New Post: Overlaying two images with opacity

Thank you! It works great now.
I'm currently overlaying the images by simply merging them, but mainly out of curiosity, if I wanted to use a CompositeOperator, what's the correct syntax for the input args? I'm writing it like this:

public bool combineImagesInCollection(double transparency)
        {
            _images[0].Composite(_images[1], Gravity.Center, CompositeOperator.Blend, transparency.ToString());
            _outImage = _images[0];
            return true;
        }

Thanks again!