When photographing hummers, I shoot fully manual.....no auto ISO.
When I shot hummers with flash in 2009 in British Columbia, I used the flash synch speed of 1/250 and f18-20. That is how the pro told me to do it! LOL! All the images in
this gallery were shot using flash except the first two images which were shot in natural light. You can click on an image, then click the "i" (information) in the upper left corner to see the capture details.
In 2023 I shot
hummers in Costa Rica using flash with two different approaches. Some with very fast shutter speeds - and some with 1/200-250 shutter speeds. You can view the capture data for each image.
HOWEVER,
my favorite hummer images were taken in 2018 using NATURAL LIGHT! Capture details are there also.