Reader Question: What Zoom Setting for an Umbrella?
Reader Jmolli asked the following question in the Strobist Flickr threads. Given that there was no single correct answer, I thought it was worth a little bit of discussion:
Hit the jump for some ideas -- and a couple examples.
______________
The first thing you have to ask yourself before choosing the flash setting for your umbrella is, how big do you want your light source to be? But before we get to that, let's make sure we all know what we mean by "zoom setting."
Remember, your flash was designed to provide coverage for a wide array of lens focal lengths when the flash is mounted on camera and firing in the direct mode. But that was (hopefully) way back in the dark ages for you. And most likely, you are now using the zoom function of your flash for more creative purposes.
By zooming from the typical 50mm setting out to, say, 24mm, you can make a flash with a beam of light that will spill into a wide area -- but at a (relative) cost of light intensity. By zooming the same flash out to, say, 85mm (or even 105mm) you can push that beam out in a more narrow -- but stronger -- pattern. If you need coverage, you go wide. If you need strength (or beam restriction) you go a little more tele.
So how much zoom for an umbrella?
That depends on whether or not you want to make use of the whole thing as a light softener. You may wish to tighten that umbrella from a 43" light source to a smaller one by zooming in the flash, or "choking up" on the umbrella shaft.
Here is a good example of using a small portion of the umbrella. This is Rick, from a seminar I did in Seattle last year. I shot him with the umbrella in close, because I did not want to contaminate the background. (We were lighting the wall with a CTO'd strobe through some drinking glasses to create a pattern.)
Since the light was so close, I choked up a little on the umbrella shaft, which kept the light from getting too soft and pretty. One does so want to preserve Rick's handsome, chiseled features and not go too milk toast on him with the light.
By choking up on the shaft, I not only make the effective light source smaller but I also make sure the flash cannot see the background directly. Remember, not all of the umbrella is being lit by the flash, so I am not going to get any raw light leaking past the umbrella's edge.
Huh?
Follow me: If the flash can see the wall directly (past the edge of the umbrella) you can get some raw light on the background. As long as that raw light is hitting an area outside of your photo, it's cool. Take this photo, for example:
This is a wide shot I grabbed while shooting a basketball player with a shoot-through umbrella. You can see that the "soft-lit" area is actually the shadow of the umbrella itself.
And since the edge of the shadow falls outside of where I will be framing the shot, I have no worries.
If I needed to fix this, I could do it in a number of ways. I could tighten the beam spread on the flash, choke up on the umbrella or move the umbrella further away from the subject -- all would work fine.
But this test shot, taken when setting up for an 11-person group photo, leaves me with a problem. The shadow edge of the umbrella (seen at right on the background) will be in my final photo. I would definitely have to choke up on the umbrella -- or zoom the flash in -- to fix it.
__________
So, before you consider whether or not you have to fill the whole umbrella to get the most size to your light source, you need to check your edges with a test photo to see if you are getting any unwanted spill. If that is not an issue, you can choose to fill the whole umbrella with light by zooming out to 24mm and placing the flash at the far end of the umbrella shaft.
This way, you'll fill your umbrella with light -- but there will be some spilled raw flash to watch out for. It is all a balance, based on what you need.
When using a shoot-through umbrella, your flash will usually not be aimed or positioned in a way to where the raw light will be a problem with lens flare. That's because your umbrella will be pointed at the subject, and the flash pointed at the umbrella.
Not so a reflective umbrella, which could likely be between your camera and the subject (a little off to one side) with the flash pointed back towards you. And that could cause you problems.
In that case, you simply want to stick a short little gobo on the side of your flash which would cause you some raw-light flare problems. Not too much of a gobo, mind you. You'll be eating up some umbrella coverage from the flash, so you do not want to overdo it. Just make it so that the camera cannot see the raw flash head sitting there on the other side of the reflective umbrella.
In general, with flashes and umbrellas, I tend to go with the 24mm setting to get full coverage. Then I gobo off the raw spill light from my camera if needed.
Quick Visualization Tip
To easily see where your umbrella shadow edge will fall before firing the first shot, just sight the umbrella from the position of the flash. This makes for a quick-and-dirty way to check things out while you are still setting up. You'll solve many problems before they have a chance to appear with this one, simple technique.
So, long-story short, how you zoom a flash in an umbrella depends on a lot of things. But if you first decide how much umbrella coverage you need and take care of your spilled raw light, it should work itself out.
___________
Do you have a lighting question you'd like to see answered? Just stick it in a comment. If I think it could be of use to a lot of people -- and we have not talked about it before -- It might show up as a future post!
"I have 32" and 43" convertible shoot thru/reflective umbrellas. I usually set the zoom on my SB-26s to 24-28mm when shooting thru the umbrellas and at 50-70mm when bouncing off of them. I've snapped shots of the umbrellas with the flashes triggering and it looks like they are evenly lit in both situations.
