Wednesday, September 12, 2012


All film cameras operate essentially the same. What works on one usually works with all. The setting of the ASA speeds, shutter angle, f-stops, etc, is the same with the Bolex 8mm series as it is for most all other 8mm, 16mm, 35mm,  and 70mm film cameras. Good thing, too. Lots of information freely available online and published.

The ASC  "American Cinematographers Manual" is the standard. There are actually 2 manuals now. The film and the newer video manual. You'll want the film:

I looked. There are a few there. Both new and used. These used to typically sell for $5-$10 used, but have become somewhat scarce in the last few years. 

See also amazon:

The manuals are updated every couple of years or so. The manuals typically cover the cameras used in that previous period. The 5th edition even covers Bolex 16mm cameras!

These are the topics from the index of the "American Cinematographers Manual", 5th edition, 626 pages, 1980:

Cameras 65mm
Cameras 35mm
Cameras 16mm
Film Stock
Exposure Filter
Miscellaneous equipment
Lab Procedures
Special Effects Photography
Special Techniques.

No 8mm material, but a lot of charts, graphs, and picture of old film equipment, etc, but still very much useful for the 8mm cinematographer. 


Film not running consistently? Film jams up in gate? Film tears at sprocket hole? Film runs a foot or two and then the camera stops? Could be a couple of things. Try this:

1) Fully wind the camera and prepare to shoot film normally. If you can, use old, damaged or expendable film stock. Worst case, use good film and perform work described below in a dark room to preserve the film. Press run (film) button so the camera runs and hold the button until it jams.

2) Stop filming.

3) Place the camera flat on a table or in palm of hand with door upward.

4) Open door all the way. 


5) Lift camera still holding flat with open case pointing up. With one hand, reach under the camera and press the run button.

6) Look at BOTTOM (take-up) reel. Is it turning?

            Yes = Is top reel turning also? Should be.
            NO = film is jammed in gate. Most likely claw is not engaging
                      sprocket holes but is in between holes. 

Goto #7.

If everything is okay and camera continues to run indefinitely, goto #10.

7) TOUCH NOTHING - Look at film coming from pressure pad and going to take-up reel. The film will rub against the suede roller. Which, by the way, does NOT roll or rotate with film direction towards the take-up spool. It's there so the film can be back wound using the back wind key to make a dissolve or in non-back wind models, its there to supply 'drag' for the take-up reel.

A) With a finger, try to rotate the take-up reel clockwise. It should not turn more than a little bit. If it doesn't turn, the film is most likely in the reel slot. If it continues to turn and turn and turn, most likely the film has popped out of the reel slot. 

If the film pops out of the slot, the next time the claw tries to engage, the upper spring roller may pull the film backwards a small amount. Now the claw cannot engage. If the film has popped out of the reel, make sure you have at least 1-2 turns on the take-up reel. I usually cut a "vee" shaped on the end of the film to make it easier to insert into the slot. If the film slot slippage isn't the problem, goto B.

B) Remove both reels of film from camera. Close the pressure pad, run the camera. Lower spindle must be turning. Pinch the lower spindle with your thumb and forefinger. Spindle should stop with light pressure. If not, that is, the spindle requires a good grip to stop it, the spindle may be partially or wholly seized up and it need to be maintenanced or replaced. 

A partially or fully seized spindle can tear the film sprocket holes as the overrunning clutch in not working properly. The overrunning clutch supplies the drag in proper proportion to pull the film onto the take-up reel and at the same time, NOT damage the film's sprocket holes from excessive pull. If the spindle is ok, goto 8.

8) Put camera on table fix the jam problem. Reload the camera if necessary. Wind the camera's motor. This time, leave the door OPEN and facing upward. Reach under as before and press run button. The film should advance. Let it run at least 15-20 seconds.

            a) Note take-up reel. It should be turning clockwise.
            b) Note supply reel. It should be turning clockwise.
            c) Note upper spring roller where film coming off of supply reel
     makes bend over top of the gate area. The spring roller should
     be going up and down or in and out depending on your view.
     But it should be moving...

