studio flash at f1.8...


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creampuff

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Jul 11, 2006
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Dover
#2
Definitely possible - aperture size should have no bearing when using any flash unit.
 

Jan 14, 2005
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#5
Why do you want to do so?? Your shutter speed will be very high...
Shutter speed has no effect on the flash exposure. You just need to ensure that the shutter speed is within flash sync speed.

BC
 

Jan 14, 2005
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#6
guys think thats possible...?


lo
If the flash can be turned down low enough, you should be able to shoot at that aperture. However, take care of the ambient lights which now may be picked up.

BC
 

ipin

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Nov 21, 2005
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#8
f/1.8 for shallow DOF? :think:
 

creampuff

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Dover
#9
Correction: It is shutter speed. :nono:

Why do you want to shoot f1.8 using studio flash in the first place? :dunno:
If you don't know what you're talking about, please don't correct and say it should be shutter speed. So long as the shutter speed used is within flash sync speed of the camera (or lens if it is a leaf shutter), one can use any aperture. Obviously since TS mentioned studio flash, the issue he will probably face when using such a large aperture is how to throttle back the flash output. So long as one can get the desired exposure, there is no reason why a large aperture such as f1.8 can't be used, perhaps to get a very narrow DOF.
 

Jan 14, 2005
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#10
Definitely possible - aperture size should have no bearing when using any flash unit.
If you don't know what you're talking about, please don't correct and say it should be shutter speed. So long as the shutter speed used is within flash sync speed of the camera (or lens if it is a leaf shutter), one can use any aperture. Obviously since TS mentioned studio flash, the issue he will probably face when using such a large aperture is how to throttle back the flash output. So long as one can get the desired exposure, there is no reason why a large aperture such as f1.8 can't be used, perhaps to get a very narrow DOF.
I think your original post is quite misleading. The aperture should have a bearing on the flash in terms of flash power to be used. It's also got a bearing on the flash used. With a 1000Ws flash, I think using large aperture becomes virtually impossible (other than using a ND filter as suggested by Splutter :thumbsup: ... didn't come across my mind :embrass: )

Correction: It is shutter speed. :nono:

Why do you want to shoot f1.8 using studio flash in the first place? :dunno:
Youhong is correct... shutter speed (as long as it is within the sync speed) has totally no effect on the flash exposure (flash strength and flash type). If you are using leaf shutter, there will be effects on flash exposure only at very high shutter speed (faster than the flash duration).

BC
 

Youhong

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photofreak-alvinz.blogspot.com
#11
Most people shoot in studio because you can use small aperature size to get sharp pictures. Why shooting at f1.8 when you can shoot at a smaller aperature size (also bearing in mind that the so called best aperature size to shoot at is definitely not the widest)???

For shallow DOF? There are also other ways of achieving that FYI...
1) Larger aperature size (as discussed)
2) Longer focal length
3) Closer subject to camera distance

For portraiture shoots, I don't see there's anything to bokeh... Maybe you are thinking of still life I presume?


 

creampuff

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#12
Apologies if my earlier post was misleading.
The aperture one selects certainly has a direct effect on exposure as every full stop represents either a halving or doubling of the amount of light passing thru the lens. Certainly the aperture one selects would be based on several considerations: DOF, maximising the optimum sharpness of the lens, flash working distance, flash power, etc.

So long as the shutter speed used is within the flash sync speed, for a given exposure value (EV), any combination of shutter speed/aperture can be used. If for example, a meter reading for a still life using a particular studio flash setup is say 1/15 sec at f5.6 (EV9). If the exposure is kept the same, one could also shoot at 1/30 at f4, 1/60 at f2.8 or 1/125 at f2. Obviously while the exposure remains the same, DOF, sharpness, etc. will differ. Could it be shot at 1/250 at f1.4? Only if the camera's sync speed is slower than 1/250 sec.

Here I'm not even talking about flash power as the assumption is that the flash output is constant. Obviously in practical terms, using such a wide aperture may be impractical or counter-productive as one would need to use ND filters, increase the flash working distance, etc. to throttle down the flash output to prevent overexposure. These are remedies to reduce light output but it doesn't prevent the use of wide apertures.
 

Jan 14, 2005
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#13
...
So long as the shutter speed used is within the flash sync speed, for a given exposure value (EV), any combination of shutter speed/aperture can be used. If for example, a meter reading for a still life using a particular studio flash setup is say 1/15 sec at f5.6 (EV9). If the exposure is kept the same, one could also shoot at 1/30 at f4, 1/60 at f2.8 or 1/125 at f2. Obviously while the exposure remains the same, DOF, sharpness, etc. will differ. Could it be shot at 1/250 at f1.4? Only if the camera's sync speed is slower than 1/250 sec.

Here I'm not even talking about flash power as the assumption is that the flash output is constant. Obviously in practical terms, using such a wide aperture may be impractical or counter-productive as one would need to use ND filters, increase the flash working distance, etc. to throttle down the flash output to prevent overexposure. These are remedies to reduce light output but it doesn't prevent the use of wide apertures.
I think you got it all wrong. When you are working with flash, you take the shutter speed out of the equation. You do not use EV.

E.g. if you set your flash for ISO100 f/8, you can use 1/25s, 1/100s, 1/250s with f/8. You will get the same exposure no matter what shutter speed you use as long as the aperture and ISO remains the same.

You only take flash power, ISO and aperture into consideration when using flash. You can use any shutter speed and it will not affect the exposure. You just need to ensure that the shutter speed is lower than your sync speed or slower than the flash exposure. This is because the flash duration is very short and is shorter than your shutter speed under normal circumstances.

BC
 

ortega

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#14
another way is to move the strobes further away from the subject
or find some other way to cut the amount of light reaching the subject or sensor
 

ortega

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#15
if flash output is constant

and the meter says that it should be f11 @ 1/60s
and if your camera's flash sync can go up to 1/200s

then using f11 aperture you can use any shutter speed from 1/200s and slower (1/125, 1/60, 1/30, 1/15 and so on )
but not to slow as the ambient light will also be captured.
 

nightwolf75

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#16
funny how the TS never appear again, while everyone is hot under the collar over the flash sync speed and watnots....

to get back to the original question, yes, u can. but u have to dial down the power of the flash or modify the light like siao to prevent over-exposure.
 

creampuff

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Jul 11, 2006
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Dover
#17
ortega sums it up best. definitely got carried away:bsmilie:
 

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