Jump to content


Photo
- - - - -

Looking for longer strobe arms


  • Please log in to reply
11 replies to this topic

#1 ileiman

ileiman

    Lionfish

  • Member
  • PipPip
  • 58 posts
  • Gender:Male
  • Location:Finland

Posted 17 January 2011 - 08:24 AM

I have a Canon 7D in Ikelite housing, with 2x Ikelite DS161 strobes on the Ikelite 6" strobe arms.
I do a lot of wide angle photography with a Tokina 10-17 fisheye, and have found the 6" arms to be too short. Even in clear waters it is too easy to get flare to the dome, and in dirtier waters there is always some amount of backscatter no matter how you position the strobes.
I also would like to get better buoyancy to the system. One Ike DS-161 strobe is 200 g negative in water, and the camera in housing about 1 kg, so camera plus two stobes and Ike arms have a total negative buoyancy of almost 2 kg. So far I have been using DIY floaters on the rig. The longest Ikelite arms are 9" and don't add that much to the reach.

The new ULCS (Ultralight) 2" thick buoyancy arms (DB-BL series) look like an interesting solution. However, it seems that to get any meaningful amount of buoyancy out of these arms, you would need really long arms, like 16"+16" arms on one strobe would give 0.7 kg positive buoyancy and with two such arms I would get +1.4 kg that would almost make my rig neutral. But, then with 16+16 arms I get a whopping reach of 38" = 97 cm on one side. Maybe that is already too much? What do you think?. Has anyone experience with arms of this size? I would think that adjusting arms this long would be difficult and create a lot of drag?
And then with arms this long, I would need also extension sync cords, which aren't exactly cheap either...

However with shorter arm segments you get much less buoyancy, and the arm length affects the price very little.

I would appreciate any comments and ideas. :)
Canon 7d, Tokina 10-17mm fisheye, Canon EF-S 60mm Macro, Sigma 10-17mm OS HSM, Ikelite housing,
2x Ikelite ds-161 strobes with Stix 12"+12" arms with floats.
Canon ixus 980is in Canon housing.
Olympus c8080wz in Olympus housing.
website www.leiman.fi.

#2 saga7

saga7

    Moray Eel

  • Member
  • PipPip
  • 83 posts

Posted 17 January 2011 - 09:26 AM

I have an 18 inch long ikelite quick release arm. Here is my post on scubaboard. I would like $45usd plus shipping. http://www.scubaboar...elease-arm.html

#3 Balrog

Balrog

    Eagle Ray

  • Member
  • PipPipPip
  • 346 posts
  • Gender:Male
  • Location:Poole UK

Posted 17 January 2011 - 12:36 PM

I have a 450D in Ikelite with 2 x DS160 and use 12" + 8" UCLS 2" dia arms. This makes the rig just an ounce or two negative depending on port and will sink at about 1/2" per second. The Ike twin strobe lead is fine with full extension each side.

An 8" port adds quite a bit of buoyancy but I use 5 oz of lead attached to the port shade to counteract the tendency for it to tip up at the front so the overall effect is almost neutral.

They do need a bit of pushing through the water if they are fully extended and you want to push on. Cruising slowly, you won't notice it. If I want to get somewhere quickly or if there's a current I put the two arms together above the camera and point the housing port down, so the arms are like the bow of a ship.

At 3:24 in this clip http://www.youtube.c...=watch_response , you'll see Cathy Church handling her Subal rig through the bridge window just holding onto one strobe. I think she is using 2 x 12" arms.

Edited by Balrog, 17 January 2011 - 12:36 PM.


#4 diver dave1

diver dave1

    Great White

  • Member
  • PipPipPipPip
  • 913 posts
  • Gender:Male
  • Interests:chess, u/w photography

Posted 17 January 2011 - 07:55 PM

You might consider Stix XL floats for bouancy, then your arm length is not tied to your lift. Adding 2 UCLS 8" arms would add some length and an 8" arm can take 2 XL floats each. You get 0.77 kg of lift for the pack of 4 floats for $35 (US Price) and they are easy to pack. If 8" is not long enough, use 12" then you could fit 2 packs of XL floats for 1.44 kg lift - 3 floats for each 12" arm, one for each 6". That would essentially triple your arm extension while taking care of your lift problem.

If you want to further separate your arm length from lift - get heavy duty shock cord from a backpacking store and make a loop. The cord costs about $0.15/ft here. Its the cord they use inside tent poles, has a lot of flex and is thin. Then you can slide your float(s) on the shock cord loop and tie it. Make the loop the length you want to snap onto where ever fits your rig to your satisfaction. When I use a macro lens and have a focus light setup extended out front, adding such a loop (with float) to snap onto the port keeps the rig from wanting to tip forward.

