Ultra-16 Viewfinder for Bolex H16M… Super-16 similar ?

Maybe you remember I converted my Bolex H16M camera to Ultra-16.  Well, for a long time I’ve been using the normal Octameter side viewfinder and frankly guessing the U16 frame !  So it’s about time I pulled up my socks and finish the modification. I really just need to know the correct frame for a 25mm and a 50mm lens and maybe a 75mm too.  My Octameter does have the adaptor for 10mm, but I decided that it wouldn’t  work well with this U16 mod, so I removed it.

Here goes…  I removed the 4 screws that hold the viewfinder together. Two of them are long.  Also removed the two screws holding the parallax knob and withdrew it along with the circular scale.  Once prised apart  you’ll see a carriage with one fixed lens and another concave lens in front that moves along,  controlled by a rack and gear wheel.  The wheel is marked with the various focal lengths and at each position there’s  a click-stop formed by a ball-bearing dropping into a small hole.  Bolex engineering !

With the focal length set at 150mm it’s easy to unscrew the 4 screws that hold the front frame.  It’s prised off carefully without losing the two tiny leaf springs ! I then filed out the frame to 29mm and painted it matte black before reassembling.

Back to the carriage.  Now, it’s  relatively easy to adjust the finder to get a wider image than the normal 25mm frame, by moving the front concave lens forward.   But then it won’t have the desired click-stop.  So to get this it’s necessary to do some work on the carriage. Unscrew the rear fixed lens, also the 3 screws and one nut holding the carriage to the chassis.  Now the carriage can be easily removed.  It needs to be brought forward by a few mm.  So the two slotted holes at the front are filed out further, and about 3mm is sawn off.  When replaced, the rear screw and nut still hold the carriage,  but only just.  The carriage is pushed forward to maximum.   Also the front (moving) concave lensmount needs to be removed and the two slots made longer rearwards by about 2mm. Screw it back firmly.

Before I put the carriage  back,  the toothed wheel with the focal length numbers had to be set properly.  This is easily done when the carriage is loose but the ball bearing has clicked on… simply adjust the cogs until the 25 comes into the window on top.  Then screw back the carriage on to the chassis.  Photo shows the correct position for a 25mm lens.  The 35, 50, 75 and 100mm positions also click properly.  But 16 and 150mm do not work on my set-up.

Now I checked to see if everything was OK when attached to the camera.  I used a Bolex Gate Focuser to first examine the image, though tracing paper works fine as well.  The shutter obviously has to be opened using a backwind key.  For now I was just concentrating on the horizontal field of view,  making sure the two images were equal.  Bear in mind though the camera gate usually takes in slightly more than a viewfinder,  as projector gates are smaller.  I tripod-mounted the camera and observed distant objects. So there was no need to attach the viewfinder.  The gate image is obviously upside down etc.

When satisfied all OK I reassembled the viewfinder casing with the 4 screws, making sure that the parallax rod connects and turns properly.  Replaced the parallax scale and knob.  When attached to the door,  and parallax adjustment closed, the mark should show infinity.

Now time to do the top and bottom masking.  I used two thin strips of aluminium: they go into the slot on the front of viewfinder. First I blackened their visible rear parts.  The aspect ratio of Ultra-16 is 1.85:1.  My H16M gate is wider than that, but I wanted the correct ratio so that the finder could be used on different cameras.  As the front frame width is 29mm its height needs to be 15.7mm.  Camera on tripod again,  I aimed it at a horizontal line on the wall,  using the gate focuser accessory.  When the line was exactly central I withdrew the focuser and attached the door/viewfinder and again compared the image.  Then inserted the two masks and carefully adjusted them until they were 15.7mm apart,  whilst observing the horizontal line midway between. I marked the positions with a scriber,  then eased them out slightly and applied Araldite.  Pushed them back into position.  Later finished with matte black paint.

