Leaf shutter light leaks

<p>Has anyone checked their leaf shutters for light leaks? I just built 'Big Red'...an 8x10 and thought I'd better check it for leaks before a shoot the next morning. I couldn't find any problem with the camera but the shutter's result was quite amazing. Try placing a torch behind the blades of your favourite shutter in a darkroom and see...</p><div></div>

<p>'Torch' being UK English for a flashlight. Just thought I'd clarify that, as a public service.</p>

<p>The shutter blades must lay flat against each other to be light tight. Each shutter brand has its sequence for assembling the shutter leaves and if assembled out of sequence they will let light in. Another cause is that a leaf is bent from cleaning.</p>

 

<p>Every shutter I tried exhibited leakage. Maybe it depends on the strength of your 'flashlight' LOL...it is more prevalent with the aperture blades wide open.</p>

<p>Do yourself a favour and get a decent Copal or Compur shutter Dean. You've obviously put work into the camera, so it seems a shame to "spoil the ship for a ha'p'orth of tar". That silver thing looks like an old Alphax or similar - bottom of the pile as far as quality and reliability are concerned.</p>

<p>None of my Copal or Compur shutters leak light; not even the early Deckel-Compurs from the 1920s and 1930s that I have - nor the Prontors either for that matter.</p>

All leaf shutter shutter blades leak light. Only a monkey would say otherwise.

 

Historically, folding cameras had been specially designed so that the lenses are automatically capped when folded. Seiko shutters in

Polaroid 180 and 195 cameras actually have a secondary set of shutter blades to keep the film from getting fogged when the camera is

folded.

 

Ironically, my least favorite shutter, the Copals, are markedly more light tight than any other shutters. So if the light leaks bother you, they

usually don't make it out of the shutter in most situations, get lenses mounted with Copal shutters.

Are you sure, Noah? I just tested my lot (Compurs, Copals, and Prontor Profs, of differing ages and sizes), and not one of them leaked.<br>So am i a monkey, or do i need to have the lot of them repaired? ;-)

<p>Noah, if we're down to trading insults, you're aptly named, since you obviously know-ah nothing!</p>

<p>You're both right and wrong Joe...that Ilex shutter is rather a junker, but it's all I have until something decent comes along, as for being wrong, Uncle Noah is both a friend and actually Noahs all....LOL</p>

<p><off-topic pedantry> Copal/Compur/Prontor shutters mostly use the same thread sizes and mount thicknesses (although the Prontors use a different naming system). American shutters, like the Ilex and Alphax, have their own idiosyncratic measurements. A partial list is <a href="http://www.sizes.com/tools/shutter_photo.htm">here</a>.</p>

<p>This means it will probably be a major pain ($$$) to transplant your lens from the Ilex to a big Copal. Outfits like S. K. Grimes specialize in that kind of work and do it beautifully, but they're not cheap.</p>

<p>If your Ilex is reasonably consistent, you can compensate for any known inaccuracy from the 'true' shutter speed. If it ain't broke, don't fix it.</off-topic pedantry></p>

<p>What I think saves the day is the 'inverse square law'. Whatever light that may enter via the blades doesn't reach the film plane due to the distance involved...unlike a leaky focal plane shutter that is situated very close to the film plane where leaky curtains will definitely cause a problem.<br>

Noah has been around LF cameras since the demise of the ark...</p>

<p> </p>

What probably saves the day for most of us are our non-leaking leaf shutters. ;-)

<p>A problem scenario for a shutter light leak is if you cock the shutter and pull the dark slide and then wait for minutes for the perfect time to take the photo -- perhaps waiting for the light to be better, to the wind to be still less motion, people or cars to move out of the way, etc. During that time the light leak will accumulate and may cause fogging or loss of contrast. So maybe a reason to keep the dark slide in or the lens cap on until tens of seconds before taking the photo.</p>