9) If it looks like the film is moving through the gate okay, stop filming. Wind the camera. Put door down towards the camera reels. DO NOT turn the lock on center of camera film door. Leave it unlocked. Press run button. You should hear the same filming sound as the film moving normally through the gate.

10) Stop filming and lock the door. Wind camera and press run. If film still jams now, suspect film door damage or that the door is out of alignment.


Because all of our cameras have been rebuilt. 

Consider the cost of an eBay camera at $25 to $75+. It  will typically be in non-serviceable condition. Okay to collect or put on the shelf, but not good for filming. Most of the cameras bought off of eBay will have something wrong with them. All will need to be serviced. After 35 to 50 years of sitting in a closet, the grease and oil will have dried up. That means total disassembly, cleaning and rebuilding.

If you buy an eBay camera, the chance of getting one with all the major assemblies in working order are slim. Usually one of the following will be present:

Fungus in lens or viewfinder
Dirt or rust in viewfinder
Broken spring motor
Light meter inoperative
Battery leakage damaging something
Spring Motor left wound- now unusable
Grease so hard the gears won't turn
Speed regulator faulty
Parts missing
Previous owner tried to "fix" the camera
Leather bindings loose or missing
Plastic dials cracked or missing
No single framing
Film unable to pass through gate
Lightmeter inaccurate
Speed control not working properly
Enter problem here_____________________

If additional parts are necessary in order to fix the first camera, a second camera will have to be purchased. No new parts for these 50+ year old Swiss cameras. Cross your fingers that the second camera doesn't have the same problems as the first. 

Disassemble both. Select the good parts. Clean, lube and replaced all damaged parts. Recalibrate light meter, etc. Clean case and polish. Add all the money you just spent. Don't forget 2x postage, insurance, etc. Multiply the total hours spent to learn and do the work. Add that to the camera parts. What's the camera worth now? $200, $500 – more?

Oh, I almost forgot. Be sure to add the tools, manuals and skills necessary to do the work. The learning curve isn't very long.  Of course, you'll make some mistakes. Loose some parts. Get frustrated.

Maybe that camera at Bolexrepair was a good deal after all!



I did some single frame shots. Then I went back to doing normal filming. After about 5 seconds, the camera stopped. I can wind the camera, but the film only runs a few seconds before the same problem appears. What's wrong?


Sound like the film has lost its registration. The claw is unable to register into the film so the camera stops running. Fix is to remove and reinstall the film to reset the "loop". Do this in the dark of a closet or inside a changing bag and you can continue to use the film as it will not have been exposed. Done with the film exposed to light will "fog" the film. See below, also.


How do I change film in daylight if the entire roll has not been shot?


Use a changing bag. A changing bag is a dark (usually black) cloth (or plastic) bag sufficient in size to hold both the camera and the film. It's construction design makes it "light tight". The camera and film are put into the bag and the operator (film changer) inserts his hands. Sometimes there is a drawstring to pull, that eliminates any light from entering. Film can then be installed or removed without fogging the film. Exposed film is returned to the canister it was originally supplied in. Here's some links to bag sellers:

You can also find others by searching for " film changing bag" at


I seem to be having problems getting my P1 Bolex to focus. Focus is okay for close subject, but when I zoom out (telephoto), the focus changes. How do I do both?


Using Zoom lever, zoom out to the farthest telephoto point past subject. Open camera iris all the way (smallest number or f=1.9). This lets in the most light to make focussing easier. Focus using split image on subject or horizontal or vertical line near subject. Now readjust eyepiece (diopter) for sharpest view. If necessary, repeat focussing and viewfinder adjustment. Focus is now set. Diopter is set. Use zoom lever to reframe subject. Adjust iris for correct light. Shoot film.


I can't seem to find fresh film. Any suggestions?


 Most sellers also do or can have done, your film developing. Some can transfer to Mini-DV or any other video format for editing, at the same time. Ask.


I can't find a replacement battery for my P-1's light meter. The original Mallory RM450 (mercury cell) is no longer manufactured. What can I do?


