Holga exposure mystery not solved

The exposure math of the Holga has always been a mystery to me, because it seems to violate the reliable Sunny 16 Rule. The rule basically states that if you set your shutter speed to the ISO of your film and the aperture to f/16, you’ll get a solid exposure in direct sunlight. (For example, if you had ISO 50 film, you’d set your shutter speed to the nearest number, likely 1/60.)

Admittedly, every Holga is a bit different, but I did have one of my Holgas tested with a shutter speed tester, and it came in at a fairly reliable 1/100 sec, which is what it’s supposed to be. As I found out while I measured for The facts about Holga apertures, a stock Holga has an aperture of f/13.3, regardless of the position of the sunny/cloudy switch. So with aperture of roughly f/13 and a shutter speed of 1/100, you should be able to shoot ISO 100 film in bright sunlight and have a proper exposure. (Technically about a half stop over as we’re at f/13.3 instead of 16, but that’s well within the exposure latitude of modern print films, so you should just get a little extra shadow detail).

So why the hell do I have to shoot ISO 200 or 400 film in bright sunlight to get a decent exposure, while I get underexposed mud with ISO 100, which should work perfectly? After thinking about it for a while, I strongly suspected that the plastic "Optical Lens" must have a good deal of transmission loss and was blocking two stops of light, so I set up a test: I pointed a Canon 580EX flash fitted with a Sto-Fen Omni-Bounce diffuser straight into a Holga with a Sekonic L-558R meter (which is extremely accurate and consistent) stuck in the back. I metered the flash through the camera five times with and five times without the lens in place and was fucking shocked by what I discovered: there was effectively no transmission loss. The readings averaged out to differ by only about 1/6 of a stop.

WTF??!? It’s not the lens. It’s not the aperture. It’s probably not the shutter: while I can allow for the possibility that the speed changes over time—it was over a year ago I had it tested—I consistently have the same exposure requirements with all of the 8-ish Holgas I have. What’s left? Light-eating gnomes?

DIY Diana flash trigger

Check out photographer Don Brice‘s excellent modification that allows you to use normal flash/strobe units on Diana toy cameras:

I enjoy using the Diana in the studio and shooting portraits and still life lit with flash. I discovered long ago that by ripping off the usual connector on the end of the syncro cable, you could bare the two wires and jam them down the two flash sockets on the Diana-F model. Ta-da. Plug the other in to your strobes and away you go…

Continue reading instructions at Brice’s blog, Blurry Thinking.

"Lightleaks" toy camera photography show, Melbourne, AU

Australian photographer/neuroscientist Hamish Innes-Brown writes:

Me and 11 other people (some from this Flickr – fotojux, mikelefevre, artpunk, maybe others?) are in a show that opens this Thursday night called LIGHTLEAKS [not the magazine]. It is called this as all the images are shot on dodgey crappy cameras with useless lenses and hideous light leaks. Sound good? Come along, they’re all for sale!

The show runs 23 February – 8 March, 2007, at Kerala Gallery, 283 High St., Northcote, Melbourne, AU.

Opening at 6:30pm 23 Feb, be there!

“Cheap Shots: The Silver Dreams of Plastic Cameras” show, MI, US

Cheap Shots show flyer

“Cheap Shots is an exhibition of photographic art created with cheap, plastic cameras, old cameras, pinhole cameras, and Polaroids. In an age of expensive, hi-tech equipment, these simple cameras offer a refreshing, lo-tech view of the world in our time. The work in this show was created by seventeen artists from the Michigan area who call themselves the Krappy Kamera Club. This will be their first public showing in Ann Arbor.”

When: Cheap Shots will run from Friday, March 23rd to Friday, April 6th, 2007. The opening is March 23rd from 7:00pm to 10:00pm.

Where: Gallery 4, 212 Nickels Arcade, Ann Arbor, MI [US]. On the second floor above Arcade Barbers.

The gallery will be open during the show Thursday and Friday from 3pm to 7pm, Saturday and Sunday from noon to 5pm, and by appointment. The show is free and open to the public.

More info on the show from Matt Callow.

Here’s a larger version of the flyer.

Call for entries: Light Box IV postal art show of toy, pinhole, and zone plate photography

Linn-Benton Community College is seeking submissions for Light Box IV, a postal art show of toy camera, pinhole, and zone plate photography.

Due: February 17, 2007

Show Dates: February 20 to April 6, 2007

Format: Two postcards with a brief statement of why the photographer uses that method of photography as a means of personal expression on each card. (Any photographic media – color, B/W, digital). Cards will be displayed together so both the image and the statement can be seen at once (see example below.

Mail to:

Kurt Norlin
Art Department
Linn-Benton Community College
6500 Pacific Blvd. SW
Albany, OR 97321
USA

For additional information, contact Kurt at norlink@aol.com

Via Slowlight Pinhole Blog via the Spitbite Pinhole List