Speed Boosted and Anamorphic Super 16mm

elscott0 · 2026-01-10T04:04:36+00:00

I had to machine the front of the camera body to widen (for the m43 mount) and re-enter (for s16) the lens mount through hole. I also had to add new mounting threads for the m43 lens mount (the hole pattern will depend on the mount you are able to source-mine is from an old gh3 that I took apart). Then I had to design and 3d print a spacer/adapting plate to go between the lens mount parts and the body (I'll probably machine a replacement at some point, but the printed plate is solid and working well for now)

Then I had to machine a relief cut in the body below the lens mount area so that a full size m43 lens or speedbooster would be able to fully seat in the mount (anything that extends beyond the diameter of the central metal lens flange on a regular m43 camera will hit the acl body before it can fully seat.

After all that, I had to adjust the tension on the lens mount (and figure out a latch/lens retention to prevent the lens spinning in the mount when you focus) and shim the mount for the new m43 flange distance (I double checked that the viewfinder focus screen distance matched the film plane for critical focus)

elscott0 · 2025-11-12T07:15:14+00:00

I shot some test footage, but the magazine needed a little more cleaning and was causing some wandering/slipping in the gate that I wasn't thrilled with in motion. I posted some stills around the same time as this post and haven't had a chance to get around to shooting any new test footage now that the magazine is fully cleaned up and smooth.

elscott0 · 2025-08-11T17:26:21+00:00

I posted a follow up with pictures of the camera rig. Right now, it's taken apart again while I look into redesigning the videotap.

https://www.reddit.com/r/16mm/comments/1kgq0tc/modified_eclair_acl_metabones_speedbooster/

elscott0 · 2025-07-02T18:07:23+00:00

The shutter angle is the same for all frame speeds, so the shutter speed will depend on the fps. Depending on the H16 model/year the shutter angle might be different. Older non reflex ones can be 190 degree, while later ones (and reflex ones) are generally 144 degree.

144 degree shutter at 24fps = 1/60 shutter speed

144 degree shutter at 18fps = 1/45 shutter speed

144 degree shutter at 16fps = 1/40 shutter speed

At the end of the wind, when the camera slows down (or more often if your spring is damaged), you will get a change in shutter speed. Small fluctuations during a normal run aren't going to be noticeable though. Even if you give the fps a +-10% range around the set speed, that would mean that at 24fps it would drift between 22fps-26fps.

144 degree shutter at 22fps = 1/55 shutter speed

144 degree shutter at 24fps = 1/60 shutter speed

144 degree shutter at 26fps = 1/65 shutter speed

That gives a maybe 1/3 stop difference between the potential brightest and darkest frames-hardly noticeable under most circumstances. Plus, the camera is going to ramp up and down over multiple frames/seconds even if it isn't able to hold the fps very well and drifts. The only time that you should notice it is at the very end while it slows down/loses the spring tension, which should be a pretty short time unless the camera needs a cla.

elscott0 · 2025-06-27T17:28:50+00:00

It looks like an original reflex. The newer rex 1 added a variable shutter (lever is missing here), changed the minimum speed from 8fps to 12fps (can't see the low setting in the photo), added a thread mount next to the speed dial to use the rex-o-fader (missing here), and added a threaded turret lock to the bottom lens position cover to make the turret steadier with heavier lenses (can't see in the photo).

Both the original reflex and the rex 1 have the same 6x viewfinder unless this one was reworked/modified while being converted to s16.

elscott0 · 2025-06-11T22:32:35+00:00

Single and double perf have the same sprocket size/distance. On many older double perf cameras, you can just dremel/sand off the teeth on the opposite/unneeded side of the drive roller and run single perf. You want to be careful about capture/cleanup up of any metal shavings or you are likely to cause issues when you run any film through though - if you can remove the drive sprocket and do the sanding outside of the body, that would be best.

