You should also take into account that the human eye is not that sensitive to changes in light level, it is well able to compensate. It is not so able to perform well, where there are bright patches of light, mixed with dimmer areas.
This is very true, living room old house had 2 x 100 watt pearl tungsten bulbs, swapped to 2 chandeliers each with 3 bulbs normally 60 watt as the 2 x 100 watt not really bright enough, as the CFL came in, dropped seem to remember 11 watt, looked rotten so we changed to chandeliers for 2 x 5 bulb chandeliers with 10 x 8 watt golf ball Philips CFL bulbs.
This was a mistake, the bulbs were very short lived, and darn expensive, had two matching chandeliers in dinning room but 3 bulb version, and bulbs robbed from dinning room, and a larger but still golf ball design from Home Bargains were used, but limited supply.
So I had bought two 1.8 watt candle LED bulbs from Lidi, not intended for living room lights, but as temporary measure put them in, rather impressed, so next lot Lidi got were 3 watt, so another 8 x 3 watt and pleased with the result, until I tried to read, then realised not really bright enough, lucky mother with a lot smaller room also used E14 bulbs, so Lidi bulbs went to her house and we got some 5 watt LED bulbs from Home Bargains, these were bright enough.
So looking at the lumen
2 x 100 watt tungsten = 2000 lumen
6 x 60 watt tungsten = 3000 lumen
6 x 11 watt CFL = 3000 lumen
10 x 8 watt CFL = 3000 lumen however they seemed dimmer.
8 x 3 watt + 2 x 1.8 watt LED = 2400 lumen
10 x 5 watt LED = 4600 lumen however it seemed no brighter that the 6 x 60 watt tungsten
What we need to remember in the days of a tungsten pearl light bulb we did not have lumen on the packet, so the values are from a web site which is likely comparing a clear bulb, which does not spread the light in same way as pearl, no way did the 11 watt CFL give out as much light as the 60 watt bulbs they replaced, but the web sites try to claim they did, but my eyes are also clearly older, so likely now I need more light.
Using a lux meter I found did not relate to perceived light, we tried flashing LED lights and over driving them, so double current for half time flashing was fast enough we could not see they were flashing, and to our eyes they seemed brighter, but the lux meter showed no change. Did the experiment with cheap red LED's so did not try reading with the light, but a light switched on/off 100 times a second looks brighter than one powered with smoothed DC to human eye, until you try reading in the light.
I have had some very odd results using a camera, my DSLR may say 1/2000 second, but really it is 1/250 second, the focal plain starts to close before it has fully opened so it scans the scene. So taking a picture of a wagon the cab can be crystal clear but trailer blurred as I was following the cab as I pivoted, not trailer and likely slowed before the shutter fully closed.
The same with LED, it can be very good, but also you can get a banding if the LED is being flashed. However the camera light meter is a really good way to compare lighting. But try reading under the light rather than seeing how bright it seems.
