Black Bar on photos - did something break!

Hi all,

I have just run into a problem and I can't seem to find anything with a search. I am using a Canon EOS 500D with a Sigma 70-300mm F5.6 DG Macro lens. I was just messing about testing a wireless flash setup when I started noticing something strange on the pictures. Half of the photo is black, as if something inside the camera/lens is in the way. The size of the black area changes depending on the shutter-speed. For example, if I am shooting at 1/500, the photo is entirely black. At 1/400 it's about 70% black, at 1/320 it's about 50% black, at 1/240 it's about 25% black and at 1/160 and below, the photo comes out fine. Here are some examples that maybe make more sense:

I took this in "M" mode with a shutter speed of 1/400:

I believe you are exceeding the cameras x-sync limit; how fast the shutter can release with flash.

Jason

It seems that your camera is not set to its "flash-synch speed" and instead is working on a shutter speed that is simply wrong for the flash. This means that the flash is only exposing a part of the frame each time. With focal-plane shutters, the whole frame must be open for the flash to expose the shot properly and here it is not.

Maybe a quick read of the camera manual is called for?

Well, you learn something new everyday! I haven't spent much time with external flashes as most of my photography has been done outside on bright days, or in places where flashes aren't allowed. I will certainly dive into the manual/google now and have a read. I just saw these black areas and panicked

The strange thing is that the other time where I have seen this black area was in one of the indoor environments where a flash isn't allowed (aquarium).

Thanks very much .. feeling less worried now!
Cheers, Ori

Orias wrote in post #16635440
...Anyone have any ideas what the problem might be? Seems like something in there is "sticking" and blocking the lens from the inside.

It's the shutter curtain. Just keep the shutter speed at or below the maximum sync speed and you'll be fine.

Orias wrote in post #16635462
The strange thing is that the other time where I have seen this black area was in one of the indoor environments where a flash isn't allowed (aquarium).

I suspect the lighting type at the aquarium was fluorescent or some other similar gas-discharge lighting operating at power-line frequency. This type of lighting requires very careful selection of shutter speeds to avoid color and intensity variation across an image.

Yah, you are probably right SkipD, there are some quite bright florescent lights in there when you hit them at the wrong angle.

Just been reading up and testing some more. I am using a Speedlight 430EX II and it seems that when it's fixed directly to the hot-shoe, then there is no limit to the shutter speed (makes sense), but when I am triggering it with the wireless remote, then it looks like 1/200 is the fastest it can go before I get the black bar. I can't seem to find any settings/options that will let it go any faster than that, so it looks like this is certainly just an issue of me overshooting the 500D X-sync level for wireless triggering.

Thanks for the help again,
Cheers, Ori

No. You must have High Speed Sync enabled, which is a different thing altogether. The max sync speed for ordinary flash is the same regardless of the position of the flash(hot shoe or off camera).

Orias wrote in post #16635506
Yah, you are probably right SkipD, there are some quite bright florescent lights in there when you hit them at the wrong angle.

It isn't the angle to the lights that makes a difference. It's the timing. The color and intensity of fluorescent lighting changes as the voltage supplied to it changes. When the light is operated at power-line frequency, you cannot use any shutter speed faster than 1/120 second (where the power line frequency is 60Hz) without risking catching the light at an odd color or intensity. When shooting with fluorescent light that's running at 60Hz power line frequency, you should really choose shutter speeds that are exact multiples of 1/120 second (like 1/60, 1/30, 1.15, etc.) so that the film or sensor "sees" the light that's created through a full half-cycle of the power or exact multiples of a half-cycle.

Orias wrote in post #16635506
Just been reading up and testing some more. I am using a Speedlight 430EX II and it seems that when it's fixed directly to the hot-shoe, then there is no limit to the shutter speed (makes sense), but when I am triggering it with the wireless remote, then it looks like 1/200 is the fastest it can go before I get the black bar. I can't seem to find any settings/options that will let it go any faster than that, so it looks like this is certainly just an issue of me overshooting the 500D X-sync level for wireless triggering.

The only way your Speedlite can allow you to use shutter speeds faster than the camera's "maximum sync speed" is to have the Speedlite operate in "High Speed Sync" mode when you set the shutter speed faster than the max sync speed.

When you have High Speed Sync (abbreviated HSS) activated and use shutter speeds faster than the max sync speed, the Speedlite turns into a very different source of light. Instead of a single very burst of light, its output in HSS mode is a continuous string of extremely short pulses of light that continue for the entire time the shutter leaves are moving. This mode emulates continuously-on light.

