On 14/05/2017 17:22, Davoud wrote:
...for eclipse photography purposes. I will be photographing the
eclipse with a "full-frame" DSLR. I have several 'scopes of varying
focal length and photographic fields of view and I want to ensure that
I do not crop the corona during totality.

Thanks!

You can't reliably predict it in advance since there will be fainter
emission further further out and streamers may or may not be present.
About 3 degrees is a good working hypothesis.

Taking a look to see what LASCO coronograph sees ahead of time might be
a good way to judge it.

Sun has been so quiet recently that a boring eclipse corona view is
possible with very little else to see when the photosphere is occulted.


--
Regards,
Martin Brown