Large Format Landscape: spot metering vs incident meter – B+W Film Photography Gossen Profisix

Описание: Allow me to explain what's going on in this and the last couple of videos. Last time I went photographing I seriously under-exposed the film by 2 to 4 stops: one sheet was almost clear. The scenes were tricky with dappled light and areas in both deep shadow and bright sunlight. I used INCIDENT metering – as I usually do – and after processing the film was surprised by how badly I got the exposure wrong, so I decided that I needed to start using a SPOT meter like other growed-up photographers.

I returned the next day to the same place and around the same time of day so the light would be similar. While I was spot-metering the scene I realised that the exposure error the day before wasn't caused by my incident metering method, it was because I was reading the meter scale incorrectly and had misread 2 (two seconds) as '2 (half a second) which is 2 stops underexposure. I further mixed up 4 with '4 and 8 with '8: if you watch the video you can see my confusion when the numbers aren't working as I do the reciprocity math in my head.

On the meter dial the whole seconds are black numbers on a light background, while the fractional seconds are light numbers on a black background, so there are visual clues that the values are different other than an apostrophe. Note that this is not a problem with the meter, it was totally my error.

I've made a short video of the moment I realised my error, it's got dramatic music and some funny editing and is intended to be lighthearted. This video is a longer version that shows the spot metering process and how I worked out what I was previously doing wrong. Thankfully the negatives from this session are very nicely exposed, but there are some issues that still need to be resolved like that the "correct" reading (2 seconds corrected to 5 seconds for reciprocity failure) is still a bit thin in the deep shadows, while the exposure with another stop (4 seconds corrected to 12 seconds) has what could possibly be too much shadow detail: is this poor technique or is the100 ISO film rating too high, should it be lower like 80 or 64 ISO?

To add to the mystery, the Profi-spot attachment had some dust and haze inside so I opened it up. Many of the glass surfaces and the mirror were covered in a thin layer of haze which cleaned up easily (pro tip: Ilford Ilfosol wetting agent can be used as a lens and glass cleaner, according to the Ilford data sheet and in my experience.) So more testing is required, which I'm happy to do.

Photographs were made with a Toyo Field 810M 8x10 camera with single-coated Fujinon W 210mm f5.6 lens in a Seiko shutter, all on an Innorel RT90C tripod and Leofoto G2 gear head. The Shanghai GP3 100 film is loaded in Toyo film holders. Light readings are made with a Gossen Profisix (sold as Luna Pro SBC in the USA) with Profi-spot attachment.