Flash – Getting Your Light on Axis

Posted on 03 July 2009 by David Tong

Page copy protected against web site content infringement by Copyscape

For those of us who shoot with off-camera flash while using a light modifier such as an umbrella or softbox, we’re bound to encounter the issue of having the flash not on axis with the modifier. Oftentimes, the bracket that holds the flash and modifier together are separated by at least 4-6″ of vertical space with the flash firing downwards at an angle towards the umbrella.

IMG_7397

If we’re using a large modifier, such as a 60″ umbrella, the problem is less pronounced, or if the flash is far enough from the area where the light will be reflecting on. However, with smaller (<40″) umbrellas, the discrepancy of light hitting the top and the bottom of the umbrella will be quite visible.

I’ve found a cheap (relatively) way to line up the flash so that the light will be bouncing off the center of the umbrella, instead of on the upper part of the umbrella only by using mini ball heads.

Here’s our main problem, with the flash standing tall on top of the umbrella holder, we can see that there’s more light hitting the top part of the umbrella, causing more light spilling on the top, while more light reflecting at a downward angle from the umbrella.

Note the light falloff on the top wall area versus the lower part of the wall.

We mount the mini ball head onto the 1/4″ stud on the light stand then mount the flash (in this case, the flash trigger receiver) onto the ball head then straighten the flash horizontally to the same axis as the umbrella pole.

We can now see how uniform the light pattern is when it hits the reflective surface of the umbrella.

Now compare the reflected light pattern of a horizontal flash position versus the image with the flash standing upright.

Notice how uniform the reflected light appears and how the top and bottom spill light on the edge of the umbrella is better controlled.

If you’re using a cold shoe mount umbrella/flash holder, you can pretty much do the same thing. The receiver below is mounted on a cold shoe, which is then clamped onto the umbrella/flash holder.

The results are the same.

We do have an issue of the flash being much closer to the umbrella now, also known as the umbrella being “choked up”. The light source became smaller and less efficient with this arrangement. In order to counteract that, we can flip down the diffusing panel of our flash or use a diffusing cup while making sure that our flash head is set to its widest setting (usually 28mm).

This is the “cheap” and easy way of doing it. The mini ball heads cost US$5 each brand new from eBay (free shipping), and they are more than enough to hold the weight of your flash. A side benefit of having a rotating ball head is it also makes adjusting the flash settings easier without lowering your light stand too much, just loosen the head and turn the flash towards you.

I will add some sort of a foam material underneath the flash head in the near future so the weight of the flash is also distributed to the shaft of the umbrella instead of just the hot shoe.

Now if you have the tools and skill to make a horizontal bracket, then all the better, you can move the flash further back from the umbrella and have more control on the light pattern of your flash to maximize efficiency. Here’s a great DIY page from DIYPhotography.net for you to try rigging a bracket at home. Good luck and do share what you’ve come up with! :)

Technorati Tags: , ,


This website uses IntenseDebate comments, but they are not currently loaded because either your browser doesn't support JavaScript, or they didn't load fast enough.

10 Comments For This Post

  1. Eduardo Bonifacio Says:

    Thanks david! Keep it comin… more flash topic… hehe…

  2. David Tong Says:

    Glad you like it, Eduardo :)

  3. Mufutau Says:

    Thanks for this information and Review. I was hoping you post a link to this Mini Ballhead on ebay. May be you could tell us the seller on ebay. This is very helpful. Thanks.

    Mufutau

  4. davidtong Says:

    Hello Mufutau… Honestly, just type "mini ballhead" and you'll get tons. I got mine from this guy</url>…

    Good luck
    Dave

  5. davidtong Says:

    Hello Mufutau… Honestly, just type "mini ballhead" and you'll get tons. I got mine from this guy

    Good luck
    Dave

  6. Han Cheng Says:

    Thanks for the tips!

  7. David Tong Says:

    You’re welcome, Han :)

  8. Domeng Says:

    Hi sir. Thanks again for this article. I have some questions:

    - should we be concern with the same issue (light not on axis) when using shoot thru umbrella?
    - with the setup above, aren't there any problems with the light stand leaning towards the umbrella (and strobe) side? (imbalance)

  9. davidtong Says:

    Hi Domeng

    - Yes
    - No, as there's no difference since we rarely use an umbrella 90-degrees on axis with the subject anyway. An umbrella is often above the subject angling down towards the subject whether using a shoot-through or reflective brolly.

  10. Michael Ty Says:

    The ballhead is a great idea. Another solution is to reverse the umbrella swivel so that the tilting part holds the flash. This compromises the ability to angle the umbrella down but works well for me when I handhold the umbrella. Pictures of the setup: http://betterfamilyphotos.blogspot.com/2009/07/h2...

2 Trackbacks For This Post

  1. Flash – Getting Your Light on Axis | David's Simple Photography | Adobe Tutorials Says:

    [...] Align your light with the center of your light modifier using mini ball heads. Read the rest here: Flash – Getting Your Light on Axis | David's Simple Photography [...]

  2. Flash – Getting Your Light on Axis | David's Simple Photography Says:

    [...] See the rest here:  Flash – Getting Your Light on Axis | David's Simple Photography [...]

Leave a Reply



Subscribe to Newsletter


Enter your email address:

Delivered by FeedBurner



Photography Art Blogs - Blog Catalog Blog Directory


Add to Technorati Favorites

Need Your Support

Websites cost money, please help me keep the site online.


________________________
UA-5534765-2