There are several "fixes". The least intrusive is to use a "WEIN CELL (MRB400)" and a spacer to take up the difference in length. The WEIN cell (1.35-1.4 VDC)  is the correct voltage, last about a year and does not requires any internal modifications to the camera. It is quite a bit shorter so a spacer is required. Depending on which is inserted first, the spacer(s) should be insulated. Some kits use flat washers as spacers. Out kit uses a double insulated aluminum "slug" style spacer which goes in first. Then WEIN cell is inserted with the PLUS (+) sign showing. Then the screw in cap is put in place. No other modifications or recalibration is necessary.


On my Bolex Reflex P-1  there appears to be dust or black speck in my viewfinder. Will this cause any problems?


If the dust or black speck is in the viewfinder, it will not show on the film. The Bolex viewfinder shows an image that is reflected off of the light that passes through the lens onto the film. Small amounts of fine dust on the primary front lens will not be shown either. You should clean or at least check the lens to see if it is clean before every shot. The viewfinder diopter is removable. Turn counter clockwise to unscrew. Don't loose any of the thin spacers that may be there. These spacers adjust the initial range of diopter focus. You can clean both the front and back elements of the diopter using a Q-tip or lens paper. Remove dust or contaminants carefully. Viewfinder lens elements are not coated, but like all glass, can be scratched. After cleaning, reinstall using same spacers. Tighten using the outer part of the diopter with the rubber eyepiece removed.


What is fogging?


Fogging is a condition whereby light contaminates unexposed film causing the film to have a "foggy appearance". This can happen when changing film rolls in sunlight or otherwise exposing the film to unnecessary light. Use a changing bag or at least, change film in a shaded area and run at least a few feet of film before shooting.


I think I overwound my Bolex camera. What is overwinding and how does it happen?


Bolex cameras are powered by a spring motor. The spring motor has a small set of gears that "turn limit" the total amount of turns the spring motor can be wound. This is about 11 ½  full turns for the 8 mm Bolexs. If too much (excessive) force is applied once the turn limit has been reached, the gears will "jump" one over the other. The camera will wind but only a small amount. It will then only run several seconds. The fix is to remove the spring motor and reset the gears to their proper relationship with the internal spring of the motor. If the camera has been left overwound for several years, the spring will be damaged beyond repair.


Bolex 8 mm cameras were very popular during the 1950s through the 1970's. That make the typical case about 45+ years old. Leather is a very durable material, but only if case maintenance is performed on a regular basis. Most cameras cases have been stored for very long lengths of time and not in good condition.

The first damage usually occurs at the attach points for the two strap ends. Flexing the most, one or both ends will break. By this time, no treatment will return the leather strap portion back to normal use. It's too dried out. The case itself is usually in better condition, even without regular maintenance as the exposed (inside)  part of the case does not dry out as quick.

To clean and recondition a Bolex cases, gently clean any dirt or grime on the case with leather cleaner. We at use LEXOL brand cleaner. LEXOL is pH balanced for leather and helps the leather to remain flexible. Follow the instructions on the cleaner. Then treat the leather with LEXOL Leather conditioner.

The condition will soften the leather and prevent cracking. Lexol products are available at most larger hardware stores. Any leather cleaner and/or conditioner can be use, such as "saddle soap", etc. Lexol is about $7.00 per 7 oz bottle for either the cleaner or conditioner. Lexol is the accepted standard for cleaning and preserving leather.

Use a small, stiff bristle brush to loosen any caked on dirt inside the case and either vacuum or blow out with compressed air. Sometime the inside "lid" of the case (hold filters) will come unglued.

