Alpha Problem: not working unflat surface

[tilililirik]

Hi,
I try to use alpha for eyes. But if I make pit/hole for pupil, alpha effect only bottom of pupil area. Edge of pupil is flat(without alpa effect) (Picture 1&2)
Only I use alpha flat surfaca (Picture-3)
Can you help me to solve this problem and make eyes alpha like tutorial?*
*tutorial: https://www.youtube.com/watch?v=nQWaLptavD0&t=104s

Attachments

[beta_channel]

switch to the standard brush and try.

[tilililirik]

oh, thank you, I didn’t think that brush could be reason of alpha problem but it works