Off Camera Flash - Newbie

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Andy
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Ok, i did a search, but i couldn't find anything basic enough, feel free to point me to some resources for a noob if you know of any.

I have a Canon 40D and a 430EX. I am familiar with the various functions of the camera, but keep the flash in Ettl.

I want to get more creative and my first step is getting the flash off the camera. I bought a wireless flash trigger kit which works geat.... except i imagined the flash would still be communicating with the camera over metering.:(

I am happy to learn but am not sure where to start with the basics.

Am i going to need a light meter? Everything is just blown out white at the moment.

Andy
 
Welcome to TP :)

For E-TTL control off-camera, the camera must communicate with the flash. The cheapest way to do that is with a cord and you can get one 10m long for £34 here http://www.talkphotography.co.uk/forums/showthread.php?t=157807 Or you can do it wirelessly with a master controller like the ST-E2 for around £140, or with another flash unit that incorporates master controller facility, such as the 580EXII. That is about £300 though there are cheaper third party options. You can also get E-TTL radio triggers like the new Pocket Wizards but they are over £400 a set.

So generally, manual control is much cheaper - that's really its main advantage. However, there is only ever one optimum exposure setting and it makes no difference whether you set that manually or let the camera do it with E-TTL. Obviously E-TTL is quicker and easier, and also pretty accurate; the advantage of manual is that you know exactly what is happening, and it is fixed until you change it, so it is very good for learning.

You can also moderate the flash while in E-TTL by using the +/- compensation on the gun so there is still a lot of control and in that sense you have 'manual' override.

If you are getting white-out on manual, then obviously you have over-exposure. Turn the flash down until it looks right, simple as really - 430EX goes down to 1/64th power. You don't need a flash meter. Remember that flash is very sensitive to distance in terms of exposure and if you're shooting close, even small changes in subject distance can make a big difference. Of course, E-TTL keeps all this under control for you but in manual you have to make your own adjustments. Just remember the inverse square law which means that when you double the distance, the flash brightness falls to one quarter - that is two stops, which is a lot!
 
Many thanks!:)

So a good move for a beginner might be to use the E-TTL cable,with the Flash off the camera, take some shots, and to use that to get some reference/benchmarks as to how the exposure is being set. With that information i could then remove the cable,m go manual and try to get a bit more creative?
 
It's fairly easy in manual mode too.

Just remember Aperature controls Flash light, shutter speed controls Ambient light

Start at say, 1/2 power on the flash. and f8 @1/250th iso 200, and then take a test shot. look at the image and decide if you want more flash or ambient and adjust the aperature or shutter speed . take another test shot and see the differance.

It's all i did, and I managed to get these images

http://www.talkphotography.co.uk/forums/showthread.php?t=200368
 
:thumbs: Really nice lighting. Thanks for the advice all. I have the ooportunity to take some food shots from our Bistro tomorrow, so i will have an opportunity to play.

Any Gotcha's with lighting on food close up's?
 
Any Gotcha's with lighting on food close up's?

i am by no means an expert on lighting, but with close ups or macro, a ring flash would come in handy, but wait for someone with experience and knowledge to confirm or batter me :)
 
Many thanks!:)

So a good move for a beginner might be to use the E-TTL cable,with the Flash off the camera, take some shots, and to use that to get some reference/benchmarks as to how the exposure is being set. With that information i could then remove the cable,m go manual and try to get a bit more creative?

The main advantage of E-TTL is convenience and speed. It will get the shot first time. With manual you might have to fire off three or four or more test shots to get to the right power setting. In terms of learning, with E-TTL you have no idea what power output the flash is firing at so iot's not so helpful.

When you have a little more time to set up, manual is good because you know where you are and the flash is then locked on that power output and the exposure won't change (unless you move its position). Use max x-sync shutter speed (1/250sec) to eliminate ambient light affecting things, although you might want to allow some ambient light in there to soften the effect of the flash - just make the shutter speed longer.

Photographing food you will be quite close and not need much power at all. There will also be strong fall-off (inverse square law) and while one side of the plate might look fine the other side could be a bit too dark and the background darker still. Move the flash back to reduce this effect - you will need more power when you do this, but fall-off will be reduced due to the greater distance. Use a reflector to fill-in the shadow side - you can make one very easily out of a sheet of white card, maybe 2x3ft, and stick kitchen foil (non-shiny side up) on one side. Or get one from FITP.

It also has to be said that direct flash on something like that will not look very nice with harsh shadows cast. You need a softbox for that (see the Flash In The Pan link I posted earlier) to make the light source bigger. That is another very important rule of lighting - bigger light source equals softer shadows. This too is sensitive to distance and if you move the light back it becomes smaller/harder relative to the subject; and closer equals softer of course but quicker fall-off.

You could do a very nice job shooting food with just a softbox and a reflector. Use a stand or get somebody to hold the softbox - try it above and slightly behind the subject, with the reflector in front. This gives nice lighting and you should pick up some nice highlights reflecting off the shiny bits :)

That's another rule of lighting - angle of incidence equals angle of reflection - meaning that light bounces off a shiny surface at the same angle it strikes it, like a snooker ball off the cushion, so you can use that knowledge to position the light and the camera to catch attractive highlights (or to avoid them). Be careful with flare if the light itself is close to the picture - use a lens hood or shade it with your hand/card. Tripods are very useful for still life/table-top; live view is good too :thumbs:
 
Many thanks again for your advise. I won't get time to order a softbox before tomorrow, but i will certainly be able to create some temporary reflectors and i am happy to bounce the flash off the white ceiling.

I get another opportunity in two weeks time, so i will try and get some ideas from tomorrow and how i can improve for next time.

Cheers.
 
Many thanks again for your advise. I won't get time to order a softbox before tomorrow, but i will certainly be able to create some temporary reflectors and i am happy to bounce the flash off the white ceiling.

I get another opportunity in two weeks time, so i will try and get some ideas from tomorrow and how i can improve for next time.

Cheers.

Quick n dirty DIY soft box. Big sheet of white card and fire the flash straight at it. The light will bounce back big and soft :thumbs:

This is not very efficient in terms of light lost (spilled/absorbed) but if you're close enough it should be fine.

Edit: shooting through a sheet or tracing paper or greese-proof baking paper works the same way. Making light work for you isn't a very sophisticated business - custom modifiers and light shaping tools are mainly about convenience, putting the right sort of light where you want it, and also keeping it away from where you don't want it. But if you know what you're doing and put the work in, the light doesn't mind if you use a £300 softbox or a bit of cardboard and gaffa tape :)
 
Thanks for all the help.

I managed to take on board most of what was said and have posted my first attempts here

http://www.talkphotography.co.uk/forums/showthread.php?t=202404

And they look pretty good! :)

I like the shallow DoF in the last one, but in some of the others I think you need a bit more. Generally speaking, having things out of focus in front of the sharp point somehow looks odd.

They also look a fraction dark, but that might just be the conversion to web.

Well done though! I would have thought they will do the job nicely.
 
hit up the strobist website for tutorials and a walkthough (lighting 101) then play and chimp, over time you get to know the settings and be ball park right first time :D
 
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