Bright lenses are as much about bokeh as they are about shooting in low light — but what about bokeh and bright light? Not every portrait shoot is going to happen under ideal, fairy-tale conditions at golden hour. And even then, sometimes golden hour is still too bright to shoot at f1.2 with a flash. But, there are a number of tools at a photographer’s disposal to mix both bright ambient light and a wide-open aperture. When it comes to mixing bokeh with ambient light, there are three main choices: ND filters for portraits, high-speed sync flash, or an electronic shutter.

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All three of these tools allow portraits with wide-open prime lenses for plenty of background blur. ND filters and HSS tackle a second problem — using both a wide aperture lens and a flash in bright light. A camera flash typically can’t exceed the camera’s built-in flash sync speed, which is often 1/200, 1/250, or 1/320. An ND filter allows for that slower shutter with a wider aperture, while a high-speed sync flash allows the camera to work as if that flash sync speed limit doesn’t exist.

But, each comes with disadvantages as well. With ND filters for portraits, for example, the autofocus accuracy can be reduced. HSS, meanwhile, can quickly drain the flash battery. Which one is the best choice?

I recruited the only member of my household willing to model in exchange for Milk Bones and tried each of the three methods to compare them side by side.

A neutral density filter blocks out all light coming in through the lens. NDs will block bright sunlight, allowing portraits at a wide-open aperture in the middle of the day. Twisting a filter over the front of the lens is a quick and easy way to shoot wide apertures in the middle of the day.

NDs filters can cut out enough light to allow photographers to use a flash without exceeding the flash sync speed. While ND filters can be used without flash, they are a popular choice among flash photographers for this reason. These filters make a bright day dark enough to use a flash, a 1/250 shutter speed, and a wide aperture.

Because NDs block out all light equally, they tend to be easy to use. If you balance the flash output with the shutter speed without the ND filter on, you can simply lower the aperture by the same number of stops that the ND filter cuts out. There’s no need to re-calculate the flash output when working this way.

However, by cutting out all light coming through the lens, ND filters can introduce a few problems. For starters, the camera’s autofocus may not work as well. Autofocus systems work fastest in good light. Cut down on the light coming into the lens, and the autofocus will perform like it would in low light, slowing the focus and, at times, even failing to lock on. The darker the ND filter, the more difficulty the camera may have autofocusing. While landscape photographers can simply focus and then put the filter on, that doesn’t work for moving subjects like with portraits.

Because the ND cuts out all light, this isn’t a solution to reducing only the ambient light — the flash power will be reduced too. An ND isn’t going to magically make a flash too weak to overpower the sun suddenly capable of overpowering the sun. If you look at the photo above and compare it to the photo with HSS, the ambient light is still too strong, creating hot spots on the grass behind the dog.

Finally, while the “neutral” in ND is supposed to mean that the filters have no other effect, that’s usually not the case. Colors are often affected. Some cheaper NDs can wreak havoc on the colors of a photo, while the high-end ones can actually create some more pleasant tones.

In our Creating the Photograph series, Editor in Chief Chris Gampat used an ND filter with a flash to get his look.

High-speed sync, or HSS, emits several pulses of light instead of one. This allows the camera to exceed the flash sync speed and shoot at much higher shutter speeds. Using a flash with HSS means you are not limited to shutter speeds at or below 1/200 (or 1/250 or 1/320, depending on the camera).

When working with a flash, the shutter speed determines the amount of ambient light let in. By increasing the possible shutter speeds, you have more control over the ambient light in the background. HSS offers more options when balancing the ambient light and the flash. The shutter speed can be kept relatively low (such as 1/500) to match the flash with the ambient light. Or, the shutter speed can be increased (such as to 1/2000) to darken the ambient light. 

HSS can help “overpower” the sun. As the shutter speed increases, the background, which is lit by ambient light, will darken. Shooting with HSS and a fast shutter speed allows the background to be completely dark. With a powerful flash or studio strobe, the shutter speed and flash power can be increased enough to even blacken a brightly light background.