So now I feel much more confident using this Bolex H16M camera for Ultra-16.  It’s worth mentioning a Super-16 mod might be broadly (excuse the pun !) similar.   Now I can be sure about the framing for three of my prime lenses.  But not 15mm. For this I have another idea…. check back in a week or two !


Tricky 16mm loading made easier… the GIC camera

That first roll I tried in the GIC 16mm camera suffered quite a bit of edge-fogging.   This is because I wasn’t used to the loading and it was tricky,  getting the film around the sprocket…  took me ages !  Remember, mine is an early model that has fixed guides. They must have realised the difficulty.  Later GIC’s  are much easier to thread.

So for my next film,  another roll of Ektachrome, I decided to make things a little easier.  I have an empty 100ft black plastic film container that has a small slot I cut in one corner, lined with black velvet.  Sometimes it’s  used in the darkroom to begin loading a developing-tank spiral, the idea being this can be done in the light without fogging the film…. when ready I turn off the light, take out the spool and load.   For the GIC camera I withdrew about 18 inches of film, then calmly carried out the loading in a good light.  Much much easier.  When I was happy with the correct loops above and below the gate I ran the camera briefly.  (However, because the 50ft spool of film was still in the container I was careful that the film didn’t  quit the sprocket teeth, or back to square one.)   Now I turned off the main room light and took out the spool, easing it on to the feed spindle while holding back the footage-counter lever that bears on the edge of the film.  This is comparatively easy and quick to do in subdued light conditions.   So I reckon far less fogging, and anticipating this I started filming almost immediately.

Notice I’ve now blackened the inside rim of the camera door, to be on the safe side.  It’s a good seal but I suppose it’s possible for the two locking knobs to work loose slightly while filming.  Note also the two countersunk bolts I fitted to hold the viewfinder accessory-shoe.

Straight 8 is now open for entries !

Have you ever thought of making a complete film on one cartridge of Super-8 ?  But without changing anything afterwards… no editing whatsoever.  And to make things worse, how about screening it at Cannes to a packed audience this coming May… But you won’t have seen it yourself beforehand !  Sounds like the stuff of nightmares.  However,  people from all over the globe are doing just that:   http://www.straight8.net/straight-8-2018/

So if you have a simple idea that can be told in 3 minutes or so,  now is your chance.  Good luck !


Converting a Bolex H16M to Ultra-16, part 2

Last time we tackled the gate widening.  Now for the sprockets.  Because the film touches areas beside the sprocket teeth,  it’s necessary to remove any metal that might cause wear of the image.  Normally this wouldn’t perhaps happen but its better to be safe than sorry.  Removal of the two sprocket wheels is simple with a screwdriver.  Firstly though, ink a mark on the wheel next to a convenient point on the camera. Note there is an angled slot at the edge of each wheel that when lined up will clear the loop-former,  so turn the camera with the backwind key to get it in the right position.  Once removed, carefully grip each sprocket wheel in a vice.  In the photo you can see how much I filed off at each tooth.  It’s brass so quite easy.  Leave some metal at the base of each tooth and don’t damage the tooth itself. Finish off with fine emery wrapped around the needle-file.  Take your time !  Now turn your attention to the other side.  There are two ridges that normally support the film. Important:  don’t  touch the outer one.  The inner ridge needs to be removed.  This can be done with a lathe, or it’s not a long job to simply file it off.  As long as it doesn’t  touch your precious image there’s no problem.  So now you have sprockets that won’t harm the Ultra-16 image in any way.

Replace the sprockets,  ensuring that they are lined up accurately within their guides.  And also line up the ink marks as before.  Don’t tighten the screws properly yet.  Place some film in the threading path through the gate so that the claw engages it,  and close the loop-formers.  If necessary,  turn the sprockets slightly so that the film hugs the top and bottom loop-former.  By trial and error you’ll find the correct position for the sprockets,  and now fully tighten their grub-screws.  With loop-formers still closed, check the movement by winding the film by hand,  and finally by running the camera normally. Also check that the auto-threading feature works OK.  Now release the loop-formers and run the film at fast speeds to see that all is well.  Pristine unused film is best so that you can determine whether or not any damage occurs.  If it does,  it’s a simple matter to find the cause,  ink-marking the stationary film at various places along its path before you withdraw it from the camera.  An old projector lens is ideal as a magnifier.  Examine each perforation and its environs very carefully.

