Red Light Distracts (not!)

Just so this forum doesn't turn into a geekfest of cameras and housings, I thought I'd write about a well known but little used method of using lights underwater without scaring off the fish. As we all know, water acts as a filter so the higher frequency colors(red) are absorbed first as distance increases.

We all know there are some amazingly colorful sea creatures but what is more important is that we also know that reef fish are less sensitive to the orange/red spectrum and more biased toward the blue/green spectrum. In fact that's why many strobe AF lights are red, to not disturb the fish before the monster strobes go off.

The first time I tried putting gels on lights was about 9 years ago, but I didn't find any really good gels and the heat from the halogens(plus seawater) helped destory the gels quickly. Then came HID and HMI. HID lights have poor CRI, lousy restrike abilities, no power variability tend to be expensive on replacements. However they run very cool and won't burn off gels as quickly. Using the HID + gels, I found that I could approach sealife a little closer, esp at night. They were not as antsy as when you shine normal light. Best of all, you don't have as much wormy thingamajings swarming your light source and ruining your shoot.

So obviously it's perfect right? No way.

When you apply gels to the lights, you are messing with colors and depending on the camera's white balance to compensate. If you don't get WB correct it can get pretty funky red. (but nothing you can't correct in post). Then you have the problem of being unable to control the amount of red in a picture. If you WB a subject 4 ft away, what's behind it is going to be extra blue, which can be great but sometimes the foreground can be a bit red hued.

The best usage of this light setup is for reef fish in the reef ( esp crespuscular creatures like the mandarin fish). Of course if you have a 20k lumens light beaming around, it'll still scare off the fish, but used with average lights, it can be less intrusive on marine life and allow a better shot.

I'll post some vid/pics of the experiments I've done over the years once I get a life.

Yeah, yeah...

I still think the A1 is a good cam/housing for the money

Seriously, good show Drew old bean.

I'll look forward to the results..Anything to make life alittle easier for our aquatic chums.

Dive safe

DeanB

Just so this forum doesn't turn into a geekfest of cameras and housings, I thought I'd write about a well known but little used method of using lights underwater without scaring off the fish.....

Ah, one of the big advantages of my cheap, old technology halogens. Instantly turn 'em on/off as needed.

Hmmm Ron... turning off the lights really work on night dives, esp for video.

Small flash light on night dives for spotting. Once I see something to film I approach, hit record and then flip on my lights. Haven't had too much problem with scaring away animal life with this method.

Well Ron, try that on mandarin fish and 2 spot lionfish for eg. Lots of reef creatures, esp nocturnal ones disappear before you see them because of the light.

Drew you spend more time on this thing than me I think.

I made up plastic diffusers for my HID's which did cut the light power back but now they are just two white glows and allow you to get real close with no hot spots. The big dome port works well as allot of the times the subjects will come right up to the port as they can see their reflection in it.

Funny as the other night I had those wormy thingamajings around one light so then I turned it off and they then swam over to the other one and stayed there even when I turned the other one back on

Have not used gels though.

Crepusclar... now there's good word.

Red filters on lights... Very interesting post Drew.

At night I generally have my LMI halogens on the medium brightness when I'm in "search mode" and then I turn them to the lowest power setting when I see something I want to move in on.

Finding that I was still scaring stuff off, I wanted even more stealth and started using black tights over them. Kept snagging them though (*insert limp wrist smiley*) so then I tried neutral density gels like 210 which reduce the light by 2-stops. Worked OK but due to laziness on my recent night dives I just left on some 281 3/4 blue gels (by Lee), the same ones I use during the day to knock back the warmth of the halogens. They reduce the light as well but I hadn't thought about it being at the wrong end of the spectrum for the poor little fishies' eyes.

Hadn't thought of trying red filters. That's a novel idea indeed. Drew, I don't suppose you know what the numbers of the gels are that you've had success with, do you?

One can get grades of gel from the likes of Rosco that are specifically for high temperature. They might last longer on halogens but to be honest my Lee blue gels are still looking good after quite a lot of dives.

Gels are available from several manufacturers:

http://www.formatt.co.uk/gels/default.asp

http://www.rosco.com/us/filters/ecolour.asp

http://www.leefilters.com/home.asp

You can get smallish quantities from theatrical suppliers or direct from Formatt in the UK. Possibly B&H too? These manufacturers or big distributors will send you a swatch book if you ask them. The Rosco distributor in Hong Kong sent me 4 books, one or each of the grades, but sadly the swatches are not quite big enough to cover the lights.

If you cut gels to the right size they just snap into the undercut behind the front of many light heads. If you want to be super professional or want to do a lot of experimentation you can use a circle cutter (Fiskars is good) instead of scissors.

As for the wormy things, sometimes I turn the lights off and sit there for a couple of minutes until they've all pis5ed off, then try to get the shot really quickly after turning the lights back on before they all come back.

Nick

I use Cokin Ref 003 Red filter and the Norman's 6x6. Usually I don't cut,maybe a dremel tool but neat is not my thing... just so long as it works.

Dremel? So those must be rigid filters designed to go in a mattbox, as opposed to the thin flexible gels I was talking about? How did you mount them on your lights?

Easy. Drill 3 holes and use thin bungie cords and wrap it round the light head.