Color My World

So your light provides accurate color, what about your modifiers

I recently posted a self portrait I made while testing the new Interfit Studio Essentials LED monolight. I got some comments about how good the color looked and asking if I did much color correction on the image. I actually did very little color work on the image (shown here). I made one frame with an X-Rite Color Checker Passport and the second frame without. Using Adobe Lightroom Classic's white balance picker, I clicked on the middle gray swatch on the Color Checker and that made a small change, -100K and -5 tint. I thought the image was a bit too saturated, so I also pulled down the vibrance slider -11 points. That was it. 

 Image straight out of camera with no color adjustment

Image straight out of camera with no color adjustment

 Image straight out of camera, no color adjustments

Image straight out of camera, no color adjustments

 Image with minor color corrections (temp -100, tint +5, vibrance -11)

Image with minor color corrections (temp -100, tint +5, vibrance -11)

Or was it????

That got me to thinking about the modifiers I have available. I see so much concern over the color accuracy of strobes, fluorescent lamps, and LEDs. But not so much talk about the modifiers. With so many types and brands of modifiers I figured there must be differences. And I was right. Sometimes big differences.

For the above photos I used two LED monolights on me each with an Interfit 1x3-foot strip box. The light on the background was a Honey Badger studio strobe at its lowest power setting. I was quite happy with the results. But what about my other modifiers.

I grabbed a few modifiers: 7-inch silver metal dish, 24-inch pop-up that comes with the LED monolights (and also with the Honey Badger), a 20-inch metal dish reflector, the same reflector with two different diffusion socks, a 22-inch white beauty dish, a Photoflex 42-inch umbrella, a Photek 46" umbrella (a Softlighter without the diffuser), a Westcott 40-inch shoot-through umbrella, a Westcott Apollo Orb, an Interfit 1x3-foot strip box, and a 32" Photoflex white translucent pop-up diffuser panel. I set the camera (this time a Canon EOS M5 mirrorless with the 70-200 f/4 IS lens. AV mode at f/4.5. 

The first set of images shows have no corrections, just as they came out of the camera. For the second set I used the White Balance eyedropper to balance on the middle gray patch. I also attempted to get the exposure evened out between all of the modifier images (click on each image for a larger version). Quite a variety of colors!!

Samples from each modifier straight out of camera with no color adjustments

Samples from each modifier with color and exposure corrections 

With the camera set to Daylight White Balance, Lightroom read it as 5000K and +9 tint. Here is a list of the color corrections for each modifier:

7-inch silver dish: 5050 (+50K) +1 (-8)
24-inch popup: 4900 (-50K) +13 (+4)
20" dish: 4800 (-150K) +15 (+6)
20-inch + speedotron diffuser: 4450 (-550K) +6 (-3)
20-inch = mola diffuser: 4250 (-750K) +14 (+5)
Beauty dish: 5200 (+200K) +10 (+1)
Photoflex umbrella: 4900 (-50K) +4 (-5)
Photek umbrella: 4820 (-180K) -1 (-11)
Shoot through umbrella: 4800 (-150K) +8 (-1)
Apollo Orb: 5000 (0) +14 (+5)
Interfit strip bank: 4900 (-100K) +14 (+5)
Photoflex disc: 4650 (-350K) +4 (-5)

For reference, a +K value added yellow, -K added blue and +tint added magenta and -tint added green.

Have you done a comparison of the effects your various modifiers have on your lights? 

I have.

Thanks for playing along...
John

 

 

Continuing the Diffusion Discussion

Size still matters

In recent posts about diffusion I have been concentrating on small light sources such as speed lights or the "standard" 7-inch metal dish reflectors on studio strobes. But what about larger sources? I was recently gifted a Speedotron 20-inch metal dish reflector. As I am no longer using Speedotrons as my main lights I adapted the reflector to an S-mount for use with my Interfit Photographic lights. This post contains affiliate links and I will be compensated if you make a purchase after clicking on my links.

