What happened here?

[push]

First time using a remote flash (cactus) and my 580ex II so I'm trying to figure out what happened. In this shot I exposed for the sky, and the plan was to use my flash that's off on the left to light up the cars a little. Instead, I am left with an image that doesn't even look like the flash fired. This was a recurring thing, and I started looking for the flash firing and it certainly did. What am I doing wrong? The exif should still be in the image. The flash was probably 8-10 feet away from the dark gray car. I was standing about 30 feet away. The 580 had a diffuser on it, and was set at 1/2 power I believe.

Here is the image i'm wondering about, this happened several times.

http://img110.imageshack.us/img110/9431/noflashkm7.jpg

Here's one where the flash worked. I exposed for the cars on this one and I think I bumped up the power to 1/1 since I wanted to rule out power being it. Clearly you can see at 1/1 no problem lighting the scene up, so 1/2 shouldn't have a problem either, I mean it should at least be noticable.

http://img68.imageshack.us/img68/6223/flashworkingmc5.jpg

Please help me out! Should I not use a diffuser when shooting these kinds of shots?

[Curtis N]

Probably the Cactus trigger is firing late. The more you read about those things, the more diversity of opinions you'll get. I've never had good luck with mine outdoors.

[push]

Probably the Cactus trigger is firing late. The more you read about those things, the more diversity of opinions you'll get. I've never had good luck with mine outdoors.
Thanks, I thought of that but didn't know if it was an issue. Most of them I've seen with the cactus are sync issues at 1/250 and not firing at all. I was right near a high tension wire, so maybe there was some interference? Maybe I'll try some other channels next time and replace the cr2 battery.

[ueb0258]

It looks like you can see that the flash fired in the first photo. Looks like maybe a slight glint of flash in the headlights of both an on the Mitsu emblem. Maybe the flash wasnt powerful enough to expose it the way you were intending.

[SkipD]

The 580 had a diffuser on it, and was set at 1/2 power I believe.What sort of a diffuser were you using?

If you were using a plastic diffuser such as the Stofen or similar products, you probably lost most of the available light from the flash unit by having it go in various directions other than toward the subject.

[Karl C]

Forgive my ignorance (I didn't stay at a Holiday Inn Express last night) but why would you use a diffuser on a flash at half power that is 30 feet from your subject?

[Jim M]

I shoot a lot of cars and have some idea of what to look for and I don't see any evidence that the flash fired at all in the first picture – at least not when the shutter was open. (Look for the reflectors to be lit up and shining back at you even in a significantly underexposed picture.) If both pictures are full frame and the focal length of the lens was the same or close to it, it looks like you were farther back in the first picture. I'm guessing you were simply out of range. Otherwise, my first suspect would be batteries in the receiving units, but batteries in the sending unit can also be the culprit. Range diminishes as the batteries weaken and eventually late firing rears its head. The late firing increases as distance increases as well. If the second picture was a crop and you were in the same position, then never mind. However, I did notice some differences in perspective, so the camera was at the very least at different heights if they weren't at different distances.

Disclaimer: My experience is not with Cactus, but with another Ebay remote trigger.

By the way, I also agree that you are doing nothing but wasting power using a small diffuser outside and from that distance. Except for macro photography, those things rely almost entirely on flash bouncing off of walls and ceilings to produce their effect and there is nothing to bounce from outside. To get any useful diffusion in your situation, you would need a good sized soft box or umbrella. It also looks like your flash was rather low to the ground. I would raise it up (watch for reflections of the flash, though) so the sharp, undiffused shadows are not so obvious and the ground near the flash isn't quite so lit up, although you can't ever completely eliminate that effect unless the flash is backed quite a ways off or the ground is somewhat shaded from the flash.

[Curtis N]

Should I not use a diffuser when shooting these kinds of shots?You can see by the second shot you posted that the flash is lighting up the cars, the building and the ground. But the shadows on the wall are still hard-edged.

The Sto-Fen will spread the light in a much wider beam but won't make the shadow patterns any different.

Without the Sto-Fen, you can control where the light goes via flash zoom and distance. To control it even more, put a snoot on the flash.

