Adventurer

Yes, but for three channels! 🤦‍♂️ R G B RED GREEN BLUE Your long text is highly misleading for the sake of making an argument. Wrong. Because of cited absorption coefficients in water and distance of blue/green background water column. Just try it , and talk to a knowledgeable underwater photographer who still shot chemical film, if you know one, for confirmation.

Hi @ChrisH I totally see your point and in your specific configuration and setup it all makes perfect sense. You are very strong fisheye user, hence your warm strobes (ex-factory warm) play out perfectly. Next influencing factor: the Nikon blues in AWB got you covered. Also a (minor) last factor: Your SiGMA Fisheye, instead of a Nikon or Canon FE. I previously owned this and remember that when even shooting this topside this lens would render the shots a little more golden than a Canon or Tokina FE. Anyway, just change your perspective to the average Joe who does it different and bought one of the cooler strobes out there, internationally sold in multiple quantities. Even Nikons, Sony and Canons System strobes are manufactured with quite cool color temperatures. So let’s look at my initial statement quoted again above. Does it always make sense to „rape“ your strobes energy output with warming diffusors ? I would like to hear more different opinions from others. You and @Chris Ross have made your point.

Double needs to be deleted

Sorry Chris, but this is wrong and I need to correct you for physical facts. Water absorbs light in a wavelength-specific manner: • Blue (~450–495 nm): Absorbed the least and penetrates the deepest. • Green (~495–570 nm): Absorbed more strongly than blue but less than red. • Red (~620–750 nm): Absorbed almost completely within a few meters. Absorption Coefficients • For blue light (~475 nm): Absorption coefficient ≈ 0.015 m⁻¹. • For green light (~525 nm): Absorption coefficient ≈ 0.04 m⁻¹. This means that green light is absorbed at approximately 2.67 times the rate of blue light in pure water. While the speed of light in water is nearly identical for both wavelengths, the absorption rates dictate how much light remains visible, making green “fall out” of underwater photos more quickly than blue. You can utilize this effect by underexposing. The green part of the histogram will overproportionally be underexposed if you lower your exposure by one stop. Sidenote: underexposing slightly for decent blues underwater is a technique coming from the film days where underwater photographers had no control over white balance in a non-digital camera. It‘s a proven relict. However if you do not meter and expose in a proper way you may be unable master this technique with your camera. Unfortunately it blows the scope of an Internet forum to teach this here and the thread is on it‘s way to go off-topic.

When a photo is underexposed, it alters how colors are rendered in the image. The effect of greenish water appearing blue in an underexposed photo can be explained by several factors: 1. Camera White Balance Cameras adjust white balance automatically or manually to ensure colors appear correct. In underexposed conditions, the camera’s white balance often shifts toward cooler tones (blues), as green and yellow tones reflect less light in dark conditions, making blue tones more dominant. 2. Spectral Light Absorption in Water Water absorbs red light more strongly than blue light. This natural property makes water appear bluish, especially in low light (e.g., during underexposure). When the image is darkened, the green component of the water reflects less light, allowing the blue hues to stand out more. 3. Perception and Color Saturation Underexposed photos tend to increase the perception of color saturation and contrast. This can enhance any slight bluish tint in the water while muting green or yellow tones. 4. Camera Color Profiles Digital cameras have specific sensitivities in their sensors. These sensors often respond more strongly to blue light under low-light conditions, which can make greenish water appear more blue when underexposed. In summary: Due to the physical properties of water, the camera’s processing (e.g., white balance), and sensor behavior, greenish water often appears bluer in underexposed images.

Interesting Balage, two questions: 1.) After setting this up via the computer you are stuck in strobo mode for the whole dive until you connect it to USB PC/MAX again and edit it ? 2.) As a Canon user, any chance this is also coming / available for the e-TURTLE 2 MANUAL trigger ?

