Second curtain flash

[gore]

In some last events I noticed problems my photos with second-curtain flash. On photos It looks like used First-curtain sync. My gear: Canon 30D and 580EX.
Look at http://izo.amebis.si/razno/slika.jpg

and

http://izo.amebis.si/razno/crop.jpg

I have second-curtain sync set on flash AND on camera (CFn 15).

Exif data:
24-105 f4 IS
Flash fired, compulsory flash mode, red-eye reduction mode.
Manual
f/11.0
1/15 sec.

What can be wrong?
I now ETTL will fire preflash, but this should not ruin photo. I also tried with Manual flash power.
Can IS have an effect? I didn't try this.

Why a hell a boy isn't sharp when flash fires (on first or second curtain ???)? I would expect that flash fires in very short time and the power of flash (batteries are full) is powerful enough to still moving.

[texaskev]

Looks to me to be as simple as this, your shutter speed of 1/15 is very slow to capture this image if you are hand held. Heck, mybe even if you are on the 3pod. I'd shoot TV, turn red eye off since you are not shooting his face and set that shutter to 1/125 at first and then 1/250 if I didn't get a sharp image at 1/125. Set the ISO up if needed. Good luck, that would be a cool capture if you can get it. Oh, you asked about IS, yeah man, that's good stuff! But imho, comes in play more with a subject a bit farther away. Experiment, when you can shoot IS you can shoot a slower shutter speed.

[gore]

Thank you. I want slow shutter speed, because I also want panning effect. But I can't find out, why first (and not second) curtain flash appears.

I love IS - it is fantastic feature.

On my blog (http://kacnje.blogspot.com) (11th August) I have some photos from bike park. I was walking with my family and take just some shoots. But there are potential shoots :D

[vondo]

My guess: 2nd curtain sync is to get trails behind a subject. But you are panning too. So where the subject is in your frame when the flash goes off and you get the most substantial exposure is then completely random. (I.e. had you panned a little too much or not enough. Looks to me that in this shot, not quite enough).

Also, the bike itself is much better defined than the rider's (moving) leg.

[xarqi]

My guess: 2nd curtain sync is to get trails behind a subject. But you are panning too. So where the subject is in your frame when the flash goes off and you get the most substantial exposure is then completely random.

That seems like a great explanation to me. Well done.
Panning too slowly so that while the shutter is open, the subject is moving backwards relative to the frame. The flash fires at the end, so presto, the blur appears in front of the flash-exposed subject.

It could be very tricky to get this right. Best bet might be to try to accelerate your pan as the subject passes.

[gore]

My guess: 2nd curtain sync is to get trails behind a subject. But you are panning too. So where the subject is in your frame when the flash goes off and you get the most substantial exposure is then completely random. (I.e. had you panned a little too much or not enough. Looks to me that in this shot, not quite enough).

Also, the bike itself is much better defined than the rider's (moving) leg.

Very good - good idea. Can be.

But I will try two more thing:
1. Much longer shutter time in dark - so I can see flash at the end.
2. Disable red eye reduction.

[Doug Pardee]

I'm guessing that you're not getting second-curtain sync at all. Try setting your shutter speed to 1/2 second or so, and see if you can see a preflash followed by the main flash a half second later.

The main reason that people don't get second-curtain sync is that they try to set it on the camera when using an external flash (like the 580EX) that has its own second-curtain sync setting. Try setting second-curtain sync on the flash.

There are some other considerations, like you can't use second-curtain sync when the flash isn't mounted on the hotshoe, or when the flash is set as a master or slave in a multi-flash setup.

[gore]

I'm guessing that you're not getting second-curtain sync at all. Try setting your shutter speed to 1/2 second or so, and see if you can see a preflash followed by the main flash a half second later.

The main reason that people don't get second-curtain sync is that they try to set it on the camera when using an external flash (like the 580EX) that has its own second-curtain sync setting. Try setting second-curtain sync on the flash.

There are some other considerations, like you can't use second-curtain sync when the flash isn't mounted on the hotshoe, or when the flash is set as a master or slave in a multi-flash setup.

I will try longer shutter speed (I'm not at home now).

I double checked and both settings (on camera and on flash) are set to second-curtain. Flash is mounted on hotshoe and flash is set to OFF (not Slave or Master).

On last wedding I have the same problem, but I was sure this was a wrong settings. But now - and here is the example (crop) - I'm sure something is wrong.
http://izo.amebis.si/razno/crop2.jpg

[m-bartelt]

Hmm.... can someone offer some good tips for getting the 'right' panning shots?

[Madweasel]

Other posters who pointed out the panning effect have the correct explanation. I think you'll get something nearer to the effect you want if you hold the camera still. Then the background will be sharp and the cyclist will have a sharp image with a trailing blur behind him. If I understand you correctly, this is the effect you were after.

[PacAce]

I think you're 2nd curtain is working just fine. If I were to make a guess, I think the reason you got the effect you did is because the rider is moving backwards and pulling up on the handle bar in order to get the front wheel up in the air.

[JDubya]

if you think your 2nd curtain is on the fritz why don't you just take like a 3 second exposure on 1st curtain then 2nd curtain while looking for the flash. Then you'll know for sure what the problem is.

