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Interceptor121

Ideal Arm length for wide angle video

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Posted (edited)

I use 8+12 inch segments for wide angle of schooling fish or large close up of sharks when i take pictures so I tried to use the same combination with a pair of Keldan 8X

 

As the ambient lights was very strong with the wide arms I had almost no effect so I changed to two 5" segments in this way I could see the effect of the light on the fish body

 

The keldan appear to be wider of my Inon strobes but obviously the power is not even close.

 

Looking at rigs it appears arms for video shooters are shorter than for still I saw a few rigs like dreifish one and I would say it looks even smaller than 5+5

 

I am curious what people use and why?

Edited by Interceptor121
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Posted (edited)

I would like to use smaller than what I am but I need the lift, especially with the tripod attached to make it neutral. Smaller arms would create less drag meaning a more compact and stable rig (to my understanding anyways)

Not 100% sure but i think I use Nauticams 70x250mm + a long nauticam arm that I think is 8 inches to which I have 2 big 10bar floats attached on each arm.

Most likely gonna leave the tripod for wide stuff in the future and try to get neutral with smaller arms tho.

Edited by Pajjpen

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My setup is basically 8" + 5" (approximately). I also use a pretty long clamp between the two arms meant to work with wide float arms. and 90 degree beam lights and WWL-1. So if I was to fully extend the lights out horizontally, they'd be about 20" out from the lens.

 

Going by the rule of thumb that your lights should be the same distance away from the lens as the subject is from the lens, this lets me work with subjects between 6" to ~20" with no beam overlap before the light hits the subject. I've found that to work quite well, as the lights don't really output sufficient power further away than 20".

 

Video lights are about 5-6 stops weaker than strobes (at best). So backscatter is less of a concern with video even if your light positioning isn't perfect. I've never felt the need to have wider arms. Keeping the lights closer to the body of the housing (and potentially using a single arm instead of a double-arm setup) would greatly improve how the rig handles in the water (especially in current!). I only use the floats I use because the housing and lights are so damned negative otherwise.

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I think 5+8 is the right spot however the amount of flotation is a challenge if your lights are heavy

 

For macro I have small sola 1200 that are perfectly adequate so no issue there besides am happy with the housing negative for wide angle there are more problems

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This is my current setup (minus lights)

 

53fc24aff93d6f0607da3f9524b96a3a.jpg

 

 

 

 

Sent from my iPhone using Tapatalk

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This is my current setup (minus lights)

 

53fc24aff93d6f0607da3f9524b96a3a.jpg

 

 

 

 

Sent from my iPhone using Tapatalk

this looks 8 + 8 or in Nauticam terms 200mm?

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My setup is basically 8" + 5" (approximately). I also use a pretty long clamp between the two arms meant to work with wide float arms. and 90 degree beam lights and WWL-1. So if I was to fully extend the lights out horizontally, they'd be about 20" out from the lens.

 

Going by the rule of thumb that your lights should be the same distance away from the lens as the subject is from the lens, this lets me work with subjects between 6" to ~20" with no beam overlap before the light hits the subject. I've found that to work quite well, as the lights don't really output sufficient power further away than 20".

 

Video lights are about 5-6 stops weaker than strobes (at best). So backscatter is less of a concern with video even if your light positioning isn't perfect. I've never felt the need to have wider arms. Keeping the lights closer to the body of the housing (and potentially using a single arm instead of a double-arm setup) would greatly improve how the rig handles in the water (especially in current!). I only use the floats I use because the housing and lights are so damned negative otherwise.

 

So 90 degrees lights 8 + 5. I would say 110 degrees lights needs more distance around 8" more so 12 + 8 looks reasonable for a 110 degrees

 

I would think this is a reasonable table

 

90 degrees light 5 + 8 segment

100 degrees light 8 + 8 segment

110 degrees light 8 + 12 segment

 

For macro the position of the lights is different so different story but for manouvre I have used 3 + 8 or locline without issues

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Tired to fight with clamps at depth, now I'm using a hybrid approach: a smal float carbon fiber arm and a locline segment. Once in the water I set the floats at 45° and then I just move the locline section to my taste.

