Getting a 580EX & so confused!

[Glen A Ford]

i don't do any of this, so here's my guess. I am guessing the light levels will be not so high, you will be using a longish telephoto lens and the distance from you and the action will be quite a lot.

You will need to make the best use of available light, use a high enough shutter speed to avoid camera shake and stop the action. The setting on the flash and the camera will need to ensure your flash power will cover the distance required. So here’s my suggestion. Apologies, the answer is a bit long.

i would set on manual or shutter priority. if there is a lot of ambient light then shutter priority will be okay if not then manual. here's the setting for manual: set the shutter speed to your flash sync (this is the speed at which the flash will be able to fire normally and you still get a picture). it will be 1/125th or maybe higher. check the manual.

use as high an iso rating as your camera will give good pictures - 400 or 800.

for aperture, use the lowest number your lens has (the largest aperture). Your camera is now set to let in as much available light as there is but maintaining the highest shutter speed you can get away with. if there is too much available light (check this with the camera) then use a smaller aperture or lower iso. In this case, probably best to use shutter priority mode and set the shutter to the sync speed.

for the flash make sure the zoom on the flash matches your focal length, as this will give you the best flash. It should do this automatically. the flash will only be able to reach a certain distance, but with the 580 this will be a long way (check your manual - it will have a table). Don’t use any diffusers (too much loss of light).

Here is some theory and also if you want to calculate without the table. all flashes have a maximum distance they can reach. this is determined by (1) the power of the flash (2) the zoom setting on the flash (3) the iso you use (4) and the aperture setting on the lens. Light falls off very quickly with distance. the distance doubles or halves for each two stop change in aperture or iso. shutter speed has no impact on flash as the duration of the flash is much, much shorter than the shutter speed. shutter speed is important for setting the amount of ambient light is let in. Each flash will have a “guide number” for each zoom setting, which you can use to calculate the working distance. Here is how it works on the 580….

for the 580 at the max zoom setting of 105mm the guide number is 190 feet. if you are using iso 400 then you can times this by 2 (two stops extra means double / half the distance) which makes it 380 feet. To get your working distance, then divide this by your aperture. so if it is an aperture of 4, then you are at 85 feet. which means the flash at max power will reach 85 feet. if less than 85 feet then the flash will just use less power. if you used iso 100, then the figure would be 47.5 feet at the same aperture and at max power. so you can see, the aperture has the most impact upon the max distance of your flash.

If you don’t like math, then just look at the screen on the back of the flash, this will indicate the distance for your camera / flash settings.

Using a telephoto lens with a wide aperture is the key for this type of photography, but they don’t come cheap. Hope this helps.

[QuadJunkies]

You are AWESOME! Thank you!
I got a migraine trying to understnad the manual,I was completly lost..Still am lol but not as bad now

I actually shoot for close up shots of riders,so I do zoom in for individual shots. Before I upgraded my lense, I was shooting ISO all the way to the highest it will go,4.5 and shutter Shutter speed was only at about 80 with a but I suspect it should be higher with the 2.8

I played with it today and had it set to Slave, I am totally clueless to a flash, I got lost on the having several Pre -set ups for distance??And of course, all that math.... Yup... I was lost alright!
lol

So Ill need to measure the flash each time I shoot the riders?They are fast moving objects, so there will be dif. distances
Ill see if I cant find a pic of the track and postit, but there is a ton of Flourescent lighting,yet its somewhat Dark,especially behind the rider.

[QuadJunkies]

this is an old pic off a Camcorder,so the pic itself is notgood.. But gives you an idea of the lighting


I like to do alot of shots like this :
I am sooo glad I finally will have a faster lense this wk end! Im about tired of Blur and alot of grain

This one was shot with as much sunlight that could beam into the building threw the doors and I still have alot of shadows and darkness


All the Haze from Exhaust fumes doesnt help matters either



JETA,hows your results so far?
I got some pretty good ones of my kids Quad rebuild, I cant believe how much a flash makes a difference!

[islandtime]

Take time and read this: EOS Flash Bible

This article explaing every setting and how/when to use it.

[Skyman]

I just picked up a 580ex as i found my 550ex wasn't giving the results i wanted with my 400d this flash seems to work much better with this camera. I am still playing, but it seems that in the auto and p modes you don't get ettl II so i am going back to my old way of working in av mode. it works much better for me anyway since i now have a 550 and a 580 i am also starting to play with the joys of wireless ettl ! i love it!

[WesternGuy]

JETA, you might be interested in this web site. It seems to be a very good introduction (and then some) to digital Canons and the Speedlites.

Cheers,

WesternGuy

http://web.canon.jp/Imaging/flashwork/index.html

[poker]

INTRODUCING THE CANON 580EX II