As I started testing this franken-reflector I noticed that the light was harder than I expected. A look inside the bowl gave some cues as to what was going on. Speedotron lamp heads have large protruding flash tubes and/or flash tube covers. This pushes the light source out in front of the mount on the reflector, allowing the light to completely fill the bowl. The bulbs on the Interfit, though they do protrude, are not quite as long as the Speedo tubes. So most of the light was coming straight out of the flash going forward and not spreading out quickly enough to fill the bowl. 

I did some cutting and drilling to change the position of the S-mount to try to push the flash tube a bit further into the bowl. That still wasn't enough. A quick experiment using a 12x12-inch sheet of diffusion gel in the shape of a dome over the flash tube confirmed what I needed. My first thought was to find a Tupperware bowl around the size of the pyrex flash tube cover, but a quick look through kitchen cabinets didn't turn one up. That got me to thinking that people used to call some speed light flash diffusers Tupperware. And I remembered that I had a very old one of those made of a hard plastic that was specific to a speed light I no longer had. I quickly found that diffuser and a hack saw and went to work.

After cutting off the bottom of the diffuser I was relieved to find it to be exactly the right size to fit in the S-mount. A bit of hot glue and clear caulk and it was fixed in place, ready for testing. And some disappointment. The light was still harder than I expected. Even with the diffuser in place, most of the light was concentrated in the middle and not filling the bowl. Then I remembered that there was a second piece to the diffuser, a dome that snaps onto it. I quickly located that and voila, the second test did show a noticeable change in the shadows and more light "wrapping" around to the side of the subject (notice the ear is brighter). Now the diffuser was doing its job--making the light spread wider to fill the bowl of the reflector. The diffuser itself didn't make the light softer, but it did make the light source larger which did soften the light. 

The next option was to add a diffusion sock over the entire reflector. This has the effect of spreading out the light across the full 20-inches of the bowl making the light source even larger and more even across the surface. Again the diffuser spread the light and evened it out. The last test was to try the sock with and without the dome inside the reflector. This showed a subtle change. With the dome the light source appeared a bit larger, as seen by more light reaching the ear. But the shadow transition was pretty much the same with and without the dome. It was just that with the dome more of the bowl was lit and the light wasn't as directional.

Let's look at the tests (click on the image for a larger version)...

Here are side views of the interior of the modified 20-inch bowl reflector with and without the dome on the diffuser. I made one more modification, not shown here. I drilled a series of small holes around the edge of the snap on dome to help the fans in the strobe head be more efficient.

180827-cornicello-0503.jpg
180827-cornicello-0502.jpg

Safety First
IMPORTANT: DO NOT TRY THIS WITH A STROBE THAT USES TUNGSTEN OR QUARTZ MODELING LAMPS!! I was able to do this with the Interfit strobes because they use relatively cool running LED modeling lamps. For comparison, the 60-watt LED in the Honey Badger is brighter than the 250-watt quartz-halogen modeling lamp in my older strobes. But the LED's temperature after being on for hours remains around 85-degrees F while the quartz bulbs reach temperatures over 300-degrees F in a matter of seconds.


So, you might ask, what is the point of all this today. It is all part of trying to dispel myths around diffusion. It is easy to look at the photos and decide that the various diffusers changed the quality of the light. But it still comes back to the fact that the quality of the light is determined by the size of the light. In these examples the diffusion spread the light to better fill the bowl of the reflector. Without any diffusion the 20-inch reflector is bright in the middle and darker around the edges, making it appear smaller than its actual size. As diffusion is added the light spreads out to fill the bowl, making it appear to be its full size.

 

 

Inconsistent exposures at "in between" ISO settings on Canon 6D mkII

Over exposure at some ISO settings

I started out this evening trying to figure out how to compare noise levels at various ISO settings on my Canon 6D Mark II camera. But instead, I noticed a pattern of overexposure at "in-between" ISO settings. By "in-between" I am referring to the settings between the main 100, 200, 400, etc. These would be 125, 160, 250, and 320.

The exposures at ISO 100, 200, and 400 were consistent with the camera in AV (aperture priority), as were those at 125 and 250. However the photos at 160 and 320 were overexposed by about 1/3 of a stop (the pattern continued throughout the ISO range up to ISO 40000). Of course the first thing I checked was the shutter speed to see if the metering was somehow off in those two photos. No, the shutter speeds were correct at 1/20 and 1/40 (see the progression of shutter speeds below). And I was using continuous light, so it wasn't inconsistent flash power.

