Spent 6 hours chasing a light leak on a Pentax K1000 that ended up being the mirror bumper foam

Got a Pentax K1000 on the bench last week with weird fogging on the left edge of every frame. Chased my tail for hours cleaning the shutter curtains, checking the lens mount, even swapped the back door. Turned out the foam strip on the bottom of the mirror box had turned gooey and was dripping onto the film plane when the mirror flipped up. Never thought to look there since the mirror itself looked clean. Whole job took maybe 20 minutes once I spotted it. Anyone else get burned by an obvious problem hiding in plain sight like that?

3 comments

3 Comments

jamie_adams6d ago

Oh man, I feel that pain. Had a similar thing happen with an old Canon F-1 where the foam around the mirror box just turned into this sticky black goo over the years. Took me forever to figure out why my frames had this weird shadow in the corner. Cleaned everything else twice before I finally pulled the mirror out and saw it. And the worst part is you think you're being smart by checking the obvious stuff first but the real problem is just hiding in the foam. Seems like half the old SLRs from the 70s have that problem now. The foam is just rotting away and getting everywhere.

felix4146d ago

Clean the foam they said, it'll be fine they said" - @jamie_adams knows exactly how that lie hits different when you're scraping goo off a mirror.

sean_green446d agoTop Commenter

That's the thing with old gear, you fix one problem and find three more hiding inside. It's like that with everything though, not just cameras. My buddy's old truck had a weird rattle, he spent two weeks chasing it through the suspension and exhaust, turns out it was just a loose screw in the glove box latch. You get so focused on the big obvious stuff, the little things just hide in plain sight until they finally break and make a mess everywhere. It's almost like the universe wants you to learn that the simple stuff is always the last thing you check, no matter how many times you tell yourself to start simple.