Winter evening Yosemite Tunnel View on 4×5 film, by Intrepid 4×5 large format film camera, Caltar 150mm f/5.6 lens, Ilford HP5 Plus film

The past week, Yosemite welcome its first snow of the season. We did not get a chance to go there until the snow stopped, and thus missed the best moment when the valley was blanketed by fresh powder. However, clear evening brought an opportunity to shoot the Tunnel View under moon light with large format film camera.

For people unfamiliar with large format photography, it was commonly accepted that night is the enemy for this form of photography due to a few limitations. First of all, it is extremely challenging to focus and compose with the ground glass in evening because there was virtually no image to look at on the ground glass. Secondly, film has a notorious problem for long exposure, namely reciprocity failure. It means that a long exposure in digital world need to be extended to an extreme length.

Fortunately, our experience had told us we could try to focus on the moon or bight stars in the evening. And in this evening, we had a clear sky with an almost full moon. It was relatively easy to focus on the moon on the ground glass because it was a big and bright circle on the sky. Bright moon light also created a not-so-bright image visible on the ground glass. It made composition possible.

The other benefit of bright moon light is that it brought down the exposure time to several minutes at a relatively low speed of ISO 400, a common speed for fast films. Reciprocity table pointed to at least 4 times of the exposure for the Ilford HP5 Plus film we used. And we decided to push it to 10 times longer, which gave us 60 minutes exposure in the end.

The result was surprisingly good. The film responded to the moon light very well, and held a great deal of details with barely visible grain. Whether this was the first attempt to capture the evening Tunnel View on large format film, we do not know. It surely was a rare one.