How about an inconsistent shutter speed? No. I changed the light a bit and tested again. Same pattern of overexposure, but this time the shutter speeds were the correct 1/25, 1/50, and 1/100. The overexposure is happening due to something else going on in the processing of the image in-camera.

SHUTTER SPEED PROGRESSION
1/10   1/13   1 /15   1/20   1/25   1/30   1/40   1/50   1/60   1/80   1/100

Here is the set of image where you can clearly see that the photos at ISO 160 and ISO 320 are overexposed compared to the other images.

I tested this on two other Canon cameras, a 5D Mark III and a M5 mirrorless, and did not see this issue with either of those. Exposures at all ISO settings were equal.

This morning I added in another set of images lit with flash and see similar results. I took my meter reading at ISO 100 (f/4) then raised the ISO in 1/3 steps while stopping down 1/3 stop for each image in the progression. Again, ISO 160 and 320 were overall a little bit brighter than the other images.

Have you done a comparison of exposure or noise at various ISO settings on your camera? If you have a 6D Mk II please let me know if you see the same exposure issues at the +2/3 ISO settings. 

Oh, here is a set of closer crops in case you want to see the noise comparisons...

At these low ISO settings I cannot see much, if any practical difference. But I will stick with ISO 100 for most of my studio work and bump it up a bit if I need a little extra aperture for more depth of field.

Thanks!
John

Diffusion Confusion (take 3)

Diffusing the situation

Time for my yearly update on the topic of diffusion and how it affects your lighting. As usual, let's start with a definition of diffusion:
• the spreading of something more widely
• the action of spreading the light from a light source evenly so as to reduce glare and harsh shadows.

I will start of by taking some exception with the second definition. The first part about the spreading of light is correct. Reducing glare earns a "maybe," but changing the angle of the light will be more effective (remember the angle of incidence equals the angle of reflection). Now about those shadows... diffusion on its own (and I am talking here about putting some diffusion material right on the light, not using an umbrella or softbox or bouncing off a wall) doesn't reduce shadows. It doesn't soften shadows. It hardly does anything to the shadows except make them less dense (lighter) by bouncing light off of more surrounding areas (walls, floor, ceiling). It mostly reduces the output of the light as it makes the light spread out wider to cover a larger area. Diffusion on the light is used to allow the light to cover a wider area when using a wider angle lens. Or it might be used to even out the spread of light across the surface of the light (useful for evenly lighting a background, for instance).

Shadow edges, which we use to describe the quality of light, are determined by the size of the light in relation to the subject. Adding a sheet of diffusion material to the front of a light does not change its size, and doesn't change the shadow transition. The diffusion will make the light disperse in a wider pattern which makes the light seem less powerful as it covers a wider area (which might be a concern for battery-powered lights). It will even the pattern of illumination to make the light more uniform on the subject (more noticeable with larger light sources). But it won't make the shadows any softer. To do that you need to make the light bigger. Do that by using a scrim that is placed a distance in front of the light and that is much larger than the light. 

Here is a set of images lit with a 7-inch dish reflector and with a 20-inch dish reflector. The first image in each series is the bare reflector. The middle image adds one sheet of diffusion material over the reflector. The third image has two sheets of diffusion material on the front of the light. Look at the nose shadow in each as you go across. 

Comparing 7-inch and 20-inch reflectors with and without diffusion on them (click on the image to enlarge it)

light-wrap.jpg

The shadow edge across each row does not change as diffusion is added. To change the shadow edge and make it softer you need to make the light larger. Notice that the 20-inch reflector with no diffusion is softer than the 7-inch reflector with double diffusion. Diffusion material on the light spreads the light to cover a wider area, it doesn't soften the light. No matter how close you bring the 7-inch reflector to your subject, or how much diffusion material you put right on the reflector that light is never going to be larger than your subject's head, and hence will always be a small/hard light source. Soft light comes from light being able to reach your subject from a variety of angles instead of just straight on. Look at the diagram here. You see that from the small light source all the rays are concentrated leading to hard shadows. A bigger source from the same position provides its own fill light to soften the shadow. Some people say that the light "wraps" around the subject, but it is all traveling in straight lines. If you were to take that larger light source, though, and back it up a ways it will become relatively smaller compared to your subject, and hence more directional causing harder shadow edges. So what about the scrim I mentioned above?