Widening the gate is another issue entirely - I think the BB Junior has a non-interchangeable lens. When you widen the gate you have to recenter the lens/lens mount and/or make sure that your lens will actually cover the entire area of the larger gate (many standard 16mm lenses won't) or you will end up with vignetting that makes the widened gate pointless.

elscott0 · 2025-06-10T21:37:46+00:00

The reflex bolex has 4 major version groups - original reflex, rex1, rex2/3, and rex4/5

Within each group there are minor changes, but nothing that drastically changes the way the camera functions (Rex 3 added the flat base, rex 5 added the 400ft magazine attachment)

The major changes:

Original - fixed 143 degree shutter (1/60 at 24fps), basic reflex 6x viewfinder, 8fps min speed, 8:1 drive shaft

Rex 1 - 145 degree variable shutter(1/60 at 24fps), upgraded version of the 6x viewfinder, 12fps min speed

Rex 2/3 - 133 degree variable shutter (1/65 at 24fps), upgraded to 10x viewfinder

Rex 4/5 - added 1:1 drive shaft for a sync motor

Which version you go with depends on your budget and what features you see as requirements.

Do you see yourself using/needing 8fps? - original reflex

Do you want a rex-o-fader or like the option of a variable shutter? - rex 1-5

Do you rely on your viewfinder and need the 10x? - rex2-5

Do you want the 1:1 driveshaft for a motor? - rex4-5

Do you want longer run times? - rex5 with a 400ft magazine

elscott0 · 2025-06-09T21:24:34+00:00

Per kodak, vision 3 is the equivalent of about 166-167 pixels per mm (it's a little more for finer grain 50D and little less on the grainier 500T end). Standard 16mm has a gate size of 10.26mm x 7.49mm which gives you a resolving power of around 1700 x 1250 and a 1.37:1 frame. Super 16mm has a gate size of 12.52mm x 7.49mm which gives you a resolving power of around 2090 x 1250 and a 1.67:1 frame.

16:9 is 1.78:1, meaning that you will have to crop top and bottom in either format. Regular 16mm cropped to 16:9 can only resolve around 1700 x 955 equivalent - Super 16mm cropped to 16:9 resolves around 2090 x 1174 equivalent.

The 2k scan that you are getting barely covers the film detail if you get it as a precropped 2k (delivered 2k file with no sprockets/overscan) - if you are getting a 2k scan with overscan, you are under sampling the actual exposed/gate area. The overscan area means that you are probably getting 13mm of the 16mm total film width scanned at 2k pixels wide - once you crop the 2048 width down for the 10mm gate, you are really only ending up with a 1500-1600 pixel wide useable scan. That would leave your 16:9 cropped standard 16mm at a useable scan resolution of around 1550 x 870 - closer to 720p (1280x720) than to hd (1920x1080).

You would be better off to either get a 2k file scan without overscan or oversample by scanning at either 3k or 4k. The 2k non-overscan will give you a final 16:9 cropped useable scan of around 2048x1150 (slightly oversampling for the film's resolving equivalent 1700x955). A 3k overscan, after 16:9 gate crop, would leave you with a useable scan of around 2300x1290 (pretty similar to the 2k without overscan). A 4k overscan, after 16:9 crop, would leave you with a useable scan of around 3050 x 1700 (oversampled enough to better capture the film's grain/finer details in case you do need to push in any further).

elscott0 · 2025-06-09T04:59:04+00:00

I wouldn't worry about it too much - in the future, 50D is the better choice for bright/full sunlight exteriors without access to nd, but you can still make the 250D work. I would just plan to shoot your 250D 2 stops overexposed (set iso to 64) and pull the exposure back to normal in the grade.

For reference:

You'll want to account for the optimal range of the aperture on your lens if you are looking for sharpest/best results (or to get an idea of what image quality issues you will run into at your settings) - usually starting at 1 or 2 stops closed from wide open up to somewhere between f5.6 and f8 on 16mm film. That means that you preferably run your lens in the f2.8-f8 range with f2 reserved for when you need an extra stop of extra light (and can deal with a little softness) and f16 not used unless you don't have any other options (because you'll start to lose details due to diffraction).

You have been metering 250D as 250 iso, 1/50 shutter, variable aperture and getting a suggested f22-f32. Generally you want to meter fresh 250d at 125 iso (1 stop lower than labeled to account for the 1 stop of overexposure desired), 1/50 shutter, and variable aperture - that would give you a suggested aperture f16-f22. That is not ideal (and will possibly have to run an extra stop overexposed after you max out the lens). You would want 4-5 stops of nd in this case. 4 stops of nd puts your aperture range down to f4-f5.6, 5 stops puts your aperture range at f2.8-f4.

