As a photographer I’ve never heard a better explanation to this matter like the one you just did Dave. Explaining the whys to beginners can be challenging and you’ve nailed it

This is the best explanation I’ve seen/heard about flash modifiers, light softening and how these concepts really work. Thank you!

This really needed a comparison between a ceiling bounce with a diffuser, and a ceiling bounce without a diffuser.

I'm using these 'diffusers' for a different purpose: if you bounce your flash straight up, you lose the specular highlight in your models eyes. Snapping on one of these caps while directing your flash to the ceiling, will create a small strip of light, which reflects in the eyes and brings back some life.

This is the most useful, clear, and concise video on flash diffusers and light that I have ever seen. The principles of light that David discusses are important and relevant for any photographer. And, after watching this video, I realized that a good light like the Profoto A1 would not meet my studio photography needs. Size is important. Thank you, thank you.

Great question! Excellent explanation and example demonstrations! I kinda sorta knew all the separate issues but could not put them together to answer this question. David, you are the best! Thank you.

Thank you for this video! Such a simple and straight forward explanation with examples!

Big help. Thanks David.

Incredible simple and efective explanation. Thanks!

Thanks David. I had the same question and you answered it perfectly.

Thanks David you are the Man!

Great video and very informative! I had the small plastic one and I pretty much found that it was useless, so now I have a magmod style bigger on camera flash diffuser that works much better. But I didn't realise the difference in how they can work indoors vs outdoors. Always learn something new, thank you David 😊

Good to know, Thanks David

I would have liked to see the difference between the diffuser aimed at the ceiling vs. standard bounce flash (and possibly another with the flash's white reflector card pulled out). But, great video!

This is a freaking incredible masterclass.

Excellent,thanks David

You are making learning flash photography easier!!

That clears up my problem. Great explanation.

Thank you David.

A typical actions speak louder than words tutorial, the best explanation I've watched on diffusers, I'm doing a " Park LIght's " switch on this evening outdoors, thankfully I came across this video and I've just taken the diffuser out of my bag. Thank you 😀👍

Great explanation of the small diffuser! Thanks David

Very helpful video to see exactly what the diffuser does and doesn’t do.

wow that was easy to understand! Thank you, David, I also thought that that was what a flash diffuser's purpose was !!

Thank you. Perfect explanation!

Excellent explanation - with evidence!

Great explanation! Thanks so much.

Thank you for this video - Have a GREAT DAY David

very thorough... very clear... thank you

Awesome information! Thanks!

Perfect explanation. Thank you very much.

I learned something new today. Thank you

Good description! I think that softness should be discussed distinct from contrast. I define soft vs hard by the shadow transition. As you note around 8:20 putting on the diffuser doesn't change the size of the light, so the transition remains the same hardness. What diffusion does is spread the light. This allows the light to bounce off of objects in the environment (environmental fill) which fills in the shadows, which lowers the contrast. We still have hard light, but with more open shadows (assuming a light color environment--in a large dark room or outdoors there is nothing to bounce off, so neither the transition or the contrast change, you just waste power). Diffusion does not soften light unless the diffuser is much larger than the light origin. As you noted, put the light in an umbrella or a softbox, or put a scrim between the light and the subject and you soften the transition. The contrast is still dependent on the environment. Now about those people who put on a diffuser and point the flash upwards while working outdoors...

I love the way you make it easy to understand...love it! Ra, Singapore

Very clear. Good job !

Thanks David! Reminds me of the olden day gaffers tape and an index card.

wow! I am beyond impressed with this video

Thank you so much for this video!

David, great video! Thank you.

Great, detailed explanations regarding a topic that may seem so simple in the surface but yet is likely still misunderstood in such detail by so many. Thank you for taking the time and expertise to create this content!

Perfectly clear. Merci

I always thought it was for reducing the specularity of the source

Use the stoffen diffuser to “convert” your speedlite to a “bare-bulb” flash/strobe. Just like you wouldn’t use a bare-bulb strobe on its own, neither should you use your speedlite with stoffen diffuser on its own. Use it with a larger light modifier, like a shoot-through/bounce umbrella, octabox, etc. And voila, you have a bare-bulb “strobe” with the budget of a speedlite. Of course, actual strobes would have much higher power available, but hey, when you’re on a tight budget, this works brilliantly.

Great explanation, thank you.

