High ISO, available light insect shots

Conditions in the garden this afternoon were warm but overcast. I was taking some available light pictures of insects coming to Marjoram flowers (Oreganum vulgare). I was trying to maintain a fairly high shutter speed (1/400 - 1/500) because I was hand holding the camera with a 100mm macro lens and at an aperture of F6.3 or F8. To achieve this, I had to let the ISO go quite high.

Gatekeeper on Marjoram (100mm Macro on Canon 80D, 1/500s, F6.3, ISO 4000)

Here is an example of a shot of a Gatekeeper taken at ISO 4000 (1/500s, F6.3). This is a somewhat cropped version (3675 x 3090) of the RAW file (Canon's .CR2 file format - 6000 x 4000) as rendered into GIMP 2.10.2 by the default settings of nufraw. Whilst noise is evident on close examination, I think the image is quite usable and is pretty impressive for ISO 4000.