I wrote an Android App last year that I felt I needed myself when I was out and about in the field photographing long exposures. I’m happy that it has now more than 2000 active installs and I have taken all comments into account and released an updated version.
As you are well aware of, most films do need correction of the exposure time for reciprocity failure to avoid underexposing your negatives for exposure times of over a few seconds. This really gets important for night photography, when using filters and for Large Format or pinhole photography. All information is contained in the App so no data connection is needed when you’re on a photo shoot abroad, on top of a mountain or in the deep countryside without any connectivity.
I do not miss the folder with printed and weather-beaten PDFs with tables of exposure correction information for the different films that I had to rely on before. 🙂
The Reciprocity App has the following features:
Easy to use and usable on Android devices of most sizes.
Lots of B&W, colour and slide film included in the App, and this list is growing with every update.
Include filter factors in the exposure time calculation.
Include bellows extension in the exposure time calculation.
Built-in timer to use the calculated exposure.
See the screenshots below.
Ease of use:
Growing number of films supported:
Details about the calculation:
In addition to the film manufacturer supplied reciprocity information, I used the findings of Howard Bond from his article in the Photo Technique magazine which had been formulated into an easy formula by Patrick Gainer.
It is a simple App, but packed with the reciprocity details of most black and white films currently being sold and a growing number of colour and slide films. Works fine on new and old Android phones as well as on Android tablets.
It’s free, make sure to grab it!
The fun part of pinhole photography is that it is so low-tech: No real lens involved, no focussing, great results without any hassle. Or so you might think. For me, pinhole photography means that I need to bring my Android tablet, a grey-card and Sekonic 758D lightmeter to get the job done and get a predictable exposure. It is probably as hi-tech as I need to get for all of my photography. 🙂
My technique with which I have now been able to get decent and reproducible results, comes down the following steps:
Use the Film Crop Assistant app to get the location of the tripod and the composition right as you cannot look through the lens, of course.
Use the grey-card and the lightmeter to get a reading.
Use the Pinhole Camera Calculator app to convert that reading into an basic exposure time that matches the f-stop of my pinhole lens.
Use reciprocity failure correction tables specific to the film that I use the Reciprocity app that calculates the exposure time to use for a given film and metered exposure time.
Use the Timer option of the Android Clock to time the exposure.
No doubt you can find similar or better tools for the Apple world.
A few weeks ago, just after Worldwide Pinhole Photography Day, I picked up a Skink Pinhole Pancake Retro Pro Pentax 67 for my Pentax 67II camera. It has the standard mount so it will fit on the Pentax 6×7, 67 and 67II cameras no doubt and with the proper adapter, I expect that it can be used on a whole host of other cameras; I intend to try it out on my Pentax 645NII later this year.
Over a few weekends I have had the chance to experiment with it. I’m happy with the results, of course the images are soft but attractive in their softness. Before I started I was expecting a bit of vignetting but there was no sign of it.
You want to turn your SLR or DSLR into a pinhole camera? I picked up one of these cheap Holga HPL-P lenses for my Pentax cameras and it works wonders. The HPL-X lenses also exist for Canon, Nikon, Olympus, Samsung NX, Sony and Panasonic cameras. They’re easy to use, at Ø=0.25mm and 28mm, it has a corresponding aperture of f/112.
Finding the correct exposure can be a bit of trial and error although it should be easy if you have an external lightmeter and bracketing will certainly help to narrow it down. If you shoot film I would certainly recommend a lightmeter and the use of this table to find the right exposure.
Note that even though these lenses are advertised to be usable on SLRs as well, do expect a lot of vignetting as the lens will not cover the whole negative and is clearly designed to work on DSLRs with cropping factors of at least 1.5.