FLASH HELP PLEASE

Hey Guys need some help. I'm new to using a flash and need help. I have a 580 EXII and 7D. I've been shooting nightime drag racing trackside occasionally and cannot get consistent results. First off I will say I dont know what I'm doing, I've read the manual and looked at videos but I'm lost. I've tried all modes with mixed results. Ok I've been shooting TV with EFS 17-55 I use high speed shooting and burst piks. Half the time the flash doesnt work or gets 2 out of 8 shots with various brightness. Am I assuming the flash cannot keep up with the fps? Please tell me what settings on my camera and corresponding flash settings are best. Also why does the flash limit your shutter speed to 250? I dont have any pix to post sorry havent had the time to figure out how to do it. I have another nightime event Sat and dont wanna miss as many shots as I did the other night. Btw the tracks are fairly well lit. Its frustrating to have great equipment and struggle to learn how to get the most out of it. If there are any others with 7Ds near Starved Rock Area in Illinois and are willing to share some expertise I would be greatful to meet up sometime

I'm not expert but have learned a few things putting a flash on my camera. No way in heck a 580 EX II is going to keep up with your 7-8 fps shooting on a 7D. The flash needs time to recycle enough power to blast its next full power flash. You probably get one good flash, the second flash of much less intensity then nothing on the next however many shots you choose to blast away with on the 7D. Also, if you overwork the flash the actual bulb element will overheat and fail. Not a good thing either.

Another thing is that even flashes like the 580 EX II aren't meant for long range work. The flash intensity will travel, but not much more than 20 yards, I'd guess.

It sounds to me that you're asking way too much from an on-camera flash and not understanding its limitations and intended usage. Agree with you though that the manual is poorly written and doesn't help a user very much at all.

There is a thread in the sports image post forum with a thread about how to use flash for night football. There may be some info there that is useful and applicable to shooting races at night.

Good luck.

dave

2 Simple answers:

Yes, the flash can not keep up. Depending on your batteries, and the power setting on the flash, it can take up to 5 seconds for the flash to recycle after firing.

1/250 shutter speed is a physical limitation of the camera. Any faster and the light from the flash would not be able to light up the entire photo. Because of this the camera automatically limits 1/250. This video explains why: http://www.youtube.com …g&feature=playe​r_embedded!

Lots of issues here. You really need to read up on flash technique, but here are a few things that might help. Your camera is limited to 1/250 as that is the fastest speed where the entire sensor is exposed to light at the same time. The shutter is made of two curtains. One opens, the other closes, the time between is the shutter speed. Anything faster than 1/250 on your camera the second curtain starts closing before the first is fully open.

You could use HSS mode which uses pulses of light instead of a single burst but it seriously lowers the power of the flash. The good news is you dont need either a high shutter speed or HSS mode. The short duration of the flash will stop motion, as long as there isnt much in the way of ambient light. Anything 2-3 stops darker than the flash is okay as the brief burst of light from the speedlite is what records the image, regardless of the shutter speed (unless you are very slow).

The burst problem is that you are shooting bursts inthe dark, the flash doesnt have time to fully recharge during your burst. You could improve the rate with an auxiliary battery pack, but probably still not an 8 shot burst.

Recycle time...if you cannot see the flash (lightning) symbol in the viewfinder, DON'T BOTHER trying to shoot...the flash is NOT READY unless the lightning symbol is visible in the viewfinder.

In the owner manual Canon specifically warns user to NOT exceed 20 consecutive flashes without rest, or else you run risk of overheating and breaking the flash unit!!!

msowsun wrote in post #12987505
2 Simple answers:

Yes, the flash can not keep up. Depending on your batteries, and the power setting on the flash, it can take up to 5 seconds for the flash to recycle after firing.

1/250 shutter speed is a physical limitation of the camera. Any faster and the light from the flash would not be able to light up the entire photo. Because of this the camera automatically limits 1/250. This video explains why: http://www.youtube.com …g&feature=playe​r_embedded!

Thank you everyone! I'm still learning...went from shooting a Rebel XT in auto mode all the time to a 7D for about a year...I appreciate all the input!

Wilt wrote in post #12987549
Recycle time...if you cannot see the flash (lightning) symbol in the viewfinder, DON'T BOTHER trying to shoot...the flash is NOT READY unless the lightning symbol is visible in the viewfinder.

In the owner manual Canon specifically warns user to NOT exceed 20 consecutive flashes without rest, or else you run risk of overheating and breaking the flash unit!!!