Make it bigger!
Yes, you can make the light bigger by using a diffusion scrim, but the scrim has to be separated from the lamp, not used right up against it. Here we have the same 7-inch dish at 36-inches from the face with "double diffusion" and next to it the dish with a diffusion scrim added about 17-inches from the face. Notice the big difference in the shadow edges. The strobe head (the origin of the light) remained in the same place. But the source of the light changed from the strobe head (small) to the scrim (large). The scrim made the light larger and closer, both of which help soften the light.

Comparing 7-inch reflector with diffusion vs. adding a diffusion scrim at a distance to make the light source larger

This is where I think the confusion comes in. In both cases the light has been diffused by translucent material. The difference is in where the diffusion is applied and how it affects the size of the light and thereby the quality of the light. 

scrimlight.jpg

Size Matters!
It comes down to this... Use diffusion to spread the light wider, use size to control the quality of the light. A large undiffused light is going to be softer than a small diffused light.

There can be an advantage to using a small light with a scrim over using an umbrella or a softbox--more control. You can place the scrim at the position you want to control the falloff of light from the subject to the background and then you can move the light in closer to the scrim making it smaller to make it harder or back it away to light up more of the scrim making the light softer.

Previous blog posts about diffusion:
2016
2017

More about light size and distance is covered in by book Anatomy of a Studio Portrait. You can help support this blog by purchasing the book at Amazon.com 

Thanks!

John

 

High Speed Sync vs Neutral Density Filters

HSS vs Neutral Density

I was reading online forums again (yeah, I know...)... I saw a discussion where a photographer was trying to figure out exposure settings for outdoor flash vs ambient light using neutral density filters. He was adamant that he did NOT want to use high speed sync (HSS) because HSS robs the flash of a lot of its power.

This got me thinking... Doesn't using ND filters also rob the flash of power? If you put a 6-stop ND filter over the lens you are effectively lowering the power of the flash 6 stops and also lowering the amount of ambient light 6 stops. If you use high speed sync to raise the shutter speed by six stops you lower the ambient light 6 stops. You also lose power in the flash, about the same 6 stops. Seems pretty much equivalent.


NOTE: Some of the links in this post are affiliate links and I might be compensated if you purchase equipment using the links. But you will also get a discount by using the link or the code CORNICELLO10 on the Interfit Photographic web site. Win/Win situation!


Testing:
So, time to do some testing. Camera is a Canon 5D mkIII with an 85mm f/1.8 lens. All of the photos were made with the white balance set to Daylight. Flash is an Interfit Photographic S1 with high speed sync capabilities modified with a 24-inch collapsible beauty dish. Ambient light meter reading was 1/125 at f/9 and the flash was a bit brighter (f/13). I wanted to make the photographs at f/1.8. 

I needed about 5 and 2/3 stops of neutral density. I had two 0.9 (3-stop) neutral density filters handy, so I stacked them on top of each other and made the first series of photos below with normal sync. Then I removed the filters and switched the Interfit S1 to high speed sync mode and made a similar set of images above the normal sync speed of the camera. The third set as the Interfit S1 in HSS mode plus TTL metering. All the photos were imported into Adobe Lightroom Classic with no adjustments made to them and then I made the following groups via the Print module. The power level on the strobe was not changed between shots in the first two sets of photos. In the third set the strobe was in TTL mode, so it did vary the power (raising it as the shutter speed increased) to maintain the proper exposure.

While this test isn't super scientific, the things I notice are a definite color cast in the photos made with the ND filter, the ND photos do not appear to be quite as sharp as the HSS photos (a complaint I often hear about variable density ND filters, but these were two single density filters), and the ND filters I used required me to take off the lens shade (something I rarely if ever do) to attach them. The ND filters make it more difficult to see through the viewfinder (6 stops more difficult, I don't want to do the math to figure out how many times darker that is). I could/should have bumped the flash power up a third of a stop or so because of the extra density. The background would have remained the same with the subject being a little bit brighter. But it is what it is. All in all a bit of a pain to work with, but it gets the job done if you have a strobe unit that doesn't do HSS.

