Calling the gurus.. I have a flash timing question..

stsinner · Jan 30, 2009

So I bought this external optical slave flash that I love for cheap money, and I created a well-read thread about it.

Well, another member bought one on my recommendation, and just as with mine, his only works in Aperture Priority mode.. It doesn't sync right in Auto, nor does it sync properly in Manual or Shutter Priority modes..

What is with the flash timing in Aperture Priority mode that fires the flash at the absolute perfect time with no misfires as of yet with mine? I don't get it.. I even tried it with my Canon P&S, and I can't get it to fire at the right time..

Aperture Priority with my Nikon thus far has been flawless...

Flash Harry · Jan 31, 2009

Possibly the 1/60 automatic sync speed. H

Katier · Jan 31, 2009

Your camera will have a max synch speed ( 1/180th on my Pentax K200D, 1/500th on my Yashicamat LM) and faster than that (not that the LM goes faster) the flash won't fire. Most people using flashes extensively will use it in full manual mode tweaking setttings etc. until they're happy.

Mike_E · Jan 31, 2009

I haven't read the other thread you spoke of but have you tried setting your flash to manual? Or in other words turning off the ttl to get rid of the modeling/pre-exposure flash?

It's the pre flash that messes up the opti-slaves because they go on the first bit of any flash -yours or some one else's.

I don't know why Aperture mode turns this off on your camera but the optislaves are very simple devices and either work or not. (OK, barring intermittent failure of course)

mrodgers · Jan 31, 2009

Mike, I am the other person stsinner mentioned. I bought the same flash because it was cheap and I only have a superzoom (Fuji S700). It sounded like a good idea because of what it would cost me (not made of money here) and I could trigger it with my popup flash.

After playing for a few days and not having any luck whatsoever of getting the flash fired at the time the image was taken, I tossed stsinner a PM and we talked a bit. He mentioned aperture priority to me and as I use manual 90% of the time, I hadn't tried Av. I can now get the optical flash to work (previous it fired, but not at the time the image was taken using manual mode).

Thus, I don't have ttl mode or manual settings for my flash. The slave is a simple thing that has only a slider to select when it fires according to how many preflashes or a slider for mounting on a hotshoe.

So, you are saying that Aperture priority turns off the preflash then, or it is to be assumed it does since the optical slave works in Av but not in anything else?

I noticed today when I have the popup flash selected in Av, the camera gives me a shutter speed of 1/40 at the widest, 1/60 as I zoom and changes to 1/125 at some point near the longest focal length (I have 38-380 35mm equiv.) So now after seeing what you wrote, I am thinking that Av indeed does turn off the preflash of the popup because it just basically sets the shutter to a preprogrammed point of 1/40, 1/60, or 1/125 depending on zoom.

I'm more or less just thinking things out with this post here. Now it's starting to make a little sense why I couldn't get it to work for 3 days (since I rarely use another mode and didn't think to try it in Av).

JerryPH · Jan 31, 2009

1. Get out of TTL mode

2. Set shutter speed to your camera's max sync speed OR SLOWER.

mrodgers · Feb 7, 2009

Going to pull this one back up again as I have a question after noticing something.

As I said above, I have a superzoom (Fuji S700) and I am triggering this flash with the popup flash of the camera. My original problem was I was in manual mode and could see the flash trigger, but could not see the flash in the shot. The shot would come out quite dark in comparison to the popup flash only. Thus, as I stated above, stsinner and I discussed it and I tried Av mode and it works great.

Now for my observation. Previously when I couldn't get the flash to show in the shot in manual mode, the flash was attached to the camera via the bracket supplied that screws onto the tripod mount of the camera. This put the flash unit right next to the camera.

When I tested it in Av mode after talking to stsinner, I didn't realize at the time, but I did not have the flash mounted to the camera. I had it mounted to my tripod which was sitting over on the side. The flash fired and I could see it in the shot. Since at the time, I didn't make the connection that I had the flash mounted on the tripod instead of the camera, I was playing around tonight (er... last night I guess) and found that it now works with the camera in manual mode as well if I do not have the flash mounted next to the camera.

So, can anyone enlighten me as to why the flash would not show in the image with it mounted right beside my camera? Again, I am using the popup flash as well because that is what triggers the slave. I put the camera in Av, of which is how I initially got the flash to work, but I left it mounted to the camera and it again, did not show in the images.

I know the main reason to have a flash unit is to get off-camera lighting, but I really mainly wanted it for the kid's birthday party shots more than creative flash photography. I wanted to be able to have the flash on the camera just to bounce it off the ceiling or use it direct for more light in my party snapshots.

Just for more information, when the unit is mounted on the camera via the bracket and is facing forwards for direct flash, the lamp is about even with the lens of my camera. Although, I also noticed the same lack of result when I held the flash away from the camera in my hand up to arm's length. If I have the flash a good distance away from the camera, meaning much further than arm's length, the flash works fantastic. I can bounce it or use it facing direct to the subject and it works.

Also more information, it is just a simple unit with no settings. It's either set for hotshoe or for optical trigger and can be set to 1 through 4 preflashes before it triggers. There's no power settings or timing settings other than setting it to how many preflashes my popup will do before it triggers.

So, why does it not show in the photos when it is too close to the camera?

Thanks for any insight to this.

JerryPH · Feb 7, 2009

Likely the obvious... the location of the sensor doesn't permit it to see the camera flash. Either throws off the timing or doesn't see the trigger flashes. Let's be honest... you got what you paid for.