Diving lights - Halogen vs LED

[zulumoose]

Hi all

I had a conversation yesterday with someone who claims a friend (who is a diver and photographer) has "given up on LED lights and gone back to halogen" because of the glare/colour issues he was having.

I know nothing about diving lights in particular, but I suggested that this was possibly due to the lumens war idea, that people buy lights for high lumens and manufacturers use LEDs with harsher, colder tints in order to bump up the output. I suggested their friend look for high CRI LED based lights and mentioned the Nichia 219 as an example of an LED designed for good colour representation.

It occurred to me though that someone into photography and underwater lighting should know all about this, and maybe I am the one who is ignorant of the issues here? Is there really a good reason to abandon LED and seek halogen lights for this application, or is it maybe a case of either ignorance or imagined/romanticised ideas about purity, like the debates around vinyl vs CD (let's not go there).

Maybe the diving industry is dominated by lumens-oriented lights, and those into that scene just aren't exposed to quality over quantity lighting unless they investigate beyond the dive shop?

Can someone educate me here? I would like to send some responses to the person involved to pass on to their friend. I feel like I should be defending LEDs, as a fan of LED flashlights, silly though that might sound (ok maybe not around here ).

 

[bykfixer]

High lumens is irrelevant if they don't go to the places light needs to go and in many cases todays 'popular' way of putting out light is too much flood for a dive light. All that extra light close up is overwhelming. And contrary to popular belief a so called high cri light doesn't mean the colors will acurately show up on digital sensors. Part because they aren't as acurate as they claim and partly because a camera may not have the algorithms built into the software to interpolate the tint of the light.

Halogen is a tried n true technology and in many cases a tightly focused beam takes place without a ginormous amount of light up close to overwhelm a cameras sensor.

It's all about the shape of the beam and how well it is tailored for a given situation. And tint needs to be such that the camera can adjust out any biases using software that can accurately predict what colors it should be showing.
Although a cool white tint may not appear as accurate as one of those so-called high cri numbers most cameras play nicer with a cool white beam than one which exagerates a certain spectrum to appear more pleasing to our eyes.
Halogen gets colors correct or at least correct enough for the camera to adapt and overcome.

Once the new cri chart is perfected and true values of the 15 colors (not the 3 or 4 current charts rate) then the algorithms can adjust better using more information for a better educated guess.

I would speculate your friends issue is more beam shape issues than lumens or tint. LED is still new to most companies who are trying to mimic a light bulb with an LED chip which produces light differently. Bulbs put out light forward, sideways and backwards. LED's push light forward. Using bulb type reflectors for LED lights is like trying to make apple flavored drink from oranges. And until dive light companies get better at LED lights he should stick with halogen imo.

 

[zulumoose]

Thanks bykfixer, looks like there are a whole lot more levels to this issue than I was aware of.

 

[bykfixer]

Water clarity plays a role too. LED lights are great. And todays lights do a great job of lighting up the night. But it is a complicated process trying to use any flashlight for photography, and under water photography... oh boy that is another matter entirely.

The other night I had to use 3 different flashlights with 3 distinct beam shapes to snap a photo correctly. One was used for it's slight blue tint, the other for its pure flood and the 3rd for it's narrow spot beam, but the trickiest part was that they could easily be too bright for the camera to get the lights correct while getting the darks correct.

Getting that shadow next to the reflective white stripe was not an easy task.
I shoot pix of fish in my aquarium occasionaly and to get a good photo.... usually requires a bunch of tries. But they are in a tank so I have plenty of time. Nature photos tend to be sudden. Wild beings don't sit around saying "cheese". Instead they are either trying to avoid being eaten or trying to eat other critters... or procreate. But through trial and error your friend should be able to grasp photography using LED lights eventually.

 

[terjee]

With photography, you often (some would say almost always) want your primary light source to be as big as possible, and LEDs often have tiny emitters, the exact opposite of what you want. One of the side-effects of this, is glare. Part of the reason you see studio-photographers using soft-boxes is this specific issue, they want to convert the relatively small lights source that is a flash or studio light, into a much bigger one.

Two options to improve upon that could be lights with diffusers, such as Zebralight F-types, but bigger diffuser and for under water use, or actually still use indirect lighting such as with a soft box.

 

[zulumoose]

With photography, you often (some would say almost always) want your primary light source to be as big as possible, and LEDs often have tiny emitters, the exact opposite of what you want. One of the side-effects of this, is glare. Part of the reason you see studio-photographers using soft-boxes is this specific issue, they want to convert the relatively small lights source that is a flash or studio light, into a much bigger one.

Two options to improve upon that could be lights with diffusers, such as Zebralight F-types, but bigger diffuser and for under water use, or actually still use indirect lighting such as with a soft box.

I understand that issue, but wouldn't the same be equally true of halogen? The filament in a halogen light is also tiny, or is the size of the source perhaps less relevant for a halogen for some reason?

 

[terjee]

I understand that issue, but wouldn't the same be equally true of halogen? The filament in a halogen light is also tiny, or is the size of the source perhaps less relevant for a halogen for some reason?

There's certainly a risk of the same happening, but halogen lights come in a lot of different types. Some have a mirror front, that bounces all the light back and out only from the reflector, so you don't have the pinpoint of the LED emitter, but have an effective source hundred of times larger. Not sure if that is *the* issue, but it could certainly make a difference.