Masking a Ground Glass for Cinema Aspect Ratios

[LabRat]

I would just use a marked overlay of mylar (free mylar from discarded lab processing sleeves), or you can develop out some fogged B/W sheet film and cut out a GG mask for your formats... You can add some kind of clip or hold down scheme for the focus panel... You can then change to any format in the field easily...

Steve K

[r.e.]

I plan to start experimenting with this over the weekend. Initially, I plan to use 4x5 sheet film to make photos that are 1.78:1 and 2:1.

4x5 at 1.78:1 aka 16:9

This is the aspect ratio for online video (e.g. YouTube) and many computer displays. I want to use this ratio to make photographs that I can include in videos without letterboxing or cropping the photo.

Metric: 12cm wide x 6.7cm tall
English: 4.75" x 2.65"


4x5 at 2:1

This will result in an image that is about the same size as a 6x12 photograph made with a 6x12 camera or 6x12 roll film back. Cropping the height of a 1.78:1/16:9 photo by about 7mm/0.28" also produces this size of image. The two aspect ratios are close enough that there's an obvious argument for shooting 1.78:1/16:9 and cropping when desired.

Metric: 12cm wide x 6cm tall
English: 4.75" x 2.38"

Masking

The photo below shows my Arca-Swiss 4x5 fresnel/ground glass. The grid of 1cmx1cm squares is 12cm wide and 10cm tall. I think that I can do this without masks. For example, composing at 2:1 is just a matter of ignoring the two top and two bottom rows of squares. However, masking may help concentration and the grid will make masking easy.

[r.e.]

Out of curiosity, I made a version of the table attached to post #4 that includes a number of still photograph aspect ratios and the Golden Rectangle ratio. See the blue cells in the table below. To me, it's interesting that 6x17 and 4x10 are narrower than anamorphic widescreen, although 4x10 only marginally so. It's also interesting how close the aspect ratio for European theatrical release is to a Golden Rectangle.

[CreationBear]

The photo below shows my Arca-Swiss 4x5 fresnel/ground glass.

Hmm, could you just back off the screws of the GG clamps a skosh so you can shim, say, an exposed 4x5 sheet with appropriate window cut in? (FWIW, I use a 4x5 negative carrier with a selection of such sheets as a "composition frame" in conjunction with a knotted string for different focal lengths.)

[C. D. Keth]

The easiest way is to create framelines in indesign or photoshop and print them onto clear acetate. That can then be placed over the back of the groundglass under the spring retainers. If the odd dust between those layers bothers you, you can use water with a couple drops of dish soap or photo flo to apply the acetate and use a squeegee to clear out bubbles.

[r.e.]

Follow up...

I use the Artist's Viewfinder Mk. II to roughly compose photographs. So far, I've found that using that app and the grid lines on my ground glass make masking the ground glass unnecessary. I talk about the Artist's Viewfinder in What Scouting/Planning Apps Are You Using in 2021? There's a photo of my ground glass attached to post #12 above.

[Drew Bedo]

Full disclosure: I am an e-idiot and can barely use PS-Elements.

I am indeed a big fan of getting "IT" on film in the camera first, but . . . .

I wonder how much of the aspect ratio/framing can be done in photoshop?

[pendennis]

I've used Chart Pak tape for masks. It comes in .125" widths. I lay out the edges using a fine point Sharpie, then "connect the dots". Mostly mine is to demarcate 6x7, 6x6, 6x9 format for roll film adapters.