Next time we’ll look at the viewfinder mod.  Currently I’m  still tackling this !

to be continued…..

Dunkirk in Imax

(photo: Kathy Palmer)

If you get the chance,  do see Christopher Nolan’s  DUNKIRK in Imax. I found it stunning,  and the audience obviously thought so too. They clapped at the end.  And before the show, the manager of the BFI Waterloo Imax cinema gave a short introduction.  With arms outstretched he held up a 24-frame length of 70mm film,  with 15 perforations to each Imax image: they run horizontally.  That’s just one second of screen time !   He was keen on putting on more 15/70  presentations,  a refreshing attitude.  At present the digital Imax is 4K resolution on a smaller screen.   And the adverts we had been forced to watch (too large in my opinion) were only 2K,  he pointed out.  There was glee in his voice:  “Now you’re going to see 18K ! ”


As for the film,  great acting from Kenneth Branagh and Mark Rylance and others.  Very realistic sea and air action.  Fantastic sound effects.  Effective music…  Do see it.  I don’t think it will look much though on a small screen.   However,  another alternative is traditional 5 perf 70mm projection.   Indeed,  most of the sparse dialogue was done in 5 perf 65mm,  with black bars top and bottom of the huge Imax screen.   A similar method was used in Nolan’s previous movie INTERSTELLAR  but that was 35mm anamorphic. This time it’s less distracting.  Why not shoot dialogue in Imax ?  Apparently the cameras are just too noisy,  and Nolan doesn’t like adding dialogue afterwards.  However,  the close shots of pilots radioing were seen in full Imax:  their mouths were covered and not visible !


Converting a Bolex H16M to Ultra-16, part 1

For some years now I’ve owned a little-used Bolex H16M camera, and had a yearning to modify it to Ultra-16.  Whenever I attempt something like this,  I first satisfy myself that the camera’s  registration is rock-steady. See  https://filmisfine.com/blog/how-steady-is-your-movie-camera/

Having no turret like most Bolex’s,  it’s quite easy to get started on the job.  It goes something like this….

Remove the leather and nameplate to expose the lens mounting plate.   Put the camera out of springwound mode and ready for backwinding.  Use the backwind key to take the shutter away from the gate area.   Remove the 4 big outer screws and gently ease off the lensmount.  Unlike the more complicated Bolex models, there’s no problem upsetting the timing.

Inside the camera remove the back pressure pad.   Unscrew the gate mounting-plate,  but as a guide for replacement its a good idea I think to firstly mark around the edges with a scriber.  Now remove the 4 small screws that hold the gate, and slide it out gently from between the side leaf springs.  It goes without saying that the gate must not be scratched at all.  Don’t  remove the top and bottom bolts.

The gate needs to be enlarged sideways to bring it out to 1.85:1  ratio.  The area between the perfs (by the frame-line) that is seen in Regular-16,  won’t be visible.  Although of course the image carries on being formed in this area,  so it is possible to use the camera normally as well.  1.85:1  is the same ratio as 35mm widescreen, if you are thinking of blowing up to 35.  With my modification I decided to go wider than 1.85:1,  something approaching  2.2:1.  However, I knew I would run into problems with the latent edge markings appearing within the image area,  unless I could find film-stock without these markings.   1.85:1  though has no such problem.  I was also a little concerned that the wide gate might not support the film sufficiently and cause unsteadiness or lack of flatness.  But happily this hasn’t happened.  The final width is 13.3mm,  leaving only 2.7mm to support the film.