The key is understanding light so you can make it do what you want.

[push]

What sort of a diffuser were you using?

If you were using a plastic diffuser such as the Stofen or similar products, you probably lost most of the available light from the flash unit by having it go in various directions other than toward the subject.
It was a stofen, I thought it was a little weird, but I had seen someone else shoot with one, and being a flash noob I thought there was a reason. I thought it would give the flash wider coverage.

[push]

I shoot a lot of cars and have some idea of what to look for and I don't see any evidence that the flash fired at all in the first picture – at least not when the shutter was open. (Look for the reflectors to be lit up and shining back at you even in a significantly underexposed picture.) If both pictures are full frame and the focal length of the lens was the same or close to it, it looks like you were farther back in the first picture. I'm guessing you were simply out of range. Otherwise, my first suspect would be batteries in the receiving units, but batteries in the sending unit can also be the culprit. Range diminishes as the batteries weaken and eventually late firing rears its head. The late firing increases as distance increases as well. If the second picture was a crop and you were in the same position, then never mind. However, I did notice some differences in perspective, so the camera was at the very least at different heights if they weren't at different distances.

Disclaimer: My experience is not with Cactus, but with another Ebay remote trigger.

By the way, I also agree that you are doing nothing but wasting power using a small diffuser outside and from that distance. Except for macro photography, those things rely almost entirely on flash bouncing off of walls and ceilings to produce their effect and there is nothing to bounce from outside. To get any useful diffusion in your situation, you would need a good sized soft box or umbrella. It also looks like your flash was rather low to the ground. I would raise it up (watch for reflections of the flash, though) so the sharp, undiffused shadows are not so obvious and the ground near the flash isn't quite so lit up, although you can't ever completely eliminate that effect unless the flash is backed quite a ways off or the ground is somewhat shaded from the flash.
So with the flash being 8-10 feet from the subject and me being 30 feet from it I can be too far away from the flash? I thought the distance that counted was distance from flash to subject, but now that I think about it it does make sense, simple physics owns me haha. Looking back at the photos, all the ones where the flash seemed to fire late was when I was backed up a good bit. I guess I will just need to invest in a shorter lens for these kinds of shots.

[push]

Here is a layout of how I set up:
http://img265.imageshack.us/img265/6936/descro7.jpg

I know now I need to invest in a 2nd possibly a 3rd to soften up the shadows I'm getting. Would having someone standing off to the side with a reflector help out at all you think?

[Curtis N]

I guess I will just need to invest in a shorter lens for these kinds of shots.Don't make things more complicated than they need to be.

One of the first decisions in making an image is perspective - Where do you want to place the camera, relative to the subject and background? From there, you select a focal length to get the field of view you want. Light placement is another important decision.

Regardless of your lens choices, changing the camera or light position to get a flash transmitter within range is a recipe for frustration.

What you need is a long PC cord. They're relatively cheap, don't require batteries and won't give you sync speed issues.

[Jim M]

So with the flash being 8-10 feet from the subject and me being 30 feet from it I can be too far away from the flash? I thought the distance that counted was distance from flash to subject, but now that I think about it it does make sense, simple physics owns me haha. Looking back at the photos, all the ones where the flash seemed to fire late was when I was backed up a good bit. I guess I will just need to invest in a shorter lens for these kinds of shots.
The problem is being too far from the receiver that sets off the flash. I sometimes run into this with my Novatrons. With them the PC cord end that plugs into the flash is the same as a household two prong extension cord. I made an adapter to go from the 1/4" plug on my radio receiver to the household plug that goes into the flash powerpack. If I need to get my pack farther away from me than the Ebay radio remote permits, I just hook one or two cheap two-prong WalMart extension cords between the adapter and the pack and move the receiver closer to me. You could probably cobble up something similar so you could keep the remote receiver closer to you than the flash, but using PC cords and hot shoe adapters instead.

[push]

I'm going to try and put fresh batteries in the receiver/transmitter. Looks like that fixed a lot of problems with them. I'm still happy with them, for $30 they have been great at closer distances.