I have recently Purchased a newEF S 10 - 22 and with it i decided to splurge and get new 100mm filters and i am extremely happy with them.
Formatt Hitech Firecrest ND 13 (3.9)
Formatt Hitech Gradual soft edge ND 2 (0.6)
3 minutes @ f. 20
As you can see there is no colour cast which is where most other filters fail! minimal vignetting (shot at 12mm) and some sun glare, which does not concern me as i was testing the filters by shooting almost directly into the sun.
The problem i would like some help with, or even an answer as to why it is occurring, is regarding the bottom left corner where you can see what appears to be the rings (and White text?) reflecting off the filter and into the . Is this because i was shooting towards the sun and duration of the shot and unavoidable or is there something i can do about this?
I took another shot 30 seconds @ f. 11 which had similar issue but it was much less noticeable so i realize this is something that gets worse the longer the .
One thought i had was getting foam tape to cover everything except with glass however cutting this/finding something the right size may prove difficult.