How to trim the film leader for your Barnack Leica

Cover image: Rama. CC BY-SA 2.0 fr via Wikimedia Commons

You have a Leica IIIf in front of you, a fresh roll of film next to it, and after two minutes you're stuck: the film leader is too short and too wide. It won't go in.

The fact that modern film doesn't fit a classic Leica is not a design flaw. The camera loads from the bottom. The film has to travel up through a narrow channel past the cloth shutter, and for that it needs a long, narrow tab. In the past, every film had this tab straight from the factory; the camera didn't need to do anything the film didn't already bring with it. Then the industry shortened the leader, and something that used to be taken for granted became a DIY task. Leitz sold a cutting template for this called ABLON, which has long since become a collector's item.

This guide shows you the leader trim in Leica's original dimensions and four ways to get there: with the original ABLON, with a replica template, freehand with scissors, and with no cutting at all. Then you load. The dimensions come from Leica's own instructions, not from forum posts. Where an outside source explains something better than we do, we link to it.

Just the dimensions? The scale drawing in chapter 2 shows length, curve and perforation count at a glance. Go to the drawing.

Who this applies to: The leader trim concerns the bottom loaders from the Leica I to the IIIf and their copies. On the IIIg and the M models the back opens, so you don't need it there. If, on the other hand, you're missing the take-up spool, the second most common reason a Leica won't load with either design, you'll find the identification table in chapter 4.

Table of contents

1. Which method you need
2. The Barnack leader trim in Leica's original dimensions
3. How to load Barnack and M
4. When the take-up spool is missing
5. When spooling your own film is worth it
6. Other cameras with the same problem
7. Developing and digitizing
8. Sources

1. Which method you need

Before you buy anything: there are two ways to feed a Barnack Leica with film. The effort involved is very different.

The second route doesn't replace the first, it comes on top. Self-loaded cartridges also need the long leader trim. That's why the second route comes at the end of the guide (Chapter 5). The leader trim comes first.

M owners can skip almost everything. If you use an M1, M2, M3 or a IIIg, you don't need a leader trim at all, because the back of these cameras opens up. All that matters for you is loading in Chapter 3, and the spool table in case your spool is missing.

2. The Barnack leader trim in Leica's original dimensions

This is where most people fail. The reason is historical: when the Leica was built, 35 mm film came from the factory with a long, narrow leader. So the camera didn't need to do anything the film didn't already provide. Only when the industry shortened the leader did a matter of course turn into a DIY job. That's why old Leica manuals don't say a word about having to trim the leader yourself. Back then, trimming wasn't necessary.

You can see why the tongue has to be long and narrow when you look at the camera from below. The film doesn't go into an open back. It is pushed upwards from below through a narrow channel, right past the cloth shutter. A full-width, stiff film leader catches there. A narrow tongue slides through.

The dimensions as specified by Leica

Drawing: Ausgeknipst, based on the specifications in the Leica Guide^[2] and the format dimensions from ISO 1007 / KS-1870^[3].

The key sentence is in the Leica Guide. It is more precise than any measurement in centimetres:

“The curve should begin between the twenty-third and the twenty-fourth lower perforation, with the emulsion facing you, and must not run through a perforation hole.”
Leica Guide, paraphrased^[2]

This specification is better because in the half-dark you don't measure centimetres, you count holes. Converted, that's about 11 centimetres: the perforation pitch of 135 film is exactly 4.75 mm, and 23 holes add up to 109 mm^[3]. Practical guides give 10 to 11 cm, which is the same length, just without counting^[4].

The width is set by the template. As a rough rule, the cut removes the upper half and leaves the lower perforation row fully intact. Three things matter more than any millimetre value. All sources agree on them: a smooth, continuous edge, no cut through a perforation hole, no corners or steps at the transition to the full film width.

