1. WelshTony

    WelshTony

    Messages:
    98
    Name:
    Tony
    Edit My Images:
    Yes
    Although I’ve been an active photographer for many years, mainly landscape and wildlife, I’ve never really got around to the use of Flash.

    The last few miserable months of rain has led me to start considering more indoor photography (portraits etc.) where flash would be essential.

    I’ve watched countless YouTube videos of studio Flash and lighting and done some experimenting with an on camera flash on my Canon 7D MkII.

    I’m now considering the next step and investing in an off camera studio flash.

    However, before I do I have a question which I hope members to this forum could answer, as I’ve looked everywhere and cannot find a sensible answer.

    Many of the videos I’ve watched the photographer states “I’ve got the flash on half power” or “the flash is on one eighth power” etc. but nobody seems to explain why they have made this decision.

    Is there some magic formulae which dictates whether you use full power, half power or even 128th power, or is it just down to trial and error and something that comes with experience?
     
  2. Faldrax

    Faldrax

    Messages:
    1,280
    Name:
    Jonathan
    Edit My Images:
    Yes
    You set the flash power to give the desired exposure according to your selection of Aperture, Shutter speed and ISO.
    Which gives a lot of possibilities!

    It's a bit simpler in most cases, as you'll set ISO to 100 (or 200, with the few cameras where 200 is the base ISO), and Shutter to 1/160-1/250 (depending on the max synch for your camera).

    So then it's just a case of choosing the desired aperture for the depth of field you want, and then adjusting the flash power to give the exposure you want.

    Which can be based on experience, or via a test - which can be a test flash and light meter or a test shot and review histogram.
     
  3. Canon Bob

    Canon Bob Loves the Enemy

    Messages:
    10,236
    Name:
    Bob
    Edit My Images:
    Yes
    There's no magic formula as it really depends on what you're trying to achieve. Sometimes you'll want to add to the ambient light and other times you'll want to overpower it.
    The placement of the light will play a big part too.....do you want soft shadows, strong shadows or no shadows?

    Bob
     
  4. simonbarker

    simonbarker

    Messages:
    1,926
    Edit My Images:
    No
    That's akin to asking what shutter speed you should use for a photo, when there is no correct answer as different settings produce different results.

    Not to worry though it's not complicated, most photographers can even get it right most of the time. ;)

    Joking aside, it'll make sense with a little practice. There's some basic rules and once you know them you can carry them to every situation to achieve the results you want. With practice you''ll know roughly how much power you need to get a certain set of results, if you're concerned about what equipment to buy you really don't need much to start with.
     
  5. Phil V

    Phil V

    Messages:
    21,922
    Name:
    Phil
    Edit My Images:
    No
    From a practical angle.

    When I start a shoot with flash only, I generally start from 1/4 power, as it’s about the best power vs recycle time compromise.

    From that I’ll attempt to balance ISO and aperture, and shift from there if necessary.

    The other starting point is a balance with ambient light if that’s what I’m shooting. And there the starting point isn’t flash power, it’s an exposure that gets what I want from the ambient before I add flash.

    It looks complicated at first, but honestly it isn’t. And like all these things, it looks really complex to people with no experience at all. Try to explain a hill start or when to change down a gear to someone who’s never driven.
     
  6. Sideshow Alvie

    Sideshow Alvie

    Messages:
    457
    Name:
    Alan
    Edit My Images:
    No
    Yes, it's a mixture of keeping recycling times down and not overpowering the ambient light too much. Try playing with both manual and automatic settings on the camera to see how much you like the various results. This was tricky stuff to master back in the days of film but with digital you can soon get to grips with this stuff. Balancing ambient light and flash well is often the mark of a good photographer.
     
    WelshTony likes this.
  7. Dork Knight

    Dork Knight

    Messages:
    183
    Name:
    Jason
    Edit My Images:
    No
    Set the ISO first for the environment that your shooting in (I tend to stick to the lowest native ISO for the camera that I'm using when in a controlled environment).

    Your shutter speed will control the amount of ambient light in the scene, so take a few test shots and chimp to see if you have the recorded the scene as you want (If not adjust the shutter speed and/or ISO to get you there).

    Here's a quick video on Aperture/Flash Relationship;

    View: https://www.youtube.com/watch?v=2yY4cNh0X60


    Much quicker to dial in the settings if you have a light meter but if not, just play around with the flash/strobe power and aperture until you get the correct exposure.
     
  8. WelshTony

    WelshTony

    Messages:
    98
    Name:
    Tony
    Edit My Images:
    Yes
    Thanks for the response - great instructive video as well - very clear to understand.
     
  9. Fraser Euan White

    Fraser Euan White

    Messages:
    1,180
    Name:
    Fraser White
    Edit My Images:
    Yes
    When i was taught basic studio flash photography many years ago 'strobes' or speedlights didn't have lots of settings so things were slightly different but I still use some of the basic 'rules' I was taught.


    (1) Get to know your flash - If it has a half power setting set it to that initially and know what aperture it gives for the correct exposure at 6ft from the subject.
    (2) to do the above buy a flashmeter - something like the Sekonic 308 is cheap/good (not as necessary now with digital cameras and LCD screens but helps learning)
    (3) Buy a light stand to get the flash off the camera
    (4) Buy a form of light modifier (softbox, umbrella etc)
    (4) Use the shutter speed to control the ambient light - faster shutter speed darker background and vice versa. (Slightly different when balancing in daylight outside where it controls the percentage of 'flash fill'
    (5) Use the aperture to control flash power - set aperture to f8, if you want to effectively go up in flash power open up the lens aperture and vice versa. (This saves walking to the flash all the time to change its power setting but isn't so relevant now with radio communication etc. & remember it will effect your DoF.)

    Trial and error is brilliant but try to understand what is happening so you can repeat it - I love flash photography and was a big reason I got back into photography after a lengthy break - still lots to learn (I don't think you ever stop learning in this hobby but there are some very knowledgeable people in this section giving great advice.)

    Here is a link hopefully showing some progress I've made in my little home studio:

    https://www.talkphotography.co.uk/threads/first-shots-in-new-home-studio.648821/
     
    Last edited: Mar 14, 2018
  10. Durbs

    Durbs

    Messages:
    812
    Name:
    Paul
    Edit My Images:
    Yes
    I'm no expert - but found this book to be excellent - not too technical, clear examples of set-ups and results and an easy read.

    Only caveat is it's fairly/very Canon Speedlight-specifc, but the techniques are still valid.
     
    Phil V likes this.
  11. Mozthecat

    Mozthecat

    Messages:
    375
    Name:
    Jon
    Edit My Images:
    Yes
    The speedlighters handbook seems to have gone out of print, the in laws ordered it for me for Xmas and are still awaiting delivery...Amazon keep pushing the date back and 2nd hand copies ( of the second edition) seem to be like rocking horse manure .
     
  12. Fraser Euan White

    Fraser Euan White

    Messages:
    1,180
    Name:
    Fraser White
    Edit My Images:
    Yes
    The YouTube Joe Brady/Sekonic videos I find very useful.
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice