Thanks for appreciating the pics; I just started SLR-ing this past November with a 60D+18-135Kit then a month ago stepped up to a 7D+70-200F4. The first two you saw are with the 7D. I kinda like the creamy background at F4. My first creamy L 
You are correct about the sunflower, but sunflower also attracts Grackles and Cowbirds who are no good. The girl at Wild Birds Limited said safflower works for Cardinals and all kinds of smaller songbirds. The only issue is Cardinals don't like tube feeders so they feed from the safflower dropped by the smaller guys. Well, in theory that sounded good but reality is different. I have seen cardinals on the deck twice but no long term clients. That's why I got the hanging tray feeder and keep it full of peanuts for the Jays and safflower for the Cardinals.
Here's one of a finch and a little blue mystery guest I caught yesterday. I caught a glimpse of him as I glanced out of my masterbedroom window on the 2nd floor and he was feeding on the sunflower/safflower mix in the feeders in the back yard. It was early evening and I got a little fuzzy capture with the kit 55-250 at 250 F5.4 ISO 6400
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