Making Noblex filters
I have had success converting screw-in filters to Noblex 120 magnetic filters and wanted to pass it on. In my case I had some 52mm red and orange filters lying around. I simply used the thin self-adhesive refrigerator magnet material (which can be easily cut with scissors). I chose the flat side of the filter (the side that would be next to the camera lens if screwed in) on which to apply the magnet. I applied the magnets in two strips, leaving about 1 inch of glass in between. The real Noblex filters have a 13/16" open area and a magnet that runs all the way around.
They are as easy to insert and remove as the original Noblex filters and this process opens the possibility of using any screw-in type filter in any size that will cover the lens.
Blindphotgrapher, if you see this reply would you be willing to send or post a couple of pictures of your solution? I am looking for Noblex filters but they seem to be very rare these days.
I don't have a digital camera that will get in close enough to show one of these filters. Let me describe it a different way. On the magnetic side of the filter, you will have a strip down the center of the filter with no magnet. On either side of that will be opposing half-moon shaped magnets. Or, saying it another way: Cover one side of the filter with a magnet and remove a strip down the center.An added note since my first post - I bought more sticky magnet sheets for more filters, but the magnet material was too thin. It seems that it needs to be at least 1/8" thick to make contact with the steel around the lens.
I too will be making some ND filters, in my case for portraits. I have found with the lens set to near focus, WIDE OPEN and subjects about 12 feet away, the background goes beautifully soft.
Thanks, I think I understand and I'll give it a try. You said you were using 52mm filters - that seems pretty large, do you think any smaller filters would work?
I had 52mm filters lying around unused, so I tried them first. I currently have only one "store-bought" Noblex filter (a graduated filter which darkens the sky and leaves the bottom half of the scene untouched). It measures a hair over 40mm in diameter. The 52mm filters will probably be less expensive because of mass production around that popular size.