Why f/8

[tjones8611]

Last weekend, I had my first experience in a studio sighting. All kinds of lights, including boxes, huge portraits, over head, and large ring lighting. It’s a whole new world of photography with models in a studio. But my question, this was a workshop and the instructor instructed us to set our cameras at 1/250 f/8 and ISO 100 for the shots as it would ensure everything was in focus and no bokeh affects. How did he know this? We were all Canon thus the ISO, but why f/8 when you have the best lighting available?
I've heard "just f/8", but why 8?

 

[kundalini]

....it would ensure everything was in focus and no bokeh affects.....

There's no reason NOT to shoot at f/8. The sharpest aperture of most lenses will be in the f/8 (+/-) range.

 

[Big Mike]

Some people will tell you that F8 is optically the 'best' aperture for most lenses. Some people say that most lenses are at their best when stopped down one or two stops from maximum. Some might say say that it totally depends on the lens in question.

 

[syphlix]

in your case it's prob the level the lights were set to...

in flash photography your aperture alone controls the level of light from the flashes while ambient light is controlled by the combination of aperture and shutter

 

[Dao]

More DoF, better performance on most of the lens. And it is in a well controlled environment.

But I do not know about the 1/250 shutter speed since your XS has a flash sync speed of 1/200.

 

[JimmyO]

Becuase thats the most logical exposure for studio lighting

 

[gsgary]

1/250 is too high, i use between 1/60 and 1/125, if you fire your camera without the flash your screen will be black showing no ambient light
I went to a camera show yesterday and on the Phase One stand they were using the new Phase One camera that can sinc at 1/1600
they took a shot of a dart imploding a baloon

 

[tjones8611]

I think 1/250 was the max for the lighting. I guess I assumed each lens would have a different sweet spot, just as the level of sharpness of the same model of lens can vary.

 

[Big Mike]

1/250 is too high, i use between 1/60 and 1/125, if you fire your camera without the flash your screen will be black showing no ambient light

That's the idea of using such a fast shutter speed, to cut out all the ambient light. That way, the studio doesn't have to be dark while you work in it.

If the flash doesn't fire, the shot it trash anyway, who cares if you get a little bit of ambient?

But I do not know about the 1/250 shutter speed since your XS has a flash sync speed of 1/200.

Good point. And depending on your trigger method, you may need/want to slow it down another step just to be sure...which brings us down to where gsgary likes to shoot. :er:

 

[KmH]

Because to get the image scale with a lens that has enough focal length to avoid distortion, you cannot get the subject far enough away from the background to warrant a smaller aperture to render a substantially out-of-focus background.

I notice many people are now using the term bokeh when they talk about depth-of-field. They are not the same thing and the terms are not interchangeable.

 

[gsgary]

I think 1/250 was the max for the lighting. I guess I assumed each lens would have a different sweet spot, just as the level of sharpness of the same model of lens can vary.

The max sinc speed for your camera is 1/200 so your shutter is not quick enough for the flash, which means your shutter was still open after the flash had finished so one side of your shot should be dark

 

[Bitter Jeweler]

My instructor had us shoot at f/11 and 1/125. ISO 100.

 

[Big Mike]

The max sinc speed for your camera is 1/200 so your shutter is not quick enough for the flash, which means your shutter was still open after the flash had finished so one side of your shot should be dark

As you increase the shutter speed past the max sync speed, the shutter starts to creep into the frame. It won't necessarily cover half the frame once you get a step over the max.
You can actually shoot well over the max sync speed if you are away of which side the shutter will creep into and account for that when composing your shot.

 

[tjones8611]

Dudes! I did get that! The right side of some of my shots were dark, about 1/25 inch. I thought I had badly positioned the lights, I guess 1/250 was my doom.

Heres a couple of shots from the weekend with the lights.... Remember, my first time with lighting but would like some feedback.


Sorry for the Fliker link, but its several pictures (about 15) and much easier. How did I do for a first timer?

Link... MMA

 

[NateWagner]

yeah, shooting past your xsync will often kill your image, unless you are planning for it (I.E. you have HSS on your flash, or you are planning on a part of your image receiving less exposure than the rest (sort of a graduated neutral density filter)