I'm curious to know what other people are using for zoom settings when shooting thru or bouncing off of umbrellas. I use the short zoom on the shoot thru because I usually have them fairly close to my subject and at higher zoom settings the light gets harsh. When bouncing I'm usually further away so I up the zoom."
Hit the jump for some ideas -- and a couple examples.
______________
The first thing you have to ask yourself before choosing the flash setting for your umbrella is, how big do you want your light source to be? But before we get to that, let's make sure we all know what we mean by "zoom setting."
Remember, your flash was designed to provide coverage for a wide array of lens focal lengths when the flash is mounted on camera and firing in the direct mode. But that was (hopefully) way back in the dark ages for you. And most likely, you are now using the zoom function of your flash for more creative purposes.
By zooming from the typical 50mm setting out to, say, 24mm, you can make a flash with a beam of light that will spill into a wide area -- but at a (relative) cost of light intensity. By zooming the same flash out to, say, 85mm (or even 105mm) you can push that beam out in a more narrow -- but stronger -- pattern. If you need coverage, you go wide. If you need strength (or beam restriction) you go a little more tele.
So how much zoom for an umbrella?
That depends on whether or not you want to make use of the whole thing as a light softener. You may wish to tighten that umbrella from a 43" light source to a smaller one by zooming in the flash, or "choking up" on the umbrella shaft.
Here is a good example of using a small portion of the umbrella. This is Rick, from a seminar I did in Seattle last year. I shot him with the umbrella in close, because I did not want to contaminate the background. (We were lighting the wall with a CTO'd strobe through some drinking glasses to create a pattern.)Since the light was so close, I choked up a little on the umbrella shaft, which kept the light from getting too soft and pretty. One does so want to preserve Rick's handsome, chiseled features and not go too milk toast on him with the light.
By choking up on the shaft, I not only make the effective light source smaller but I also make sure the flash cannot see the background directly. Remember, not all of the umbrella is being lit by the flash, so I am not going to get any raw light leaking past the umbrella's edge.
Huh?
Follow me: If the flash can see the wall directly (past the edge of the umbrella) you can get some raw light on the background. As long as that raw light is hitting an area outside of your photo, it's cool. Take this photo, for example:
This is a wide shot I grabbed while shooting a basketball player with a shoot-through umbrella. You can see that the "soft-lit" area is actually the shadow of the umbrella itself.And since the edge of the shadow falls outside of where I will be framing the shot, I have no worries.
If I needed to fix this, I could do it in a number of ways. I could tighten the beam spread on the flash, choke up on the umbrella or move the umbrella further away from the subject -- all would work fine.
But this test shot, taken when setting up for an 11-person group photo, leaves me with a problem. The shadow edge of the umbrella (seen at right on the background) will be in my final photo. I would definitely have to choke up on the umbrella -- or zoom the flash in -- to fix it.__________
So, before you consider whether or not you have to fill the whole umbrella to get the most size to your light source, you need to check your edges with a test photo to see if you are getting any unwanted spill. If that is not an issue, you can choose to fill the whole umbrella with light by zooming out to 24mm and placing the flash at the far end of the umbrella shaft.
This way, you'll fill your umbrella with light -- but there will be some spilled raw flash to watch out for. It is all a balance, based on what you need.
When using a shoot-through umbrella, your flash will usually not be aimed or positioned in a way to where the raw light will be a problem with lens flare. That's because your umbrella will be pointed at the subject, and the flash pointed at the umbrella.
Not so a reflective umbrella, which could likely be between your camera and the subject (a little off to one side) with the flash pointed back towards you. And that could cause you problems.
In that case, you simply want to stick a short little gobo on the side of your flash which would cause you some raw-light flare problems. Not too much of a gobo, mind you. You'll be eating up some umbrella coverage from the flash, so you do not want to overdo it. Just make it so that the camera cannot see the raw flash head sitting there on the other side of the reflective umbrella.
In general, with flashes and umbrellas, I tend to go with the 24mm setting to get full coverage. Then I gobo off the raw spill light from my camera if needed.
Quick Visualization Tip
To easily see where your umbrella shadow edge will fall before firing the first shot, just sight the umbrella from the position of the flash. This makes for a quick-and-dirty way to check things out while you are still setting up. You'll solve many problems before they have a chance to appear with this one, simple technique.
So, long-story short, how you zoom a flash in an umbrella depends on a lot of things. But if you first decide how much umbrella coverage you need and take care of your spilled raw light, it should work itself out.
___________
Do you have a lighting question you'd like to see answered? Just stick it in a comment. If I think it could be of use to a lot of people -- and we have not talked about it before -- It might show up as a future post!
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by David, at 12:00 AM.
22 Comments:
I tested the light output of an SB-24 and an SB-800 at different zoom settings and was surprised by some of the results.