 

Don't bother to the DIY tripod on my setup; I was just experimenting.

 

 

post-32954-0-83636200-1553849752_thumb.jpg

 

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Today I gave assembled my rig again after my trip to Tiger Beach

On paper what dreifish says it’s true and so is my table however with short arms am having a hard making my rig neutral without float arms that are mot easy to manouvre

So I have gone back to 8+12 so I can add almost 2 KG positive lift with stix floats

eeb48c2a2ca2cc5be9cb42a3c39025fd.jpg

This looks more reasonable and I can always avoid extending the arms in full. At the same time if there is something really over 1 meter I can give it a go

 

 

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Things to consider when choosing arms type/lenght:

 

https://youtu.be/Rs3XXeJF0qY

 

 

I think I have gone well past this video to be honest but I do see the point. When you had 60 degrees video lights you tended to have single arms but now with lights 95 degrees and more you start needing longer segments. Yesterday I was in the pool with the Divepro G16 plus lights and they are very heavy 370 grams negative

I made the mistake of having the more buoyant arm close to the camera so I ended up having torque and the lights dropped also after testing I can say 8 + 12 is far too long for what the lights can do 8 + 8 is pretty decent

 

So it may be true that you can to keep all the rig compact bit if your lights are very wide you will end up with two segments and if the lights are negative you need buoyancy on the sides not the centre

 

Besides look at Florian rig he has two 8" float arms ... with his keldan

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So it may be true that you can to keep all the rig compact bit if your lights are very wide you will end up with two segments and if the lights are negative you need buoyancy on the sides not the centre

I would add that during the winter here the water can be very murky so to avoid back scatter I have two options:

#1 use double long arms completely extended to find the sweet spot.

#2 don't use in camera lights but use lights of a dive buddy who sacrifice himself

#3 both above :)

 

Here my buddy sacrificing himself for a good cause!

 

post-32954-0-84478000-1554459862_thumb.jpg

post-32954-0-50107600-1554459868_thumb.jpg

 

Besides look at Florian rig he has two 8" float arms ... with his keldan

Where?

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I would add that during the winter here the water can be very murky so to avoid back scatter I have two options:

#1 use double long arms completely extended to find the sweet spot.

#2 don't use in camera lights but use lights of a dive buddy who sacrifice himself

#3 both above :)

 

Here my buddy sacrificing himself for a good cause!

 

attachicon.gif1DSC9887.jpg

attachicon.gif1DSC9906.jpg

 

 

Where?

Keldam advertising flyer i was at Reef photo he is clearly using 4x8 inch small float arms he has a big dome I believe acrylic and 4 8x keldan in the picture

 

Anyway I tried the two 8" segments with my lights and the transportability is crap so back to 5+8 as dreifish suggested not out of choice am afraid

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Keldam advertising flyer i was at Reef photo he is clearly using 4x8 inch small float arms he has a big dome I believe acrylic and 4 8x keldan in the picture

 

Anyway I tried the two 8" segments with my lights and the transportability is crap so back to 5+8 as dreifish suggested not out of choice am afraid

 

If you need additional floatation, I suggest rigging up a float across the top of your rig connecting the two ball mounts on the handles. You could always also try making the 5" arms the inon mega-float variety and/or adding some floatation foam directly to your lights.

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If you need additional floatation, I suggest rigging up a float across the top of your rig connecting the two ball mounts on the handles. You could always also try making the 5" arms the inon mega-float variety and/or adding some floatation foam directly to your lights.

The issue is not balancing the rig overall but balancing the light. There is significant torque at the handle clamp so the whole arm drops. Keldan is coming up with new floats that make the 8X almost neutral and therefore the arms don’t move and you require much less float for the rest

With the DivePro lights and no float there is the torque and although the rig is neutral the arms drop when in operation

 

 

Sent from my iPhone using Tapatalk

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If you need additional floatation, I suggest rigging up a float across the top of your rig connecting the two ball mounts on the handles.

Bit hard when a monitor is used.

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