David, you ré the only one on earth answering and explaining correctly. (except that the sun is not the biggest light on the galaxy, but on of the smallest. The biggest in our solar system, just in case you have astronomers following your channel ) thanks for your precious advice

You nailed it. Looking fwd to a simple explanation for what you mentioned at 7:30

Fantastic video! I'd love to see you explain how you balance flash and ambient light outdoors in another video 👌👌

Holy crap I didn’t even realize this. Thanks for explaining it do well!

Dave is the best ! Ty sir

I was always taught that to use the Stofen, the flash head should be at something like a 45° angle, and not pointed directly at the subject...

Good explanation!

Awesome exolaination, thanks

very good explanation of these diffusers! what these diffusers can do is make the speedlight behave more like a barebuld flash, where the light emits in all directions. It is good to use if you are taking photos at close distance to people, or close to groups of people and need to spread the light really wide. Sure the speedlights have zoom functions and even a wide angle diffusion panel, but the plastic diffuser will make the most omni-directional light. The other most important point made about bounce flash, is bounced light will take on the color of the surface you are bouncing off. So, if you are bouncing light off a ceiling that is made out of unpainted wood, the light that then falls upon your subject is going to be quite warm in color. If you are mixing this bounced light with the direct light that is coming from your flash, you will have mixed colors, as your flash color temperature is alot cooler. Even a ceiling or wall that appears near white, say a cream color, can actually change the effective color temperature of the light coming from it. The key, be carefull when bouncing light, and know what it is doing to the color of your light.

Hi David, very good explanation, thanks a lot!

Great stuff Bergman

Good explanation. It’s nice to hear a professional explanation instead of from the “plug-in filter” photographers.

Great video! Thanks

Finally I know that small plastic is how to use, thank you very much.

Learned something again... thanks

Ugh it took me a bit of Googling to find this answer because it has been bothering me for a while! I just did the same test in the darkness as you with an octobox to prove the diffuser does not equal softer light, but I kept searching for a clearer explanation because I found it very odd nobody has talked about this. I think a lot photography teachers mislead people by saying modifiers make things softer, it’s fine colloquially but in all my tutorial watching paid and free I’ve never seen anyone make this distinction and I’m sure some of them don’t really understand it or haven’t thought of it much themselves. Which is bad, because it’s only by truly understanding the fundamentals that we can properly push things further. Good video, and always there’s a feeling a relief when you find a video on just what you were asking for and you don’t feel like you’re the only one with this question.

great demo!

Two years ago, I grudgingly put up what I thought was a little too much money for a plastic pop-up flash diffuser. But it paid for itself that very weekend: a grand total of zero complaints from the eight rock bands I photographed about my flash getting into their eyes, and an additional zero complaints to this day!

great information.

Solid advice

You are really good at explaining. I watched other videos and left scratching my head 🤔

Thank you so much for explaining flash diffuser only working limited indoor by bouncing light around but not working in big hall and completely not working for straight from flash diffuser to subject that is the same hard light without diffuser.

Well said. The stock diffusion dome does make a bigger difference at closer lighting distances of 2-5 feet where the bounce reflections and apparent light source size work in your favor. Think pet, still life, and head shot, photography. As an event photographer I wrestle with the exact situation in your video, and the ceiling is always too high for a bounce.

Hello David. Even you speaking quite fast for a Brazilian understand, you are great on the simplicity of your explanations. Thanks for your videos.

One thing a diffuser can help with outdoors is getting full flash coverage for an extreme wide angle lens. If you use a straight flash designed for 18mm or greater lenses with a 10 mm lens, the flash will tend to spotlight the center of the photo and fall away at the edges. A diffuser can help scatter the direction of the light and produce a better shot.

Many thanks.

Thank you!

Excellent video...

Such a great explanation, I'll give this another try. I normally bounce off my ceiling and use the little white bounce card to throw a bit forward but this seems like it might be another option to try.

Ok we'll enjoy

Thank you

Great explanation :-)

Well done

So softbox it is! Ok. Got it. Thx!

Excellent 👍🏾

Damn! Your video really helps me realize how useless my diffuser is. I will try this on my next wedding photoshoot especially on my group shots at the church. Thank you!

This is helpful

I like ur tutorial videos sir...

According to Canon, it's a bounce adapter and not a diffuser. Can be used outdoors to scatter and cover bigger area though.

nice test!

