Welcome to the forum!

As an adjunct to the Tangents blog, the intention with this forum is to answer any questions, and allow a diverse discussion of topics related photography. With that, see it as an open invitation to just climb in and start threads and to respond to any threads.

Overpowering sun questions

SkipperlangeSkipperlange Member
edited July 2014 in home

What exactly does this mean "we have to get f11 @100 iso out of the flash…"?

(The text below is from NVN's recent Tangents post.)

Does this mean if you use the hand-held meter in flash mode and set the iso to 100 and the shutter speed at X (desired shutter speed) the meter will tell you to set the aperture to f11?

How does one 'get f11' or get any f-stop from a flash?

Secondly, why do you want to get f11? Is the purpose (assuming sunny 16 is correct) to create a flash-powered exposure more powerful than the sun and therefore rendering the sun irrelevant and therefore the flash is the sole light source?

Thank you.
+++


FROM NEIL'S POST:

06) flash output needed to overpower the sun

With manual flash, we have 4 controls for the flash exposure – aperture, ISO, power, distance. SInce the Sunny 16 rule tells us that we’re most likely in the region of: 1/250 @ f11 @ 100 ISO … this means we have to get f11 @ 100 ISO out of the flash, or more. We only have the flash’s power and distance-to-the-subject to work with then to get that f11 @ 100 ISO (or there-abouts). Since we’re probably working at full power anyway, or close to it … this then only leaves us the distance to work with. In other words, you have to get the flash close enough to your subject to give you that f11 @ 100 ISO (or more).

So for us speedlight shooters working in bright sun, it is usually not so much the flash output per se, but rather the distance between the flash and the subject. Oh, and while we’re on that topic, going into High Speed Sync mode will not solve your problem, but will worsen it … unless you have plenty juice to spare in your speedlight. Taking your shutter speed over maximum flash sync speed into high-speed flash sync, means less flash power.

Comments

  • Hey skipper how u doing ,, that sunny 16 rule of ( F 11 @ 100 iso ) is just a sweet spot for Ambiant exsposure on a sunny day .
    Basicaly to kill that light thats over baring on the subject .
    In other words if u have much less of an apperture or shallow DOF as u know the ambiant is guna be well washed out ,so F 11 and F 16 will bring in less light on THAT sunny day.
    Hence that flash has to pretty close at full power for a correct exposure on the subect to get through that tiny hole thats created at F 11 or F 16 .
    Also no one realy wants F11 or F 16 the way i see it thats all thats left to kill the ambiant exposure, unless u use a ND filter or a higher shutter speed , and u know higher shutter speed equals HSS leading on to lack of power.
    To get F 11 from the flash , find out your ambiant exposure , set your shutter speed and iso to your camera settings on your light metre and fire your flash on your subject with the light metre , if the metre reads 5.6 for example then u need to bump the flash power up until u get F11 or move the flash closer. That will give u correct balanced exposure on that image .
    I hope i havent told u to suck eggs on this pal. If u wana chat and smash things through bell me any time .
    I have to say this.
    Neil covers this in his craftsy course , on and off camera flash its to bob to buy please get it ive got both and gone over the course stacks of times and neil personley answers your questions . I have it as an app and its fab .
    Regard
    Steve

  • Thank you Stephen, I don't think you've told me to suck eggs. What does that mean, to go to hell?

    You say "To get f11 from the flash, find out your ambient exposure...." Why do I want to find out the ambient exposure if I'm just going to try to kill it? Is the answer to know how much I need to kill?

    So, if the ambient exposure is ss250 @f16 with ISO 200 would I set meter to 250 with ISO 200 and boost flash power until meter read at least f16?

    It's hard for me to understand why this doesn't just deliver a double whammy of light to subject, overexposing him or her. Hard to grasp that all that sunlight just disappears. And why do I want it to disappear if all I'm going to do is match it back? To even it out and have control over it? To eliminate the shadows by throwing an equal amount of light over the whole scene/face?

    Thank you again.

    Thanks for Craftsy suggestion. Will look for it.

  • Sorry jon. I dont mean littery kill the light. I mean to get correct exposure.
    Earlier today i was playing with me camera shooting up to the sun experimenting .
    If u go out now and point your camera to the edge of the clouds where the light hits hard. Then to give u correct exposure u need to anchor your setting as this. Your camera max synch speed. Lets say 1/250. U cant go higher than this for your flash gun to be used , Your ISO at its lowest. U dont need any more light. So your only left with is apature ;F11 F16. Or 22 if u will .
  • So if the ambiient is ss 250 etc. skipper ses
    The answer is yes
  • Neils crafsty is broken down in sections so u can go straight to the subject your stuck on. Ps i bought a light metre so just to undeerstand what neil was teaching. And ten used the light metre to metre all sorts around the house and out side. I understand it. But the key thing is to keep going over wat ive learnt
  • Shooting against bright light. ,, Theres more on here jon but could nt fit it all on. Ive got both. On camera and off camera. U will not find any better tuturing trust me ive looked for two years now.
  • I must remember to post these links. Its a lot quicker than myself rambling :)
  • The links are great but no your rambling is very helpful, thank you Stephen. The links don't answer some questions, because after all they're tutorials not books. Thanks for all yr thoughts on this.

    Thanks for the link Neil.
  • Good tutorial Neil, thanks again. In this lesson you're always shooting into the bright sun. Would this technique be the same if you were shooting in the same bright sun but not shooting into the sun? Say, if the sun we're behind you or to the side. Would you still choose max sync speed, lowest ISO, and full power on the flash?

    If you wanted a shallower depth of field (let's say instead of the f11 in your lesson) couldn't you do that and then use less flash power? Or is the aperture determined first for correct background exposure and then you're stuck with it?
  • Neil vNNeil vN Administrator
    Then you adjust accordingly.

    You turn your car's steering wheel. You change the channels on your TV. You adjust your camera's settings,
  • devdev Member
    Using TTL flash fill on a SB910
    I have not been able to formulate a quick way to set up for
    using fill flash on a sunny day. Using the SB910 on a D800,
    can you explain where to start with the settings on the camera
    and on the flash. Thank you so much!
  • Neil vNNeil vN Administrator
    edited July 2014
    When trying to match the sun with flash, the best algorithm is usually:
    - maximum flash sync speed,
    - lowest ISO,
    - find the aperture for your brightest area that you want to expose correctly for.

    Since you only want fill-flash, and you are using TTL, just dial your FEC down.
Sign In or Register to comment.