focus light Inon S2000 - Focus Light question

[blipstream 2]

Hi.

I shoot on a TG4 with 2x Inon S2000. Now I want to add a focus light to the setup. I am looking at the "X-Adventurer M1000-WRA Smart Focus Video Light" at the moment. It has beam and red mode but no spot beam. Is spot beam needed for a focus light? I want to use the auto-off function and don't want to highlight things with it. Thanks in advance

Edited April 24, 2021 by blipstream

[TimG 62]

Hi blipstream

No, you don't need a spot beam. Generally lights for focussing are not especially "Wide-Angle" coverage but neither are they especially narrow either. A bit Goldilocks!

Sadly the S2000 doesn't have a built-in modelling/focussing light so if your TG4 is struggling to focus, then a light could well be the answer. 

I can't comment on the X-Adventurer but there are loads of focussing lights out there: Inon, L&M Sola etc etc.

Auto-Off is nice to have but the power of your strobes would likely overwhelm the focus light anyway so, unless it is super powerful, a hot spot shouldn't be an issue even without Auto-Off.

[blipstream 2]

Hi Tim!

Thank you for your reply. 

The lack of a built-in focus light is no problem for me, as the strobes are mostly not pointed directly at the fish etc. anyways.

I will go for the X-Adventurer then. The price is good (69€ online) so if I need to replace it with another it is not a big deal.

But I also thought about a Video/Focus light 2in1 solution. I have 2 Volador 3000 lumen flood lights from amazon (pretty cheap, no website, still quality seems good and they have been reliable so far). The thing is, the distance of the flood light seems very weak underwater. I mean how many lumen for 2x video lights do I need for filming critters etc. that are, let's say 7-10 feet away?

 

[TimG 62]

Yeah, at $69 you can't go far wrong - although, gotta to say, one of the lessons I have learned with a lot of u/w gear is that you buy cheap, you buy twice. But then at $69 you could buy many times! I'd have said about $250-$300 normally for the sort of focus light you're talking about so ... yeah, $69.......

On video light power, I will bow to others to chip-in: I'm not a video guy. However, my partner is using a GoPro with one Orchatorch 910v which is 5000 lumen. That's good for about 3 feet. Based on what I have seen with my partner's system, I'd have thought you need at least 10,000 lumen. But, as I say, let's see what the videoistas reckon.

 

 

 

 

[blipstream 2]

Wow, 5000 lumen for 3 feet sounds not far for that amount. But I expected such numbers. Yeah, let's see what others have to say.

Right now I have a Paralenz (old model) mounted on top of my TG4. I just let it record during the whole dive and the colour correction is pretty good. But the focus is not always on point and there is no zoom. So I was thinking about starting to record with the Olympus. The problem is that means:

- Paralenz (under 100g underwater) + 2x video/focus lights (more weight) so I also need to add floats to keep the buoyancy. Would result in a way more bulky build. And of course two 5000+, or as you estimated even 10.000 lumen lamps would be not cheap.

Edited April 24, 2021 by blipstream
Misspell

[TimG 62]

58 minutes ago, blipstream said:

- Paralenz (under 100g underwater) + 2x video/focus lights (more weight) so I also need to add floats to keep the buoyancy. Would result in a way more bulky build. And of course two 5000+, or as you estimated even 10.000 lumen lamps would be not cheap.

Yep, my partner found the same with the GoPro. She's now got a tray with two handles and an arm between them loaded with Stix floats plus an arm for the light. 815gms of buoyancy in total. Even then it's pretty negatively buoyant - hence the lanyard! See photo.

[blipstream 2]

Seems like high lumen video lights and low uw weight is not really achievable. At least I haven't found a suitable lamp yet.

And I forgot that in case I would really like the idea of adding a remote for the video lights. I don't even know how to build a rig with 2 strobes, 2 video light with a remote some floats and 4 cables 

Edited April 25, 2021 by blipstream

[ChrisRoss 150]

16 hours ago, blipstream said:

Hi Tim!

Thank you for your reply. 

The lack of a built-in focus light is no problem for me, as the strobes are mostly not pointed directly at the fish etc. anyways.

I will go for the X-Adventurer then. The price is good (69€ online) so if I need to replace it with another it is not a big deal.

But I also thought about a Video/Focus light 2in1 solution. I have 2 Volador 3000 lumen flood lights from amazon (pretty cheap, no website, still quality seems good and they have been reliable so far). The thing is, the distance of the flood light seems very weak underwater. I mean how many lumen for 2x video lights do I need for filming critters etc. that are, let's say 7-10 feet away? 

