This shot is two images combined. The two birds landed on the same branch within the same minute. The shots were taken on a tripod so the distance was the same and so was the light and background....their respective positions on the branch are as photographed... The two shots were simply lined up inside a double width frame in photoshop on top of one another as two seperate layers and one layer was erased to reveal the house finch below...thought it worked well to show an exact comparison of the two species...mind you not all male Purple Finches look exactly the same ...ditto for male House Finches....