580EXII User Help

[conkeychua]

Hi,

I have read alot on the webs and manuals of my 580EXII flash but when it comes to pratical use, it seems to be different.....

1) My understanding is that the flash can cover up to 58meters? I really doubt so. Please correct me if im wrong.

2) I tried shoot at subject about 15metres away, flash do not seem powerful enough. ( Am using cheap batteries for the moment cause waiting for my eneloop )

3) Using ETTL, and 55-250mm lens, would the flash calculate when to full blast? As in equalvalent to 1/1 105mm on the manual mode? or this mode has to be manual? Not that i need it but just need to know ETTL limitation if any.

4) If my distance understanding of the 580EXII is correct 58Meter, whats the rough distance to subject after i pulled out the difusser?

5) Would it be advisable to use a external difusser cap on your flash given that the flash has some limitation after you pulled out the built in difusser.

Cheers!

 

[Octarine]

You are asking about a piece of Canon equipment. Why don't you post it in the equipment forum for Canon?

 

[bengchiat]

assuming u r using iso 100 with the lens more than 105mm(135 eq.),
the guide number is 58m.
now lets say u r using f4,
that makes the working distance to be 58/4m.

so u either push ur iso or use a faster lens.

btw, 58 is the guide number(power) of ur flash at iso 100 with the flash head set at 105mm.

 

[conkeychua]

You are asking about a piece of Canon equipment. Why don't you post it in the equipment forum for Canon?

Oh... I thought posting on the newbie thread would be more appropriate....

Apologies..

 

[conkeychua]

assuming u r using iso 100 with the lens more than 105mm(135 eq.),
so u either push ur iso or use a faster lens.QUOTE]

So meaning to say that the higher the ISO the flash will emit more power?

Thanks alot

 

[Fragnatic]

higher ISO will allow the camera to be more sensitive to light.. your 580 will still emit the same power, just that more light will be captured.

time to read up on the basics of flash photography

 

[conkeychua]

higher ISO will allow the camera to be more sensitive to light.. your 580 will still emit the same power, just that more light will be captured.

time to read up on the basics of flash photography

Hi bro, have been reading flash photography for th longest time but still doesn't states anything about the flash increasing power when I zoom in at say 20m away! The problem us when I switch it to manual and shoot it at full power, the subject actually ended up over exposed but when it's back to auto, it loses that power again

 

[jonathan920]

Hi bro, have been reading flash photography for th longest time but still doesn't states anything about the flash increasing power when I zoom in at say 20m away! The problem us when I switch it to manual and shoot it at full power, the subject actually ended up over exposed but when it's back to auto, it loses that power again

Can we adjust the % of flash emitteD? or only can set 0%, 50% , 100%

 

[Dream Merchant]

Hi,

I have read alot on the webs and manuals of my 580EXII flash but when it comes to pratical use, it seems to be different.....

1) My understanding is that the flash can cover up to 58meters? I really doubt so. Please correct me if im wrong.

2) I tried shoot at subject about 15metres away, flash do not seem powerful enough. ( Am using cheap batteries for the moment cause waiting for my eneloop )

3) Using ETTL, and 55-250mm lens, would the flash calculate when to full blast? As in equalvalent to 1/1 105mm on the manual mode? or this mode has to be manual? Not that i need it but just need to know ETTL limitation if any.

4) If my distance understanding of the 580EXII is correct 58Meter, whats the rough distance to subject after i pulled out the difusser?

5) Would it be advisable to use a external difusser cap on your flash given that the flash has some limitation after you pulled out the built in difusser.

Cheers!

Best to get a basic understanding of how a flash works - first

http://www.chem.helsinki.fi/~toomas/photo/flash-faq.html

 

[Snoweagle]

IIRC, 58m is at 50mm, ISO 100, f/1.0.

