Robin Feeding Young

Recently we noticed robins flying out of what is an ornamental spiral evergreen that we decided to let grow in. The tree is located just off our driveway near the corner of our brick house. The backside the tree is mostly open due to the proximity to the brick and we presume also by the heat generated by the all day sun that area receives. Checking it out we found a nest with 4 blue robin eggs. Observing the birds from about 20' away they always came and left from the rear open side. I positioned a Nikon D750 with 18-35 lens on a bogen tripod with the tripod center post horizontal just inside the front of the tree utilizing one of the 'growing in' openings from the spiral nature of the tree. I took no pictures but waited to see if the birds would become accustomed to the camera so as not to endanger the babies. Within an hour they were landing on the camera as a way into the nest area. I then, and wish I had done better as a background, attached a camouflage jacket to cardboard and put it approximately 3' from the nest against the bricks. Again I waited to see if would effect the birds at all. They soon ignored it. Using a wireless remote and sitting in my car I hit the shutter whenever the birds would enter the nest especially hoping for feeding shots. I could not see the nest at all from my location but from the tweeting of the babies could tell when it was feeding time. This was the only shot of the worm actually being put into one of the young robins mouths by it mother.