Convoy S2+ has a challenger ( Nemo )

[ulf]

38 minutes ago, colinbm said:

Also Total Irradiance is not so useful when you are using the bright area for your photography, but the size of the spot with its irradiance in mW/cm2, is a useful guide.

If the spot is really pointy you can have a high intensity at maximum, but then it is not that practical for photography. The Convoy S2 is a bit like that.

Ideally you would have an evenly illuminated spot that is wide enough, (what that means depends on the application). That wide enough spot should also be sufficiently strong.

 

It is quite easy to reach a locally high power density by focussing to a small spot.

That is what is done with cutting lasers where the spot diameter is smaller than a millimeter.

 

With suitable optics I could easily increase the power density of a torch several times by creating a more focussed spot. That focussing will make the beam lose total optical power. Just measuring the way you suggests is not an ideal way to determine fully how useful  a torch is for UVIVF.    

[colinbm]

But is their an 'ideal' way.
Stating watts is totally useless.

[Stefano]

It depends on the application, if you want to illuminate objects far away you need a tight beam, if you want uniform "wide-angle" illumination then you need to have no beam at all (in this case the best thing to do in my opinion is to have a bare LED with no optics at all, if there's no lens in front they have almost 180° of illumination).

 

There's nothing wrong in Colin's measurements, they show you one side of things. It's not the full story, as one might also want to know the total optical power, beam angle, beam quality, etc.

[lukaszgryglicki]

I think all those flashlight shoudl clearly specify hoiw much of input power converts to the output (radiant) power, then they shoudl provide a spectrum (chart) of radiation they emiit and finally the beam angle and intensity drop as angle chnages from 0 degrees to max. That 3 items would make everything perfectly clear.

The single item I hate most in those specs is that most companies just specify input W which gives basically no useful information at all - othe rthan how fast will it drain the batteries.

 

[Stefano]

Unless you buy from professional companies like Thorlabs, Edmund Optics etc, it is unlikely to find that type of detailed information.

[ulf]

18 hours ago, moondigger said:

Does anybody know where I can get one of these Nemo lights in Dec 2023? I mean the one Ulf describes with constant current ICs to help keep output levels steady. I was leaning toward getting a Convoy S2+ or S21- model, as I don't have any 26650 batteries, but do have 18650s and 21700s. But the higher output of the Nemo has me reconsidering.

After some searching I found the exact model as a branded Alonfire SV13.

https://vi.aliexpress.com/item/4001165789043

Before there were several sellers of the Nwemo type.

I am quite confident that this is the same model as the tested Nemo.

 

It is a bit more expensive than a S2+, but the SV13 includes the needed VIS-blocking filter.

All S2+ I can find are lacking that filter, that you have to source separately.

There are some 365nm S2 with filters.

You can normally run a torch for 26650 with a 18650 if you get a cheap plastic adapter tube that gives the 26mm diameter outside the 18650.

I think the kit with the 26650 battery is a god alternative if you want to get a battery too.

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If you do not already have a universal battery charger I can tell you that I am very happy with my Miboxer chargers. 

The most advanced is the C4-12 that I have https://vi.aliexpress.com/w/wholesale-miboxer-charger-c4%25252d12.html

 

There have been several other models of the C4 and I also have a C4+.

Cannot find that model anymore, only the C4.

https://vi.aliexpress.com/item/32843228093.html

It is more compact as the AC PSU is built in, while the powerful C4-12 needs an external power supply brick.

 

I have had several models of MiBoxer chargers and always been happy with their performance.

The older ones have been given away or on loan to friends, when I upgraded to later models.

Yes, I have more chargers than I need! ;-)

 

[ulf]

For stationary use there have popped up an interesting alternative:

https://vi.aliexpress.com/item/1005005236028768.html

With a suitable power bank it can also be very portable.

 

[lukaszgryglicki]

9 hours ago, Stefano said:

Unless you buy from professional companies like Thorlabs, Edmund Optics etc, it is unlikely to find that type of detailed information.

I actually buy from them usually, just not too often for known reasons...