A really really dumb question (probably) about flash...

Hi all,

As the title states, this probably is a really silly question - but here goes: I've recently bought a 430exII and am having loads of fun experimenting with on (and off) camera flash - you're all right, it really does open up LOADS of new creative possibilities! Anyhow, the question. If I want to use my flash as the main lighting source (for example, in a low-key, low-light portrait), the subject will obviously be dark before the flash fires. How do I work out what power to use with the flash; how to focus; what is the best f-stop to use? Do I turn on the main lights first to focus? I'm assuming I do everything in manual; I'm learning to use manual but I'm not an expert by any means!

So there's my question(s)!

Any help GRATEFULLY received!

Thanks

David

Flash Exposure Compensation (FEC) is how you control the flash's output. It's the same theory as the standard exposure: + for light subjects and - for dark subjects.

You can focus using the 480EX's focus-assist beam. It'll work even in pitch dark. Quite well in fact.

That's assuming you want to make it easy on yourself and take advantage of E-TTL with the flash on camera. Using Manual flash on a light stand complicates things. I'd say wait until you get E-TTL mastered and then work towards the full manual stuff.

There is always more than one way to skin a cat, or should I say flash a cat.

You are probably best off overpowering the room lights. If you want to use manual, use manual on the camera and set the exposure so that the room lights are significantly underexposed. Set the flash to manual and take a trial exposure. If it is too bright, turn it down or adjust the camera (ISO or aperture). If it is too dark, go the other way. If you want to use E-TTL, then set the flash on E-TTL and adjust the intensity with FEC. The main point is that it isn't necessary to completely kill the room lights as long as they are being significantly under exposed and I think the best way to do that is with the camera on manual.

David,

Tons of info on manual off-camera flash here:
http://strobist.blogsp​ot.com

Basically there are two ways to meter manual flash:
1) Test, chimp, adjust, repeat as needed.
2) Use a flash meter.

The room doesn't need to be dark. Just underexpose the ambient and let the flash do the work.

Hey,

Thanks for all the info - plenty for me to try! Will let you know how I get on!

David

It's all about testing, retesting, and testing some more...

here's a tip.. use the b/w histogram... the screen can deceive you...

go to strobist and look at 102: balance... as its all about balance...

this is what i normall start at...

f4, iso 400, 1/100 at 1/4...

if i need more ambient i change my settings to... f4, 1/50, iso 200 at 1/4

if i need less ambient, i change my settings to... f4, 1/200, iso 400 at 1/4

its harder to explain it within having your camera next to you. LOL

It's frustrating to hear this I'm sure, but the answers to your questions depend largely on the situation.

• How to focus? Turn the lights on. Remember, you're exposing for the flash, not the ambient. Your shutter speed may be high enough that no ambient light is recorded. The 430ex in combination with an umbrella and reflector is powerful enough that you shouldn't need any ambient light.
  
• What aperture? The correct one. Could be f/4, could be f/16 depending on how much depth of field you want. The 430ex is powerful enough that you should be able to go all the way down f/8, even thru an umbrella.
  
• Flash power setting? The correct one. Could be 1/32, could be 1/1. Depends on the subject and any modifiers/reflectors you use, distance from subject, ISO, etc.. The 430 has decent power. For high key product shots, I find even 1/1 thru an umbrella is often too powerful.

Thanks for all the advice guys...experiment and see! I have a clear idea of what I want to achieve - it's getting there that I'm struggling with!!!

I'll try what you've suggested...and let you know how it goes!

Thanks again

David

Hi all,

Took some of your advice and took some photos last night. I've posted one here:

https://photography-on-the.net …php?p=7734351#p​ost7734351

I'd really appreciate some advice on how to improve; I only have the one flash at the moment so this is the light I am working with.

Thanks

David