ground glass mask for 6x9 roll film in Sinar F+greenspun.com : LUSENET : Large format photography : One Thread
Please tell how can I build a ground glass mask for 6x9 roll film. If it's too difficult, where can I buy a cheap one? I'm using a Sinar F+
-- Paulo Ogino (email@example.com), January 10, 2002
I guess it depends on exactly what you are looking for. I make masks for my gound glass on my inkjet printer using overhead transparency material. I put a center indexing cross hair at the center so I can line it up with the center mark of my ground glass. The 6x9 area is clear except for the center mark, sometimes I'll put a fine dashed line in to indicate an 8x10 print proportion. Outside the film area I'll use a red fill pattern. That way I can still see what is outside the frame but makes it very easy to identify the 6x9 image area.
It is easy to fix this to a Sinar ground glass since you have the raised castings at the edge of the glass on each end and the little retaining clips for fresnel and other accessories. Cut the film so that it nestles down against the glass but provides just a little catch at the edges where castings, clips, etc. are. You could hold it in place with a piece of drafting tape if you need to. I made an envelope on the side of my ground glass cover to store the mask when not in use.
-- Dave Schneider (firstname.lastname@example.org), January 10, 2002.
Since I want to use a roll film holder (which I still haven't bought), I need to know if is enough to center the 6x9 area in the ground glass, or I need to measure the ditances in the holder, so I can get an exact match...
-- Paulo Ogino (email@example.com), January 10, 2002.
Don't know if this would work for Sinar, but if the corners are clipped on your G.G., you can cut a mask out of plastic. I used fairly thin plastic purchased in a hobby store. It has lines indented longitudinally to make cutting straight lines easier. I cut 3/16" wide by 3/8" long tabs on each corner of the mask so that they extend through the corners of the G.G. to the base that supports the G.G. This keeps the mask mounted to the inside of the G.G. I couldn't find black plastic, so I purchased white and painted it black.
-- neil poulsen (firstname.lastname@example.org), January 11, 2002.
I likewise have had good luck printing transparencies at home with my Epson 1270 printer. In my case, I compose and shoot exclusively in a 6x6 format using a 6x7 back on a 6x9 camera ... if I could get around the need for movements, then I'd live quite happily with just my TLRs or perhaps a Hasselblad Arcbody. One of these days...
But I digress. In my case, to line the back up with the ground-glass, I cut a piece of paper to fit under the g-g and then used a pencil to lightly burnish the edges of the film opening. With this, I was then able to determine where the center was and used other known reference points to transfer these measurements to the g-g. It took a while to do this accurately but not that long and it wasn't that difficult; it only needs to be done once, too, as my g-g mask is going on two years old and is holding up just fine.
-- Jeffrey Goggin (email@example.com), January 11, 2002.
Do you have no marks for 6x7,6x9,6x12 on the groundglass. I think a Sinar should have it. Have an exact look at your groundglass. Good luck!
-- Armin Seeholzer (firstname.lastname@example.org), January 11, 2002.
Paulo, On both my Toyo and sinar cameras, using the Toyo and Graphic roll fim holders, the centers all line up with <1 mm error.
-- Dave Schneider (email@example.com), January 12, 2002.