 

Realistically 7-10 feet away is a bit optimistic even for a strobe, which is orders of magnitude lighter than even the brightest video lights.  The fact the TG shoots at f2.8 at the wide wide will help a bit but that also increases ambient light and what you are trying to achieve with the video light is adding enough light so that you restore the colours, it may not be enough to give you full daylight exposure but it needs to be a significant fraction of the total light being used - white balancing will help shift that colour balance towards daylight balance - this is why you need to do a custom white balance for video the auto WB will be fooled by the ambient light and you don't have a huge scope to WB video after the fact.

The other thing you need to consider is the other half of the light spec - the beam angle,  the lumen rating is how much light is generated and the beam angle determines how many lumens illuminate the subject per square metre of beam, a relatively small change in beam angle makes a big difference - a 60° beam at 1metre distance illuminates just over 1 m2, a 100° beam at the same distance illuminates 4.4m2.  This means that the lumens/m2 on your subject will be 2940 for a 60° beam at 1m and 675 lumens/m2 for a 100° beam or only 25% of the light. 

The summary of all this is low lumen video lights work if they are very close to your subject, generally well under 1m. 

and also what this means is you don't need many lumens for a focus light if you get a light with about a 60° beam but you need 4x as many lumens to get the same effect with a video light with a 100° beam. 

Weight for video lights is always going to be an issue - you have are carrying a lot of battery and there's not much empty space inside the light to provide buoyancy so they are near as heavy in the water as they are in air. 

[blipstream 2]

 

1 hour ago, ChrisRoss said:

Realistically 7-10 feet away is a bit optimistic even for a strobe, which is orders of magnitude lighter than even the brightest video lights.  The fact the TG shoots at f2.8 at the wide wide will help a bit but that also increases ambient light and what you are trying to achieve with the video light is adding enough light so that you restore the colours, it may not be enough to give you full daylight exposure but it needs to be a significant fraction of the total light being used - white balancing will help shift that colour balance towards daylight balance - this is why you need to do a custom white balance for video the auto WB will be fooled by the ambient light and you don't have a huge scope to WB video after the fact.

The other thing you need to consider is the other half of the light spec - the beam angle,  the lumen rating is how much light is generated and the beam angle determines how many lumens illuminate the subject per square metre of beam, a relatively small change in beam angle makes a big difference - a 60° beam at 1metre distance illuminates just over 1 m2, a 100° beam at the same distance illuminates 4.4m2.  This means that the lumens/m2 on your subject will be 2940 for a 60° beam at 1m and 675 lumens/m2 for a 100° beam or only 25% of the light. 

The summary of all this is low lumen video lights work if they are very close to your subject, generally well under 1m. 

and also what this means is you don't need many lumens for a focus light if you get a light with about a 60° beam but you need 4x as many lumens to get the same effect with a video light with a 100° beam. 

Weight for video lights is always going to be an issue - you have are carrying a lot of battery and there's not much empty space inside the light to provide buoyancy so they are near as heavy in the water as they are in air. 

Thank you for the detailed answer. The focus light from X-Adventurer that I am looking at has 1000 lumen and a 100° beam. If I get it right a 60° beam with 1000 lumen would be better?

How many lumen (2 lights) do you recommend for a distance of like 4-5ft? I know 7-10 was a bit over optimistic. Or can I even be good with 1 light? Like for example mounted on a flex arm on top of my camera. Would be much easier to install than 2.

Edited April 25, 2021 by blipstream

[ChrisRoss 150]

3 hours ago, blipstream said:

 

Thank you for the detailed answer. The focus light from X-Adventurer that I am looking at has 1000 lumen and a 100° beam. If I get it right a 60° beam with 1000 lumen would be better?

How many lumen (2 lights) do you recommend for a distance of like 4-5ft? I know 7-10 was a bit over optimistic. Or can I even be good with 1 light? Like for example mounted on a flex arm on top of my camera. Would be much easier to install than 2.

Not necessarily - 1000 lumens is more than enough light purely for a focus light, you don't want you focus light too bright - many fish swim off if you shine your focus light on them for example. 

I don't have a good feel for what is needed for video, just know that 7-10 feet was pushing things a bit.  Closer is always better.  You could use a single light but getting good coverage may be an issue.  The bare TG cameras it should be possible because your field of view is small ( approx 32mm full frame equivalent field of view at widest without any sort of wet lens). 

