These Fresnel lenses are designed to be installed so that the grooved side of the Fresnel is touching the outside (shiny) side of your ground glass screen. This is not a focusing screen.

I stock the following sizes: 3 1/4 x 4 1/4” (Quarter Plate), 9x12cm, 4x5”, 4x5” Clipped Corners, 4 3/4 x 6 1/2” (Half Plate), 5x7”, 13x18cm, 6 1/2 x 8 1/2” (Whole Plate), 18x24cm and 8x10”, 10x12”, 8 1/2 x 15”. Half Plate, 5x7” and 13x18cm also available as special long focus types which are ideal for reducing backs (with longer focus lenses).

I also hold a small stock of Fresnels to fit specific camera brands/models: Shen Hao 4x5" (Clipped Corners), Graflex Speed/Crown Graphic 4x5”, RB Super D 4x5”, Graflex Home Portrait 5x7”, Argentum 5x7” Wide Angle, Argentum Long Focus 5x7”, as well as others.

My Fresnel lenses have been selected to provide the following benefits:

• Increase in apparent brightness and more even illumination over the frame. Corners are visible without needing to hunt around the frame, meaning time under the focusing cloth is better spent.

• Fine grooves. The fine groove width allows ease of focus through the Fresnel with a loupe.

• Protection of the ground glass. 1.8 to 2.0mm thick acrylic material.

• Each Fresnel comes supplied in a tin case. Ideal for you to store an emergency ground glass screen.

N.B. Ideally, a Fresnel lens screen works best when the focal length of the Fresnel roughly matches the focal length of the lens being used. In the table (photo 3) I have added +20% to the focal length of the Fresnel to mark the upper limit of the optimum range. Lenses of a shorter focal length can of course be used, however the brightness-boosting effect will become less noticeable the wider the lens is. If you have a specific question, please get in touch!