Digital Large Format

Last Update: 31.03.09 ! Please scroll down !

On this page, I will report about my latest project, modifying a Sinar F 4×5 inch monorail camera in order to use it with a DSLR for architecture and panorama photography.

The idea to “go really large” came after several tries getting distortion free panorama photographs or architecture projects done. A medium format lens with a shift-adapter was already some improvement, but still not what I considered the optimum solution. After some research, I decided to try and find a monorail view camera and modify the rear standard in a way that would allow to attach a DSLR instead of the classic film holder.

A custom made adapter replacing the ground glass in the rear standard was the first step. Let’s have a closer look at this adapter: First of all, access to some machine workshop is a must, as some precision machining is needed here. As we need a Canon EF-mount, a macro-extender was sacrificed. To allow the desired left-right-movement of the camera, an aluminum panel (10 x 23 cm) with a central hole for the EF-mount was machined. A rectangular aluminum board with a large central opening is fixed using the original Graflok mount of the Sinar rear standard. The sliding-adapter is kept in place with the help of two L-shaped bars (visible above the blue ruler. The same part is visible on the lower side). Allowing a clearance of 0,1 mm guarantees the necessary play to have smooth movements. A drop of machining oil can be of good use here. Finally, a black matte surface coating was applied.

As the sensor of the DSLR is displaced remarkably compared to the plan film the camera is constructed for, there are a few implications concerning the choice of lenses to be used.
In order to be able to focus to infinity a focal lens of around 120mm (or more of course) works fine.
Taking my setup as an example: A Canon EOS 5D mounted via an "EOS EF to 4×5" adapter comes with a distance between CMOS sensor and EF-mount plane of 65mm. As large format lenses are usually symmetrically built, another 30 to 40mm for the rear lens element have to be taken into account. In the end it’s simple math. One should be careful not to risk touching the rear lens with the tube extension of the adapter. A so called bag bellow might be also needed in order to keep the flexibility to profit from all the possible movements of the rear standard.

Fell free to check out my Architectural Photography Gallery to see some works done with this camera.

Another fascinating field is macro photography. The following sample images were taken with the Digital Sinar Setup, described above and the Schneider-Kreuznach Super-Angulon 90mm lens.

Digital Large Format Macro Photography

What might that be ? Well this detail of …. we will see later … is a 100 percent crop of the full size image, at 300 dpi.

Digital Large Format Macro Photography

Zooming out, we start seeing what we have in front of the lens …

Digital Large Format Photography

Now it’s clear ! We are looking at the backside of a 2,5inch hard drive. The next image shows the fullscale photograph, which has a size of 11300 x 6600 pixel. This results in a print size of 96 x 55 cm at 300 dpi, or 192 x 111 cm at 150 dpi which would be more than sufficient for a print size like that.

Digital Large Format Macro Photography

This image was photomerged out of 25 RAW files using Photoshop CS3 (1,17 GB file size).

So much for today. Stay tuned, as this story …. will be continued!