[Curtis N]

It takes a bit of thought to logically predict the effects of 2nd curtain vs. 1st curtain. But it doesn't make diddly difference unless the subject is moving in relation to the camera.

If you're panning and trying to follow your subject, you'll either get motion blur or not depending on how good (lucky) you are with the panning. 2nd curtain will only put the blur (which comes from the ambient exposure) in a different place relative to the sharper flash exposure. If the ambient contributes significantly to the exposure, then adding flash won't magically eliminate motion blur.

To understand flash photography, you need to disect each shot into its separate parts - the ambient exposure and the flash exposure. Think about each part separately.

[FlashZebra]

motion blur.

Curtis,

I am working on emotion blur, any ideas?

Enjoy! Lon

[Jim M]

Don't pan with second curtain. The blur being in the wrong direction is from panning too fast, not from panning too slow. But don't pan.

In the wedding picture, I think your first assumption was correct. If the second curtain is set on the camera, but not on the flash, the flash will override the camera and you will get a first curtain flash. This is extremely easy to get wrong (word of experience here). I swear the flash resets itself when you aren't looking.

[gore]

Thank you - all of you.
I understand how Canon flash is working, but ... :roll: ... it happens.

I simply made a mistake when pressing a button on flash unit. I tried yesterday and everything is working like it has to.

I obviously pressed a button one more time by error and then :evil:


Thank you and sorry.

[apersson850]

At least Canon has adressed this confusion later. On the 40D with a 580 EX II, the settings are done through the camera's menu system, where it's very easy to read what you've actually set up.

[Jim M]

At least Canon has adressed this confusion later. On the 40D with a 580 EX II, the settings are done through the camera's menu system, where it's very easy to read what you've actually set up.
How does that work? Did they take second curtain selection away from the flash or does the camera just override the flash command. With the 580 EX and 30D, the flash overrides the camera command. I set second curtain on my camera to get it with my Novatrons, but if I use my 580 EX, it has to be set on the flash.

[apersson850]

The last setting done is the one it uses. You can set 2nd curtain sync, for example, on both the flash and the camera. If you set it on the camera, it will show up on the flash, and if you then disable it on the flash, the new setting will be shown in the camera menu.

The only priority thing is the FEC. There, if you set it on the flash, that has priority, regardless of how the camera is set. You have to set it to zero on the flash for the camera setting to have any effect.
If you set it on the flash first, the camera will tell you it can't command FEC. If you set it on the camera first, then on the flash, there's no warning or anything. This is probably done for compatibility with older cameras.

[Jim M]

The last setting done is the one it uses. You can set 2nd curtain sync, for example, on both the flash and the camera. If you set it on the camera, it will show up on the flash, and if you then disable it on the flash, the new setting will be shown in the camera menu.
Is this a function of the 40D or the 580EX II or does it take both? I just rechecked my 580EX and 30D combination and it doesn't work that way at all. Flash takes priority no matter what was set last. Too bad. Sounds like it would be a handy feature.

[PacAce]

Is this a function of the 40D or the 580EX II or does it take both? I just rechecked my 580EX and 30D combination and it doesn't work that way at all. Flash takes priority no matter what was set last. Too bad. Sounds like it would be a handy feature.

It's a feature of both the flash and the camera combined.

[apersson850]

Exactly. If one of the two items are of the older type, i.e. either the camera is a 30D or the flash is a 580 EX (not 580 EX II), what I described will not work. It can still be done, though, as the 580 EX II allows for setting this on the flash itself, for example, but not through this integrated menu setting system.

[Jim M]

Exactly. If one of the two items are of the older type, i.e. either the camera is a 30D or the flash is a 580 EX (not 580 EX II), what I described will not work. It can still be done, though, as the 580 EX II allows for setting this on the flash itself, for example, but not through this integrated menu setting system.
Thanks. One more reason to upgrade, but my stuff just won't wear out so I can replace it and stay married.

[Curtis N]

Don't make this more complicated than it is. If you're using a flash with a second curtain setting, set it. It's one button on the flash you push a couple times. The LCD on the flash will be a constant indicator that it's set.

No need to dig through the camera menu unless you're using the built-in flash or an E-TTL compatible hotshoe flash with no second curtain option.

[gore]

As Curtis said - the flash unit will have priority. So the simplest way to enable/disable second curtain is via button on flash unit. Without digging in menus.
I also use flash compensation via flash unit (and not via camera settings). It is faster and more intuitive.

[apersson850]

As Curtis said - the flash unit will have priority.When combined with older cameras I assume that's true. I haven't tested it with my 400D, but I could, of course. But it's not true when you put a 580 EX II on a 40D, for example. So the simplest way to enable/disable second curtain is via button on flash unit. Without digging in menus. Using the second curtain sync is very easy to set on the flash, yes. So it's probably faster than using the menu.
I also use flash compensation via flash unit (and not via camera settings). It is faster and more intuitive.Something which isn't true, if you want to apply FEC whilst still looking through the viewfinder. Now, when Canon got the ISO/FEC button out to the far right, it's very quick and easy to use while still looking through the viewfinder. Setting it on the flash unit itself requires taking the camera down from your eye to handle the wheel on the back of the flash.