In the middle set, using the flash in manual exposure mode with high speed sync. Again, I should have/could have bumped up the power of the flash as I went above 1/3200 sec. on the shutter speed. But the last three are still OK and salvageable. 

The set with the S1 in high speed sync mode and TTL exposure seems to be the winner to me. I was able to adjust the shutter speed to make the trees in the background lighter and darker while at the same time keeping the exposure on the subject pretty consistent. I did not make any adjustments on the flash.

Until fairly recently, I hadn't used HSS or TTL all that much with my flashes. I've been a pretty strict manual mode and in the studio type of photographer. Working with the Interfit S1 strobes has changed my mind about this. What are your thoughts about using neutral density filters to balance flash and daylight versus using high speed sync? 

For those interested in how to figure out the exposure using ND filters, here is how I do it.

  • Take a normal meter reading at 1/125 sec. shutter speed (this gives me leeway to raise the shutter speed slightly to darken the background without going over the sync speed of the camera)
  • Example: ISO 100, 1/125 Sec. at f/11
  • Adjust the output of your flash to read the same f/stop (f/11 in this case) or a bit higher WITHOUT THE ND FILTER (I went for f/13 above)
  • Decide on the aperture you want to use for depth of field. In this case I wanted f/1.8
  • Figure that from f/13 to f/1.8 is 5 and 2/3 stops
  • Find a 5 and 2/3 stop neutral density filter or adjust your aperture to match the ND filter(s) you have. If you have a 3 stop filter you can go from f/11 to f/4, with a 4 stop filter you can go to f/2.8, with a 6 stop filter you can go to f/1.4 (I opted for stacking two 3 stop filters above)
  • Take the photo with the ND filter(s) in place
  • Adjust the shutter speed up/down to darken or lighten the background
  • Adjust the power of the flash up/down to get the proper exposure on the subject
  • Deal with focus and color issues

To figure out the exposure with high speed sync

  • Decide on the aperture you want to use
  • Set the camera to that aperture
  • Make sure your flash is in HSS mode
  • Adjust your shutter speed up/down to darken or lighten the background to how you want it to look
  • Adjust the power of the flash to give proper exposure on the subject or use TTL if available

Do note that HSS on speed lights will run through batteries quicker. The folks at Interfit, though, tell me that the S1 battery actually lasts longer in HSS mode. HSS may also shorten the life of the flash tube. But everything is a tradeoff in photography.

Revisiting Shutter Speed In Relation to Flash Photography

How shutter speed affects flash in and out of the studio

 Does this ever happen to you?

Does this ever happen to you?

From in-person discussions, q&a sessions in CreativeLive classes I’ve been involved in, and from online discussion groups I have come to the conclusion that shutter speed when using flash is a difficult concept for photographers to grasp when first introduced. We’re all familiar with the three legs of the exposure triangle: ISO (sensitivity), Aperture (amount of light passing through the lens), and Shutter Speed (how long the light is allowed to reach the sensor. For a more in depth look at how shutter speed affects your photos please visit this guide on the PhotographyTalk site). When we add flash into the situation there are another two legs added, the amount of light and the duration of the flash. And at the same time, the Shutter Speed leg’s effect is somewhat tossed away. This makes it sound more complicated than it actually is.

exposure_variables

It is a double exposure
I find that it helps to think of flash photography as making a double exposure with one click of the shutter button. We have an exposure for the existing ambient light that is controlled by the big three (ISO, f/stop, shutter speed). And we have a second simultaneous exposure for the flash that is controlled by ISO, f/stop, and flash power. As ISO and f/stop affect both exposures we can eliminate them from the exposure equation. That leaves us with shutter speed to control the ambient light and flash power to control the flash light. More about that when I talk about working with flash outdoors in sunlight. Let’s start with studio lighting.

In The Studio

What I am saying is that in studio flash photography in the studio the shutter speed doesn’t matter all that much within a certain range, usually around 1/30th of a second to 1/200th of a second. That’s around a 3-stop range. How can that be? What about motion blur at 1/30? 

