Everything I know about flashes and lighting

[JackieHollow]

can fit in a thimble. :rofl And I learned that thimble full last night/this morning.

Ok everyone, this will probably be a rambling post. But it helps me to talk things through (with others that understand what I'm talking about). Feel free to correct me anywhere that I'm wrong.

My flash has 2 settings. M (manual) and TTL (through the lens). M is obviously more accurate, but you have to know more about your flash to use that. LOL So for now I'm gonna concentrate on TTL (and play in M after I get the basics down).

So if I am using flash indoors in very low light, I want the flash to be my main (key) light. That means TTL will power it up for me itself. But if I set my camera settings at 400, 2.8, 1/200, the flash will "overtake" ambient light. I *THINK* this will lead to a "cave looking" appearance, but I'm not sure???

If I want to let in more ambient light, I can set my settings to 400, 2.8, and 1/25. The shutter speed has no input on my exposure on the subject, just on the background/ambient. The flash freezes the motion, as long as there's not too much ambient light (how much is too much???).

I made a better bounce card myself (with several modifications). I can set my light to shoot straight up into the card, using it as a scoop, or as a bounce card. If I use it as a scoop (say my ceilings are too high or not white), then the "card" catches most of the light and reflects it forward. This makes the background darker. If the ceilings are low enough, I can "open' the top part of my card, so my light bounces off the celieng (but also some is reflected forward from my card). Since the light is more evenly spread, more ambient light is let in, resulting in a less flashy look.


????? When do you know to change your ISO? I know the higher the ISO teh farther the reach of your flash, and the less power it uses. But when do I know to change it?


OUTSIDE/FILL FLASH
Set the flash directly on subject, using a high shutter speed. (I think the settings of your camera here need to be "normal" since you are just using the flash to eliminate shadows). Since your SS will most likely be high, you may need to use high sync flash mode.

HOWEVER, if you need to use fill flash for close ups, you need to make sure to use a diffuser. Also, for fill, is when you will mostly need to utilize the flash compensation. This can go up and down in 1/3 stops.


OUTSIDE LOW LIGHT
Outside there is no where to bounce the light from, so (and this is where I haven't gotten a chance to practice so... I'm guessing here). I would use my bounce card. If the flash is straight up, and the card is on it with the back facing me, in scoop mode, it would reflect the light forward onto my subjects. My goal is to figure out how to let as much ambient light in as possible. So at those night weddings, ouitside, with candles and twinkle lights all around... do I still try to drag the shutter (I'm assuming this is the way). How low can my shutter go?


And that's all I know. PLEASE feel free to correct, laugh at (just not too much. http://www.digitalphotopros.com/forum/images/smilies/wink.gif ), or add to anything I already know, don't know, or think I know. LOL I just got my 430 EX II yesterday, and I'm desperate to figure it all out. :dunno

[pathfinder]

Hi Jackie,

Welcome to dgrin.

You do not need a diffuser for fill flash in sunlight

You can find a lot of information about the EOS flash system here (http://www.dgrin.com/showthread.php?t=70330)

After you master these links, if you have any questions, come back and we'll try to find the answers for you.

[Tim Kamppinen]

You will also benefit greatly from the following websites:

http://www.planetneil.com/tangents

http://www.strobist.com

The first is all about on camera flash and the second is all about off camera flash. The both have links to the "beginner" material on the right side of the respective pages. The on the first page I think it's called "Flash Photography Techniques" and on the Strobist blog it's called "Lighting 101." Both are excellent resources that have taught me a great deal.

[Qarik]

I read through your whole dang post...your line of thinking is correct for the most part. That is no small thing.

Your question..when do you need to change your iso? Well let me correct one assumption you made about the 1/25s..while the conceptof "dragging the shutter" to allow more ambient light in, I would be highly wary of using 1/25s in any real world setting like handheld unless you shooting quite wide. My min safe setting for mid range zoom might be 1/80s or so. That 1.5 stops you lose.

The only way to get that back is ISO. You will know to change it by looking at your histograms and the picture itself to see if they are satisfactory. In many real world event type settings with crappy light you will find you will need to be at or close to your highest acceptable iso for your camera.

wrt to outside fill flash. I would highly suggest going manual on this one. full TTL may overpower the ambient and casue specular highlights (shiny forehead for example). All you are trying to do typically is just lift some of the shadows in the subjects. It's no that hard.. 1/8 or 1/16 power is all you many need. You can even use your onboard flash for this (the only time onboard flash is useful outside of a buitl in commander mode!)

[Tim Kamppinen]

A sync speed of 1/25 could work in a few specific situations.

1. If there is no ambient light in your exposure and the entire scene is lit soley by flash. In this case it doesn't matter what your shutter speed is. The length of your exposure effectively becomes the flash duration.

2. If the background is only lit by ambient but the subject doesn't have any ambient contributing to their exposure. Here you may get some camera shake or motion blur in your background, but it might still look great because your subject will not be affected.

3. If there is significant ambient contributing to both the subject and background, but you're ok with that. I'm thinking especially of shots where people are moving, such as at a dance or someone running, etc. Here you would want to use rear curtain sync so that the flash fires at the end of the exposure. That way, even though you still have motion blur, you also have a sharp flash-produced image of your subject, and because of the rear curtain sync the blur is BEHIND your subject in the image, producing a more natural looking result. If you don't like the way it looks, then you need to raise your shutter speed and increase ISO to get the same exposure without the blur (or open up your aperture but of course you'll have less depth of field that way). Sometimes this looks really cool, but on other occasions it comes out looking sort of sloppy. I think it's usally best when there's plenty of motion because the blur looks more intentional.

[JackieHollow]

Thanks everyone!! I'm still trying to learn, and play. I feel like I'm about to step into a whole new level of photography... and I'm ready to embrace it. As soon as I wrap my mind all around it. ;)