I need help with this too. Actually, I wrote this exact issue down on my whiteboard over a year ago (it's still there!), did some research & tried a few things but was not successful. I believe the answer lies in the com.apple.ImageCapture plist in the ByHost folder; autolaunchApplicationPath key. Setting it to an empty string should do the trick, but I never was able to get this to work... I'd love some guidance. Or just a straight-up solution.

Hi
The file you need to edit is located

~/Library/Preferences/ByHost/com.apple.ImageCapture2.18A005D8-DCA6-5F28-9E05-39A4B8348DD0.plist (numbers at the end of the name will be different)

The section that changes when the iPhoto preference is changed is

<key>HotPlugActionPath</key>
    <string>/Applications/iPhoto.app</string>

You should be able to remove the <string> section and after a restart, the default app changes to "No Application"

Tested with iPhoto v9.5.1

** Edit: The problem you may face is the numbers on the end of the file name may be different.

I know if you open iPhoto and go to Preferences you can just change the setting from there.

thanks for the responses. Pointed me in the right direction. I now have this working. I have basically created a package which drops the plist without the UUID appended into /var/tmp. I then have a post install script which appends the UUID to the plist and copies to the default user template.

This is the script if it helps anyone

#!/bin/bash

#Author James Durler
#Written 3/10/2014

#This script is deployed with the iPhoto No Launch When Connecting Camera.pkg. The package drops a plist
#which specifies to not launch iPhoto when the user plugs a camera in. The script then gets the machine UUID
#and then appends this to the end of the preference file as this plist exists in the byhost and appends UUID
#to the end of the plist. Once the name has been changed it then copies the new properly formatted file to
#the default user template.

#Revision 1.0 : Improved the system_profiler command time to return machine ID by running the command at detail #level basic

#path where the imagecapture2 plist is deployed by the package

filepath="/var/tmp/com.apple.imageCapture2.plist"

#grab the machine UUID

machineid=$(system_profiler -detailLevel basic | grep "Hardware UUID" | awk '{print $3}')

#append the UUID to the string .GlobalPreferences.

imagecapture="com.apple.ImageCapture2.$machineid.plist"

#copy to the default user template

if [ -d /System/Library/User Template/English.lproj/Library/Preferences/ByHost/ ]; then

#move the file from /var/tmp to the default user template
mv $filepath /System/Library/User Template/English.lproj/Library/Preferences/ByHost/$imagecapture

else

#Create the directory if it doesn't exist. I have seen some circumstances where the ByHost folder is not in the default user template

mkdir /System/Library/User Template/English.lproj/Library/Preferences/ByHost

#move the file from /var/tmp to the default user template
mv $filepath /System/Library/User Template/English.lproj/Library/Preferences/ByHost/$imagecapture

fi

#exit gracefully

exit 0

Anyone has any questions feel free to ask!

@jamesdurler Hi James, do I have to delete the value in the initial key line from the plist too?

For example:

Hi James @jamesdurler you can improve the speed of the script quite a bit more if you drop system_profiler altogether in favor of ioreg. Here's the code to get the Mac's UUID:

ioreg -rd1 -c IOPlatformExpertDevice | awk -F'"' '/IOPlatformUUID/{print $4}'

@mm2270 How come ioreg is faster?

@bpavlov Try them both and see.
I ran the system_profiler code in the script above as is to get the UUID on my Mac and it took several seconds to complete. I did not time it, but it was at least 4-5 seconds. Running the ioreg command it returns the UUID in about 1/2 second if not less.
system_profiler is always slow. I don't really know why though, you'd have to ask Apple about that :) I have noticed the first time it gets called when it hasn't been used in a while it takes a particularly long time. If you run the same command again right after it returns a result a little quicker, but that's probably just because the system_profiler code is being cached or something. Its always been a bit sluggish though, even when run repeatedly.

Edit: I should just note for the record that system_profiler can be run faster if you direct it to only print the section that you're interested in pulling info from, like this-

system_profiler SPHardwareDataType | grep "Hardware UUID" | awk '{print $3}'

Its still not quite as fast as ioreg, but much better.

@mm2270 Thanks for that speed boost tip. I replaced the System Profiler line of the script with yours.

Do you know if I should delete that key value, though?

@itupshot No problem. I don't know specifically because I haven't really tested out the script or this process. So I can't actually answer that.

Revisiting this since I had some down time - big shout-out to @jamesdurler for the script and to @mm2270 for the ioreg tip. One important thing I encountered was that appending the complete UUID to the ImageCapture2 plist filename didn't work for my 10.9.x machines. I had to grab the last section of the UUID and just use that. Anyway, it appears to be working and for that I thank you. Seriously, this item has been on my to-do list for over a year.

glad you got it working :D

The challenge I'm finding here is that it seems the option to open a different app - like Image Capture - instead of Photos is device-specific, as the preference is tied to the device's specific ID.

Is there a way to get around this, or am I missing something?

I'm currently running the defaults -currentHost write com.apple.ImageCapture disableHotPlug -bool true command on a per user basis.

Ideally I'd like Image Capture to launch regardless of the camera device connected.