With your twin S-2000 setup you could consider INON's accesory mount:  http://www.inon.jp/products/le_light/acc.html#stlhlf

scroll down to strobe light holder LF.  This places the lights co-axial with the S-2000 and would probably simplify your setup if you wanted to add video lights - they are designed to INON's lights but any light the same diameter would fit.

 

[troporobo 244]

I’ll offer one more data point.  My focus light is 1000 lm with a 100* beam.  I use it at 50% or even 25% for macro focus duties.  At 100% it is good for adding a little color within 1 m but nearly useless beyond that distance.  

[blipstream 2]

Thank you all very much for your input.

Considering all this new information I will buy the mentioned 1000 lumen focus light and will stay away from video lights (at least for now, who knows...).

As said I want to keep my system compact and light. I am a warm water diver during 2-3 holidays a year and meeting the weight restrictions for luggage is tricky enough already with all the diving equipment.

The paralenz does a good job for zero effort needed. And as I am still a beginner when it comes to uw photography/videography it might be too much for me to focus on both at the same time without missing the beauty of a dive.

[blipstream 2]

I found two other focus lights I might consider: (more expensive but the control sounds very good)

http://inon.jp/products/le_light/lf1100h-ewf.html

http://inon.jp/products/le_light/lf1300ewf.html

Only difference seems to be the kelvin 5000 vs 6500. What would be recommended?

[TimG 62]

By coincidence I've been looking at these two lights too.

I came to the conclusion I'd go for the 1100-ewf. You don't need (as you know) huge amounts of power for a focus light - and it's good enough for a general purpose dive light. Using AA batteries is also very convenient.

The Kelvin variation is, to me at least, neither here nor there if you are using it for a focus light or a dive torch. Slightly warmer light, slightly cooler light. So what?! Different if i't good enough.t was a video light - but they are not that.

The only issue is, who sells them other than Divervision? No-one in the US seems to stock them. Or my DuckDuckGo search isn't good enough. I've ordered from Divervision before: they are good but it can be a bit slow from ?Taiwan

[blipstream 2]

But what if I think about using it as a macro video light? Wouldn't 6500k be too warm?

[TimG 62]

It's really not powerful enough for that, it's only 1100 lumen. Fine for focus light but not to light for video photography. 

[blipstream 2]

2 minutes ago, TimG said:

It's really not powerful enough for that, it's only 1100 lumen. 

Oh ok. They also re-released there 3100 lumen video light (5000k) as 2400 lumen (6500k) but I cant see the point. Isn't that high kelvin counterproductive? Bit off topic though.

[TimG 62]

Not sure that Kelvin variation makes a huge difference but we need a view from a video expert. The Kelvin variation is just a measure of the warmth of the light.

Have a look at this for Kelvin variation:

https://halo-headlights.com/articles/led-color-chart.html

The main point though is that 2400 lumen is really not very much for video. I think I said my partner is using a 5000 lumen light on a GoPro and reckons she can light an area approx 3' x 3' from 3' away (depending of course on the ambient light and particulant etc). You MIGHT get away with 2400 lumen for macro video but it will be very limiting.

If you are thinking relatively inexpensive video light, take a look at the Orcalight 910v - 5000 lumen. That will do you video macro and some wide-ish angle (as explained above). You could use it for focus light too as it has 3 power settings and you can turn it down.

[ChrisRoss 150]

The temperature of the light is only important for photo work where you are balancing ambient blue in the background and your artificial light - but you are talking about macro video, so just lighting your subject.  The WB of the camera will take care of your colour balance, you may have to do a custom WB, but it will get the video back to daylight for you. 

I tried out my INON LF-1400 light and at f6.3 and ISO200 achieved a shutter speed of about 1/50 which is probably usable.  Light was at 1400 lumen and has a 60° beam achieved with a diffuser.  The torch was 300mm away from the subject - I would expect you could achieve something reasonable with the TG-4 under these limitations - macro video is a little different to a Go-Pro as you are working in so much closer.  f6.3 is the stopped down aperture of the TG at full zoom, you could also shoot at f4.9, 1 stop faster. 

I do like the INON torches and if you can get them to work they are very nicely made and simple.

[blipstream 2]

14 hours ago, TimG said:

The only issue is, who sells them other than Divervision? No-one in the US seems to stock them. Or my DuckDuckGo search isn't good enough. I've ordered from Divervision before: they are good but it can be a bit slow from ?Taiwan

You can get either the 1100 or the 1300 on ebay. There is an Italian seller, where I did order the 1300 a few minutes ago. But as you are from the USA, there are also sellers from Japan I think.