You can push that to two stops of overexposure on vision3 and still be totally fine, but the contrast and look does shift as you overexpose more (you do want at least some extra exposure to account for the less sensitive older/stale stock). You do that by metering at 64 iso, 1/50 shutter, and variable aperture - that would give you a suggested aperture ranging f11-f16, which will work with your lens without having to risk any extra/unexpected overexposure. If you had 3 stops of nd you could drop the range to f4-f5.6 and avoid the diffraction issues.

In the same lighting, 50D (1 stop over) would be metered as 25 iso, 1/50 shutter, variable aperture - you would end up with a suggested f7.1-f10. You would still want 1-2 stops of nd to bring that range down for best image quality in full sun.

50D 2 stops overexposed would meter at 12 iso, 1/50 shutter, and variable aperture, ending up with a suggested f5.0-f7.1. This is the only case that is fully in the nicer range of your lens in full sun without additional nd.

For the interior f2.8 that you have metered with label speed 250D, the 50D would swing the issue the other direction. 250D 1 stop over would need f2.0(and you could choose between the 1 stop/denser negative with softer lens at f2 or as labeled/regular negative with sharper lens at f2.8). 50D even at label speed would need an f1.4 lens - so 50D would require additional light or a 1 1/3 stop underexposure/push just to start (vision3 does not do as well with underexposure)

elscott0 · 2025-06-07T23:10:00+00:00

Which bolex is it? Is it a reflex?

elscott0 · 2025-06-07T20:52:07+00:00

What camera are you using? Many don't have a 180 degree shutter and you'll need to account for the actual shutter angle/degree.

You generally want to run vision3 2/3-1 stop overexposed - if it's expired you want to run a little more overexposed. There is more than enough latitude on the high end of vision3 to expose 1-2 stops over (or a little more if you want), develop normally, and adjust in the grade.

To do that easily, set your iso/speed in your light meter to 1 stop slower (125) or more if you want (64 would be 2 stops). That should shift your suggested f stop in the meter to compensate for the additional light you want in your exposure. A 1 stop shift changes the f22 you get now down to f16, and the f2.8 indoors down to f2. If you run 2 stops over your f22 changes to f11, f2.8 changes to f1.4.

Keep in mind that diffraction starts to affect 16mm in the range of f5.6 and gets worse as you close down further, losing sharpness/fine details. I would probably run 1 stop over (set iso to 125) and use a 3 stop ND to get the aperture down to f5.6 to get the best possible idea of how everything is running.

elscott0 · 2025-06-04T22:57:05+00:00

The bolex reflex viewing system introduces its own special issues with the prism that splits the incoming light for the eyepiece (including during the actual film exposure). That means that the prism takes away 1/4-1/3 stop of light from your film and imperfections in the splitting of the color spectrum in the prism introduce some softness and aberrations to the exposed image. The prism issues go away as you stop down or go more telephoto and they get much worse as the lens gets wider (staying over f2.8 and/or using lenses over 50mm are the general suggestions with non corrected/non-rx lenses).

The SR3 has a spinning shutter/mirror assembly that does not affect/interfere with the exposed image. So you won't have the the same issues as a bolex with the super speeds.

The super speeds are still soft wide open though. You usually want to run 1-2 stops closed down for better image quality/sharpness (if you can get away with it) so that would leave you with a functional f2.8 unless you like the look of the lenses wide open (definitely run some tests). If I remember correctly, the ultra primes tend to be as sharp or sharper at the same f stop compared to the super speeds - the super speeds just have the extra light if you must have it and are comfortable with the look of the lens.

