backscatter due to focus light

On my last dive trip I took along my new Fisheye LED500. The light is great but I had a problem with something I have not experienced before. I was getting a lot of backscatter from the focus light, even when I had it on its lowest setting. I generally only need a focus light at night and had a heck of a time avoiding this on my night shots. I tried all kinds of aiming tricks to try and sidelight subjects with the focus light, but was only slightly successful. I tried using the light mounted off of both the right and left side handles with a ULCS triple clamp and I tried all kinds of positions with the strobes to try and offset this but was never completely successful. My current housing does not have a cold or hot shoe on which I could mount the light, but I can't imagine that would have helped.

Any suggestions? I really like the light but am not pleased with this situation. Perhaps it will improve when Fisheye produces a diffuser for it?

Thanks

Wish I had an answer. This is why I prefer lights with a sensor and an auto-cut-out, which turns the focus light off for a second when the strobes fire. The Fantasea Nano, Fantasea 360 (discontinued, sadly) and Big Blue lights have this feature. I don't think the other big names have it, for some unfathomable reason. Works great!

I'm interested to hear what others think, though, about ways to avoid it.

There's a big thread on focus lights that's been active in the past few days, we've been lamenting the passing (discontinued) of the Fantasea 360, which would have been perfect ... had they been able to ship lights that would stay dry inside.

I think the problem is due to the "white" intense light of your focus light .... I bought a cheap (US$ 42.00) focus light with a very narrow beam and auto-off feature from 10bar in HK which suits me quite well for macro work in low vis, dark environment or at night. Give it a try and retain your "pro" focus light as a dive light or focus light in perfect vis conditions.

All the Best ..... Francesco

On my last dive trip I took along my new Fisheye LED500. The light is great but I had a problem with something I have not experienced before. I was getting a lot of backscatter from the focus light, even when I had it on its lowest setting. I generally only need a focus light at night and had a heck of a time avoiding this on my night shots. I tried all kinds of aiming tricks to try and sidelight subjects with the focus light, but was only slightly successful. I tried using the light mounted off of both the right and left side handles with a ULCS triple clamp and I tried all kinds of positions with the strobes to try and offset this but was never completely successful. My current housing does not have a cold or hot shoe on which I could mount the light, but I can't imagine that would have helped.

 

Any suggestions? I really like the light but am not pleased with this situation. Perhaps it will improve when Fisheye produces a diffuser for it?

 

Thanks

Are you shooting in very low vis? I've used the light on two trips with lots of night diving and haven't had any backscatter problems. I hate to ask this, but are you quite sure the backscatter is coming from the modeling light and not from strobe placement? Even at full bright setting, the FIX 500 is not nearly as bright as a strobe.

I believe auto off function of some modeling lights was to eliminate a "hot spot" in the frame more than avoiding backscatter.

I have both the older Fisheye HD20DX and LED48DX, and have been very pleased with them.

The HD20DX is very bright and with it on its brightest setting and night diving I have not had backscatter problems. In low vis diving in Lembeh Straits with a lot of junk in the water I did not have significant backscatter problems. As per the above note, I wonder if it may be a strobe placement issue.

The water had more particulate than usual on my last trip, but nothing amounting to low viz. My first thought while there was that had my strobes positioned badly, and tried all sorts of positions with no real improvement. I normally try to use edge lighting and I try to keep the strobes positioned fairly far to the sides, and in the past have not had much issue with backscatter. I had no issues with my daytime shots on this last trip without the light.

I really thought it might be the light, which is brighter than anything I have used before as a focus light, but I certainly can't claim to be 100% sure it wasn't my strobes.

The water had more particulate than usual on my last trip, but nothing amounting to low viz. My first thought while there was that had my strobes positioned badly, and tried all sorts of positions with no real improvement. I normally try to use edge lighting and I try to keep the strobes positioned fairly far to the sides, and in the past have not had much issue with backscatter. I had no issues with my daytime shots on this last trip without the light.

 

I really thought it might be the light, which is brighter than anything I have used before as a focus light, but I certainly can't claim to be 100% sure it wasn't my strobes.

I assume you tried taking a shot with, and without, the light, to be sure the light was the culprit.

Right?

I have had problems like this when I take wide angle shots and forget to switch my strobes (ikelite TTL housing) from TTL to Manual. The TTL causes a full dump and the backscatter is awful even with edge lighting. Make sure you are properly controling the amount of light and you may see better results.

I use a pretty powerful focus light and don't ever have signficant backscatter from this source. Try a difusser on your focus light if you don't have one alreayd, but I think the Fix500 does.

Dave

The water had more particulate than usual on my last trip, but nothing amounting to low viz. My first thought while there was that had my strobes positioned badly, and tried all sorts of positions with no real improvement. I normally try to use edge lighting and I try to keep the strobes positioned fairly far to the sides, and in the past have not had much issue with backscatter. I had no issues with my daytime shots on this last trip without the light.

 

I really thought it might be the light, which is brighter than anything I have used before as a focus light, but I certainly can't claim to be 100% sure it wasn't my strobes.

I have been using the Dive Rite Backup LED flashlight with good results. It is dimmable in 3 steps. Another light to try but not dimmable is the Pelican 2410 Recoil LED.

I have been using the Dive Rite Backup LED flashlight with good results. It is dimmable in 3 steps. Another light to try but not dimmable is the Pelican 2410 Recoil LED.

I would steer clear of the Pelican 2410's, unless they've improved them in the past 2 years. I flooded three of them (and believe me I was careful after the first flood, and moreso after the second). After the third flood, Pelican's replacement (which was cheerfully provided, after I shipped back the dead one) was relegated to bedside emergency flashlight duties. Three months later, I tried to use it, and it was dead.

I stopped bothering to return them to Pelican. More hassle than they're worth.

I assume you tried taking a shot with, and without, the light, to be sure the light was the culprit.

 

Right?

Yes and no. I was only able to do one night dive with camera gear and the neither of the two small lights I had with me in addition to the focus light were very suitable as focus lights, having very narrow and bright beams and of course not mounted in any way on the camera. I did have my dive buddy use his light as a focus light on a few shots. It didn't work out too well but I did not have the backscatter problem.

It was too dark to focus with no light.