Maybe a follow-up demo of bouncing flash light off the ceiling with and without the diffuser? Does it make any difference then?

All true, David. Some speedlights/speedlites have this pull white out tab reflector. If you go to the end of the video, the bounce flash is introduced. This can make the light very soft as the size of the light source is defined by the flash angle and its consequent lit spot on the ceiling, and a wider flash angle gives a very large source. But the reflected light comes from above and gives dark shadows under the chin, or over the eyes and under the nose. Pulling out the speedlight's white tab will reflect part of the flash light horizontally directly forward and fill these shadows. (Based on assumptions about angles being middle of the road.) Sometimes it is more interesting to direct the speedlight at a white side wall instead of at the ceiling and mimic a window shot - and here the white tab can fill too. As you explained, David, the dome steels light from you, recycling time and pops reserve in your battery. In these bounce scenarios it also throws some light to where it contributes nothing. I have a couple tiny speedlights that have no pull out tab and with these I occasionally use dome in bounce flash. A rubber band with a white (or aluminum?) plastic card would be better, for me.

Very very very true…mostly. It's still a layer of diffusion. It wont make the light technically softer, but it will make it more diffused. It's like using a softbox without diffusion panels versus using it with them. The strobe will still fill the softbox and make it a large light source without inner and outer baffles, but it'll be more specular and directional than if you have them. In a speedlite's case, the entire fresnel head does not emit an even surface of light. The light is coming from a smaller area in the center and is blasted straight out. A diffuser cap will diffuse that and even soften it a tiny bit. I can totally see a more even spread of light in this video with versus without, though since it's such a small light source it's still less impactful than if it was larger.

Hi David, I would've liked to see a like, for like comparison. Sadly you increased the flash by 1 1/3 stops which doesn't actually show a true comparison, because you've compensated for the deffuser. Maybe you could make a part 2.

Legend!

Bounce is always best but those little dome covers are good breaking up direct light from a speed light and hitting folks a little ‘softer’ If your in dive bar shooting a band with black walls and ceiling skin tones look better those also.

I had a very interesting and educational experience back in 1972 of assisting Monte Zucker, the wedding photographer/ author / teacher who introduced the idea of using dual speedlights for shooting altar and reception photos. He had started in the era of shooting weddings in B&W with 4x5 Speed Graphic camera and a single flash (bulb) gun on camera. That worked for B&W because the dynamic range of the B&W film and print could record the full range of detail from the folds of the groom’s black suit to the separation of specular highlights and solid whites on the satin and beadwork on the bride’s dress. But when finally switching to color in the late 1960s and early 1970s photographers discovered like digital camera sensors today the color negatives and prints could not record the entire range with a single flash on camera. Biasing exposure for the white dress would cause a lack of detail in the shadows of the dark clothing. The solution was quite simple, used two light sources in a key over fill configuration as done with studio lighting. The challenge was finding a way to do it while moving around covering a wedding and controlling lighting ratio and exposure. Flat near-axis flash mounted on a camera hot shoe does not appear “natural” because we are accustomed to light sources - natural and artificial - coming from overhead which places the specular highlights from the source on the upper part of 3D objects and the shadows they cast below. Hot shoe flash shots look “fake” because the highlight and shadow clues the brain uses to discern 3D shape in 2D renderings are in the “wrong” places. Monte understood that and corrected the problem by mounting the flash on camera on a custom make bracket which put the center of the flash head about 18” above the taking lens of the 2-1/4” format Rolleiflex twin-lens reflex cameras (equipped with eye level pentaprisms) we used. Raising the flash directly over the lens put the specular and shadow clues in the “right” (i.e. “natural looking”) places on the face with the shadows falling down and mostly out of sight of the camera in single flash shots. The problem of recording the full range of detail in black and white objects was solved by adding a second identical flash on a rolling (modified medical IV stand) which was placed 45° to the side of the nose and above the eye line so the shadows it cast fell naturally downward. Part of the perception of light being “hard” or “soft” comes from the tone of the shadows. With the two flashes in an overlapping key-over-fill arrangement the lighting could be made softer looking by placing the off camera key light at the same distance as the flash over the camera. Placing the off camera key light so it was 2x or one f/stop brighter resulted in a 2x key+1x fill over 1x fill (3:1 reflected) ratio which was exactly the ratio needed to render everything in the foreground with detail from black to white (and everything in between) with “seen by eye” tonality and natural “mid-afternoon” 45° downward key light modeling, all without any modifiers on the flashes, instead using the key:fill lighting ratio to control the perception of “softness” via the tone of the shadows and carefully controlling the placement of the specular highlight and shadow clues on the faces via the direction of the light sources relative to the faces and camera. Exposure and ratios were controlled via the inverse-square law. Two identical flashes placed at 11ft on camera and 45° off to the side will produce a soft looking 1key + 1 fill : 1 fill (2:1) “soft” reflected lighting ratio. Moving the off camera “key” flash to 8ft when shooting from 11ft makes the key light 2x brighter than fill creating the 2key+1 fill: 1 fill (3:1) “normal” looking full range lighting ratio which is what we used most of the time. If moving into 8ft for a tighter crop the off camera flash was moved in to 5.6ft to keep it 2x or one f/stop brighter than the fill and the aperture was closed by 1-f/stop to adjust exposure. By systematically shooting from 16, 11, 8 or 5.6 feet with the off camera flash placed at 11, 8, 5.6 or 4 feet, respectively, it was possible to cover the entire wedding with lighting which gave evert photo in the wedding album the appearance of being shot in a studio or Hollywood sound stage - without any use of diffusers, just expert control of the lighting. I didn’t start experimenting with diffusers on my dual flash set-ups until 2001 when I switched to shooting digital. The only significant contribution they make is in the appearance of the specular highlights on damp or oily skin. What I found worked best were “scoop” style reflectors I constructed from 8-1/2” x 11” “fun foam” sheets with an internal stiffener with a top flap which could be opened on the fill flash on bracket over the camera to also bounce light off a low white ceiling for added “spill fill”. I shared my experiments and instructions how to make them on photo fora back in 2004-2012 time frame.

