View Full Version : Bush Pressman Light Leak... Where is it coming from?

30-Apr-2009, 20:36
Hey everybody,

I've been shooting lately with this Pressman 4x5 camera and Fuji Velvia quickloads with a Polaroid back, and about 50 percent of my shots have been showing a very obvious light leak/ flare that I can not pinpoint the source of. I got the same exact flare with both my 137mm and 120mm lenses, so I don't believe the lens is the issue.

Here are some example photos. All of which were taken on the same day, under overcast conditions.
This one is a really good instance of the flare. Usually it's only visible in the lower left hand corner, but this time there are two distinct instances.
This is a lesser example of the flare, also in the lower left hand corner. It's pretty minimal, but very distracting none the less.

This is a setup I took a test shot of before I set up my flashes. You can see the flare visible in the lower left hand corner, although it is cut off a bit toward the left side of the frame.

Here is the same shot as before, this time with the flashes. The F-stop has been closed down more and the shutter speed has been increased. The flare is minimized, but still present.

I don't see any pinholes in the bellows when I inspect it in the dark room. Does anybody have any ideas where the light leak may be coming from? Thanks a bunch!

Gem Singer
30-Apr-2009, 21:07
The light leak is obviously coming from the area where the Polaroid film holder meets the camera back,.

Either the Polaroid holder does not seat properly, or it has a light leak on the end where the film is pulled (where the rollers are located).

Perhaps you are accidentally separating the film holder from the camera back while pulling the film sleeve.

I had difficulty using Fuji Quickloads in a Polaroid film holder. Solved my problem by switching to a genuine Fuji Quickload holder.

30-Apr-2009, 21:11
Looks like it is sneaking in via the camera back -- perhaps where the holder sits in the film back. The light is coming in a shallow angle, since there is a shadow of the film holder keeping the film from being fogged at the very edge.

It looks like something easy to find -- just put in the Polaroid film holder, remove the lens and stick in a flashlight from the lens end (while in a dark room). A mini maglight works great for this -- take off the end of the flashlight so you just have a bare bulb (the light shines in all directions that way.) Pay attention to the right side of the camera (right side looking from the back of the camera) as that is the direction the light is coming from.

I have to do this ASAP with my 8x10 -- lots of light leaks from my last shooting sessions in Yosemite (the light baffles on the camera back are minimal on the Zone VI 8x10 -- one of its only faults...besides its weight).


Gene McCluney
1-May-2009, 09:25
Some cameras do not allow a polaroid back to sit flush, due to the end where the rollers are resting on the camera, pushing that end of the back away from seating. I don't know about your particular camera, but that is the most likely issue. Your examples show leaks coming from almost the film plane, which means it is SOMETHING right there very near where the film sits. The first thing to check would be the seating of the film holder. Second would be the seating of the back on the camera.

Alan Davenport
1-May-2009, 13:06
I've never used a Pressman camera, but I had exactly the problem Gene mentioned with my Calumet monorail (graflock back.) I had to mill off a protruding bit on the camera back that was lifting the end of a Grafmatic holder when it was inserted. You might have a similar problem.

Chauncey Walden
1-May-2009, 21:25
Grafmatics and Kinematics work fine on a Pressman D (but not on a B&J Watson Press.) Besides, the leak is on the other end. Karl, do you keep your dark cloth over your film holder when shooting and manipulating the holder?

Gene McCluney
1-May-2009, 21:38
Grafmatics and Kinematics work fine on a Pressman D (but not on a B&J Watson Press.) Besides, the leak is on the other end. Karl, do you keep your dark cloth over your film holder when shooting and manipulating the holder?

If you turn the sample images upside down (as they would be imaged by the lens on the film in the holder, then the majority of flare is coming from the side that you insert the film in, the roller side. A properly seated and working film holder (of any type) should not need manipulating under a dark cloth.

1-May-2009, 22:50
Thanks for the replies everybody. The Polaroid back is an older metal one, so it's possible it may have a leak. The same could be said for the Pressman as well. I'll be checking the camera as Vaughn suggested a little later.

Regarding the dark cloth question, I do not keep the cloth over the holder when I'm shooting. It's possible that light is sneaking in.

2-May-2009, 05:08
Holder is not seated right. Take the back off and insert the holder and look at the back and where the holder sits. You will see at the end where the holder slide into the back it is not seated right.
Causes may be the back does not let the hold go all the way in so the lock rib does not sit in the grove, something on the roller end is preventing the holder from seating right.

Chauncey Walden
2-May-2009, 09:11
Gene, by other end, I meant the darkslide end. The problem with Grafmatics and Kinematics on some cameras comes from the first inserted end riding up on the far end of the slot and causing a light leak on that end (the right side in an image). As for the darkcloth, that is called "insurance";-)

Chauncey Walden
2-May-2009, 09:16
I had no problems using an old 500 Polaroid back on my Pressman D with Polaroid or Readyload films. Are you using a 545, Karl?

2-May-2009, 09:25
While we are discussing Fuji Quickloads......
Do they work ok with Kodak Readyload holders?
David Silva

Ivan J. Eberle
2-May-2009, 16:35
QL work well in RL holders, I've found, but hear that RL don't work as well in QL holders (now that Kodak has extincted RLs).

For the OP, the Pressman Ds have revolving backs, I'd pay particular attention to the light-trap here as well. What I did when I thought I might have a similar light leak with my Meridian was to rack the bellows out with a Maglight stuffed into the front standard, sealed with gaffers tape. After a minute or so in the darkroom, it was soon obvious that a Readyload holder was the cause instead.