Somewhat complicated because brightness of the LT1 is affected by the CCT - temperature it’s set at (brighter with cool/blue and dimmer with warm/yellow). For these pictures I set the LT1 at the coolest/bluest/lowest-CCT level. All pictures are in manual mode, with WB set at 5000k. For subjective evaluation I raise both lanterns above head and look at the room.
The quintessential question for flashaholics, which lantern is brighter?
1. If you set SP36 at Turbo level it is much brighter than LT1, but of course this is not going to last long because of rapid step-downs. SP36 that is initially set at Turbo will have step-downs, over the next 10-15 minutes, that eventually reduces brightness about 3 step/level down from peak.
2. If you set SP36 roughly one to two steps down from the max/Turbo level, the illumination is about same as LT1 at max. Per a review in1lumen, this is somewhere between 1000-2000 lumens for the SP36 5000k (mine is 4000k version). Even at lower setting like 2 levels down from Turbo, the SP36 undergoes step-downs. Extrapolating from the 1lumen SP36 review article plus my sequential pictures, I would guess the step-downs reduce brightness to about 500-600 lumens eventually (equal to 3 levels down from Turbo), where the brightness reaches steady state and stabilizes.
3. The SP36 may be bright and impressive for the first few minutes (and people may mistakenly think it is therefore “better”), but in the long run, because of the SP36’s step-downs, the LT1 is superior. LT1 has ZERO step-down from its max level and after 10-15 minutes, becomes the clear winner. It stays at same brightness level during my test run. Because of this, used as a lantern at camp site around the dinner table for example, it is far superior. Having said that I do wish for more brightness, maybe a Turbo mode be added to future version of the LT1, however brief that maybe.
4. OTOH for brief use that is not long enough to invoke step-down, the SP36 is brighter, especially at Turbo level where it is much brighter.
Above discussion reminds me of the tortoise vs hare race. LT1 is the tortoise that starts out slow but wins the long race. (Although to be absolutely correct, LT1 is not THAT slow, it’s just not as fast as Turbo SP36.) SP6 is the impressively bright rabbit that was slowed by step-downs. Both tortoise and hare could be useful depending on the task at hands.
Speaking of Tortoise vs Hare, what about run time? Per 1lumen article of LT1, run time is 6.5 hours at level 5/5, and 12 hours at level 4/5. 1lumen article of SP36 shows run time of 24 hours, but this 24 hours occur at a fairly dark step-down level that the SP36 invariably and consistently steps down to, which per my sequential pictures is roughly 3 level down from Turbo. At a higher setting, the run-time would not be 24 hours obviously.