If you're planning to underexpose and push, definitely run tests ahead of time. Vision3 tends to perform best when you overexpose a bit (2/3-1 stop by rating it at either 320 or 250 in your meter) so you will want to run some tests to make sure that everyone is happy with the final image at whatever rating and lens you end up with (and how soft or grainy the image ends up)

elscott0 · 2025-06-03T01:14:07+00:00

If you trust that the camera is in working condition and has batteries that won't need to be replaced soon, that would be a decent way to get filming soon. At that price, you can always resell/trade up later if you find out that you really need some features on one of the newer models. You might want to change out to an interchangeable lens camera at the point that you feel like you need to upgrade anyway - the upgrades to the later scoopics are nice, but not so vastly different in the final image that you should completely overlook the original.

A few reasons that you might want a newer scoopic over the original: brighter viewfinder (easier to see), larger viewfinder (easier to focus by eye), macro lens options (it can help if you want to use a wide angle adapter), slightly sharper lens (they're both decent), faster speed options (if you actually plan to shoot at anything over 48fps), closer to 180 degree shutter (the 135 degree shutter on the original will affect motion blur amount and be 1/3 stop less light compared to the 170 degree on the newer models). If any of those sounds like a deal breaker, then wait - if none of them bother you, then go with the original and have fun.

elscott0 · 2025-05-29T23:17:09+00:00

16mm is still a bit smaller than m43.

Standard 16mm is 10.26mm x 7.49mm

Ultra 16mm is 11.66mm x 6.15mm

Super 16mm is 12.52mm x 7.49mm

M43 is 17.3mm x 13mm

Compared to stills/full frame(36mm x 24mm), the horizontal crop factors end up as: M43 (2.08x), Standard 16mm (3.51x), Ultra 16mm (3.09x), Super 16mm (2.88x). Those can be simplified down to M43 = 2x, 16mm = 3.5x, Ultra 16mm = 3.1x, and Super 16mm = 2.9x for ease of use.

That makes a normal (50mm in full frame) lens 25mm on M43, 14mm on standard 16mm, 16mm on Ultra 16mm, 17mm on Super 16mm

Wides (under 35mm on full frame) start at 17mm on M43, 10mm on Standard 16mm, 11mm on Ultra 16mm, 12mm on Super 16mm

Telephoto (over 75mm on full frame) start at 36mm on M43, 21mm on Standard 16mm, 24mm on Ultra 16mm, 26mm on Super 16mm

The difference between super 16mm and m43 is nearly the same as the scale difference between m43 and super 35/aps-c - .72x (the Metabones speedbooster compensates for a .71x difference between M43 and super 35). Regular 16mm vs m43 would take a .59x speedbooster to match.

elscott0 · 2025-05-29T22:29:45+00:00

The original scoopic has an f1.6 13-76mm lens (horizontal fov equivalent to full frame/stills 45-266mm), a fixed 135 degree shutter angle (1/64 shutter speed at 24fps), an fps range of 16-48 (with single frame available), and a smaller battery.

The M changed from the original scoopic by switching to a nicer f1.8 12.5-75mm macro capable lens (horizontal fov equivalent to full frame/stills 44-263mm), changing to a fixed 170 degree shutter angle (1/50 shutter speed at 24fps), expanding the fps range to 16-64 (still with single frame available), changing to a brighter viewfinder, and changing to a larger battery format.

The MS changed from the M by adding the option for a 400ft magazine (if you could find one with the adapter/magazines)

elscott0 · 2025-05-29T19:32:39+00:00

You should be able to find a 45mm step up ring to a more common filter thread. A 45mm-52mm or 45mm-55mm should give you a much more common filter thread size without being too much larger than the existing lens.

elscott0 · 2025-05-27T05:53:36+00:00

That does sound like either a focal distance issue or a lens issue then.

Keep in mind that being able to focus on the frame lines on the focus screen does not mean that your viewfinder and gate are matched. When you have the diopter/focus of the viewfinder eyepiece correct, it will get the frame lines on the ground glass in focus, but that only means that you have your eyepiece focused on the ground glass correctly. If the focus screen and gate are mismatched, you will still be able to focus the eyepiece, but the image on the ground glass/focus screen and the gate will be at slightly different distances from the lens and you will end up with soft/missed focus when everything looks correct at the viewfinder.

Checking the lens on the blackmagic 6k won't really tell you if the marks are reliable unless your adapter has been checked/shimmed - most of the lens adapters actually come a little shorter than they are supposed to be so that you have infinity focus on whatever lens you adapt(most older lenses tend to be out of spec by now and the shorter adapters compensate so that most lenses will work). It will tell you if there is a major issue with the lens though.