You would benefit greatly by studying how the flash system you are using actually works and how your camera functions when using it. You'll find a lot of info in the "Small Flash and Studio Lighting" area of the forums.

Orias wrote in post #16635506
...I am using a Speedlight 430EX II and it seems that when it's fixed directly to the hot-shoe, then there is no limit to the shutter speed (makes sense), but when I am triggering it with the wireless remote, then it looks like 1/200 is the fastest it can go before I get the black bar. I can't seem to find any settings/options that will let it go any faster than that, so it looks like this is certainly just an issue of me overshooting the 500D X-sync level for wireless triggering...

Actually, no... that's not true. Even with the flash in the hot shoe on your camera the max flash sync speed is also 1/200. (Note: some other models have higher sync speeds... 7D is 1/250. 1D series is 1/300.)

However, 430EXII (and many other Canon flashes) has a High Speed Sync (HSS) mode. This feature allows you to use the flash at speeds faster than the max sync, but seriously limits the reach of the flash.

So if you are able to use faster than 1/200 with the flash in the hot shoe, you must have HSS set... and are not getting anywhere near the reach the flash is capable of doing.

I never use built-in/on-board wireless triggering (it has too limited range, I use an ST-E2 instead), so can't say if it's usable with HSS or not.

Also, you cannot use HSS and Rear Curtain Sync at the same time. The two are mutually exclusive. I find myself using Rear Curtain Sync a lot more often than HSS, just due to the nature of what I shoot (moving subjects, mostly).

Here's a little secret...

When using flash as your primary light source, the shutter speed really doesn't matter (very much).

The reason for this is that the flash itself acts as a shutter, with a short duration of light output, usually equivalent to about 1/720 shutter action.

Now, with ETTL and Canon cameras, it depends upon the exposure mode you are using, whether or not you are getting "full" flash that the camera treats as the primary/only light source. You have to be in Manual (M) mode for the flash to be treated this way.

If you are in any of the auto exposure modes (Av, Tv, P), the camera will try to expose based upon the ambient light conditions, then fire the ETTL flash as "fill", reducing it's output by about 1.5 to 1.7 stops. Just enough to open up shadows and, hopefully, balance with ambient light.

Whether using the flash as "full" or "fill", you can dial it's output up or down with Flash Exposure Compensation (FEC), which behaves the same as Exposure Compensation that's on the camera and used to modify the auto exposure modes (Av, Tv or P).

So, again, when using "full" flash, the shutter speed you set on the camera doesn't matter.... much.

You do need to keep it to the sync speed or slower (unless using HSS). Also, if you set too slow you will start to see ambient light mixed in with the flash... that can throw off exposure, cause surprises, or risk shake/movement blur that looks like ghosting. So, there's a range of shutter speeds you'll need to work with. But it can be a lot slower than you'd normally risk. If you set the camera to, say, 1/30 and use full flash, thanks to the flash you will have anti-shake and subject-movement-stopping capability of around 1/720 (there are special flashes with shorter and longer duration output). Shutter can be set to 1/15, 1/60, 1/125... whatever. The results will be about the same (except for ambient light, see below).

Your ISO and aperture settings control the reach of the flash... distance to the subject. Depth of field considerations still apply, so that might dictate what aperture, and thus what ISO you need to use.

Your 430EXII displays a scale on the bottom of its LCD screen, showing the distance the flash is serving with the settings you've made on the camera and flash (scale can be set to read out in feet or meters, whichever is more convenient to you). If in doubt, pre-focus on your subject and read the distance from the lens (if your lens has a distance scale... some don't).

Although not exactly addressing your issue because it is a Canon QuickGuide you might want to go to http://www.learn.usa.c​anon.com …ite430EXII_Quic​kGuide.pdf and download the 430EX II QuickGuide. It's a PDF file and when printed is just two pages. Some of these QuickGuides I get printed at a local staples onto cardstock and carry with me for a quick reference.

Thanks John, that's certainly useful. Might print and laminate that one!

Well, after trawling through the manual and various online resources, I think I have finally discovered that my camera doesn't actually support High Speed Sync mode on the Speedlight 480EX II.

No matter how hard I try, I can't get it to do the "strobing" that is referenced when it's set to HSS ... but on the very last page of the manual it says that "Type B cameras (TTL autoflash EOS camera)" do not support the High Speed Sync (FP Flash) mode, so I guess my 500D falls into that category!

Thanks again,
Cheers, Ori