45 minute exposure at f/11 with Kodak E100VS slide film. Mamiya 7II with 43mm lens (21mm equivalent for 35mm cameras).
The technique necessary to make a 45 minute exposure with a digital SLR would be either to:
- Shoot for 45 minutes with noise reduction on, and then wait an additional 45 minutes for in-camera noise reduction to run
- Shoot multiple shorter exposures and stack them in Photoshop (e.g., 9 exposures of 5 minutes each)
My shooting strategy for the last few years has been to use a medium format film camera for long exposures of 45-60 minutes, while shooting with a digital SLR for the more typical 5-10 minute exposures. Not only does shooting with 2 setups help with productivity, but the medium format film work provides an excellent guide to post-processing the RAW files from the digital SLR. During the 80's, 90's, and into the aughts, medium format film defined the look of color night photography. Slide film reads as night. Emulating the look of slide film when post-processing in Lightroom and Photoshop helps the digital images read as night, too.
Calculating film exposures for images lit by the full moon is pretty easy. Start by taking a few test shots with your digital SLR -- I typically use 10 seconds at f/4, ISO 1600 as a digital test exposure. If the histogram looks good, this exposure equates to 5 minutes at f/8, ISO 200 -- or 10 minutes at f/8, ISO 100. When using Kodak E100VS, you'll need to almost double the digital exposure time to help cope with reciprocity failure -- about 18 minutes at f/8 during the full moon. When shooting at f/11, add another stop and a half -- 45 minutes at f/11. Depending on the amount of shadow detail you're trying to capture and the position of the moon in the sky, 60 minutes at f/11 may be more appropriate. With exposures this long, you have quite a bit of flexibility -- the difference between a 60 minute and 45 minute exposure is only a 1/2 stop.
Remember these simple rules when dialing in the exposures with your favorite film:
- When using slide film (E-6), overexposure risks blown highlights (just like digital) -- when in doubt, underexpose for night photography
- When using negative film (C-41), underexposure risks a thin negative with blocked up shadows -- when in doubt, overexpose slightly for night photography
And remember -- you don't need a fancy camera to shoot long exposure night photographs. Even a $25 Holga does the job quite nicely. Give it a try next full moon!