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I'm starting to learn about flash photography and purchased a basic flash to try out. When using ETTL mode I get a strange behavior when bouncing off the ceiling.

Camera: EOS 1300D Flash: Neewer 562c

All shots at 1/60 F9.0 ISO:800

Without Flash:

1/60 F9.0 ISO 800

So I turn on the flash, its set to ETTL, I point it straight forwards and get: 1/60 F9.0 ISO 800 ETTL Flash

I try pointing the flash straight up to bounce the light off my white ceiling and get: 1/60 F9.0 ISO 800 ETTL Flash pointed up

I have no idea how that bar of odd exposure at the top is being formed.

If I then set the flash to manual at 1/16 still pointing up I get a reasonable image:

enter image description here

Any ideas greatly appreciated.

Edit: As stated flash works fine in manual mode. Taking flash off camera yields same results. Taking burst shots occasionally results in a good image. At 1/40 and 1/80 there is no odd bar of exposure but image is entirely underexposed.

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  • \$\begingroup\$ Have you tested with other shutter speeds? Your third image makes me think that there's a timing problem. Try using a 1/2 second or even 1 full second exposure. Do you get the same result? \$\endgroup\$
    – OnBreak.
    Dec 16, 2019 at 22:08
  • \$\begingroup\$ At 1/2 a second the odd bar of exposure is not visible. The images looks bright enough but it predictably blurry. I tested 1/40 and 1/80 also. At these speeds the bar is not visible but the images are very underexposed. \$\endgroup\$
    – Matt
    Dec 16, 2019 at 22:46
  • \$\begingroup\$ I carried out a further test with the flash off camera. Same results however I tried a 3 shot burst and 2 were well exposed. However repeating this did not yield same results. So the diagnosis of timing issue seems correct, I just need to determine if the cause is the camera or the flash. \$\endgroup\$
    – Matt
    Dec 16, 2019 at 23:49
  • \$\begingroup\$ You state that things work perfectly well in manual mode...perhaps something to do with the calculations occurring for e-ttl or possibly a problem with the flash using too much juice in the preflash and then not having enough to fire for the actual flash? Timing seems like a correct diagnosis though. I encourage you to edit your question to include all of these new details and to hopefully attract more answers \$\endgroup\$
    – OnBreak.
    Dec 17, 2019 at 0:31
  • \$\begingroup\$ This appears to be a synchro issue. However, have you tried changing the 'Shooting (red tab) 1 → Flash control → External flash C.Fn setting → E-TTL II meter.' setting from 'Evaluative' to 'Average'? Many third party flashes underexpose in bounce mode using E-TTL with Evaluative metering. \$\endgroup\$
    – Michael C
    Dec 18, 2019 at 0:41

2 Answers 2

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You can see the "bar of odd exposure" on your second image, too: it starts at the bluish disk above the "Star Wars" tool on the left. I don't see it in the first image without flash though it should be on-frame and I don't see it in the last image. The "straight-up" bounce shows a white clock face in that bright stripe, and it would appear that the clock face is more or less exposed correctly.

The camera is a DSLR. My personal guess would be that you have a shutter and/or mirror problem. The camera is probably not entirely new, and you may be getting a bit of the preflash exposure added to the top of the sensor.

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At 1/2 a second the odd bar of exposure is not visible. The images looks bright enough but it predictably blurry. I tested 1/40 and 1/80 also. At these speeds the bar is not visible but the images are very underexposed.

This pretty much confirms that your problem is in the timing. I would guess that your camera uses a shutter that opens from top to bottom, which given an inverted image, means that your frame is exposed bottom to top. Since it's the top part of your image that has the flash, this leads me to conclude that the flash is firing too late.

Normally, the camera sends a signal to the flash to fire right as both curtains are open, thus flashing the scene and getting it 100% captured in the frame.

In your case, the timing is off and the curtain is already closing when the flash fires, so it only exposes part of the frame.

With this type of problem, you can generally get varied results by adjusting the shutter speed to get more or less of the frame exposed. Obviously, though, I'm sure you'd like to use any shutter speed up to the sync speed, no?

Unfortunately, I have no idea how to actually solve your problem - having no experience with off brand speed lights. Good luck!

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