When I have the long arms on and need to move quicker or fight a current, I tilt the dome pointing down similar to Balrog to reduce drag.

Just a thought.

Nauticam D7000, Inon Z-240's, 60 micro, 105 micro, Tokina 10-17

www.shiningseastudio.com


#5 Balrog

Balrog

    Eagle Ray

  • Member
  • PipPipPip
  • 346 posts
  • Gender:Male
  • Location:Poole UK

Posted 18 January 2011 - 01:48 AM

If you do decide on 2" dia arms, you will need to use the UCLS AC-CSB clamps which have a bigger centre distance, otherwise the arms don't fold together.

#6 ileiman

ileiman

    Lionfish

  • Member
  • PipPip
  • 58 posts
  • Gender:Male
  • Location:Finland

Posted 18 January 2011 - 04:19 AM

At 3:24 in this clip http://www.youtube.c...=watch_response , you'll see Cathy Church handling her Subal rig through the bridge window just holding onto one strobe. I think she is using 2 x 12" arms.

Indeed those do look like 2x12" ULCS thick arms:
cathychurch_arms.jpg
It doesn't look too bad, and as can be seen from the video, arms like these do provide a lot of flexibility.
The sync cords do look seriously stretched, and I would be a little concerned about the strain to connectors, but maybe I'm just being too cautious.
I tested myself, and it seems that the Ikelite #4103.52 dual coiled cord does stretch over 1 meter to each side, so even using dual 2 x 16" arms should be possible without extension cords - provided the strain doesn't cause an issue.
Canon 7d, Tokina 10-17mm fisheye, Canon EF-S 60mm Macro, Sigma 10-17mm OS HSM, Ikelite housing,
2x Ikelite ds-161 strobes with Stix 12"+12" arms with floats.
Canon ixus 980is in Canon housing.
Olympus c8080wz in Olympus housing.
website www.leiman.fi.

#7 ileiman

ileiman

    Lionfish

  • Member
  • PipPip
  • 58 posts
  • Gender:Male
  • Location:Finland

Posted 18 January 2011 - 04:33 AM

You might consider Stix XL floats for bouancy, then your arm length is not tied to your lift. .....

If you want to further separate your arm length from lift - get heavy duty shock cord from a backpacking store and make a loop. The cord costs about $0.15/ft here. Its the cord they use inside tent poles, has a lot of flex and is thin. Then you can slide your float(s) on the shock cord loop and tie it. Make the loop the length you want to snap onto where ever fits your rig to your satisfaction. When I use a macro lens and have a focus light setup extended out front, adding such a loop (with float) to snap onto the port keeps the rig from wanting to tip forward.

Even with ULCS buoyancy arms I would need some additional lift. So using Stix floats in addition may be a good idea. I could then fine tune the buoyancy with those depending on lens+port combination I use.
Currently I have been using DIY hack with pool noodle pieces, as can be seen in this picture:
Posted Image
The bad thing with those pool noodles is that they compress at depth and lose some buoyancy. The Stix floats seem to be more resistant to depth.
I actually have done a loop like you describe, but out of heavy duty hose, which is strong enough to be used as a carrying handle on surface.

Thanks for the good ideas. :)
Canon 7d, Tokina 10-17mm fisheye, Canon EF-S 60mm Macro, Sigma 10-17mm OS HSM, Ikelite housing,
2x Ikelite ds-161 strobes with Stix 12"+12" arms with floats.
Canon ixus 980is in Canon housing.
Olympus c8080wz in Olympus housing.
website www.leiman.fi.

#8 ileiman

ileiman

    Lionfish

  • Member
  • PipPip
  • 58 posts
  • Gender:Male
  • Location:Finland

Posted 18 January 2011 - 04:49 AM

If you do decide on 2" dia arms, you will need to use the UCLS AC-CSB clamps which have a bigger centre distance, otherwise the arms don't fold together.

I suppose the ULCS arms - having 1" balls - can be attached on the Ikelite 1" balls & clamps, so I could reuse by Ikelite quick release base adapters and strobe adapters?
So I only need the ULCS arm segements and AC-CSB clamps between those. I wouldn't necessarily need the BA-IKT and AD-125 adapters and clamps on those?
Canon 7d, Tokina 10-17mm fisheye, Canon EF-S 60mm Macro, Sigma 10-17mm OS HSM, Ikelite housing,
2x Ikelite ds-161 strobes with Stix 12"+12" arms with floats.
Canon ixus 980is in Canon housing.
Olympus c8080wz in Olympus housing.
website www.leiman.fi.