That’s the key difference between NDs and HSS. NDs cut out all light, keeping the balance the same. HSS provides a wider range of options to balance the light. With HSS, photographers can make the ambient light darker by using a greater range of shutter speeds. The photo above was shot with HSS and doesn’t have the hot spots on the grass that the photo with an ND filter had because I was able to increase my shutter speed to properly expose the ambient light.

That doesn’t mean it’s impossible to balance the light with NDs; increasing the flash power and widening the aperture will also make the flash appear to be brighter than the background. Photographers using NDs can control the light balance through flash output and aperture. Photographers using HSS can control the light balance through flash output, aperture and shutter speed: three ways to balance the light rather than two.

Don’t go on a power trip just yet, because while HSS offers more way to control the light in a scene, there are some disadvantages. First, firing lots of little pulses of light is going to drain the flash battery much faster than a single burst of light. HSS can also make the flash more prone to overheating.

Using HSS also reduces the flash output; it’s not as powerful as a single burst. When switching to HSS, the flash power will need to be turned up, or the flash moved closer to the subject than that same flash without the HSS mode on. When the flash power is turned up, the recycle time is reduced, so HSS means waiting longer between shots. You can’t tell by looking at the photos, but I had more shots where the flash failed to fire when shooting with HSS than I did when shooting with the ND filter.

While the faster shutter speed makes HSS sound like a tool for sports photography, it’s actually not always necessary. In flash photography, it’s the flash duration that freezes action, not the shutter speed. A 1/200 shutter speed can freeze action because the flash, not the shutter speed, will freeze action. While HSS can also be used to freeze action with fast shutter speeds, it actually creates a longer flash duration. Longer flash durations don’t freeze action as well as shorter ones. When lots of flash power is needed, using the regular flash to freeze the motion is sometimes the better approach because HSS reduces the flash power and decreases the flash duration.

Another downside is that HSS typically isn’t available from budget flashes. While there are some HSS flash options for a few hundred dollars — like the Flashpoint Zoom Li-Ion III — it’s a feature not typically found on the lowest-priced models.

What about using a wide-open aperture in bright light without the aid of a flash or filter? The electronic shutter allows the camera to increase the shutter speed past the limits of the mechanical shutter. The electronic shutter allows photographers to shoot at f1 on a bright, sunny day.

The benefit to using the electronic shutter rather than an HSS flash or NDs is that it is simple and doesn’t require buying accessories. Some cameras will require turning on the electronic shutter in the menu, but that’s it. There’s no flash stand to lug around. Most mirrorless cameras as well as many DSLRs are already equipped with an electronic shutter.

But, there are some definite downsides to working with an electronic shutter instead of an HSS flash or an ND filter. First, electronic shutter can introduce a rolling shutter distortion, which changes the shape of objects. This is most noticeable with moving subjects, like when taking portraits of children. But, I’ve seen the odd effects of rolling shutter distorting the background even on seated portraits. Electronic shutters can sometimes introduce more noise into the image.

Of course, using an electronic shutter instead of an ND with flash or an HSS flash also means that all of the benefits of a flash are lacking. There’s no flash to create catchlights, fill in shadows, or add depth and dimension to the face. The portrait of my dog here is really dark, with no catchlights and no definition to his fur. His features are lost in the shadows. While I could turn him so that he’d be facing the sun, that makes him squint. In bright light, without a flash, the sky is typically overexposed white. To get good light, natural light portraits are limited to locations where the lighting looks good as is.

While many photographers will choose NDs, HSS, or electronic shutter and stick with solely that tool. Others will choose the tool that best fits the vision for the shot. ND filters are best for preserving the flash power and battery, and HSS is best for controlling the balance between ambient light and flash output. The electronic shutter meanwhile, offers the fewest creative tools but remains the simplest way to shoot portraits in bright light.

To recap, here’s how each tool plays out: