One of my all-time long exposure photographers is Australian photographer Alex Wise. (not sure if you can say “long exposure photographer”, but I just did.
He usually shoots with uber-strong-high-end B+W 110 or Hoya ND400 ND filters, but recently he took a 10 stops welding glass (around $10 on Amazon) and swapped his high-end glass for cheap working-level welding glass.
Unsurprisingly results were pretty good, and Alex shares a few tips on shooting a daytime exposure with those filters and how to correctly post process them.
This basic video shows how easy it is to correct for the notorious green cast.
There are many good tips on the post, but here is the one that specifically caught my eye:
“Ignore photography purists who will tell you that using welding glass is a terrible idea as you will lose sharpness, have issues with flare and the like. I disagree. If you take a close look at this crop I have of two edited images which are both un-sharpened you can see for yourself that there is negligible difference between the two.” [Click the image for 100%, 6MB view]
Head over to Alex’s blog for more great tips on this technique.