Extract by Attributes error with extract.save

Discussion created by aaridd18 on Apr 11, 2012
Latest reply on Nov 26, 2013 by tlaxson
On the following code block (specifically, the last line), IDLE throws this error:

ERROR 010093: Output raster format UNKNOWN is unsupported.

for raster in arcpy.ListRasters(): 
    outpoint = workspace + raster + "af"
    extract = arcpy.sa.ExtractByAttributes (raster, " VALUE = 6 OR VALUE = 8")
    extract.save (outpoint)

I feel like it shouldn't be necessary to specify a format since the output is saving into a geodatabase. Also, is there better documentation on extract.save somewhere? I've found very little on it and am just imitating the syntax example used on the Extract by Attributes tool page.