Whimbrels! - 23 - 29 May 2023

The annual Whimbrel migration through the Great Lakes Region appeared to have occurred during the period 22 May to 29 May 2023. I managed to document the migration through Pt. Mouillee SGA, Monroe Co., MI  USA on the 23rd, 26th and 29th with the peak occurring on the 26th when I counted over 200 birds. 

I did have the opportunity to digiscope several birds during this period using the Swarovski STX85, 25-60X eyepiece (at 25X), Sony a1, Sony 40mm f/2.5 lens, and Digidapter™ DLM. I was shooting electronic shutter at 30 fps at ISO's between 100 - 3200 with minimum shutter speeds of 1/1000 sec. I used the Sony RMT-P1BT Remote whenever possible. The scope was mounted on a Bogen 3020 aluminum tripod w/ the Manfrotto 501HDV video tripod head. For added weight I would hang my Sony a1/600mm f/4 rig off the tripod.

Here are some images from 23 May 2023:

A single individual was my only subject on 26 May 2023 despite recording 200+ birds (all in flight):

A single individual was found along the North Causeway of PMSGA on 29 May 2023:

One issue that plagued me during this period was distortion from convection currents / moisture in the air that would render consecutive frames soft or blurry while other frames were sharp and crisp. One question I had was whether "rolling shutter" could be an issue at 30 fps and electronic shutter? However, after seeing the same results shooting at 30 fps vs. 20 fps vs. 10 fps vs. 5 fps I concluded that the air currents were causing the blurry images. 

Simon Brumby did raise the question whether in-body stabilization (IBIS) could be contributing to the issue. I will have to check!