Footage test: Edmund Optics 8mm

Zzz · May 11, 2018

Found this 8mm f/2.5 "red series" lens from Edmund Optics for $95. Running a fresh installation of a mRo GPS, I shot some riveting footage of the neighorhood...haha.

So, while the resolution numbers for this lens are off the charts (145 lp/mm on-axis and 125 lp/mm full field) I cannot seem to bring the edges into focus. It had no integrated IR cut filter, so I have a IR cut and ND8 stacked behind it.

RichWest · May 11, 2018

I'm no expert on lenses, so this is a comment based on mechanical elements. Could either the IR cut and/or ND8 be the source for the edge focus issues?

Looked really nice otherwise. I started seeing the blur on the second run through. Really enjoyed the drop down at :45, shows off the narrow lens really well. You guys in the PNW area have some scenery. Thanks for the share.

Zzz · May 11, 2018

RichWest said:
I'm no expert on lenses, so this is a comment based on mechanical elements. Could either the IR cut and/or ND8 be the source for the edge focus issues?

Looked really nice otherwise. I started seeing the blur on the second run through. Really enjoyed the drop down at :45, shows off the narrow lens really well. You guys in the PNW area have some scenery. Thanks for the share.

It's possible. I'm using the filters that came with my Backbone Ribcage Air. They came with these black perimeter donut stickers that I assume are to prevent light leaks or scratching of the filters should there be any particulate between them. They are difficult to apply though and left a little adhesive that was difficult to clean thoroughly. I'm not convinced that's the cause though between the filter discs are much larger diameter than the ocular end of a M12 lens.