(10-14-2019, 09:54 AM)Brightcolours Wrote:(10-14-2019, 07:25 AM)davidmanze Wrote: Yeah, nothing like a nice epiphany moment BC .....Which photo will show the bird issue?
Ok, it's got to be something along those lines ...... the connection is that when the sun is high in the sky shining down on birds heads causes exactly the same effect.
My theory about the darkening blue colour of the sky through branches or in this case feathers "doesn't" hold up for the counter yellow fringe underneath the bird's head.
I've put out the question on the astro photography DPreveiw forum ...... there are a lot of knowledgeable guys there!
The first reply says that:
"This is something that an ADC, or Atmospheric Dispersion Corrector would eliminate, although I am not sure if you can get an ADC to fit a regular camera lens. A chap at my astronomy society uses an ADC with very good results on his Meade 16" Schmidt Cassegrain telescope."
A link to this ADC is here:
Looks to be a unusual bit of kit
Both of these shots had a blue fringe on the top edge of the birds head for example, (you have to zoom plenty) ....... not so easy to see on Flickr.
Most of the images that suffered from the effect were also spoiled by troubled air and as a result are deleted.