Does The Profoto Frost Dome Make A Difference At All?

For years photographers and YouTube commenters have been telling us that in order to get the most out of our Profoto B1 and D1 lights, we need to add the Profoto Frosted Glass Dome to our strobes. Today I test this add-on to see if it makes a difference at all, and the results are surprising.

What does the Profoto Frosted Glass Dome do exactly? When Profoto released their portable all-in-one D1 mono lights, some photographers were surprised that the flash tube was recessed deep within the D1's housing. Photographers who were used to Profoto's Acute and Pro heads argued that by removing the protruding flash tube and glass enclosure, the new D and B series mono lights fail to illuminate many of Profoto's light modifiers evenly. The most cited light modifiers that suffer from this lack of light dispersion are the Profoto Beauty Dish and the larger Profoto Softboxes and Octaboxes

I wanted to test this theory for myself so I ordered a frosted dome from B&H Photo and tested it in both our beauty dish as well as our Profoto 3' Octabox. I called up former Miss South Carolina Teen Erica Wilson to stand in for a few test shots, and we created some simple images to compare side by side.

The first test was using the Profoto Beauty Dish. The beauty dish we own is the standard white dish, and because of its design, I was skeptical it would show any difference in light quality with or without the frosted dome. The reason I questioned if the glass dome would make a difference is because all of the light coming out of a beauty dish is either bounced directly into the side bowl, or double reflected after hitting the plate in front of the flash head itself. There are some photographers who like to use the tiny little gap in between the bowl and the plate but for this test I wanted to just place the beauty dish in the more traditional location: about 24-36 inches away from the subject's face. Below are the resulting images. 

As you can clearly see, there is a pretty significant difference in color cast caused by the two glass diffusers. The glass plate was definitely more cool in color when the camera was set to a white balance of 5000k, and the frosted dome looked more warm and natural in color. However, these color differences could easily be adjusted in Lightroom, especially if they are your only light source. There may be a slight increase in exposure in the glass dome image but it appears to be less than a 1/3 of a stop in light. When you compare the shadows — which is where the biggest difference should appear — they look almost identical to my eyes. There might be a slightly softer light with the frosted dome as seen in some of the skin texture, but for an image like this, both photos would probably go through extensive retouching before being published. Other features like the catch light shape, light falloff, and specularity all look similar enough that I would not be upset shooting either one of these setups. 

I'm curious to know what you guys think though. Feel free to vote in the poll below if you agree or disagree with my assessment on this set of beauty dish photos.

Next up was the 3' Octabox. I was most interested in this test because it would seem more likely that the recessed flash tube and flat glass plate combination would probably cause a more defined hot spot in the middle of a large softbox than the Profoto B1 strobe outfitted with the frosted glass dome. Since Profoto has discontinued making their huge 7' octabox, we decided to use the 3' Octabox because, well, we don't own the 5' Octabox they make. The big question with this test was "will the frosted dome help illuminate the octabox more evenly, and therefore create a more balanced photograph?" Let's look at the resulting images below.

This test does show some slight differences in image quality but it was definitely not as big of a difference as I would have thought. You can clearly see that the glass plate has a slightly hotter exposure on Erica's face compared to the frosted dome. As we will see in the photos below, this is because there is a slightly larger hot spot in the middle of the octabox which will contribute to more light output in the middle of the modifier. How much of a difference is this? To my eyes it looks about 1/3 to 2/3s of a stop of light. It is definitely measurable and noticeable but I think I might prefer the slight increase in exposure when comparing the two images. 

Strangely, the shadows in the frosted dome image appear to be filled in ever so slightly especially around Erica's nose. It's subtle and it may be splitting hairs, but you can definitely see it when the images are stacked in Photoshop. However, much like the beauty dish example, many of the other nuances like light falloff, overall scene exposure, specular highlights, catch lights, and shadow to highlight transitions are pretty similar at least to me. 

To help illustrate the differences in exposure across the face of the octabox, I also took a photo showing the front of each light modifier. For these exposures, I wanted the smallest hint of blown highlights so that we could see exactly where the flash was firing the most amount of light. As you can see in the images below, the glass plate does have a significantly larger blown highlight distribution in the middle of the octabox when compared to the glass dome. What's interesting to me though is that even with the recessed flash tube, the B1 straight out of the box is still able to produce some blown highlights around the edge of the light modifier. This is probably caused by the internal baffles in the octabox, but it does prove that some of the same light intensity found in the middle of the octabox is able to reach the outer most edge of the octabox. It's safe to say that anything directly in front of this hot spot will get a slightly brighter exposure, but once you move out towards the edge of the softbox, the effect is negligible in my opinion. 

