Swirly Bokeh lens information please

[Pere Casals]

So according to you two I should be looking to cover 4x5 or 5x7 and will give swirly bokeh at infinity.

Which brings up another question, how do I know if a lens will be circular(thanks for the proper term) at infinity?

Edit:
I just looked up magic lantern lenses and they seem to be projection lenses. Is this correct? If so How do I figure out what will cover 5x7 or 4x5?

Because of geometry the swirl is in the outer part of the image circle, as you stop the lens the inner circle having no swirl grows. If you focus near then the image circle grows, so the sheet takes less swirl, anyway you can always make a shift/rise to take a share of a not centered swirl.

So you should take a lens that covers the format with not much excess if you don't want the swirl outside of the sheet.

This is a search in flickr for 4x5 petzval : https://www.flickr.com/search/?text=4x5%20petzval you can make many searches... Some mentions the lens, or you can ask the photographer...



Note that in this shot there was a rise movement (image inverted...) that placed the swirl around the head...

https://www.flickr.com/photos/bracan...8MsA3W-aEcQuW/

[aaronnate]

Thanks Pere. That was very helpful.