Strobist Question - DPChallenge Forums

Nikon AF-S DX 18-105 f/3.5-5.6 ED VR

03/19/2010 12:43:56 AM · #1

Hi Guys

I'm a newbie, and have been messing the last couple of days trying to capture falling water drops (yeah I know...)

Anyways, I have a Canon 5D Mark II with 2 Canon 550ex connected as slave / master via a ebay wireless trigger (Well, it's supposedly better than the really cheap ones)..

I'm shooting in Manual mode, with a Canon 100mm f2.8 macro lens at f8.

1. I notice that at a shutter speed faster than 1/100, I usually end up getting a dark band from the second curtain. Quick Googling has suggested that canon flashes should be good to sync up to 1/200 at least... what am I doing wrong?
2. Is it possible to sync the second flash that it fires a few milliseconds later?
3. How do I enable multiple flashes? I did turn the dial to "multi" mode, but it didn't seem to work...And is it possible to control the frequency of flashes in multi-mode?

Many thanks!
Manav

millsa

Nikon D7100

03/19/2010 12:54:59 AM · #2

Could just be the ebay triggers aren't giving you the response you need for >1/100th, but I question why you need it? To "stop" the motion your flash does the work, in order of 1/10000th if its set at low power. If your in a dimly lit room 1/100th is way more than enough, I'm usually a lot slower than this.

As for strobe on the canons I can't comment, I don't use them, sorry.

Message edited by author 2010-03-19 00:55:50.

Nikon AF-S DX Zoom-Nikkor 18-55mm f/3.5-5.6 ED

03/19/2010 12:59:04 AM · #3

Oh. Thank you.

So in M mode, what do you dial the power to?
Also what should the "zoom" be set to when I got a 100mm macro lens connected to my camera?

It is possible the delay might be from the triggers (and if its in milliseconds, I obviously won't be able to spot the delay manually)..but I do get a dark band at the lower half of the picture...

I personally end up with the settings as mentioned, and the flash dialled to 1/16 of its power...i've been playing with various focal length settings on the "zoom" but haven't reached any conclusions yet...

Sorry I'm kinda trying to figure this out as I go along..and after about 6 to 7 hours over two days I'm not sure whether I know any better

Thanks again.

Joker1114

Nikon D7000

03/19/2010 01:05:55 AM · #4

Im not 100% but it sounds like its the ebay triggers, a good frien of mine uses canon and with her 580 her usual sync speed is 1/250,
im not positive but i belive you can take one of ur flashes and put in on ur camera and use it as a master flash useing the other flash as a slave, it should be in the custom setting menu on the flash, if you need to pull out the book for the flash, but say do that and fire the on camera flash to the side in to a reflector. hope ive been some help good luch shooting, best wishes

Panasonic LUMIX DMC-LX100

03/19/2010 01:07:39 AM · #5

Thank you Joker1114, gonna try that tomorrow!

spiritualspatula

Nikon AF-S NIKKOR 24-70mm f/2.8G ED

03/19/2010 01:13:24 AM · #6

Firstly, I've seen some other talk about the 5d mkII being slightly slower in practice than it's purported sync speed which I thought was 1/200? A combination of this and the triggers as

millsa said is what I'm betting is causing your banding. But yeah, no reason to keep it that high if you're having problems.. increase your shutter duration. You might consider using one of the 550ex's on camera, because it can trigger the other one via infrared and will let you avoid that time delay you're experiencing with the cheap triggers. The zoom on your flash is going to just influence how directed the light is... if you feel you need more concentrated light, zoom the flash more.
Your power choice will be dictated by the flash duration... the 550 is 1/833 at full power, and the duration will decrease as you step down the power (couldn't find a resource for the actual numbers, sorry). Basically, if you feel that you need it to be more crisp, decrease the flash power and move it closer to keep the same amount of light falling on it.

millsa

Nikon D7100

Nikon AF-S DX 18-105 f/3.5-5.6 ED VR

03/19/2010 01:29:16 AM · #7

Careful in using the 550 and a master slave setup, there is a delay and a preflash (a communications flash before the shot to sync camera and strobes) this can lead to a bit of delay in the shot. My suggestion would be.

1. set up so your camera is on a tripos and the flashes are where you want.
2. hold a pen or something where the drop will be and focus on that, set the fstop so you get the depth of field you want take a couple of shots to see this is right.
3. lower the lights and in manual mode set the shutter to something that works with the triggers. (without flash the shot should be pretty dark)
4. Take some test shots with the flashes at low power (lower power is the fastest speed), move the flashes back and forth to get the exposure you want, you don't need to change any power fstop or shutter settings.
5. Start shooting hundreds of drops and enter the good one :)

So under this setup
Fstop = depth of field,
Flash power = exposure time (lower quicker),
Shutter speed = available light exposure (ie you want available light exposure to be pretty non existent most of the time, you just want the flash taking the shot)
Flash distance = flash exposure