Now for the widening !  I used a chunk of wood that I’d  used on another U.16 job,  attaching the gate firmly with drawing pins cushioned with cardboard.   Over the top I mounted a magnifying glass,  and started filing away with a needle-file.   Lots of breaks is a good idea with this kind of intricate work.  You don’t want to jab the gate by mistake.  Later on I changed position and filed from below, see photo.  I also paid particular attention to the top and bottom edges to make a smooth bevel,  and rounded off the corner bits where the film would touch.  Afterthought:  it may have been safer to completely cover the gate moreorless with card, as surgeons paper over patients !  Finally, I  wrapped fine emery cloth around the file and worked with this.  Then to finish off, the finest emery grade.

I now placed the enlarged gate into the mounting-plate again and loosely put it in position.  Obviously it was also necessary to remove some metal from the front plate,  so I first scribed marks either side and then filed away.  This is quite hard steel.  After finishing with emery I cleaned everything thoroughly,  then painted all the filed parts including the gate edges,  matt black.  When satisfied all was OK,  I reassembled the gate into the camera,  in precisely the same position and making sure that none of the 4 screws protruded.   With the camera laying on its back,  I then eased the lens plate back into position,  making sure the claw was out of the way,  and then turned the backwind key.  All looked fine and so I replaced the 4 big screws,  tightening them diagonally. Then stuck on the leather.

Next I loaded some dummy film and ran the camera.  The movement looked fine to the eye.  How it really performed would be tested later.  When the gate was taken off black paint came off also,  so I touched up all this again so that the important light seal would remain.  This is how the gate and front plate looks now, with some film loaded.                                       to be continued….

How Steady is your Movie Camera ?

DSC00165Good registration is extremely important in a movie camera.  It’s a good idea to put it to the test,  next time you have a few feet of film to spare.

Set up the camera on a very rigid support.  Perhaps a piece of wood screwed to the underside of the camera and then clamped on to a solid table.  Find a magazine or newspaper and tape it to the wall.  Focus carefully,  then shoot about 10 seconds of film.  If it’s a super-8 camera that’s it. You’ll see the result when processed. Actually it’s best to wait a few days after it comes back in case the film is still ‘green’ with some moisture in it.   On projection you can easily determine  whether the camera is acceptably steady.  Adjust the projector’s framing so you can see the frameline between the images, and  watch the newsprint to see if it moves against the frameline.  If the frameline itself moves it’s probably an unsteady projector !    By  ‘acceptably steady’  I mean just that.  The design of the film cartridge and the way the film is transported through the camera gate,  normally does not give an absolutely rock steady image.  Individual super-8 cameras do vary however, and you could be pleasantly surprised.

With regular 8mm and 16mm you have the choice of a more critical test.   Because the film is normally wound on a roll it’s  fairly easy to wind it back and do a second pass.  So any unsteadiness between the two images will show up clearly.  If your film has backwind it’s very quick and simple (keeping the lens covered !). Without backwind the camera has to be opened in the dark and the film rethreaded.  Using this superimposition method it’s best to underexpose each pass by one stop, so the combination is correctly exposed.  It is not necessary to align the images exactly.  The idea is that the small print in the double image will dance around slightly if the registration is not perfect.  A vertical jitter could be due to the claw in the camera not working properly, or more likely the pressure pad needs adjusting.  Horizontal unsteadiness is usually due to insufficient pressure of the side springs in the gate, if fitted.  A 16mm camera in good condition should give a rock steady image.  8mm cameras can be very steady too,  but are not usually as good because the projected image is magnified much more, and also the fact that most cameras are not sprocket-driven.   The film is pulled through the gate only by the action of the claw.

Once you are clear about how steady your camera is,  you will know its limitations if they exist.  A camera with less than perfect registration should not be used for intricate superimposed effects, and it may  not  be too good for static shots on a tripod.  On the other hand  it will likely look fine for handheld shooting,  as the natural movement in the image camouflages any unsteadiness in the camera transport.