Version:            (using Devel)
Installed from:    Compiled sources
Compiler:          gcc4.3 
OS:                Linux

When going through zoom with zoom buttons there are unnecessary steps:

Let's say we are going from 100% down, there are steps: 
 
100% -> 91% -> 78% -> 66% -> 52% -> 50% -> 42% -> Fit screen 
 
Change between 52% and 50% (one of special cases) is really small. Don't 
know if it is possible but I would suggest some "thinking" before 
deciding about next step: 
 
66% -> next step is 52%, it is less than 5% from 50%, snap to 50%. 

This should apply to all special steps: Fit to screen, 50%, 100%.

Also not only related to Image Editor but also zoomin in Album GUI.

And last but not least: I think that would be good to consider smaller number of steps. 10-15% steps are too small when you want to quickly change size of image. IMO 20-25% would be better. With that correction snapping should be not 5% but 10% of size.

Related to Bug 161085