#9 Balrog

Balrog

    Eagle Ray

  • Member
  • PipPipPip
  • 346 posts
  • Gender:Male
  • Location:Poole UK

Posted 18 January 2011 - 09:23 AM

I suppose the ULCS arms - having 1" balls - can be attached on the Ikelite 1" balls & clamps, so I could reuse by Ikelite quick release base adapters and strobe adapters?
So I only need the ULCS arm segements and AC-CSB clamps between those. I wouldn't necessarily need the BA-IKT and AD-125 adapters and clamps on those?


Yes. Exactly as you say, you only need the longer clamps between the two large arms. Ike clamps are fine elsewhere and work with the UCLS balls.

I also progressed from pool noodles to the 2" dia arms and find them a little better. I set up the noodles so that rig was buoyant on the surface and became negative by 6m. I have to say it was quite a secure feeling for shore entry or being handed down from the boat having it float on the surface.

I found a switch to the shorter Ike quick release arms was of benefit with longer arms.

I'm still using my original dual cable 2 years on.

Edited by Balrog, 18 January 2011 - 09:38 AM.


#10 ileiman

ileiman

    Lionfish

  • Member
  • PipPip
  • 58 posts
  • Gender:Male
  • Location:Finland

Posted 02 February 2011 - 05:56 AM

I finally ended up buying Stix arms.
The ULCS arms were out of stock at Backscatter, but they had Stix arms available immediately, so I got those instead.
Now that I got them and tested them in the pool, I am really glad I about the decision, they are great :P
I was able to balance my rig to perfectly neutral buoyancy.

For each of the 2 strobes I built new arms with 2x Stix SX-312 12" (= 31 cm) segments with jumbo floats on them.
The segments are joined with Stix SX-C clamps, and connected to Ikelite DS-161 strobes and Ikelite housing's quick grip with the original Ikelite clamps
Posted Image
These arms can extend almost 70 cm to the side, which should get rid of all flare and backscatter even in the worst of conditions. For transport and swimming you can fold them into a tight package.
The Ikelite coiled dual sync cord does extend to allow maximum reach with these arms.

All 20 of the jumbo floats on these arms would give a total buoyancy of 2.4 kg, which is a lot more than I needed. But you can remove the floats you don't need. I also got kits of large and small floats, which allowed me to find tune the rig to find the perfect buoyancy. I was able to balance the rig so accurately that I could leave it just hanging on its own in the mid water, and it would stay in the same depth. For the Tokina 10-17 in 8" dome I needed only half of the jumbo floats plus a few smaller floats for fine tuning.

For other lens+port configurations you can simply change the amount and sizes of floats.
Canon 7d, Tokina 10-17mm fisheye, Canon EF-S 60mm Macro, Sigma 10-17mm OS HSM, Ikelite housing,
2x Ikelite ds-161 strobes with Stix 12"+12" arms with floats.
Canon ixus 980is in Canon housing.
Olympus c8080wz in Olympus housing.
website www.leiman.fi.

#11 ileiman

ileiman

    Lionfish

  • Member
  • PipPip
  • 58 posts
  • Gender:Male
  • Location:Finland

Posted 02 February 2011 - 05:59 AM

This shows how far the arms can go:
Posted Image
Canon 7d, Tokina 10-17mm fisheye, Canon EF-S 60mm Macro, Sigma 10-17mm OS HSM, Ikelite housing,
2x Ikelite ds-161 strobes with Stix 12"+12" arms with floats.
Canon ixus 980is in Canon housing.
Olympus c8080wz in Olympus housing.
website www.leiman.fi.

#12 ileiman

ileiman

    Lionfish

  • Member
  • PipPip
  • 58 posts
  • Gender:Male
  • Location:Finland

Posted 02 February 2011 - 06:06 AM

You can detach the balls at the end of the arms, which allows you to remove, add and change the floats.
Posted Image
On 12" arms you can fit up to 5 floats. Floats come in 3 different sizes.
Canon 7d, Tokina 10-17mm fisheye, Canon EF-S 60mm Macro, Sigma 10-17mm OS HSM, Ikelite housing,
2x Ikelite ds-161 strobes with Stix 12"+12" arms with floats.
Canon ixus 980is in Canon housing.
Olympus c8080wz in Olympus housing.
website www.leiman.fi.