I don't know how to determine sex when it's on a 20 hour light cycle. Everything I have read and videos I have watched are telling me to start the 12 hour light/dark cycle to determine sex.At 4 months old it should have already shown sex.
The picture at the beginning of this thread is taken through a loupe magnifying glass w/ assistance from the optical zoom on a digital camera. What we are looking at is barely visible w/ the naked eye, it's about the size of the tip of a sharpened pencil, not very large at all. I actually tape my loupe to the lens of my camera after it's zoomed in all the way (otherwise the camera lens moves). I use this more to look at the trichomes on my more mature buds and it works fairly well. The only downfall is that you have to focus by slightly moving the camera closer or farther away.Give it a few more days and it'll show.
Yes 12/12 helps determine things faster but a plant of that age should show sex regardless of light schedules.I hate to agree with others but i would think that by the size of that pod we would see a hair comin out if it was female.Do you have any kind of loop or microscope to get a better look?