 

[Octarine]

Hi bro, have been reading flash photography for th longest time but still doesn't states anything about the flash increasing power when I zoom in at say 20m away! The problem us when I switch it to manual and shoot it at full power, the subject actually ended up over exposed but when it's back to auto, it loses that power again

What do you mean by "zooming in at 20m away"?
The Auto mode will try to expose properly depending on the existing conditions and based on average presets within the camera. No camera can read your mind. Flash output is adjusted by using ETTL metering (read up about that!). When using manual flash then this metering and subsequent adjustments in the camera are skipped. The camera takes the picture without considering the flash output - because that's your job in this mode. Time to read up about the very basics (e.g. meaning of ISO) and next (as second step) reading about flash, metering with flash etc.

 

[Octarine]

Can we adjust the % of flash emitteD? or only can set 0%, 50% , 100%

Please get your camera manual and read about Flash Exposure Compensation (FEC). If you happen to have an external flash (e.g. 430, 580) pick up that manual as well and check for manual flash settings. It's all there.

 

[bengchiat]

IIRC, 58m is at 50mm, ISO 100, f/1.0.

hw i wish too :>
makers love big numbers as consumers r suckers for them,
so they always quote what their max zoom head can offer.

 

[bengchiat]

Can we adjust the % of flash emitteD? or only can set 0%, 50% , 100%

u can,
but its in fraction :>
1/2, 1/4,..... with 1/3 stop in between them.

 

[bengchiat]

Hi bro, have been reading flash photography for th longest time but still doesn't states anything about the flash increasing power when I zoom in at say 20m away! The problem us when I switch it to manual and shoot it at full power, the subject actually ended up over exposed but when it's back to auto, it loses that power again

few things,
canon tend to under expose a little bit :dunno:
u might want to check for
-ur flash compensation,
-any object infront of ur subject?
flask cuts off if that object is near overexposed.

btw, the 20m indicator is a guide to the max distance
for the setting u hv them,
based on flash's power over the cam's iso n the lens aperture.

 

[conkeychua]

What do you mean by "zooming in at 20m away"?
The Auto mode will try to expose properly depending on the existing conditions and based on average presets within the camera. No camera can read your mind. Flash output is adjusted by using ETTL metering (read up about that!). When using manual flash then this metering and subsequent adjustments in the camera are skipped. The camera takes the picture without considering the flash output - because that's your job in this mode. Time to read up about the very basics (e.g. meaning of ISO) and next (as second step) reading about flash, metering with flash etc.

Hi Bro Octarine,

What i mean was i am 20m away from subject with my 55-250 lens. zooming in and took a picture, the picture was under exposed. Not like i need the camera to read my mind but i would have expected the ettl to understand from the camera on how far or how exposed the subject is and then shoot the flash accordingly? ( Wishful thinking again huh? )

Cheers!

 

[conkeychua]

Best to get a basic understanding of how a flash works - first

http://www.chem.helsinki.fi/~toomas/photo/flash-faq.html

Thanks alot for the link. Will read up and hopfully it lowers my expectation of my flash..,..;p

 

[conkeychua]

hw i wish too :>
makers love big numbers as consumers r suckers for them,
so they always quote what their max zoom head can offer.

Yah and i got sucked into it and am confused now....

 

[Snoweagle]

hw i wish too :>
makers love big numbers as consumers r suckers for them,
so they always quote what their max zoom head can offer.

Well that's what it says. 58m is only at those conditions. :dunno:

 

[Octarine]

What i mean was i am 20m away from subject with my 55-250 lens. zooming in and took a picture, the picture was under exposed. Not like i need the camera to read my mind but i would have expected the ettl to understand from the camera on how far or how exposed the subject is and then shoot the flash accordingly? ( Wishful thinking again huh? )

First question: which mode? The metering works differently, depending on the shooting mode you are in. Easy to check: take a slightly dim room, take out your cam, use Auto or P mode (flip up flash in P) and half-press the button. Note down the values. Switch to Av , dial to the same aperture value as seen in Auto or P and half-press - you will see an obvious difference. The reason is that Auto/P has a different target when metering, compared to Av mode (and also M).
If your subject is still underexposed try a) increasing ISO (not possible in Auto) or b) using FEC to get better illumination.
More about EOS and flash: http://photonotes.org/articles/eos-flash/