Don‘t get me wrong (Camera/RAW)Profiles (Portrait,Landscape,Neutral,Standard, Adobe Landscape etc) + ColorProfiles (AdobeRGB, sRGB) are to a large amount available in both, camera and raw converter. So with your phrase above I now struggle to understand if you refer to ColorProfiles or (Camera/RAW)Profiles. The fact that (Camera/RAW)Profiles also heavily influence color balance does not make it easier for everyone to communicate about this 🤭🤣. @Chris Ross the fact that you shoot OM-1 explains a lot. Color science varies hugely among camera brands and even models in some cases. But if you get exposure right you will also be able to shift between green and blue background without touching white balance. I stay with that advice and experience on many different brands I had to shoot over the years. Give it a 2nd try and watch that you do not underexposure too heavily, otherwise you will not notice the effect. @ChrisH let’s come back to warm strobes or gels topic. Mr. Ross pointed out that sometimes he might not be close enough with his Z240s. This is an important factor. I see with you that you are mainly mastering the fisheye lense which usually gets you ultra close! In this case I would subscribe to your algorithm. The warm color temp of the strobes will definitely hit the foreground and also use the warm spectrum. But now let’s imagine you have to be more far away and will use a more tele end lens, such as 17-55 or 14-35. You want to shoot it on the zoomed in end of wide angle underwater photography. This is not uncommon when shooting portraits of mid sized pelagics such as sharks or dolphins or shy reef sharks with strobes. There the warm color in the foreground will be quickly absorbed and have no use, because you are simply not close enough. Same applies when you do not have sufficient stuff to fill the frame in the foreground. In that scenario I would opt in on the cooler strobes and try to avoid diffusers, as I want the maximum energy of the strobes to penetrate the water column as far as possible. Cool color temp of the strobes spectrum will travel more far than the reddish parts emitted or filtered. There is a second thread going on right now where that concept is discussed and exaggerated by even adding cooling filters to video lights or strobes. This is also the reason why Backscatter offers blue Diffusors for there HF-1 strobe. However if you want maximum energy penetration through the water column then cool native color temp strobe, without any diffusors or filters is the way to go.

Camera profiles are a strange beast and were for a long period the origin of high color discrepancies between your camera (Canon/Nikon/Olympus/Sony) and Adobe Lightroom. In Lightroom you can pick stuff such as „Adobe Standard“,… „Adobe Landscape“, … „Camera Standard.“ ,.. „Camera Landscape“ - many photographers agree that the profile should be picked early in the editing workflow. They should not be mistaken with Creative Filters (of Cameras), Presets (Lightroom) or Color Profiles (AdobeRGB, sRGB etc). (Camera) Profiles are the way how the camera or raw converter interpretes the early data in your RAW file. This can lead to huge variance in color and contrast.

I think everyone’s intuition that particles or subjects have to move to emit less backscatter reflection is not mandatory. If you are familiar with astro photography image stacking you might develop a good intuition on what might be enough for the initial statement to be true. In HSS the light pulses are usually less strong so they will cause a less strong reflection compared to a classic single strobe pulse (equaling the quantity of light that all HSS pulses together have). As the shutter travels down (line by line) during the (less strong) pulses, less backscatter reflection is captured, compared to a single strong strobe burst, giving out all at once and not in tiny slices.

Nice pictures @ChrisH - must be magic „Nikon Blues“ in AutoWB 😉👌without postprocessing. @Chris Ross I would like to get us all on the same page and look what’s different. I assume that both of you do not shoot RAW+JPEG out of cam, are you? So all your image go through the Adobe (Lightroom) workflow? What color profile do you have set in your cam? In my Canon‘s I occasionally like to use the magic „Landscape“ profile. This might be one of the reason, why we come up with different results and experiences. Next to that, I‘d like to stick with my statement that if not correctly exposed for the blue water, the image may get a green tint or cyanized. This also results the phenomenon that you can tweak greenish water into the blue spectrum with traditional in camera technique (exposure) on auto white balance. Even though Chris Ross came up with a fresh lab test argument/example about greenwater, I do not agree with his results and conclusion. I took a look at your Instagram account, Chris Ross and my impression is that you did not nail the blue in the majority of your shots. When compared to Christian‘s results, Mr. Horras has definitely very pleasing blues in his examples. There are different levers that you can push in your camera to get the desired blue background. With the AutoWB and general color science camera brands act very differently, so this may also come into play.

