I used to be able to disable it in iPhoto but now iPhoto is not part of the OS, I don't want to download iPhoto to just use it to disable itself and Image Capture. Any way to kill the auto pop out feature?
Okay, got it finally.
First you need to eject your SD card. And then you should plug it back in. Once you do that, the IC will pop up. There is a small icon looks like ejection on the lower left corner (poor design, Apple), click the icon and it will pop out a menu, where you can choose "no application" for your SD card.
Unfortunately you have to do it with every single SD card of yours. Another poor design choice from Apple.
As an addendum it seems to tag which cards to not auto launch for in files stored on the card itself, so formatting the card in the camera resets this, in effect meaning if you use a workflow where you format the card in the camera every time (which is a standard workflow) you will have to dismiss auto capture every time for the same cards.
James, there is no eject button. You may be referring to an older version. The Image Capture with Yosemite seems to have no method to be disabled.
James Wayne's answer works, but only covers the single device or memory card that you edited in Image Capture.
To affect all devices/cards, open Terminal.app (use Spotlight to find it) and type the following, pressing enter at the end:
defaults -currentHost write com.apple.ImageCapture2 HotPlugActionPath ''
This works for me on 10.10.5.