In the studio we have control over the ambient light situation. We can make the studio completely dark so that even a full 1-second shutter speed at a typical aperture of f/8 or f/11 will not record anything on the sensor. Then we add the flash. The flash provides the powerful light that does record on the sensor. But it only records for that split second that the flash is firing (the flash duration). So out of that 1-second the shutter is opened, the flash is only firing for a fraction of the time. Maybe 1/300 of a second for a big old powerful studio power pack and head system or only 1/9000 of a second for a newer flash unit. The flash duration has effectively replaced the shutter speed in terms of both providing the light for the exposure and for providing the speed necessary to stop motion. Now I am not advocating a shutter speed of 1/30, just using that as an example. Go ahead and test this yourself. Set the ISO and aperture you would be using in the studio (ISO 100 and f/8 is a good starting point) and turn down the ambient light to have a darkened studio. Before connecting and turning on your flash take a photo with those settings to see what gets recorded. In many cases the frame will be black, or show just a faint image. If you see too much image raise your shutter speed to 1/60 and try again.

So why set 1/200 as the other end of the range for studio flash photography? That comes down to how the focal plane shutter in our camera works. With a focal plane shutter (which is what we have in most dSLRs and many mirrorless cameras) there is basically a set of two curtains (simplified, as some have multiple blades, but the effect is the same). When you press the button to take a photograph the first curtain slides out of the way to allow light to reach the sensor. Then the second curtain slides across covering the sensor to end the exposure. To synchronize this with a flash the flash has to fire when neither curtain is covering the sensor. The fastest shutter speed at which there is no curtain in the way is the sync speed for that camera.

Here is an illustration of what happens. On the left we see the first curtain open up to expose the entire sensor in the camera. Then the flash fires, exposing the entire scene. Then the second curtain closes to end the exposure. On the right we see that above the sync speed the first curtain opens, then the second curtain starts to close before the first curtain clears the sensor. Then the flash fires and gets blocked by one of the curtains causing a black band along one edge of the photograph.

 Syncronized shutter

Syncronized shutter

 Out of sync shutter

Out of sync shutter

Your camera specifications might tell you that the sync speed is 1/180, or 1/200, or even 1/250, so why not go that high with the shutter speed? That number is usually in relation to using a dedicated flash on your camera in the hot shoe. As an example, look at the user manual for the Canon EOS 6D mark II. On page 280 it says:

Non-Canon Flash Units
Sync Speed

The camera can synchronize with non-Canon compact flash units at 1/180 sec. and slower speeds. With large studio flash units, the flash duration is longer than that of a compact flash unit and varies depending on the model. Be sure to check before shooting if flash sync is properly performed by test shooting at a sync speed of approx. 1/60 sec. to 1/30 sec.

Additionally, the use of a remote radio signal flash trigger can add a little bit of a delay to the firing of the flash, requiring a slower shutter speed than expected.

So, what happens if you do set your shutter speed too high? You will notice a dark band along one edge of your photo or no image at all. Here is a set of test images I created with the Canon EOS 6D Mark II and studio strobes (two Interfit Honey Badger flashes, one on the subject and the other on the background). The shutter speed for each photo is shown above the mannequin head. You can clearly see that the flash synced at speeds up to 1/125, but at 1/250 there is the start of a black band along one edge and at 1/2000 the frame is completely black. With some lower cost remote flash triggers you would even see the black band at 1/125, so you would need to set your shutter speed to 1/80 sec. or 1/60. If you have had that black band along the edge of some of your flash photos, here is the explanation.

 Studio flash at various shutter speeds

Studio flash at various shutter speeds

High Speed Sync

For some time now dedicated camera flashes (I will refer to them as speed lights here) have offered a feature called High Speed Sync (HSS). This feature is now becoming available in studio flash units like the Interfit S1. It allows the flash unit to synchronize with faster shutter speeds. This comes in most handy when working outdoors in daylight and you want to make photos at wider apertures such as f/2.8 or wider and want to provide some fill light from the flash or even use the flash as your main light source. The issue there is that a typical mid-day exposure at ISO 100 and f/2.8 might call for a shutter speed of 1/2000. As we saw above, the flash won’t have any effect on the image at 1/2000 sec. 

