I have also had my Fuji GSW 690 camera whose 6x9 negative does not fit my original Meopta enlarger as it can only handle up to 6x6 negatives and an old MPP 6x9 rollfilm holder for my Intrepid 4x5 MkIII. This experience has reminded me that I am missing some key components from the enlarger. Namely I need a 4x5 and a 6x9 mask. I have a 6x8, 35mm masks that came with it. Previously I found I could suspend a 4x5 negative in the negative holder but it is rather tenuous and difficult to place it in the right position. I also learned in my last round of printing that light leaks around the negative and can produce noticeable glare on the print. This situation could not persist. To no avail could I find the requisite masks online.
Fortunately I had recently been experimenting with a new online service I discovered called RazorLab. They will laser cut from different material any design you submit. I opted to see if this could help me here.
I chose as a material black mount board as this is cheap and is the right thickness. The challenge with this service is to find ways of solve problems in material that is essentially 2 dimensional. Here is what I ended up with.
First let's see what I am imitating. This is an example of the factory Durst mask for a 6x8 negative. It consists of 2 aluminium plates with locating studs on one side and matching holes on the other. Note the inset for a single negative to sit. I cannot make this in RazorLab so I ignored this. Also in general I do not separate negatives as they are difficult to manage in sleeves. The locating studs also serve to align the negative.
|Original 6x8 masks|
|6x9 mask outline|
|Finished Cut Parts|
|Negative in mask|
As mentioned I also made a 4x5 version of the mask. Again I used the same outline but of course a larger window (119 x 95 mm) made by careful measurement of the image area of negatives. The window needs to be slightly smaller than the negative of course to keep it from falling through.
I also changed the alignment strategy as I am dealing with sheet film. This allows me to use a corner location strategy for alignment in both dimensions. The Inkscape drawing follows...
|4x5 mask drawing|
|Finished 4x5 masks|
|Alignment strips in action|
Here is a video explaining and showing the finished pieces.
Finally I want to comment on further improvements. 1) The 6x9 alignment strips are too close together for some films. Indeed on reflection there is no real need to have them match the exact width of the film as you only needs one strip to align the image properly in the mask. The other is useful to keep the two masks aligned. 2) It may be useful to have the top mask slightly wider than the image as this may make it easier to see how the image is adjusted (left/right) with respect to the top mask. 3) The base mask alignment slots could be narrower to make for a tighter fit for the strip. The top mask should remain somewhat wider to make the whole thing easier to assemble.
My final design file will include both widths of 6x9 negative for my two cameras. It will also have the one alignment strip further away from the window to make it accommodate more variation in film width. Finally I will make the bottom mask slot narrower.
Finally some links...