What do you think about these two images? Can you say one of these examples is definitely better than the other?


So at the end of the day, this wasn't the most scientific test, but for me it represented a real world situation well enough that I can say — without a shadow of a doubt — that I personally do not see enough of a difference to justify buying and installing the frosted glass domes on my B1 and D1 mono lights. Installing these domes is kind of a pain and I have no doubt with a lot of use I would most definitely break a few of these throughout the year. It would be great to simply install these frosted domes and keep them on my lights permanently but they don't work with Profoto's grid system and they also take up much more space when packing in your grip cases and camera bags. Also, did I mention, they are $183 a pop?!

There might be some very specific situations where the frosted glass dome makes a big difference, and if so, I'd love to hear your experiences in the comments below. As much as I love Profoto, and they are by far my favorite photography lighting system, I tend to believe this specific light shaping tool might be more like snake oil than something that completely changes the quality of light coming out of your strobe heads. This was a test I have wanted to do for a long time and I'm glad I finally set some time aside to see if all the snarky YouTube commenters were right. That being said, the final thing I will leave you with is a link to all the positive comments on the frosted glass dome sales page on BH. I am clearly in the minority when it comes to improvement this light modifier makes to your strobes. 

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Benton Lam's picture

It seems to fill in the shadow a bit more with the frosted dome + beauty dish, which made that picture a bit better.

With the Octa and the diffusion cloth in front, I honestly couldn't tell the difference.

I wonder, could you put diffusion cloth in front of the beauty dish, with the standard glass plate, and see what the shadows are like?

Adam Ottke's picture

It's pointless to put a number on it, but there's MABYE a one-percent difference in these shots. There's just the slightest difference on her forehead MAYBE in that first shot. But I even prefer the cooler glass plate since I think it's more neutral as opposed to cool (I think the glass dome is actually a bit warm, which would just shift the subject-to-background ratio a bit...but I'd rather mess with that in post if I needed to).

I find it odd that so many people think it makes such a difference. Maybe my eyes are going bad...hmmm.

Spy Black's picture

You forgot add "The frosted dome is the Emperor's New Clothes" to the poll...

Tony Clark's picture

I saw years ago when assisting that I preferred the dome over a flash tube. My mentor used Dynalite and I saw the difference between the base and bitube flash heads. I’ve been a Profoto owner for nearly twenty five years and love the system.

John MacLean's picture

Was that because the Dynalite bi-tube has the flash tube inside the dome, rather than behind it?

Tony Clark's picture

Yes, I believe it was the 4040 flash head.

Doug Birling's picture

she seems to look just a little happier in the standard glass photos... it's very subtle, but I can see the change in expression!

Dominique Richardson's picture

I was riding with the dome until I clicked the link and saw the price...$200 oh hell naw ...are the images warmer and more pleasing to me..yes...can I use a $2 lightroom filter and get the same look you betcha'

John MacLean's picture

or you can slide the WB Temp for free! 😉

Dan Donovan's picture

In my opinion, the color temperature should not be considered. That can always be changed. The quality of the light is what I feel is important. The dome gives a slightly softer light, with smoother highlight to shadow transitions. For instance, look at the shadow under her chin in the beauty dish photos. That said, the difference is not as big as I thought it would be!

Deleted Account's picture

I agree. I think they should have shown a second set for each image, with the color balanced.

Russell Jones's picture

A few comments from someone who has done a great deal of testing in terms of these type of design differences (in terms of the real world image results!).

First off, this style of frosted diffuser put on a Profoto doesn't come close to what happens with another style of strobe where the light can fully fill the softbox in a full 180 degree spread. If they really wanted to duplicate that type of light, they would have put a convex chrome type deflector at the end of the frosted tube to send much more light back and out to the sides. There would be a hole in the center of the deflector allowing a certain amount of light to pass straight through. The size of the hole in the center would be calculated for a fairly equal mix of light going straight through versus deflected to the sides. They didn't do that, or anything even close to that.

