I hope your Olight SR90 lasts longer than mine did. Turn it on and it goes dim in about 10 seconds, with a big hole in the center of the beam. Both batteries checked our OK on another light. This light was one of the early ones. Called Battery Junction and they gave me an RMA. BJ said that after they check it out, it will have to go back to China. Could take 3 to 4 months or longer. Lucky I have a TK 70 to hold me over.
Short answer is that you can't - the lights look the same (externally)How can I you tell whether the model I have is "old" or a "new" version of the SR90?
MY SR90 keeps takin a lickin and keeps on tickin too.
We just finished a search and rescue last night, and it was about the only light that still had a charge on it when we got back after ~ 2 hours of searching. I bought it used, dedeomed it, and use it regularly....and it still charges to 4 lights pretty quickly...and lasts a long time on a charge.
The VPT2 Turbo on the same search petered out after maybe an hr. The Fenix TK70 cells were down to a trickle, but it still lit at least. The HIDs die off in minutes not hours typically, and so forth. The SR90 has been a very useful search and rescue light.
The TN31 looks really nice, and I was considering giving one a try. I HAVE dropped the SR90 though, and it can take it. All the large heavy lights, like the TK70, SSR90, etc, which also survived some abuse of its own, of course are more easily damaged in a fall due to the simple physics of a heavier and longer form factor flashlight...so I'm OK with that given the performance gains. I have not dropped the VPT Turbo yet...I do worry about the rotary switch in that context though. I have dropped/whacked its little brother, the Lambda Light 3C many times w/o damage though. (I am not holding all of the lights...I might have one and a spare, and distribute one and a spare to several others in the party, so a dozen of my lights might be out in the search/field, etc...but I might only be personally holding 1-2 of them. Damage reports are therefore sometimes second hand)
For searches, depending upon the context, you tend to either be on high the entire time, like searching river banks during a flood, etc, or, throttling up/down to conserve power like a foot search of woods and fields. The last night was a wood and field type search, so all the lights were going up/down depending upon the range needed (Looking for an 87 yr old guy who wandered off from a senior housing facility, long enough to be called in as a missing person...and the call came in from the dispatcher a bit after midnight...).
A chopper with search light had just exhausted itself sweeping the area w/o finding the guy...and the less exposed/harder to resolve potentially supine, etc, figures down in areas, such as the wooded/canopied areas, had to be searched by foot. There were trails, but with drop offs and gulleys, etc, an old guy could trip and roll down into for example.
The VPT Turbo2 is great for this type of search with the rotary power option, as it can be dialed up/down as needed, seriously useful for this varied range search procedure...but it does get seriously hot and have limited run time in this context. The SR90 runs longer/cooler in practice, but only has high/low...but the low is very economical. The SR90's beam pattern, overall, is better for longer range, given how focused the beam is. The TK70 is also super useful in this context, also due to the floody nature of the beam combined with its long run time/variable outputs, etc....but its less useful when the range gets too far to see well with it. The range it has though is perfect for this type of search though.
The SR90 is dedomed to increase the range for longer range searches that the TK70 is short on. I only just added the VPT to the rotation recently, so the past few weeks are its only field use, but performance wise, its promising.
@TEEJ, Thanks, its great to have that kind of insight for the purposes that an S&R light are intended.
My SR90 sadly sits on a shelf gaining dust as I purchased it out of curiosity at the time and have never found a need for it other than to show off.
I'm very curious to know, however, if you have ever used HID lights for S&R and how you compare them for usefulness to the SR90 in this regard.
The HID's are great for some types of searches, albeit the run times are pretty limited for most of the handhelds.
I use HH HIDs as well, but really just for long range/small spot scenarios where I need a short burst of long range light. For a sweep of a wooded area, the beams typically don't have a good pattern when you need to look close and far in the same location.
Where the HIDs work best in searches are when they are used from a rig with a power supply. This solves the run time issue, and when searching from a rig of some type, typically, you are looking at greater distances anyway.
There are of course some amazing HID torches that might have some incredible range, over a mile in cases, etc...I just don't happen to have any. A natural issue when searching is that you need to be able to resolve your target. At over ~ 500 yards or so, your EYES become a limiting factor as well. Think of it this way...if there's a guy laying in the grass a quarter to half mile mile away, in broad daylight...with your eyes, would you notice him, and, if you could, could you tell if he was hurt, or armed?
How about in moonlight? Most of the listed ranges assume that you have 0.25 lux on your target as the definition of "in range"...that's about like moonlight.
The other eye related issue is that if your eyes are night adjusted, you are MOSTLY using black and white vision....you see almost no color. Add to that that you can't see straight ahead as well...the central ~ 2º of your cone of vision can hardly see in the dark at all compared to the other 98% to the periphery. So, normally, in bright day light, looking at a guy a half mile away provides a target that you can focus on with your sharpest 2º vision (Fovea), and with color information. With night adjusted vision, a half mile away in essentially moonlight scenarios...you are limited to peripheral vision and very little color info to resolve that target.
IE: When searching in the dark...you look to the SIDE of a suspected target to see it better, where your eye essentially gathers light better. (Rods working better than cones in the dark....).
In search and rescue for example, one issue that really catches newbs is the POSITION a person might be in when you shine on them. Most people expect to see a man standing, sitting or laying down....and our eyes are looking for patterns that are associated with that. In reality, the body might be wrapped around a tree limb, half under a rock, and/or twisted into a more pretzel-like shape. When you sweep a light across them, the brain doesn't register what its looking at...the arms, legs, head are not where they "Should be" to register as "a man". The smaller the spot of light, the harder it is to get the CONTEXT of what you are looking at....and the harder it is to realize "HEY, that's a man!"
Of course, for HH lights...the lumens can only travel out there so far w/o dissipating...so, you are compromising between range and context. If you have amazing range (Aspherical lensed lights for example), you typically have a teeny spot of light. If you take the same lumens and spread them out to give more context...you don't have much range left. So, the compromise tends towards proportionally larger heavier HH lights with large reflectors...to get as much context downrange as feasible.
This is a long suit for the SR90. Its hot spot is pretty large considering the range, and the form factor can be carried for hrs on a long search. The TK70 and the VPT I mentioned have similar characteristics, but with a context bias over range, while still having great range. This is WHY I dedomed the SR90, to concentrate its smaller amount of total lumens to work with, stealing from its generous spill into a tighter, longer range pattern...into its hot spot....putting more lux on target at range.
Add it all up, and a night search is not easy....having to look near you can glare on nearby objects, reducing your night vision, so that when your light sweeps out to further distances, you see less, and the reduced amount you CAN see is further compromised by not being able to focus as well on distant dim targets.
This is one reason we tend to divide searchers into near/far roles...so one group is primarily beating the bushes so to speak, and the other group is sweeping distant targets....and together they overlap a search area.
You have a wealth of information up in your head.
Have you ever thought about writing safety manuals or S&R training manuals etc?
I was a Professional Photographer with my own Photolab for many years whilst being a Licensed Electrician and IT specialist, so I know where you are coming from with your technical explanations of optics and so forth.
Are you a volunteer S&R or Full Time S&R guy?
What other background trades, work or hobbies have you dabbled in?
And also you must be near my age to gain such a vast amount of knowledge as I am pushing 59 now.