Oh, jeeez, that's a really complicated subject, Dines! You've done a decent job, though.
Well, look at the deep shadows that fall into the eyes in the reference. That's actually a fantastic thing to see and realize about eyes. I know how reluctant I used to be with such stark contrasts and still am, but such a reference helps to recognize just how bold you could become, if you allow yourself to.
Hmmm, I hope you don't mind, but here's a little step by step on how I'd go about this one...
Look for the brightest color on the borders of the iris, because it's easiest to have those colors there already and then just blend brighter and darker colors into those...
- owl_step01.jpg (15 KiB) Viewed 3387 times
Do the harsh shadows as deep as they need to be... fairly easy.
- owl_step02.jpg (14.03 KiB) Viewed 3387 times
Do the bright parts where the light goes...
- owl_step03.jpg (15.26 KiB) Viewed 3387 times
Do the pupils and bevels around them. This also shows where you need to brighter or darker. Bit of smudging...
- owl_step04.jpg (16.94 KiB) Viewed 3387 times
Add the highlights, not just on the eye itself, but also around it while you're at it...
- owl_step05.jpg (19.04 KiB) Viewed 3387 times
Now just paint the feathers and try to understand their streaming directions. Try to get a feel for what they look like. Where are highlights, where are soft areas and so on...
- owl_step06.jpg (86.66 KiB) Viewed 3387 times
This is all in Vervette, of course... super fun to do those!