I have just started building my portfolio to get into birth photography, where obviously, there can be little to no light at times. I purchased the D810 before the announcement of the 750 was made. I really love the 810, but I'm wondering if the 750 would best fit my needs due to its high ISO capabilities and being able to focus at -3ev. I keep reading how it can practically focus in the dark and it handles high ISO beautifully. There were times at my last birth, where my D810 could not focus due to the low light and I am awful at manual focusing. Also, due to the high MP on the 810, I'm thinking the photos taken at high ISOs would be more noisy than if taken with the D750. Is that the case? I would love to hear your thoughts on the 2 cameras based on my needs. I have a short window now where I can exchange out the 810 for the 750, if I should so choose. Thank you so much in advance.