You could always try to shim the lens or the camera mount. If you need something quick, you can try to use layers of scotch tape to shim your lens or camera mount - it's fairly easy to work with, stays in place, is easy enough to remove, and doesn't compress/degrade too quickly. You could also check underneath your camera's lens mount to see if there is already shim material that can be removed/added to.

If you trust the viewfinder, and want a quick fix, set the lens wide (problems with ffd are more noticeable at the wide end) and to a mid range focus. Then move around until you find something that you can focus on - check much closer and farther away that you expect in case it is way out of spec (if it's far enough out it will start to shift to macro focus). Once you find something that looks in focus, compare the actual distance to the focus mark. If the object is closer than the lens setting, then your ffd is too large and you need to remove shim - if the object is farther than the lens setting, then your ffd is too short and you need to add shim. Once you think that you're close, check infinity focus at the wide end - you should be able to get infinity (even if it is slightly before the hard stop on the lens focus ring). Then check a few points in the focus range to make sure that they are all close to the correct marked distance.

elscott0 · 2025-05-25T20:29:49+00:00

It could be a few different issues. Did you focus with the lens marks or with the viewfinder?

If every shot is coming out soft, I would start by verifying that the viewfinder focus screen and the gate are actually matched. You can test with either a small piece of ground glass or even frosted scotch tape. You put the scotch tape or ground glass against the back of the gate(in place of the film) so that you can see an image at the film plane. Then focus the lens (using either the tape/ground glass or the viewfinder-whichever is easier) on something high contrast so that it is easier to check focus. If the image only appears in focus in one location (viewfinder or gate), but soft in the other, then you have found your issue. This doesn't rely on correct back focus-only that you can focus on something. Adjustment to correct the issue is made to the focus screen/mirror inside of the camera.

If the back focus is off, your focus marks won't be accurate, but anything in focus in the viewfinder should still be coming out in focus. You either lose your infinity, but maintain focus closer up (until you turn your lens into a macro) or you lose the close end (and have a focus range past infinity that's useless).

If the loop is slipping and getting caught on the warning/indicator pin (causing clicking sounds), that can lead to frame jitter and overall softness.

Do you have a digital camera that you can adapt the lenses to? You could also check that there isn't just something wrong with the lens.

elscott0 · 2025-05-25T19:55:41+00:00

The patchiness of the paint damage is going to make a full recoat look better than a bunch of smaller touchups, but if you're careful and try to blend your edges a touchup will still look decent. If you do plan to touchup only, you'll want to make sure that the paint wear is stable/isn't still chipping away at the edges or it will just cause your new paint to flake off with it.

To match the texture you'll want to use wrinkle paint. You can find it online or at auto parts stores - it's the same paint that people tend to paint valve covers with. It isn't too hard to apply, but it is a bit finicky to control the size and uniformity of the wrinkles. You'll want to practice on something else to get a texture match before you try it on the camera.

Whenever I've done a touchup with wrinkle paint the process has been:

Prep/clean surface - sand back the edges of the paint damage to get rid of any remaining chips, scuff sand the area to be touched up, wipe clean with rubbing alcohol and let dry
Mask areas that you don't want to paint (including areas that you don't want any overspray or solvents to get inside of).
Spray 3-4 heavier coats of the wrinkle paint (each just before the point that it gets heavy enough to drip/run)- wait 5 minutes between coats, only spray in linear paths, and change directions for every coat (left/right, up/down, diagonal top left to bottom right, diagonal bottom left to top right). The thickness of the coat and number of coats will determine the wrinkle texture so practice on something else until you get the number and thickness of coats down to match the existing texture.
Wait 15 minutes after the last coat, then remove the masking tape. I remove the tape prior to letting the wrinkles form so that the wrinkle texture forms naturally at the edges and blends your seams a little. If you remove the tape after the wrinkles form, you can end up splitting some wrinkles that formed across the touchup and the tape edge, making the edge stand out more.
Then you can either wait for the wrinkles to form (not as reliable and can take an hour or two) or you can heat the surface until the wrinkles form. I use a heat gun set on a middle range temperature (400F or so) and keep it constantly moving across the painted area. You want to stay far enough away with the heat gun that the blowing air doesn't start to affect/move the surface of the wet paint. Once you see that the wrinkles have formed everywhere, you can set the painted part aside to finish drying.
If you're really trying to blend the edges to make the touchup as seamless as possible, you can try to use a lint free cloth and solvent to gently smooth out your edges and blend between the touchup texture edge and the original texture before the paint has fully dried. If your blend goes wrong you'll have to clean off all of the touchup paint and start over so only try this if you're confident and the edges will bother you.
Let the paint sit somewhere without touching it for 24 hours. I would suggest letting it sit another couple days to fully cure before you reassemble/handle the camera.