The SB-24 is actually weaker at 35 mm than at 24 mm or 28 mm, and still weaker at 50 mm than at 28 mm.
The beam of an SB-24 is very even, whereas the beam of the SB-800 has some falloff from on-axis to off-axis at all zoom settings.
thanks for the interesting post, although it took me a while to understand what you meant with "choking up" the umbrella ...
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have to say, your blog and all the strobists out there are a huge motivation and inspiration - thanks dave and everyone else
I'm using sunpak 383s. They have on zoom so I have to move the umbrella closer or further from flash to make the effective light bigger or smaller.
Thanks for this post, Dave. Untill now I always made the wrong assumption that zooming out the flash will make it a larger light source. It just hit me that this is not the case. You only (potentially) add other (soft) light sources to the equation by increasing the amount of spill.
This is where modeling lights can really help with adjusting for spill.
The best umbrella tip I heard was: shoot wide behind the umbrella to see how much raw light is spilling (if any). Choke up on the umbrella just until there's no spill. That way, you're maximizing every photon.
Note: if you choke up too far (although sometimes you will want to do this), shoot the interior of the umbrella and you'll notice if you're not maxing it out.
You don't necessarily need to check your LCD; if you squint during the test-fire, you'll see the same effect... but your eyes might not be happy.
In your first example photo, were you using a shoot-through or bounce umbrella setup?
thank you mr. strobist! i've run into the spillage situation at receptions when using reflective umbrellas to light the first dance. your awesome explanation just helped me visualize how to fix that problem!! thanks again for all the awesome info
(i personaly dont have the gear to try it out, but...) maybe using an omnibounce on your flash and sliding the flash further into the umbrella will make the 'shadow' and the softlight-area larger.
This has been a recent topic I've been playing around with, didn't see the original discussion on the Flickr board so I'm glad I caught this.
Good examples and explanations as always. It is particularly useful to me as I have been trying to light some larger objects and am playing with the zoom settings to get even fill without contaminating the surroundings with light.
Your site has definitely been an inspiration for me.
There is another important aspect to this question. The quality of light will change depending on the distance from the light source to the diffusion material - an umbrella in this case. Generally, a light will be softer the further it is away from the diffusion material, more specular if brought in closer. One more reason to buy the Dean Collins DVD set. He covers this in great detail.
That's a good question and a good post on it. I've also been thinking about this. I thought that you are supposed to use the widest zoom setting but 2 weeks ago I ran into some spilling problems when taking interior shots with umbrella and wide lens.
I put a dark wood panel on the floor and tried to take pictures of the "cross-cut" of the beam on different settings but it didn't work out so well. Maybe the test photo method is easier and better.
Never mind all the cool and useful information in your post...
What's really important is that I point out that the word is "milquetoast," not milk toast.
Come on, Hobby... get it right. sheesh.
;)
Todd
Great article Dave. I hope there can be more discussions like this on Strobist. I think getting a firm grip on the basic concepts like zoom/spill ratio will make us all better photographers.
General question / in depth post request: I'm good at most things strobist, but color always gets me. I'd like to see a very in-depth post about color - gels, color shifting, dealing with ambients other than flourescents and tungstens (ie what about those "sodium vapes?"), flash and daylight - how to make them the same color, etc. Like I said - anything and EVERYTHING about color, because that's the achilles heel in my photography.
Here is a blow by blow with added resulting measurements of zoom setting results at two different distances (12" & 24") on an SB-24.
http://www.flickr.com/groups/strobist/discuss/72157603815427494/
I needed this info two weeks ago. DOH!
I'm VERY glad you posted it as I too have been using the wide angle on the flash with my umbrellas.
I can't really think of any lighting questions per se' unless you can figure out how to teach me to 'see' my light before I set up my stuff in one blog entry. LOL
Thank you very much for the info in today's blog, I needed it and will remember that in future set ups.
Jonathan-
We will be hitting on that in Part 7 of Lighting 102.
-DH
During my apprenticeship i learned that to see flashlight you just need to squeeze your eyes together to almost shut and fire a testshot. It looks totally stupid but it allow you to see the contour and shadows of the light. Works both to evaluate the scene and the lightsource itself.
Same trick works if you need to determine how dark the shadows are in a scene and what will turn black.
Good information, thanks.
I'd be interested in reading more about "the right way" to take a photo using flash to freeze the subject in combination with zooming the lens to create a "zoom effect" around the subject.
Thanks!
i'm a little embarrassed that i didn't realize this myself. haha, great information - this little tip would have saved me some serious headaches.
Wow, I'm honored that my question was answered by the master himself! I was disappointed that it had only received two short replies on flickr.
Thanks David for such a comprehensive answer! And thanks for your Strobist site, with only a small investment on my part, it has made a huge difference in the quality of my shooting.
John
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