You can use any common "white glue", such as "Elmer's"  or rubber cement ( we use "Pliobond" brand) to re-attached the inside top lid. If you use rubber cement, coat both inside of the case and the back side of the lid with glue. Allow to dry tacky. Press both pieces together. With a minute or so and then pry the two apart. Then assemble one last time and put pressure on the lid to hold in place until the glue sets. New leather straps can be attached to the existing leather band which is usually still on the case. Be sure to use rivets or other mechanical fastener to attach the strap to the case. I have seen glued straps. Not a good idea.

bolex leather cases.doc



Note the orientation of the small copper backwind roller spring. It's located on the very bottom end of the cover (as installed). On the other end is the film tension roller. Note its orientation. I suggest a small, hand drawn diagram if you are not sure of how the orientation of these two parts are installed. Install with the film pressure plate removed. Before attempting to install, push the lever (in the center of the cover) towards the gate (lens) of the camera (as installed). This will place the index pin of the pressure plate release in the correct position and make installation possible.

Insert with copper spring end (left side) first. Then center to mounting screw hole, while holding the film tension roller between right thumb and forefinger. I can do it first time usually, but anybody not familiar (no experience) will usually loose (fall off the cover) either or both the small copper backwind roller spring and the film tension roller. Then they won't know which way to install, etc. A diagram really helps. It’s a 3 step process:

1) install small copper backwind roller spring

2) center screw over hole

3) install film tension roller and move end of same into small hole in top plate. The cover supports one end, the hole in the cover plate supports the other.

When the cover is in place, the backwind spring will engage the backwind roller 'teeth", and the bottom end (tip) of the film tension roller will be in it corresponding hole. Some cameras have a plastic spacer on the tip. You can use a very small amount of grease to hold the spacer in place.

Now insert lid latch button and screw. The lid latch button sometimes has a 'lip', so there is an "upper and a lower" side. This lip compensates for the door closing clearance. It is not found on every camera. If the door will not lock or is loose, remove the screw and flip the button upside down. If this doesn't help, the problem is usually with the cover not being centered.  You can actually 'feel' a click when the cover pops into place. Don't force anything.

Check that the small copper backwind roller spring does indeed work by trying to roll the bottom roller back and forth. It should go only one direction, indicating the spring is doing its job. Check the film tension roller. You should be able to push it towards the front of the camera and it should pop back on its own. If not, the spring supplying tension has slipped. Remove the cover, reset the spring (use diagram now!)  and start over.


Ektachrome 100ASA 4x faster than the 25ASA film shot in Bolex's B8SL. So, some adaptation is necessary. This particular Kodak film is rated at 100 ASA. Your camera is set up for 10-25 ASA film. The shutter is fixed. Because it's fixed, there is no "half-shutter" option.

Later Bolex 8mm cameras do have a variable shutter, and can do a half or even less shutter. Closing the shutter has the effect of cutting the amount of light entering the camera by reducing the shutter angle. 

Shutter angle is the time as expressed in either:

1) degrees of angle and 

2) fractions of a second when computed with the Frame Per Seconds (FPS) setting of the camera.

To use a 4x faster film (25 ASA compared to 100 ASA) you need to cut the light in half, two times, or 2 stops. 100 cut in half is 50 ASA, 50 ASA cut in half is 25 ASA.

You can do this by several ways:

1) Using a neutral filter (ND) to cut two stops. Referring to the ND CHART located here:


It says that a .6 ND filter will cut two stops. You will need a screw-in type filter holder compatible with the thread of the lens used. Camera stores sell these. Although, they made need it to order it for the Bolex lens'. You may or may not also need and adapter ring to adapter the thread sizes.

Sometimes the lens threads are not the right size and use of a step-up ring/adapter is common. Avoid using two or more filters. Although a .3 ND (1 stop) and another .3 ND (1 stop) do add up to a .6 ND (2 stops), the use of multiple filters can sometimes introduce artifacts. Especially if the camera points towards a strong light source.
2) Close the lens f-stop by 2 stops from what the manual tells you to do. This effectively compensates the 100 ASA film to act as 25 ASA as its now not getting enough light (2 stops less). This is what John Schwind recommends. Unfortunately not all Bolex 8mm lens are capable of stopping down to f-22.

3) Calculating the actual f-stop required with a light meter.

