How did Atta Kim do his 8-hour exposures - video inside!

[PaulSchneider]

Hi guys,

I was always fascinated by Atta Kim's 8-hour-long exposure project:

http://www.google.com/search?client=safari&rls=en&q=atta+kim+on+air&oe=UTF-8&redir_esc=&um=1&ie=UTF-8&hl=en&tbm=isch&source=og&sa=N&tab=wi&ei=7OsBT_X2LcTb4QS1saySCA&biw=1443&bih=802&sei=8esBT_H_Is2M4gSZs8GNCA

And I also always wondered how he did it.

So I found this video on vimeo, where we can see the man at work:

http://vimeo.com/20987684

He seems to have used for his project:

A toyo 810 field camera with a 210 SSXL lens.

Also I see a Lee filter shade but no ND filters.

Also, even if he did use ND filters, the diameter of the biggest ND filter in LEEs system is 100mm x 100mm, less than the diameter of the 210 SSXL.

Did I miss something?

Any ideas what film and how to get to 8 hours without ND?

Kind regards

Paul

[Ari]

Maybe he had a screw-on ND filter on the rear element, and just "forgot" to mention it.

[Brian C. Miller]

According to a Google search, I found a blog entry claiming that two pieces of "welding glass" were taped together to form the filter. Based on the video, whatever filter he uses must be behind the rear lens group.

[Jim Michael]

Aluminized mylar is used in production of solar filters for telescopes. I don't think it's magic mylar so the stuff you can buy from McMaster Carr etc. should work as a very high density filter and it should be optically flat with little adverse color effects.

[ic-racer]

According to a Google search, I found a blog entry claiming that two pieces of "welding glass" were taped together to form the filter. Based on the video, whatever filter he uses must be behind the rear lens group.

Yes, behind the lens would be the best place. When putting a filter on the lens without a screw flange, there will be 2000 times less light leaking around the filter when it is over the rear element (stopped to f45) compared to putting it on the front of the lens.