Wider arms for Ikelite DS-125 Strobe

[Hidroj]

Hello to everyone!
Sunday, the 31st (I needed a last dive, it's becoming a tradition), I tried for first time the DS-125 SubStrobe together with a 12-24mm wide angle lens. I know I've got to go on trying and testing, but I got the impression the arm system was a bit too short for wide angle (and what will happen when I ever get the Fish-Eye I'm interested in?).
I'm carrying the standard Ikelite Strobe and Arm set, and that means the extended mount + 6" arm (and two clamps, of course). If I want more distance I can order the 9" arm, I know.
The subject I'm now interested in, is to know your opinion about that. Is my concern about more distance a complete nonsense? Are the 6" arms more then enough? Should I start thinking about getting a second strobe (it will arrive, some day)? Has anyone developped some interesting, unusual system to achieve maximum distance between his camera and the strobe?
Thank you very much!
Hidroj

 

[Warren_L]

A lot of this depends on the quality of water you're going to be shooting in. From where I am, the visibility tends to generally be on the low side with lots of particulate matter in the water, in the 20-30ft range typically, and often times less than this. I was recently in California and was treated to some great viz (by my standards, but by SoCal standards it was below average) and I had about a 2 ft span per side. My arms reach about 40 inches each side of my housing. I didn't come to the conclusion that I needed this length right away. I started with about 16 inches, went up to 2 feet. Then 3 feet. Then 40 inches, which seems to be about the point where backscatter in the waters that I generally shoot is more or less gone. The backscatter would lessen and lessen as I moved to longer arms.

Here is what my rig looks like.

Right off, it sounds like 6" is going to be too short if you're shooting wide angle. I shoot with both 12-24mm and 10.5mm lenses, and always use the 40" arm setup. They are two 16" ULCS buoyancy arm segments per side, plus the clamps, which brings it to about 40". When shooting wide angle in clear waters, I generally go with a 2 ft setup.

 

[Hidroj]

Wuauuuuuu! That's a rig! At least I see I wasn't wrong at all.
Which ball joints are you using, Warren? I supose Ikelite's 1,25"? Or isn't it necessary?
Thanks a lot for your feedback! Tomorrow I'm going to fix a second 6" arm to my strobe, let's see if there's any difference (I hope the clamps hold strong enough).

 

[Warren_L]

The ULCS buoyancy arms have 1" ball joints. However, as much as I like Ike, I prefer the ULCS clamps as they are easier to use and hold better. My ULCS arms with clamps hold well when fully extended, but do move a bit in strong current. Remember that with arms of that length, they have to be folded up before taking out of the water and unfolded and positioned each time when getting in the water.

 

[Hidroj]

Hy!
Here some examples, from Sunday and from this morning. On Sunday the strobe arm was around 8" away from the camera, today something around 15". Not much difference, I think. I assume I'll probably have to work much more with the direction in which I position the strobe. The best example for bad positioning is the picture were even the reflection of the light on the dome is visible.

Backscatter and dome reflection

The strobe a little bit better positioned

Still some work to do

and maybe acceptable

(all pictures have been shot with a Nikon D70 inside a Ikelite Housing, Nikon 12-24mm and one single Ikelite DS-125 strobe. First two with the 8" dome, the other ones with the 6" one).

I hope I'll go on showing my progression. Thanks for your advice!
Hidroj
Barcelona, Spain

 

[joewr]

Hi, hidroj,

I typically use two ulcs 12" arms with a 20mm lens or with a zoom that starts at 18mm. That works just fine in tropical waters--50-100+ feet clarity. The real trick is to aim your strobes and the longer the arm, the more skill it takes.

Using a diffuser is nearly manditory with a wide angle lens...nearly manditory.

One of the things you can do the make certain you are using the optimum angle for your arms is to check the histogram for your photo. It should be well-balanced across the spectrum.

I hope this helps--and your photos look like you are on track.

joewr