[BarryE]

Anyone got any ideas what's happening with these shots, please?

K1. 2 Cactus flashes fired off Cactus trigger. Formatted. SanDisk Extreme pro cards.

Occasionally I get images that look like this. I'm duplicating the images onto two different cards in camera. I'm using RAW only. When I review them on the LCD I get no indication that there's a problem, however when I load them onto pc (viewing in ACR) I see the problem. I checked both cards and they both show the same problem. So I can view the previews on the camera and all look fine, but when downloaded they are not. The fact that I don't see the problem on the camera to give me a warning is a concern.

I'm puzzled. Any ideas ? (See my inconclusive summary in later post. Not anywhere nearer knowing what is causing this, sadly.)

Attached Images

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View Picture EXIF

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Last edited by BarryE; 08-18-2019 at 06:58 AM.

[pschlute]

So I can view the previews on the camera and all look fine, but when downloaded they are not. The fact that I don't see the problem on the camera to give me a warning is a concern

In-camera you are viewing the jpeg preview that is contained within the raw file. When you open them in ACR you are viewing the raw image. Have you tried updating ACR or tried another converter ?

[Tau-Ceti]

Hmm, looks to me like a corrupted file. I am very certain, that this was caused by a defective sector on a SD card.
As you said, you copy them from one card to another AFTER the data was written to one card. Try using the redundancy setting for your SD cards.


There are several Tools with which you can test them for Errors.
For example H2testw from the Heise Media Group. (The tool basically fills up your storage and then checks the written data for errors.)

H2testw | heise Download

[BarryE]

In-camera you are viewing the jpeg preview that is contained within the raw file. When you open them in ACR you are viewing the raw image. Have you tried updating ACR or tried another converter ?

Thanks Peter, the ACR is the latest CC version. The problem also shows in DCU5 - saving the DNG as JPEG or TIFF, both end up with faulty versions.

For now I've swapped to writing a RAW and a JPEG to see if there's something recoverable when it happens again.

I'm still puzzled with what might be going on here. The embedded JPEG is obviously fine, but something in the RAW file isn't. ACR and DCU5 both convert the RAW file to show a corrupted version. I'm beginning to wonder if there's some interaction between the Cactus trigger and the camera, perhaps during the writing to the cards, though as it is corrupting both card's RAW file, it is unlikely to be a transient effect, unless the cards are really written in parallel, which I don't believe they are.

---------- Post added 08-18-19 at 11:54 AM ----------

Hmm, looks to me like a corrupted file. I am very certain, that this was caused by a defective sector on a SD card.
As you said, you copy them from one card to another AFTER the data was written to one card. Try using the redundancy setting for your SD cards.


There are several Tools with which you can test them for Errors.
For example H2testw from the Heise Media Group. (The tool basically fills up your storage and then checks the written data for errors.)

H2testw | heise Download

Thanks for helping. I am using the dual card setting in camera, so it's not likely to be a card problem as they both exhibit the problem. More likely to be a writing problem, perhaps related to the trigger ????

[Tau-Ceti]

I see. I doubt that the Cactus can have such an effect. Afterall they are simple transceivers and i am using them too without such an effect.
After the Image is taken, it gets processed and then stored in the cameras buffer from which it will be written to the card. Perhaps the buffer of your camera is faulty.
You could check for this by taking a series of images and checking if you can reproduce the error more or less regularly.

I would still check the SD Cards though.
(I had about 3 files this year, which look like this. Saddly i did not find out in time to check the redundand images on the other card.)

[BarryE]

I see. I doubt that the Cactus can have such an effect. Afterall they are simple transceivers and i am using them too without such an effect.
After the Image is taken, it gets processed and then stored in the cameras buffer from which it will be written to the card. Perhaps the buffer of your camera is faulty.
You could check for this by taking a series of images and checking if you can reproduce the error more or less regularly.

I would still check the SD Cards though.
(I had about 3 files this year, which look like this. Saddly i did not find out in time to check the redundand images on the other card.)

Thanks again. I've been trying this and I can't see any correlation with a fault occurring and the method I'm using. I worked on a shoot last week and I got one failure in 215. This morning I've had five failures in 67 - not so good.

[Tau-Ceti]

Did you shoot in high continuous shooting mode until the buffer was completly filled?

[BarryE]

Did you shoot in high continuous shooting mode until the buffer was completly filled?

No. Remote. Tripod. MUP. Slooow shooting.

I've just shot a sequence of 30 frames with no trigger attached. No problems. I then shot a sequence of 30 frames with a trigger attached. Again no problems. Before I was only saving DNG whereas these two sequences I was saving DNGs and JPEGs. The 60 frames may not be significant number of test frames I appreciate, but the problem showed up often earlier this morning. More puzzled !!

[Tau-Ceti]

Hmm, perhaps i am wrong and this is a frimware issue.
What Cactus device do you have attached?
A RF60 Flash or a V6 Trigger?

You can download a special Pentax Firmware for the Trigger at least.

[BarryE]

Hmm, perhaps i am wrong and this is a frimware issue.
What Cactus device do you have attached?
A RF60 Flash or a V6 Trigger?

You can download a special Pentax Firmware for the Trigger at least.

The latest Pentax firmware on a V6ii. I'll take a break now and run some more tests later. Thanks again, Rene ...

[ramseybuckeye]

Have you formatted the cards?

[jbinpg]

I would also try shooting in PEF format to see if the problem persists.

[BarryE]

Further tests and none the wiser, sadly.

Formatted cards. Dual card write. With and without writing JPEGs. Same (USER) settings. Same trigger unit. Fresh batteries in all (as before). One and two flash set-ups. 150 frames. Waiting and not waiting for yellow LED to stop flashing. No problem. Grrrr.

I will set my USER settings to add high quality and L JPEGS for now, as if I have a RAW write problem, maybe then I'll have a usable JPEG. I will also wait for the yellow card write LED to have finished flashing.

I don't believe there's a camera/card problem. What I am suspicious of is that there might be an timing/interaction issue between the Cactus V6 trigger and the camera's card write. I've not seen a problem when I include RAW and JPEG and neither when I've been waiting for the yellow LED to extinguish. When I was testing this morning I was only using RAW and I was not thinking about waiting for yellow LED.

I have a shoot this Tuesday. I'll report back if I get any extra info.

(Extra - from DCU5 I can extract a low quality JPEG from the RAW file. Guess this confirms there's a corruption in the RAW portion of the DNG file)

Thanks for your help ...

{edit: I wonder if when the flashes are on high power (I'm using them in manual mode) and I fire the shutter before they have recycled the problem is more likely to occur? My later testing was at 1/256 to preserve power, whereas in use earlier they were around 1/2 power. Perhaps there's some signalling that is going on between the camera, trigger and flashes that causes the occasional fault}

[Not a Number]

How are you transferring the files? Via USB cable or a card reader? Try a different cable, port or reader.

[Dericali]

If problem persists, try with different SD cards