I think this is an ArcMap (I'm running 10.2.0.3348) problem rather than an Image Server problem.
We have two Image Server services, NAIP_2009 and NAIP_2011, on 10.0 ArcGIS Server at https://gisservice.mt.gov/ArcGIS/res...MSDI_Framework
If you add these services to a data frame that is using a NAD27 coordinate system and zoom in closer than the raster resolution (about 1:3780), data from both services is transformed correctly to NAD27, regardless of whether the correct transformation is set. The data should not display properly if you set the transformations to none, but they do.
If you zoom out to a scale smaller than the raster resolution, the NAIP_2009 continues to be transformed to the correct location, regardless of the transformation settings. the NAIP_2011 IS NOT transformed and the data appears in the wrong location, whether the transformations are set or not. All other data, (local raster and vector and ArcGIS Server 10.0 map services), that I have put in the data frame behave correctly, transforming or not transforming depending on whether the transformations are set or not.
I wonder if ArcMap is ignoring the transformation settings when it has to project and resample Image Server data. The NAIP_2009 service is in NAD83 and the one-step transformation for this happens whether it is requested or not. The NAIP_2011 service is in NAD83 HARN and the two-step transformation for this does NOT happen, whether it is requested or not. The behavior of the NAIP/Montana_2013_1m_NC service at gis.apfo.usda.gov is also consistent with this.
We have two Image Server services, NAIP_2009 and NAIP_2011, on 10.0 ArcGIS Server at https://gisservice.mt.gov/ArcGIS/res...MSDI_Framework
If you add these services to a data frame that is using a NAD27 coordinate system and zoom in closer than the raster resolution (about 1:3780), data from both services is transformed correctly to NAD27, regardless of whether the correct transformation is set. The data should not display properly if you set the transformations to none, but they do.
If you zoom out to a scale smaller than the raster resolution, the NAIP_2009 continues to be transformed to the correct location, regardless of the transformation settings. the NAIP_2011 IS NOT transformed and the data appears in the wrong location, whether the transformations are set or not. All other data, (local raster and vector and ArcGIS Server 10.0 map services), that I have put in the data frame behave correctly, transforming or not transforming depending on whether the transformations are set or not.
I wonder if ArcMap is ignoring the transformation settings when it has to project and resample Image Server data. The NAIP_2009 service is in NAD83 and the one-step transformation for this happens whether it is requested or not. The NAIP_2011 service is in NAD83 HARN and the two-step transformation for this does NOT happen, whether it is requested or not. The behavior of the NAIP/Montana_2013_1m_NC service at gis.apfo.usda.gov is also consistent with this.