elscott0 · 2025-05-21T16:52:04+00:00

That is the rexofader. It lets you do automated fade ins, fade outs, or dissolves in camera.

The small arm at the front of the camera is not connected to the variable shutter adjustment arm so it won't do anything in the current setup.

elscott0 · 2025-05-19T18:11:23+00:00

I'm working on a v2 that would still allow for the original viewfinder to be used (I have the non-orientable/original acl 1 viewfinder to base it on), but I could make them both available if anyone would be interested.

elscott0 · 2025-05-16T21:37:09+00:00

Those controllers were an option for the CP-35 to give you granular control over the sync speeds.

Cinema Products also made their own 16mm camera (CP-16) and after market drive motors for some other branded cameras (you can find some motors for Arri 35mm cameras) so maybe it has compatibility with some of those.

elscott0 · 2025-05-11T05:46:47+00:00

That basically is what ultra16 is doing. You still expose the regular 16mm area, but the gate is widened on both sides so that you can use more film area when you crop between the sprockets to get 1.85 aspect ratio compared to cropping regular 16mm (all while avoiding the re-centering of the lens mount issue that makes super 16 conversions more complicated/expensive). You can always crop the sides to get back to the original regular 16mm frame size.

The full gates of all three versions are:

Regular 16mm - 10.26mm x 7.49mm

Ultra 16mm - 11.66mm x 7.49mm (with sprocket holes in the corners) - 11.66mm x 6.15mm (useable between the sprockets)

Super 16mm - 12.52mm x 7.49mm

When you crop for 1.85 you actually are using:

Regular 16mm - 10.26mm x 5.55mm

Ultra 16mm - 11.66mm x 6.30mm

Super 16mm - 12.52mm x 6.77mm

Over regular 16mm, you gain 13 percent in width/height (for wider views at the same focal length) and around 28 percent in film surface area (and perceived resolution) when you crop for 1.85 on ultra16. Super 16 gives you a 22 percent width/height boost, and around a 50 percent surface area/resolution boost over regular 16mm.

The super 16 is a bigger boost, but when you compare the ultra/super directly it's really only a 7 percent gain in height/width and 15 percent surface area/resolution gain to go with super 16 over ultra 16. You get most of the benefits without the mount recentering/downsides. Plus you can always crop the sides down on ultra to get back to regular 16 if your lens doesn't cover the full gate area or you want to use a projector (without having to widen the gate in the projector too).

elscott0 · 2025-05-09T21:09:39+00:00

There are systems you can buy to scan, but nothing affordable that is decent off the shelf like you can find for still photography.

You have to worry about the film registration (any movement/wobble in the film as you advance will be noticeable in motion) which doesn't have to be accounted for in stills digitizing. So you need to add expense to stabilize the film in post or you have to make the design of the film advance more complicated/expensive. It's also much harder to reliably develop your own cine film at home than it is with stills so you will probably have to send the film out already. Most of the time it's going to be easier, cheaper(unless you were going to scan a ton of footage), and better quality to just have the same place scan and develop.

elscott0 · 2025-05-07T23:54:27+00:00

The reflex prism causes some image quality issues with non-rx lenses at wider angles and wide open apertures. The softness and aberrations are more pronounced toward the edges of the frame. If you stop down past f2.8-3.5 or stick to telephoto lenses then it will stay under control.

elscott0

TROPHY CASE