Another situation is where you want to darken the ambient light exposure so that the flash is the main light on the subject. Changing your ISO or aperture will affect the flash exposure as well as the ambient exposure, so your control over the ambient light is your shutter speed. We’ve seen that you are pretty limited in available shutter speeds with normal flash sync. Only being able to speed up to 1/180 or 1/200 doesn’t give you all that much control to darken the ambient light.

Enter HSS
With HSS the flash fires in a stroboscopic fashion (pop, pop, pop, pop, pop) synchronized to the movement of the shutter curtains during the exposure. This happens very quickly, too fast for the human eye to see the multiple flashes, so it still looks like one flash burst. Here is a visual explanation of high speed sync...

 On the left there is too much available light to be able to work at f/1.8, everything is overexposed. On the right HSS has been enabled and the shutter speed set to 1/8000 sec. to take the background ambient exposure way down and have the Interfit S1 battery-powered flash provide the main exposure on the subject. Here the S1 is being modified by a 2x3-foot softbox.

On the left there is too much available light to be able to work at f/1.8, everything is overexposed. On the right HSS has been enabled and the shutter speed set to 1/8000 sec. to take the background ambient exposure way down and have the Interfit S1 battery-powered flash provide the main exposure on the subject. Here the S1 is being modified by a 2x3-foot softbox.

Trade-offs
While HSS allows the flash to sync at shutter speeds up to 1/8000 sec., there is a catch. Everything in photography is a trade-off. With HSS the trade-offs are power loss, battery life, and a shorter lifetime for the flash tube. If you have used flash before you are most likely familiar with recycle time. Each time the flash fires it releases energy stored in capacitors. Those capacitors need to charge up again to provide the power for the next flash. Depending on the flash, the time for the recharge can be from  a bit less than 1 second to 8 seconds or more at full power. The time to recycle goes down as the power of the strobe is turned down. Do you see where this is going? In order to have immediate recycle times to allow a number of rapid fire flashes within 1/8000 of a second (as per our example) the power of the flash has to be set way down--you get much less light out of the flash. Right now it seems that most HSS flash units have a maximum power output of around 500 to 600 watt seconds. Anything more powerful would not recycle fast enough or would require larger/heavier power units and be much more expensive. This limits us in that the flash has to be in pretty close to the subject, especially if using big modifiers like soft boxes or umbrellas. Or you end up using smaller/harder light sources and have to deal with the consequences of that. And all that rapid firing of the flash can shorten the lifetime of the flash tube (which is usually a user-replacable item).

 Without High Speed Sync you can see the shadow of the shutter curtain when the shutter speed is set higher than the sync speed of the camera

Without High Speed Sync you can see the shadow of the shutter curtain when the shutter speed is set higher than the sync speed of the camera

Do we need High Speed Sync?
It depends.
Yeah, I hate non-commital answers like that. But it does. If you want to totally blur the background on a portrait of one person yes, you might want to make the photo at f/1.4 or f/2.0. And for that you will need to use HSS to be able to work at the high shutter speeds you need in daylight with those apertures. But if you have multiple subjects like a family group you will often be working at f/8 or f/11 or even f/16 to get everyone in focus. At those apertures there is a good chance your shutter speed might drop down to 1/200 or slower and you won’t need HSS.  Even with an individual, if you can pose them someplace where the background is far enough away, you might be able to still get some separation at smaller f/stops and not need HSS. 

For more information about shutter speed in general and how it is used in non-flash photography please refer to this excellent article on the PhotographyTalk website

Thanks for following along! I cover all this and more in my book Anatomy of a Studio Portrait. I also teach lighting classes in the Seattle area at Glazer's Camera and at Photo Center Northwest. Private instruction is also available. Now please go out and light up the world!

John

 

Baffled by Baffles

Is it a baffle or a diffuser?

Being my pedantic self again here. And maybe this use of the term baffle has been going on for a long time and I've just ignored it. But recently I have seen a lot of photography sites using the terms baffle and diffuser interchangeably. I see references to the "inner baffle" on a softbox (try this Google search on softbox baffle). One ad mentions a "white diffusive baffle." This isn't just photographers writing about light, it is also in the descriptions of modifiers on the websites of lighting companies.

