John, from looking at your frame grab, I can tell you were shooting with a 35-III version 3 camera. That was the last version of the 35-III. It was the 35-III that is guaranteed go to 130fps with out worrying about long- term damage to the motor’s armature cage under high centrifugal forces.
Yes, the 2 horizontal light lines are a reflection from the 2 chrome bars on the pressure pad on the gate. The 35-III v3 was the only version that had the 2 chrome bars on the pressure plate.
This model also had the ‘washboard’ film guide (aperture plate), and gate with the pressure pad.
“Less obvious, there's also a series of smaller horizontal lines running along the whole right edge of the image. Again, these lines mirror the surface of the pressure plate.”
Those lines are the edges of the ‘washboard’ gate. Arri had this to say about this design:
‘A fixed gap film channel keeps the film in an optimal position between the film gate and the film guide. The special finish of the filmgate guarantees minimum friction at all filming speeds.’
35-III version 3 gate:
‘though are somewhat shiny on the pressure plate side, as they have similar "ridges" where it seems the black paint has rubbed off.’
The valleys between the raised ridges seem to be painted black, but I can’t see how the paint would have been removed or worn down, over cleaning possibly. Would need to see more pics of your gate/pressure pad or film guide showing the worn spots.
However, your statement told me the cause of your problem right away.....
(I’m surprised you didn’t pick up on this, Simon)
"I'm also wondering if the lack of an anti-halation backing on the b&w film exacerbates the issue."
I have to ask, light heartily, why were you shooting film with no anti-halation backing in an Arri 35-III? All the late model 35mm cameras, along with Arri, were cameras designed for film WITH anti-halation backing. They had shiny gates/pressure pads, or parts on the pressure pad that are shiny.
Was there an effect you were trying to achieve because of the lack of the anti-halation layer? Usually, when shooting without the anti-halation backing, one would want the effect of the light bouncing off the shiny pressure plate back onto to film to create a 'halo effect' around the subject. I don't think there is a filter that can replicate that look.
Did you shoot any film with anti-halation backing with this camera for your project? If so, was it ok?
Anti-halation Backing: The anti-halation backing is the dark coating applied to the back of the base. It is there to prevent light from passing through the film, reflecting off of the pressure plate, and then passing through the film again, causing a flare or flash in the image or a double exposure.
Light penetrating the emulsion of a film can reflect from the base-emulsion interface back into the emulsion, causing a secondary exposure around images of bright objects. This secondary image (halation) causes an undesirable reduction in the sharpness of the image and some light scattering. An antihalation layer, a dark coating on or in the film base, will absorb and minimize this reflection.
In the mid 1990's, commercial shooters re-discovered Infrared film. While Infrared film (RIP Kodak Infrared film) had its own unique characteristics, it had 1 thing in common with your film, no Anti-Halation backing.
Clairmont Camera met the demand for cameras that were able to handle Infrared film by making black pressure plates to solve the 'halation' problem. They wrote a Tech article about this for their site:
There can be problems with certain cameras using infrared film. The black & white infrared film is very translucent and the color infrared film, though less translucent, is still a problem. Because of this, the camera must have a black pressure plate or the light will pass through the film and reflect back causing an exposure problem and making the photographic impression of the shiny bars on the pressure plate. Arriflex 2C's and Mitchell cameras do not have this problem since they do not have chrome pressure plates. All the modern cameras have chrome pressure plates. Clairmont Camera can provide black pressure plates for the Arri 435, Arri 3's, Moviecam and Eyemo cameras and we're working to get black pressure plates for all other cameras.
A II-C pressure plate...
As you can see the pressure plate is solid black, so no light would bounce back (Ok, there’s a small scratch in the black paint on this pressure plate, but this camera has only run film with Anti-halation backing. This is also a gate pic from an Arri II-A, but the II-C gate is the same). Or, you could remove the black paint and have a shiny pressure plate to create the halo effect.
The fact that the metal tab on the G.G. is missing, is not good. Not only for light piping as Simon explained, but also for proper seating of the G.G. in the metal holder on the camera. The spring loaded retainer is set for the thickness of the metal plate with tab. Your G.G may not have been seated properly (effecting left to right composition). Remove the aperture plate/film guide, and you can gently push the defective G.G. out. Replace that or repair it.
As for light coming from the lens and bouncing around causing reflections and fogging the film, my 1st thought would be from the ground glass surface facing the gate.
Arri fought this problem since the inception of their spinning mirror shutter for reflex viewing. It has to do with the proximity of the G.G. to the aperture. The 35-III was the next generation from the 2-C, but the problem was still there, somewhat lessened, lack of 3 lens turret on the 2-C, but still a possibility. The 435 eliminated it, as did Arri’s 35 BL series of cameras.
Arri solved this light scattering problem with ‘light baffles’ on the Arri I, II, II-A, II-B, II-C and 35-III. They claimed it eliminated the problem.
Please take a moment to read this article linked here, page 105. It explains what is going on with the baffles.. middle of the page...
Up to the 2-C, there are 4 matte black baffles over the G.G…..
(the next 2 pics show the baffles reflected into the closed shutter)
The 35-III reduced it to 2 baffles (no G.G. in holder).....
But, some opertors hated the 4 baffles on the 2-C, and the 2 baffles on the 35-III…. a distraction for framing while shooting..... waaaaaah. With the rise in popularity of video assist, many questions were asked in video village by the client…’what are those 2 black lines for?? Will they be on my film??’
So, some people not understanding what the baffles were for, started pulling them off….’aaaaah, you don’t need them, they just get in the way’ .. etc.
Well, they do prevent stray light from scattering and flashing the film. I never shot with a camera with them removed. There was always talk of…. ‘well, in certain conditions’. But no one ever listed those specific conditions. One was kept guessing. (to this day)
John, did your 35-III camera have those 2 light baffles removed? If so, that could be part of the problem, especially in low light conditions.
All the suggestions given by the other posters in this thread are great, and should be checked also.
What you should do to trace this problem down is, get the camera and lens you used, recreate the set-up you originally shot with the same lighting and light levels, shoot it with the B&W film without Anti-halation backing and then shoot it with film with Anti-halation backing. Then compare the 2 films.
After looking at your frame grab, I’m still leaning towards the B&W film with NO anti-halation backing as the problem.
I would like to know what film you were using. And again, what look were you going for. I’m all for experimenting with different film stocks, love it, and I applaud your efforts going for a different look, I’m sorry you had a problem.
There is another light reflection problem that has a name that I can’t recall. It’s where the light forming the image is reflected off the emulsion back onto the rear element of a fast lens (large rear element) that is close to the aperture, it is then reflected off that rear element back onto the film causing a superimposed ghost image around the original image. Anyone ever hear of that? I think it was Panavision that discovered that phenomena.