Not a great deal of light is actually routed back and to the sides in the frosted design that you tested (just think about the light angles and the design of it).

Second, as you guessed, using a deflector (on the beauty dish) negates 90% of the difference that you're testing for. By definition, the deflector is sending light back and (to some degree) to the sides. So I would expect very little, if any, difference in your beauty dish test.

A situation where there's likely to be much more of a difference (between a strobe that blasts light out sideways and the recessed Profoto) is a regular or shallow octabox (or Hexadecagon softbox) that is not too deep, and where the inner diffuser is on but no outer diffuser is used. Some fashion photographers like that style for the mix of soft and contrasty light (central soft diffused light combined with contrasty and hard light on the outer edges, so you reduce some of the hard shadow issues). This is where the difference between the style of light from the Profoto recessed tube (due to the difficulties in filling the back half of a softbox with light) versus some others, becomes much more pronounced. All depending on your personal preference, of course!

Other important disclaimers:

- A good decent size convex deflector will offset much of the difference between recessed strobe tubes (including other light manufacturers where a significant portion of the tube is too far back in the speed ring / mounting ring area).

- Depending on the diameter / size of the softbox, how deep the softbox is, can heavily make up for any problems with a recessed light tube (think of the direct lighting line of sight).

- Multiple layers of diffusion can heavily negate the original issue / problem.

So the details REALLY matter.

Now if you're just comparing Profoto to itself with a "somewhat" effective frosted dome, combined with either deflectors and / or more layers of diffusion, well you're going to see that much less of a difference.

But don't think that compares to other light tube styles that have a clear sideways blast of light. Unless the issue is negated, to some degree, by one of the methods that I've already mentioned.

Time to get off my soapbox now!



Alexis Cuarezma's picture

Patrick, you go into this saying you think the difference or what people say is "bullshit", so what do you think you're going to find? You start off your video saying that which pretty much sums up your mindset for the entire "review".

As with anything, it all depends how picky you are and what's important to you. I personally dislike the recess light. It's a built in 77 degrees reflector instead of spreading light all around. Your light is modified from the start. When you put it into a beauty dish or softbox, you're putting a modifier on top of a modifier essentially.

The light quality is also different. Look at highlights on your samples. There's a difference. But again, it all depends how picky you are. If you do a test of softboxes with silver vs white lining.. you would be hard press to find a difference if you're not picky about how your light looks. Light shaping, as with anything when you get deep into it is in the small details and personal preference.

Try this, put the beauty dish on the B1 w/o the dome. Turn on the modeling light and shine it on a person or wall. Move it around, and you'll clearly see it throws a shadow in the middle b/c of the little plate in front due to the beam spread being modified to 77 degrees. A beauty dish isn't suppose to do that. The softbox you used is also pretty small. If you do it w/ a bigger one you'll see it better. But again, it all depends how picky one is with lighting.

I'm certainly not trying to sell you on the dome or convince you. Clearly you've come to your conclusion and found what works for you. But saying that people who like the dome or see the difference is "bullshit", is a bit condensing on your end.


Jay Jay's picture

Profoto, while priding itself as "lighting for professional photographers", seems to be completely out of touch with what the community really wants. It's also the reason i can't buy their B1's as much as i like them, because they're fairly useless with the recessed bulbs, and completely useless on a parabolic. Why they chose to do this, and even more strange, why they continue to sell a strobe with a recessed bulb is beyond me. Godox doesn't seem to mind as they're happily stealing Profoto's customers and potential customers with a near identical product at a vastly lower price point.

Going to guess it wont be until Profoto sees a big drop in yearly sales and starts to analyze the cause, will be the only way they'll do something about it. (Though why not have 2 versions of the strobe, one recessed and one exposed, for the majority that wants it?)

And yes, from every review i've seen, that frosted dome is useless.

Lee Christiansen's picture

Not sure which reviews you are reading. I've found enough of a difference to buy three of the things.

Jay Jay's picture

That would be every review i've read on that dome. This one is the most complete review of it in regards to using profoto with a parabolic (a useless endeavor).

Tihomir Lazarov's picture

I think they've made the frosted dome just because people were complaining, not beacause it would make a huge difference. This way they can profit from those who wanted it and gain good feedback as a company "which listens to its customers." It's a smart business move, I think.

