Re: long exposure light leak?
you can put the light into the lens board hole. in a darkened room, inspect the entire camera with the bellows extended to check everything for the slightest leaks. be sure to put a film holder in with the dark slide removed as well.
this is the best way to find light leaks.
Quote:
Originally Posted by
Louis Pacilla
I would take your camera with a holder inserted in the spring back in a dark room put a bright flashlight inside the bellows and sit for 5-10 min until your eyes adjust & see if you get a hint of light making it's way out anywhere camera bellows,spring back.
You will also want to make sure you have no leaks in the holder/holders so do a paper test in your holders by putting a piece of RC paper in each side of the holder put them in strong light for a few hours then develop in Dektol or like paper developer and see if your troubles there. I doubt this but worth checking.
1 Attachment(s)
Re: long exposure light leak?
Quote:
Originally Posted by
ic-racer
Some view of the negative might be helpful so one does not have to guess. Otherwise, guessing most people would insert the film holder from the top when making this shot, so that puts the light leak at the film notch side, yes? Do you open the film bags at the notch side? Maybe the bag is not sealed to light after opening? Do you process in some kind of tank with the film notches up? Maybe to tank top leaks light. Or check light leaks on the attachment of the bellows and film back on the bottom of the camera.
Thanks for your time. Here is a shot of the negative
Attachment 198504
Re: long exposure light leak?
Quote:
Originally Posted by
Doremus Scudder
Uhhh, film notches can go on either side of the film holder... just depends on how you like to load your film. Many people load filmholders with the notches up. My notches are always at the bottom (flap-side) of the holder so they have less tendency to impinge on the image area and so I can check to make sure the emulsion side is up just before closing the flap and inserting the dark slide.
I concur that the leak may be due to a misfit between either the camera back and holder or the camera back itself, but don't rule out leaks from the top of the back/holder area either, since that is where the light comes from... Do check the fit of both back and holder, but don't discount a small bellows leak just forward of the rear standard on the top of the bellows or where the bellows attaches to the camera.
Light traps in film holders aren't designed to be left open for minutes at a time either. Using the dark cloth over the whole camera for long exposures is a good idea if the wind allows. If not, you can do what I have: build a small cover out of old film boxes (they're black) that slips over the top of the filmholder when the slide is pulled.
Best,
Doremus
Hi, thanks for your help!
I load my film with the notch flap side too.
I shall try covering the whole camera tomorrow morning with the dark cloth.
1 Attachment(s)
Re: long exposure light leak?
Quote:
Originally Posted by
Doremus Scudder
Uhhh, film notches can go on either side of the film holder... just depends on how you like to load your film. Many people load filmholders with the notches up. My notches are always at the bottom (flap-side) of the holder so they have less tendency to impinge on the image area and so I can check to make sure the emulsion side is up just before closing the flap and inserting the dark slide.
I concur that the leak may be due to a misfit between either the camera back and holder or the camera back itself, but don't rule out leaks from the top of the back/holder area either, since that is where the light comes from... Do check the fit of both back and holder, but don't discount a small bellows leak just forward of the rear standard on the top of the bellows or where the bellows attaches to the camera.
Light traps in film holders aren't designed to be left open for minutes at a time either. Using the dark cloth over the whole camera for long exposures is a good idea if the wind allows. If not, you can do what I have: build a small cover out of old film boxes (they're black) that slips over the top of the filmholder when the slide is pulled.
Best,
Doremus
OK took the photo again. Put the dark cloth over the front standard, bellows and rear standard.
Attachment 198525
Light leak still in the same place :(
Shall start taping all the joints...
Re: long exposure light leak?
do the light test from the front as well as from the rear. it can be the lensboard not seating too.
Re: long exposure light leak?
How sure are we this is not a lens artifact?
Re: long exposure light leak?
Quote:
Originally Posted by
scheinfluger_77
How sure are we this is not a lens artifact?
Maybe due to stacking the centre-filter, polariser and grad?
Shall try again with them removed...
Re: long exposure light leak?
Quote:
Originally Posted by
MattKHardy
I have only ever used ND filters either behind the lens or screw-on the front. I have never seen a slide-in filter holder that seals light effectively, so it looks like that is the issue; light leak between the nd filters and the lens.
1 Attachment(s)
Re: long exposure light leak?
Quote:
Originally Posted by
scheinfluger_77
How sure are we this is not a lens artifact?
Hi,
Pretty sure its not a lens artifact. I repeated the photo today with the same setup: centre-filter, grad filter, polarizer, f22, five minute exposure on Delta 100.
This time in landscape orientation:
Attachment 198550
Rotating the Graflok back to landscape orientation seems to stop the light leak. This must point to the seating of the Graflok?
Re: long exposure light leak?
Quote:
Originally Posted by
MattKHardy
... This must point to the seating of the Graflok?
That's where I'd look. From the look of the negative, the light-strike is definitely happening in-camera.
BTW, taping flaps on filmholders does nothing but hold the flap... The flaps have baffles, and as long as the flap is closed, no light makes it in from the bottom. The tape is just a hinge (and keeps the flaps from falling off :) ).
Keep at it; you'll find the problem eventually.
Best,
Doremus