To calculate the actual f-stop required for any film requires using 1) shutter angle, 2) film FPS (speed) and 3) the film's ASA number. Once the f-stop is calculated for that particular films ASA number, you need only dial it in on the lens.

From the tag located on the Bolex's body, and referring to the "American Cinematographer Manual", 4th edition, I calculated (estimated) the shutter angle for the camera running at 16 FPS, to be 170 degrees or 1/35th of a second. We'll use this "ballpark" setting of 135 degrees for filming at 16-18 FPS.

I'm indoors. Using a Sekonic Studio Deluxe L-398 light meter, I set the ASA to 100. Then I put dome of light meter under chin of subject after the indoor lighting is set. Then press and release the meter 'read' button. The meter shows the incident light reading falling on the subject face.  I might check a couple of other places in the scene where there might be more light in the background than on the subject. If there is 2 people, I would check them both. The light reading of the subject is the reading I'll use.

This is one way to take a meter reading. Hollywood cinematographers use this method commonly. Then, I turn the meter's EV/F-stop "dial ring" until the pointer points the incident light value. In this case, it's about 40.

I look at the "cine scale" and read the f-stop opposite the shutter angle which is expressed in fractions of a second. I know the angle is 1/35 of a second. I see the numbers: 1/30th and 1/60. I figure the value is under the "0" of the 30 (slightly to right of the 30 mark). 

Opposite that 1/35th value (guessed!) I see the f-stop scale. It says about F-2.0. I try to set f-2.0 on the camera lens. I see that the lens I'm using only goes down to f-2.5. Not enough light. Solution: add more light(s). A half stops worth. Since this is film, I could probably get away with using the f-2.0 setting anyhow. Picture will be slightly (1/2 stop darker) than "normal". Whatever "normal" is.  Keep track of finished footage. If consistently darker than you like, adjust f-stop slightly more open than calculated (more light).

Let's say I'm outdoors. I press the button, the needles jumps off the scale. Oops. Too much light outside. I insert the "high slide" that comes with the meter. The high slide cuts the light to a corresponding scale on the meter. I do the reading as before. The reading is about 140 with the high slide inserted. So, I read opposite the RED colored pointer (high slide pointer).

It says to use f-19 (best guess) for the f-stop setting. This lens goes to f-16. I need to reduce the light by 3 more stops. Looking in my kit bag, I locate a .9ND. That's 3 f-stops reduction. I screw it in and set the f-stop on the lens to f-16 which is the top limit of that particular lens.

There are other considerations. Lenses themselves are usually "little liars". They might say "I'm a f-2.5" on the lens barrel but they might test out to be f-2.9. .4 of a stop darker. And at the other end, the F-16 might actually be something else.

You might put a #85 filter on top of the ND to convert type A film to outdoor. The #85 filter handout says "cuts light by 2/3 of a stop".   2/3 rds of a stop plus .4 equals about 1 full stop. So knowing this, I might add one stop to the lens opening it up to f-16. And another adjustment is I may have used this film type before and it actually looks the best when shot through the Bolex if I set it to 1/2 stop more closed than what is calculated.

When the film is developed, it usually done on batches. If done towards the "end" of the chemical run, the film may be underexposed. Sometime you can ask the developer to wait until he changes chemical and then run you stuff at that time. Or your could pay extra and have you stuff given preference immediately. Ask you friendly developer for advice. Work with them. Ask them what you can do to bright down the processing charges and make their life easier. This is a common practice with film students.

Film has a high latitude for light. 1/2 to 1 full stop either way is typically considered, "ballpark". Not so with inexpensive digital video cameras where you only have a 5 stop range. Go one stop over the limit and the picture is blown out. No detail in the light areas. Go one stop to low and no detail in the dark areas. With film, if you keep records of how a particular film and light meter/camera combination looks when finished and what you did to get it that way, you can alter the final finished product by adjusting the f-stops one way or the other.

Or you can just slap a .9 ND and use the 100 ASA film! Keep a written record of how everything turns out. Adjust f-stops accordingly. If you film is consistently too dark, opening up 1 stop on that lens.










Links come and go, but you can always search for the article title