NOTE: A third version of these readings (this being the second) has more recently been completed (20/7/2013) with more lights added and a with the light and lux meter repositioned to effectively eliminate the throw bias, which was still present to some extent in this version. You can see these results here: http://budgetlightforum.com/node/23282.
This is a comparative table of lumen readings taken using ceiling bounce in a white room with a photometer in a set position. These readings are estimates, and there may be a slight bias in favour of more focused/throwy lights, but not enough to make a significant difference unless the one being measured is almost full flood.
The columns, left to right are: Torch ; Mode ; Lumen reading ; Corrected lumen reading (108%)
The ‘Corrected’ column is because having completed the list I thought it was under-estimating actual readings. Any suggestions on a more accurate % for the correction are welcome, but remember that any % added to/taken from one will have to be added to/taken from all of them.
More lights may be added in time, but I have done most of the ones I have.
Also, I apologise for the poor quality image format of the table. I had tried organising the information into a normal post but whenever I preview or post something all formatting disappears and everything gets pushed up together again in a big mess. So the only way I could think of doing it was to save the spreadsheet as a .png, upload and then link to it. If anyone has any better ideas (which I’m sure someone has) then please let me know Now sorted, thanks SashiX
A few interesting links: