When normalizing the HDRI and candle, what is your goal when adjusting the exposure?
So, if I'm understanding correctly, the issue is that the HDRI range isn't realistic, resulting in non-realistic phenomena like that super bright candle. So you then did the following process:
1.) Add a sun lamp for reference and set power as appropriate for your scene (here it was 750 for regular sun on a cloudless day)
2.) Set HDRI strength to 0
3.) Change exposure... <--- QUESTION: What are you looking for or tweaking here? Are you trying to get the candle to match what it would look like under an actual sun? Maybe it was just hard to see on my screen, but I saw you adjust the exposure but couldn't see the candle even a little.
4.)Delete Sun Lamp
5.) Increase HDRI strength until the candle's illumination matches what it did with the "reference sun."
Am I understanding this right?