 15 and FA 31 in P-TTL mode in Av and f/5.6 at ISO 400-800.
Operation successful: pre-flash and exposure flash fires.
Results: well exposed images in the above circumstances.

Operation time: 7 minutes.
Cause of fault: idiopathic.
Response: all smiles from me; saves $650 in buying a new replacement flash (for now).

[pschlute]

Operation report.

Fantastic news, well done you.

Best wishes to the patient.

[Ash]

Fantastic news, well done you.

Best wishes to the patient.

Many thanks. I hope it will be a further few years of life expectancy for her.

As for the Sigma EF-500 DG Super, I have noted a workaround with it being used in TTL mode with the K-1.
It seems to only flash during exposure but does seem to meter with the camera without pre-flash. It just needs to have FEC dialled down to -2.0 to get consistently well-lit (not over-exposed) images. I tried shooting it in a range of apertures and sensitivities, and they seem to expose fine. Can't quite figure that one out since none of the modern flashes (AF540FGZ II and AF360FGZ II) have any auto or TTL metering capability, which I then assume the K-1 also doesn't communicate to the flashes. So how is the Sigma able to meter well without pre-flash?

[mcgregni]

That's great you got your Pentax 540 fixed, they are really nice flashes, and I still really like the high number of direct switches and buttons on the older version. Your electronic DIY skills are commendable!

We have heard about one particular aspect of incompatibility between the K1 and (original) AF-540FGZ, and that relates to the AF assist. The newer "MkII" versions do of course support AF assist on K1s, albeit with the front LED beam rather than the "red cross hair" type.

I have not heard of issues with P-TTL exposures however, from K1 and AF-540FGZ owners. Certainly myself, I have found that exposures are accurate and perform the same with both old and new 540 versions ..... But this is with a K7.

[Ash]

That's great you got your Pentax 540 fixed, they are really nice flashes, and I still really like the high number of direct switches and buttons on the older version. Your electronic DIY skills are commendable!

We have heard about one particular aspect of incompatibility between the K1 and (original) AF-540FGZ, and that relates to the AF assist. The newer "MkII" versions do of course support AF assist on K1s, albeit with the front LED beam rather than the "red cross hair" type.

I have not heard of issues with P-TTL exposures however, from K1 and AF-540FGZ owners. Certainly myself, I have found that exposures are accurate and perform the same with both old and new 540 versions ..... But this is with a K7.

Very fortunate fix, worked out by isolating the problem (exposure firing) and surmising that the problem will be an electrical connection rather than a catastrophic device failure. I then proceeded to investigating the connections from the hotshoe to the flash body. I can't say it was an obvious fault, since no connections were clearly loose, but it may have just been one small connector that dislodged slightly and that's all it took.

Anyway, the AF540FGZ should work seamlessly as it has in the past, only on the K-1 it requires no FEC adjustment to get well balanced images all around. The Sigma however needs an FEC dial down to -2.0 EV to be right. It does very well on the K-5 IIs however.

[vectrln]

This is more of a 540FGZ flash issue and not a K-1 II specific issue.

Just wanted to comment that my AF 540FGZ exhibited the exact same behaviour (only preflash, but no exposure flash) as the OP. Googling "540fgz no p-ttl" eventually led me to this post since I noticed there was only a preflash when the flash was on the hotshoe of my K-3.

I was about to have it checked out for repair but decided to open up the bottom to check the wiring first. It turns out that the connector on the board for the hotshoe cable was slightly raised on the left side.

The flash had earlier impact damage where it fell out of my pocket and hit the ground, so I suspect that may have been the cause or at least a contributor to what I was seeing. However it continued to work fine until recently.

After bending the connector back down to be level with the board, reconnecting the hotshoe cable, and the screwing the hotshoe back in, the flash started working again!

Not sure if this is a permanent fix, but at least the flash is working for the moment.

Thanks to Ash for sharing your solution as it saved me some $ as well.

[Ash]

It should be a long-term fix unless an event, like dropping it again, dislodges the connector from its slot.
I’m not game to do fiddle with soldering the bits together myself, but so far, since the last post, I’ve had no problem with my own 540 FGZ.

[Ash]

It should be a long-term fix unless an event, like dropping it again, dislodges the connector from its slot.
I’m not game to do fiddle with soldering the bits together myself, but so far, since the last post, I’ve had no problem with my own 540 FGZ.