THANKS!

gonzogolf wrote in post #12987521
Lots of issues here. You really need to read up on flash technique, but here are a few things that might help. Your camera is limited to 1/250 as that is the fastest speed where the entire sensor is exposed to light at the same time. The shutter is made of two curtains. One opens, the other closes, the time between is the shutter speed. Anything faster than 1/250 on your camera the second curtain starts closing before the first is fully open.

You could use HSS mode which uses pulses of light instead of a single burst but it seriously lowers the power of the flash. The good news is you dont need either a high shutter speed or HSS mode. The short duration of the flash will stop motion, as long as there isnt much in the way of ambient light. Anything 2-3 stops darker than the flash is okay as the brief burst of light from the speedlite is what records the image, regardless of the shutter speed (unless you are very slow).

The burst problem is that you are shooting bursts inthe dark, the flash doesnt have time to fully recharge during your burst. You could improve the rate with an auxiliary battery pack, but probably still not an 8 shot burst.

THANKS!

snyderman wrote in post #12987499
I'm not expert but have learned a few things putting a flash on my camera. No way in heck a 580 EX II is going to keep up with your 7-8 fps shooting on a 7D. The flash needs time to recycle enough power to blast its next full power flash. You probably get one good flash, the second flash of much less intensity then nothing on the next however many shots you choose to blast away with on the 7D. Also, if you overwork the flash the actual bulb element will overheat and fail. Not a good thing either.

Another thing is that even flashes like the 580 EX II aren't meant for long range work. The flash intensity will travel, but not much more than 20 yards, I'd guess.

It sounds to me that you're asking way too much from an on-camera flash and not understanding its limitations and intended usage. Agree with you though that the manual is poorly written and doesn't help a user very much at all.

There is a thread in the sports image post forum with a thread about how to use flash for night football. There may be some info there that is useful and applicable to shooting races at night.

Good luck.

dave

THANKS!

hey buddy your not alone ...

The 580EX is not powerful enough to light over long distances. And... it cannot keep up with your camera in burst mode.

You can buy a modified Lymedyne unit which can produce up to 2,400 WS ( http://www.lumedyne.co​m/ ) but, this is a very expensive solution and is rather heavy. I don't know if the Lumedyne lights can work in HSS, so you may be stuck with 1/250 Second.

If you use a 300mm (equivalent focal length) or above lens, the Flash Xtender Better Beamer will provide a better concentration of light. I have not tried this but would guess that using a 70-200mm lens on a 1.6x camera even down to 180mm (288mm equivalent) would not vignette too much. I have not thought of doing this but will try it within the next few days.
( http://www.amazon.com …35&ref=pd_sl_7o​8pkpthru_e )

There are auxillary battery packs for the 580EXii but, although they will cut the recycle time somewhat, none will keep up with the burst mode, especially since each flash will be full power...

You might need to shoot in single shot mode rather than bust.

If you have enough light, perhaps shooting available light might work - expecially at a very high ISO...

Don't be scared of using a high ISO with your 7d, it can handle it. Your results will improve dramatically if you do. Start with an ISO of 1250 and put it on TV mode with a high shutter speed of 1/800th and go from there and see what you come up with. (I don't shoot sports, someone else can better tell you a good starting point for high iso and shutter speed.) You can fire off as many fps as you like without the flash, which is useless from that distance anyway). If you shoot RAW, you can adjust the color balance from the racetrack lighting quite easily.

suecassidy wrote in post #12990794
Don't be scared of using a high ISO with your 7d, it can handle it. Your results will improve dramatically if you do. Start with an ISO of 1250 and put it on TV mode with a high shutter speed of 1/800th and go from there and see what you come up with. (I don't shoot sports, someone else can better tell you a good starting point for high iso and shutter speed.) You can fire off as many fps as you like without the flash, which is useless from that distance anyway). If you shoot RAW, you can adjust the color balance from the racetrack lighting quite easily.

Thanks, I have used auto ISO at night without flash and had very good results although there was lots of noise. It chose very high ISO though sometimes 3200. I see there is an option for high ISO noise reduction but read it slows down FPS.

jimeez2010 wrote in post #13005798
Thanks, I have used auto ISO at night without flash and had very good results although there was lots of noise. It chose very high ISO though sometimes 3200. I see there is an option for high ISO noise reduction but read it slows down FPS.

Start choosing your ISO rather than leaving it to fate. Noise reduction can be better done in post than in the camera. One of the problems that you will encounter in these circumstances is that you are working at the extremes of all your variables, ISO, Aperture, shutter speed, and flash power. When you have to push the envelope on more than one variable you start to lose quality.