EagleTac D25A Ti - What are the actual levels?

Hi,

Does anyone know what are the real modes & output levels are on the EagleTac D25A Ti Clicky? The manual says that in moonlight mode, the sequence is Moon > Low > Med; and in normal mode the sequence is Low > Med > High. However, I am able to visually discern a difference between modes that should be, in theory, exactly the same (e.g., step 1 in normal should be the same as step 2 in moonlight mode, but on mine it clearly is not). So it appears that there are really perhaps 6 or 7 completely independent levels.

The specs are not only wrong in that they omit the difference between modes as noted, but also because they only list 4 output levels (0.5, 9, 85, 141 ANSI lumens) when there should be at least 5 (moonlight, low, medium, high, turbo).

I've also noticed that Turbo is only very slightly brighter than High, although it's possible that it's quite a big jump in lumens, just not really very noticeable visually. Currently I'm just using the Duracell that came with it. Should I expect very different results with different chemistries?

Speaking of battery chemistries, is the EagleTac OK with all chemistries (Alkaline, Lithium Primary, NiMH, Eneloop, Li-Ion). I recently noticed that Titanium has a much lower thermal conductivity than Aluminium, which makes certain torches prone to overheating. I think it's OK on the basis that the spec says 14500 Li-Ion cells are OK, and those are probably capable of delivering higher current and voltage than any of the other chemistries, I believe, but I'm not 100% certain about that.

I don't care so much to know what the exact luminosity is, but it would be handy to have a better guide to the expected battery runtime at each level. The specs also don't mention which battery chemistry was used to obtain the results shown, but I believe if they supply a Duracell with the torch, then according to ANSI specs, that's what they should use for their testing. In any case, it would be useful to get either a rule of thumb or an accurate formula that can be used to convert between expected run-times for one chemistry under a given load to another. I don't know if such a formula exists or is even calculable, but an approximation would be more than adequate.

you are right, the light has many brightness levels. too many to list neatly in a manual. i worked hard to list them accurately:

http://www.candlepowerforums.com/vb...ac-Clicky-Ti&p=4351299&viewfull=1#post4351299 (table)


my lumens numbers are scaled after Fenix lights. it was UPz who had introduced this term with his integrating sphere and he calls it "Fenix lumens". See how the D25A compares to similar small lights:

http://www.candlepowerforums.com/vb...ac-Clicky-Ti&p=4359027&viewfull=1#post4359027 (graphs)



The table and graphs are self-explanatory. Please compare with your personal sample, e.g. by measuring the tailcap current with a multimeter, measuring the runtimes (dunk the light in a glass of water), or similar actions. And most importantly, believe my posts

They are based on my own measurements combined with UPz accurate Fenix lumen measurements cheers

The listed ET numbers are for the moonlight-on program - if you click on the specification link of that page there's a footnote showing the moonlight-off differences for L and M - 0.5/9 lms goes to 4/20 lms, the 85 and 141 are same as before.

I have a lightbox, calibrate to Fourseven lumens, do runtime tests, and find ET D25A (I have an XML1 and N219) specs to be excellent (both lumens and runtime), if perhaps a little too conservative . As an example on Eneloops, my D25A XML 75lm/2.5hr mode spec tested spot on for me and matches up exactly (lumens and runtime) with my SC52 108lm/3hr mode. ZL claims ~70% greater efficiency (lumen-hours) in it's spec though - the same result can be seen from the second link in Kreisl's post (although Fenix lumens are also less stringent than ET/47s).

The D25As moonlight doesn't have great regulation though - it will start out at ~0.5 lms on fresh cells, but drops to half that below 1.3v or avg NiMh's. You can estimate runtime for the other L/M levels using ~200 lumen-hours as a benchmark.

Can you visually see the regulation of the moonlight mode? In other words, if you're reading a book, do you notice any ramping down of the light, or is it extremely gradual and still useful light?