I do not (fully) agree Chris. Actually you can turn green water background into blue color by just alternating the cameras shutter speed. If you look at a prism / color spectrum you will find that blue and green live next to each other on that scale. By cutting off wavelengths you can move slightly in this gradient.

„HSS will minimize Backscatter compared to a single strong pulse of the underwater flash.“ What do you think about this?

classic terms in photography is quality and quantity of light, not really including the color temperature. The quantity is referring to light output, but that can be also very concentrated on a single spot. The most extreme example would be a laser pointer. Quality of light refers to the distribution of that power. Hence you can imagine it‘s less in important in macro photography than wide angle. All underwater strobes today and even many torches have enough quality of light for underwater macro scenes. But as many don’t have enough quality of light for large wide angle scenes it likely you buy a second strobe or two new strobes once get into serious underwater wide angle photography. Dr. Alex compared it to the jam on your toast. You want it evenly spread and not all in one corner of the bread 😉

Hello, please help me to understand something were I basically do not agree with the mainstream advice given these days: So when in tropical waters (bluewater) many (pro) underwater photographers recommend a warm color temperature strobe as it should render background blue more nicely when balancing foreground reef and background bluewater. This piece of advice is given very often in forums, YouTube videos. Last but not least Dr. @Alex_Mustard himself has convinced several manufacturers to offer warming filters if the underwater strobe itself has a cold color temperature. In most cases this comes with the price of sacrificing strobe power as the warming gels and diffusers will absorb photon energy. My classic approach is to render the correct bluewater by shutter speed - not too much by white balance. Of course your replies will also include that strobe color temp will very much depend on personal taste, but please let’s spare everyone with that argument and concentrate on getting the best technical result or a time saving digital workflow. So basically what’s the real benefit ? I have used warming diffusers on Backscatter HybridFlash HF-1, Marelux Apollo III 2.0 and INON S-220 with Canon R6 Mark II in the Red Sea and must say I really cannot subscribe to the effort. It makes me wonder if I understood @Alex_Mustard or @DreiFish correctly, when they vote for warm gels or diffusers? So question to both of you and others: Do you leave the cameras white balance on AUTO or do you MANUALLY WB on the strobes color temp to get the best foreground background mix? How should this benefit the RAW file when adjusting WB during image processing? Is this considered beneficial for competition photographers who participate in traditional categories with minimal editing allowed? Most contest categories today allow separate masks + processing of foreground and background, so this becomes obsolete there. Get your image done correctly on location would be a time saver argument. Personally I found that my AUTO WB with warming diffusers got distorted pretty badly compared to cooler strobes in tropical waters and also varied heavily depending on diving depth. When manually white balancing the strobes with warming diffusers + working distance on sand the results got pleasing directly out of the camera, but if the depth, angle and scene changed the colors got pretty bad. You would need to redo manual WB several times during the dive, to stay optimal. This would make you loose quite a few wildlife scenes that happen spontaneously. So what’s your say ?

I was about to take out the new HF-1 on a dive trip, but upon packing testing I was surprised to find that their “automatic mode” just supports Sony and Olympus ( now OM Systems). This is explicitly described in Backscatters written manual and also I did not find flash converter / TTL trigger manufacturers which supports the HF-1. Having said that, the HF-1 might not be the first choice for Canon and Nikon mirrorless shooters. I don’t understand why Backscatter did not make that product just as versatile as the SEA&SEA YS-D3 DUO or the Marelux Apollo strobe line. The technology is obviously out there. what a downer 😵‍💫