I was asked earlier on Twitter to share the reciprocity failure chart I use for slide films – I printed two of these on a single sheet of A4 and then laminated them back to back so that I can still refer to it when the weather is bad (well, good in my book ). It covers Fujifilm’s Velvia, Provia and Astia emulsions, but I’ve also added the data that’s available for Kodak’s E100G slide film – I haven’t used the film yet and haven’t been able to find any reliable data beyond Kodak’s statement that no reciprocity correction is required for exposures from 1/10,000th to 10 seconds. I do hope to get some E100G soon though, as I’ve been particularly taken by its colour palette in the images I’ve seen made with it.

Reciprocity Failure chart for common slide films

Fuji doesn’t recommend exposing Velvia 50 for longer than 30 seconds, but I know several photographers who expose it for much longer with great results – I’ve not got experience myself, but even in cases where I’ve had to expose well into reciprocity territory, I’ve not had any problems. Velvia 100 and Velvia 100F are much more receptive to long exposures, so if you do need exposures of longer than 30 seconds (at ISO 50) give either Velvia 100 or 100F a try as you’ll get an equivalent of an extra two stops without any reciprocity problems to worry about. I’ve included colour correction data as well, but I don’t use any colour correction filters during the capture phase – I do make corrections if there’s a distinctive and unwanted cast during the post production phase, though.

For negative film, I’ve only used the two new Kodak Portra films so far and I’ve not encountered reciprocity failure yet as my exposure times have been mostly below one minute – I’ve got a couple of sheets of Portra 400 that I’ve exposed for well over 4 minutes that I’m waiting to get back from the lab. I’m hoping they’ll be OK as, even if you underexpose by a stop there’s so much dynamic range available that, if you do encounter reciprocity failure, you are unlikely to lose much.

If anyone has some more complete reciprocity data for Kodak’s E100G, please do shout up and I’ll add it into the table!