dedicated transceiver or use camera flash to trigger flashgun?

[wideangle]

Is there any benefit over buying a flash transceiver over a camera that can use the inbuilt flash to trigger a remote flashgun?

[Kym]

I use the camera flash, which on Pentax is set to controller, i.e. it puts out little light but triggers the wireless signal.

[wideangle]

I use the camera flash, which on Pentax is set to controller, i.e. it puts out little light but triggers the wireless signal.

So you don't find that the inbuilt flash used as a trigger effects the light output?

[arthurking83]

As long as you set the on camera flash to commander only(from memory you have Nikon??) ... then for all intents and purposes, No!

It may actually add some light to the overall exposure if the subject is at very close distances such as some macro distances and the flash power level used was very low, but it's very hard to determine the actual amount of light it adds.

I once set up a small quick unscientific test with the D300 to see how much it adds, using only the added light from the on camera flash set as commander, and the exposure was barley usable. I had the main flash pointed away and hidden from the subject matter so that it wouldn't add any light in the test.
In the test where the flash was actually used, there was no difference between the histograms of the sample images, one where the light from the onboard flash was allowed through to the subject, and the other where the light was blocked/restricted. ie. in real terms no effect.

Haven't tested the D800, and only because I expect it works similarly or better than the D300.

[I @ M]

Is there any benefit over buying a flash transceiver over a camera that can use the inbuilt flash to trigger a remote flashgun?

Yes there is in some cases. Sunlight can "confuse" the onboard flash trigger signals or the receiving flash if strong light is hitting either. Obstacles such as walls, windows etc can "block" the light signal. Even photographing with the camera in vertical orientation may cause light transmission / reception issues if the two units cannot "see" each other.

A radio trigger generally eliminates all those problems.

[Wretched]

I'd be worried about adding extra light to the foreground of the scene (which may be unwelcome) if I was using the camera's flash to trigger the others.

[johndom]

Both. Or, it depends.

Generally if you only want the light from your off camera lights, then a trigger you will need.
You can get a bit of fill by using the on camera flash to bounce into the ceiling and it should trigger most nearby flashes.
Sun and sometimes fluorescent lights can confuse the receiving port on some flashes so be aware and turn the port toward the triggering source.
There doesn't seem to be a trigger system that doesn't randomly fail for no apparent reason. Even my elinchrom sky port thingy has stopped for no apparent reason. Having 2 options is good.

[wideangle]

So will an on camera built in flash trigger multiple off-camera flashguns?

[I @ M]

So will an on camera built in flash trigger multiple off-camera flashguns?

As in the above advice that you have been comprehensively given by others ---- yes, an on camera flash can trigger multiple off camera flashes IF there are no obstructions to the optical path, you are prepared to accept that some light from the on camera flash might influence the exposure and that the off camera flash units have the ability to be triggered optically.

You really need to be more specific about what camera will be used, what flash units will be used, how many of them will be involved and how far they will be from the camera otherwise you will be going around in circles trying to work it out.

[wideangle]

Just trying to get my head around why an on camera flash can trigger multiple off camera flashes, whilst if you went a radio trigger why you need one for every single flash that you want to trigger.

As in the above advice that you have been comprehensively given by others ---- yes, an on camera flash can trigger multiple off camera flashes IF there are no obstructions to the optical path, you are prepared to accept that some light from the on camera flash might influence the exposure and that the off camera flash units have the ability to be triggered optically.

You really need to be more specific about what camera will be used, what flash units will be used, how many of them will be involved and how far they will be from the camera otherwise you will be going around in circles trying to work it out.

[MarkChap]

On camera trigger will only fire multiple flashes in 2 instances -
1 (and least favourable) - Each remote or slave flash has a basic optical trigger built in, this will cause your on camera flash to add light to your scene and you cannot controll any variables such as power level from your camera to the remote
2 (and better option) - Each remote flash is of the same brand as your camera and has the built in remote function for that brand (Canon 430, 580, 600Ex for a Canon system or the SB 910, 900, 700, 600 etc for Nikon system.) This also allows you to control all your variables from your camera. This is possible because the manufacturer builds the technology into their own equipment,

Radio triggers are an after market option, so you need receivers for each remote to tell the flash what to do. The ONLY Exception to this rule is now teh Canon 600EX-RT series of flashes that have the radio receiver built into the flash, but you have to use the canon trigger