diff --git a/flows/instruments/__init__.py b/flows/instruments/__init__.py
index 0ff55da..dd2eb5b 100644
--- a/flows/instruments/__init__.py
+++ b/flows/instruments/__init__.py
@@ -1 +1 @@
-from .instruments import INSTRUMENTS, Instrument
+from .instruments import INSTRUMENTS, Instrument, verify_coordinates
diff --git a/flows/instruments/instruments.py b/flows/instruments/instruments.py
index db28055..cb02a88 100644
--- a/flows/instruments/instruments.py
+++ b/flows/instruments/instruments.py
@@ -1,5 +1,32 @@
 """
-Load image code.
+Instrument classes that inherit from the base class.
+Modify to add your own instrument.
+
+Identifying relevant image properties:
+
+`site` = required, add manually.
+`peakmax` = optional, add manually or provide header.
+The rest of `exptime`, `obstime`, `photfilter` use the
+following (overrideable) base functions. Override
+if the default one from the baseclass does not fit
+your instrument. See:
+    ```
+    self.image.peakmax = self.peakmax
+    self.image.site = self.get_site() 
+    self.image.exptime = self.get_exptime()
+    self.image.obstime = self.get_obstime()
+    self.image.photfilter = self.get_photfilter()
+    ```
+
+Identifying the instrument for an image:
+
+Each instrument can define (one or many) of `origin`, 
+`telescope`, `instrument` fields correspinding to the 
+standard fits headers to help uniquely identify itself.
+More advanced logic is possible using `unique_headers`
+field as a dict of key,value pairs in the header. Ex:
+unique_headers = {'PRODCATG': 'SCIENCE.MEFIMAGE'}.
+These are all optional, defaults are set in baseclass.
 """
 # Standard lib
 from __future__ import annotations
@@ -72,7 +99,7 @@ class HAWKI(Instrument):
     telescope = 'ESO-VLT-U4'  # Fits Header name of TELESCOP
     instrument = 'HAWKI'  # Fits Header name of Instrument (can be partial)
     origin = 'ESO-PARANAL'  # Fits Header value of ORIGIN (if relevant)
-    unique_headers = {'PRODCATG': 'SCIENCE.MEFIMAGE'}
+    #unique_headers = {'PRODCATG': 'SCIENCE.MEFIMAGE'}
 
     def __init__(self, image: FlowsImage = None):
         super().__init__(image)
@@ -101,6 +128,10 @@ def get_ext(hdul: fits.HDUList, target_coords: coords.SkyCoord = None,
         if target_coord is None:
             raise ValueError("TARGET_COORD is needed for HAWKI images to find the correct extension")
 
+        # Incase this is not a multi-extension imageL
+        if len(hdul) == 1:
+            return 0
+
         # For HAWKI multi-extension images we search the extensions for which one contains
         # the target, Create Image from that extension.
         target_radec = [[target_coord.icrs.ra.deg, target_coord.icrs.dec.deg]]
@@ -367,7 +398,7 @@ def get_obstime(self):
 
     def get_photfilter(self):
         hdr = self.image.header
-        photfilter = {'H_Open': 'H', 'K_Open': 'K', }.get(hdr['FILTER'], hdr['FILTER'])
+        photfilter = {'H_Open': 'H', 'K_Open': 'K', 'J_Open': 'J'}.get(hdr['FILTER'], hdr['FILTER'])
         return photfilter
 
 
@@ -488,12 +519,9 @@ def get_photfilter(self):
 class Schmidt(Instrument):
     siteid = 26
     peakmax = 56_000
-    telescope = '67/91 Schmidt Telescope'  # Fits Header name of TELESCOP
-    instrument = 'Moravian G4-16000LC'  # Fits Header name of Instrument (can be partial)
-    origin = ''  # Fits Header value of ORIGIN (if relevant)
-    unique_headers = {
-        'SITELAT': 45.8494444
-    }  # Unique key value pairs from header for identifying instrument.
+    telescope = '67/91 Schmidt Telescope' 
+    instrument = 'Moravian G4-16000LC'
+    origin = '' 
 
     def get_obstime(self):
         obstime = Time(self.image.header['DATE-OBS'], format='isot', scale='utc',
diff --git a/flows/load_image.py b/flows/load_image.py
index aff04f9..5151a1a 100644
--- a/flows/load_image.py
+++ b/flows/load_image.py
@@ -8,7 +8,7 @@
 from astropy.io import fits
 from astropy.time import Time
 
-from .instruments import INSTRUMENTS
+from .instruments import INSTRUMENTS, verify_coordinates
 from .image import FlowsImage
 from .utilities import create_logger
 logger = create_logger()
@@ -39,6 +39,7 @@ def load_image(filename: str, target_coord: Union[coords.SkyCoord, Tuple[float,
         for inst_name, inst_cls in INSTRUMENTS:
             if inst_cls.identifier(telescope, origin, instrument, hdr):
                 logger.info(f"Image is using instrument {inst_name}")
+                target_coord = verify_coordinates(target_coord)
                 ext = inst_cls.get_ext(hdul, target_coord)
                 mask = inst_cls.get_mask(hdul)
                 # Default = None is to only mask all non-finite values, override here is additive.