You are getting different exposures cos your metering is not consistent. You might be metering at different parts of the sky when you are shooting. 1# has the best exposure among the 3 but also realised that 1# and 3# should be taken at roughly the same time since the cloud formation is almost similar ya? So it has to be your metering problem.
Anyway, as mentioned, try again and experiment which method is the best! :thumbsup:
metering not consistent meaning he using diff modes or he is metering on different areas... how do i noe which is perfect area to meter for optimum exposure? and generally under wat circumstances do we use exposure lock (AE-L)? thx
I remember the good old film days when I took down the settings for each frame and learnt which shots are good or bad. Nowadays, for digital it's alot easier to review the settings and learn from there. For sunsets I like to bracket the exposures, alternatively many tips on the Internet like this one http://best-family-photography-tips.com/sunset-pictures.html