Alexis Cuarezma's picture

No, the frosted dome is not a perfect solution but it actually does help. It certainly changes the beam spread from 77 degrees.

Tihomir Lazarov's picture

I think it would mostly affect modifiers such as the beauty dish or a very small softbox and only if they are used at a very specific distance. Otherwise, when used further away from the front element of the modifier (like in the softbox case) there won't be a noticeable difference.

Even in this case with the beauty dish, aside from color difference, I don't see much benefit light quality wise.

Kasimir Szekeres's picture

How did nobody ever noticed you cannot use a Profoto Beauty dish with the B1/B2 or D1 heads. :o

It's my favorite light modifier with pro heads but I was in shock when I found out that I get this black shadow when using it on my B1. Also with frosted glass or this dome you still get this dark spot.

To fix this you can use a diffuser like on the B2 beauty dish, but you lose that special beauty dish characteristic light.

Tihomir Lazarov's picture

That's a common thing with any beauty dish. It's not meant to be fixed, but to be used like that. The "shadow" is actually "less light," because the light from the periphery of the dish is hitting that spot and thus making it brighter. This is the beauty dish light. When you add a diffuser, you turn it into a small softbox. You can get a cheaper softbox instead of an expensive beauty dish with a sock on it.

Kasimir Szekeres's picture

Its because the light is not evenly spread. Because of how the B1's are build.
And you cannot fix this with this frosted dome because the flash tube is still inside the lamp.

When using the beauty dish with pro heads (where its designed for) you get nice even light.
This shadow should never happen, you could of course use it as a artistic feature. :)

Tihomir Lazarov's picture

I understand your point, but read my reply below to Alexis to see what I meant.

Lee Christiansen's picture

Very true. The Pro heads give a beautiful quality of light wit the Profoto dish. You don't and shouldn't get this ugly shadow.

However, I've come up with a mod to give very good results with the D1 / B1 strobes, along withthe required dome. I'm trying to get Profoto interested, (cost of the mod is about £1.50) but alas so far they're not biting.

No I'm not telling here... but yes it is possible to get very good results with a little thought. Maybe I should produce a kit... ha.

Alexis Cuarezma's picture

Tihomir Lazarov , you're mistaken. That is not a common thing with any beauty dish. That shadow is not suppose to happen. A beauty dish is not meant to be used w/ a light that has a beam spread of 77 degrees. That shadow is being made b/c you're putting a pre-modified light in the BD. It's like slapping a grid on light and then putting inside a soft box.

When you have a proper head w/ a full spread of light, it hits the BD in all direction and the disc is meant to keep direct light from hitting your subject, not to make a shadow like that. With the built in 77 degree reflector, you actually get some direct light hitting your subject and that's why it make that shadow.

Tihomir Lazarov's picture

The beauty dish is sort of a ring light but with a wider ring surface (with diffused light) and with a narrower circle in the middle. When you place the ring light or the beauty dish close to a wall (like a few inches), you will get a darker spot in the middle and brighter ring on the outside. The more you get further away from the wall you will get that middle dark spot ligher and lighter. At a certain distance and beyond, the dark spot won't be noticeable from the ring on the outside and it will look like a softbox light (even without a diffuser).

It's a matter of distance from the subject to have the shadow in the middle completely gone.

That being said, the shadow is a normal thing, but its darkness depends on two things: the light beams spread from the bulb (here's where the frosted glass comes into play) and the geometry of the dish itself which may focus the light from the periphery of the dish more or less towards the center in the direction of the subject.

Having a non-frosted glass just makes a different look. It's not an "improper" or a "proper" look. That's why different light modifiers are different. See Elinchrom's regular and deep octa's for example. Same front diameter, but different depth creates a different result.

BTW, I'm always talking about the beauty dish when it's used with the deflector.

Kasimir Szekeres's picture

I'll do some distance tests next time and compare it with a pro head, just to see what is the real difference.

Tihomir Lazarov's picture

Please share them here. It would be great for all of us.

Felix Wu's picture

There's no ring light when used with Prohead. The glass dome somewhat mitigates the poor light spread when used in a beauty dish. So evens test: prohead > glass dome > glass plate. On portrait you could barely see a difference but on a more sophisticated shoot the difference would be noticeable.

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