Slope on mosaic to new raster

[karreno]

I have several .tifs which I have mosaicked into a new raster. I then did a slope analysis on this new raster. The slope analysis on this new raster it is not giving each individual cell a slope value instead it is creating what appears to be contour lines.

If I do a slope analysis on each individual .tif I get what I would expect - 

I have used the same method on another project and it worked fine i.e. mosaicked a number of .tifs to a new raster did the slope analysis and got a slope value for each individual cell in the raster as per eg below -

I don’t believe I have done anything differently with this project. Any suggestions as to why it may not be working this time please?

[curtvprice · Accepted solution]

It appears your mosaic process is truncating the DEM values to integer, leaving out detail in your 1m DEM and causing your slope artifacts.  Perhaps you can solve this problem by making sure your mosaic process doesn't truncate the data to integer.

[karreno]

Thank you! It was a simple error on my part which I figured it was going to be but I just couldn't see it.