Let's start with the dictionary and the definitions of baffle and diffuser...

Baffle 
noun
a device used to restrain the flow of a fluid, gas, or loose material or to prevent the spreading of sound or light in a particular direction.

Diffuser
noun
a device that spreads the light from a light source evenly

From the definitions, these seem to be opposites. A baffle would be more akin to a grid on a light that restricts the light to make it more directional and prevents the light from spreading out. The inner translucent panel in a softbox is diffusing the light and spreading it out and trying to avoid having a directional hot spot. The outer diffuser does the same thing. And some photographers put multiple diffusers over the outside of their softbox/octa/softlighter. None of these things are acting as a baffle in my mind.

 Diffuser vs Baffle

Diffuser vs Baffle

Am I just the old curmudgeon who can't get with the new terminology? Or should we be more precise in our descriptions?

Loving that light!

A great pairing of lighting equipment

If you have been following me for a while you are probably aware of my love for the 60-inch Photek Softlighter II. I've had mine for 20 years and sometimes stray away from it to use some other modifiers. But then comes a day when I put it back into the mix and ask myself why I haven't been using it as much as I should.

You also know that I have come to embrace the Interfit Photographic Honey Badger as my go-to lighting instrument. But I have not talked much about using them together. Do to the design of the Honey Badger I think it is a perfect mate for the Softlighter. And later in this post I will tell you why. But first some photographs...

Yesterday I got to photograph some Elizabethan outfits from my friends at Period Corsets and I am very happy with the results. Hilary made the outfits and Megan was our model and makeup artist. We had two full outfits to photograph plus the undergarments (which are totally safe for work). For these I elected to light with the Softlighter from camera left and with a 1x3-foot gridded strip box from the left rear for a small accent. The fill "light" was a large sheet of white foam board on camera right (lighting diagram provided below)

Lighting diagram for the Period Corset photos

The Softlighter imparts such a wonderful glow on Megan with good overall coverage and nice falloff to the background. The background is 9-foot wide roll of gray seamless paper with a length of floor board molding from a local home improvement center resting along the bottom to finish it off. All of the textures on the background were added in post-proccessing.

My process for building up lighting for a photograph is to start with one main light and then add accents and fill as needed. In 90% of the situations the fill light will come from reflectors of some sort and not from a second light. Any additional lights will be for accents and will tend to come from behind the subject.

The Dynamic Duo
Now about the pairing of the Honey Badger and the Softlighter. The softlighter consists of a 10-panel umbrella and a diffusion panel that goes over the opening of the umbrella. The diffuser panel has a heat-resistant elastic sock in the middle of it that goes around the lamp head to hold things in place. I prefer to use lights "bare bulb" in the Softlighter. That is, without a reflector on the light which might narrow the beam and not fill the Softlighter as much as possible without the reflector. In the past this could be an issue with studio strobes employing a 250-watt quartz-halogen modeling lamp. Those lamps get HOT HOT HOT. And if the sock on the Softlighter was to slip forward a bit it could come too close to the light resulting in a bit of smoke and a really foul smell. I suspect that if left in contact long enough it would set the sock on fire. Yes, I know this from experience. 

Enter the Honey Badger. This light has a ring around the face of it for attaching slip-on accessories such as the 24x24-inch softbox that comes with the Honey Badger. This black ring works perfectly to hold the Softlighter's sock in place. Of course, the Honey Badger has a 60-watt LED modeling lamp, so while being brighter than the 250-watt quartz lamps on other lights, it remains relatively cool (around 85-degrees F) and won't set the sock to smoldering or burning.

The Interfit Honey Badger with the mounting ring on the front

The Honey Badger with the Softlighter diffuser held in place by the mounting ring

The diffusion panel attached to the umbrella

The elastic sock slipped forward and came into contact with the glass diffusion dome on a strobe head with a hot 250-watt quartz halogen modeling lamp

As an Interfit Creative Pro I can offer you a 10% discount on any equipment purchased directly from the Interfit web site. Just use the code CORNICELLO10 at the end of the checkout process.