This is exactly what my canon speedlite manual says to do with the diffuser, bounce the light off the ceiling/walls and the diffuser will throw a little of the light forward adding a little highlight to the subjects eyes. Works well, without it the highlight is lost.

Terimakasih infonya

Reminds me of the training video I saw years ago, from a well-known 'name', where they pointed their flash straight up ... when they were outside!!!

hmm... helpful for face shots yes sure. but I've got the latest fancy expensive on camera sony flash and when doing full body, that diffuser that comes with it is REALLY helpful for spreading the light so that it's not just lighting up half the body. so in a way this video is a bit misleading in that sense. as in, direct front on, yes definitely I will be using the little diffuser.

I don't know how many times I've seen event photographers shooting with a flash and defuser pointed up at a ceiling that is 20 feet high. Do these "photographers" even know how bounce lighting works? I'm not going to mention how press guy shoot outside with the flash pointed to the sky. The good old Omni Bounce worked best with an 8 foot ceiling.

I've always had this suspicion, that a larger diffused light source was needed to render a "soft diffused" light on the subject..... Not some small little light.

Hi David great to catch your video on this topic! I like to use these mini diffusers on a speedlite with an umbrella or softbox to help spread the light about for potentially more even light within the box or brolly more than the square recessed speedlite does on own - also tried the small diffisers that flip down out of the flash which also work a little for this approach - what do you think of that have you noticed that little doodad helping at times? many thanks!

Very well detailed video on this subject. Super well done David... Question Please: How are you getting zero ambient light at F/4 with 100 ISO and 200sec? I have a Canon 5D4 and although I have not tried this, I do shoot school portraits outdoors a lot it seems I would be still picking the background (on a cloudy day) and it would not be black. Granted I use a different lens (Canon 24-105 f.4 v2), but would love to know how you achieved a black background. Very interesting. Thanks and again super well done and interesting video. Philip NYC Area

Many thanks David, from Spain, sorry for my poor English. I absolutely agree with your words. I was very surprised when I saw profoto's promotion videos of their the round speedlite using the sphere dome in the street. They said several times it was for diffusing the light. They were in a very open space in the middle of the street. To me, using the dome in that situation is simply wasting energy. They are supposed to be experts on lighting, so I am still wondering why they present the dome as a diffuser in open spaces. Your thoughts please? Many thanks!!!

thanks for the video, David! So you don't use the diffusors when shooting on concerts? What technique would you recomend for shooting at the party in the evening outdors?