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?

Exposure exhibit opening TONIGHT, Pittsburgh, PA, US

EXPOSURE Official Announcement for DEBUT

Exhibition announcement:

People are using cameras in ways previously reserved for "the professionals". Digital photography is allowing us to capture the images we see, and make images we feel.

So many photographers are making so many different styles of photography – and the best is yet to be discovered – because its hiden away on a hard drive.

Now we go a step further.

EXPOSURE takes these images from hard drives to the gallery walls – celebrating the modern day photographer – each with his or her own vision and completely unique perspective. We avoid competition. Instead we embrace our differences, then feed from the inspiration that they yield.

Flickr has provided a hub – a global online community. Individuals from every corner of the planet are sharing their work with thousands of people. This incredible resource has given today’s photographer a new playing ground.

Some professionals still say that these photographers don’t do it the way they used too. That might be true. But we choose to focus on the way we need to do it now and look towards the future!

EXPOSURE is that FUTURE!

OUR DEBUT GALLERY SHOW will Feature the work from 15 photographers, and will be headlined by DEAN M. BEATTIE (DMB05)!!!

Dean’s career spans more than 13 years of professional image making and a wide spectrum of genres, wedding, photojournalism, corporate, architectural, portrait, and fine art.

For the first time his fine art nude figure studies will be on display.

Other Photographers on display:

Craig E Biertempfel
Hans Rosemond
Stephen A. Hall
David Kent
Robert Strovers
Dan Buczynski
Jim Orsini
Cate Whitehead
Sharon West
Todd Hryckowian
Chris Nicholson
Matt Niemi
Charles Schneider
Julie Schneider
Joey Kennedy

Music will be provided by DJs Kelly Carter & Walter along with live sax/flute by Jason May.

COME! Be apart of this community known as EXPOSURE!
7-11 pm
FRIDAY April 7th 2006
@ GarfieldArtWorks
[4931 Penn Ave, Pittsburgh PA]

—> Gallery show will be followed by an A F T E R P A R T Y @ LOT 17 , LocationL: 4617 Liberty Ave [Bloomfield]

10pm-2am with DJs Joyboy & Kelly Carter

Lot17: 2 blocks up from the Bloomfield Bridge, opposite side of the street <--- Flyer design: Dan Buczynski aka Macwagen