A corner tears, a hole tears first. Every sharp corner on the leader trim is a predetermined breaking point. If the cut runs through a perforation hole, the film will tear there as soon as you advance it. The tear usually only shows up after a few frames, right in the middle of your subject. If you end up with a corner, it's better to recut the leader and sacrifice two frames.

And what if the film is already in the camera?

A second check value is just as firmly documented. When loading, the trimmed film leader may only stick out of the cassette a little. The IIf/IIIf manual states: “With correctly trimmed film, no more than 2 perforation holes should protrude from the cassette or cartridge”^[1]. On the original Leica cassette, an embossed curve on the outer sleeve shows the correct position. If you have to pull out more film for the leader to fit, you've cut it too short.

Four ways to trim the leader

The template is the most convenient way. It is not the only one, and not the best in every case.

How to cut with a template

1. Pull the film out of the cassette until the factory leader is completely out. The emulsion side, i.e. the matte one, faces you.
2. Count the lower perforations. The curve starts at 23; that's where the edge of the template goes.
3. Place the film in the template and press it flat. Nothing may bulge, otherwise the cut will wander.
4. Run a narrow, very sharp blade along the guide in one stroke. A scalpel cuts thinner than a utility knife. Stopping and starting again creates exactly the steps you want to avoid.
5. Alternatively, trace the outline with a pen, remove the template and cut with scissors. This way is slower, but more forgiving.
6. Check the edge with your fingernail. If you feel a step anywhere, touch it up.

Shavings are the invisible damage. Cutting produces tiny scraps of film that get caught in the template and travel along next time: into the cassette, into the camera, onto the negative. Templates that can be taken apart are therefore not a luxury. A quick tap usually does the job, a soft brush is better.

What it looks like when someone shows you

In this video, Camera West walks through the entire process: trimming, spool, inserting, checking. If you'd rather watch than read, this saves you the first failed attempt.

Video: “How To Load Film In A Leica Screw Mount Film Camera”Camera West TV

Film cutter template for Leica Barnack (like ABLON) (from EUR 24,95) · 35mm film respooler & roll splitter with frame counter (EUR 49,95)

Disclosure: we make and sell a template modelled on the ABLON ourselves. The trimming in this chapter works just as well with the original, with templates from other suppliers and with a good pair of scissors. The dimensions above come from Leica, not from us.

3. How to load Barnack and M

Now film, cartridge and spool are all together. The rest is craft. The 1952 Leica instructions describe it so clearly that we are largely translating here rather than reinventing.

Both parts go in from below at the same time

Photo: Rama. CC BY-SA 2.0 fr via Wikimedia Commons. The three controls that matter when loading: rewind knob on the left, A/R changeover lever in the middle, frame counter dial under the winding knob.

1. Changeover lever to A. Before you insert a new cassette, set the lever all the way to A (Aufnahme, i.e. exposure). Wind the shutter once and release it to check that everything runs. Then wind it again, but do not release it.
2. Remove the base plate. Turn the key to “AUF” (open) and lift off the plate. Put the plate somewhere it can't roll away.
3. Take out the take-up spool. If you use a quick-load spool, it stays in.
4. Film leader under the clamping spring. Spool in your left hand, loaded cassette in your right, both with the knurled knobs facing down. Push the trimmed film leader as far as possible under the clamping spring of the spool. The perforated edge must sit close against the spool flange.
5. Two holes, no more. Pull the film out of the cassette just far enough that no more than two perforation holes of the trimmed edge are outside.^[1]
6. Insert spool and cassette at the same time, spool knobs facing up, so that the trimmed film slides into the guide slot on the camera back. If the cassette jams, turn the rewind knob a little. The emulsion side faces the lens.
7. Close the baseplate, turn the locking key to “ZU” as far as it goes. Only now is the camera light-tight. An original Leica cassette also opens its slit at this moment.
8. Take up the slack and check. Carefully turn the rewind knob in the direction of the arrow until you feel slight resistance. Release the shutter, wind it. As you do, the rewind knob must turn along, against the engraved arrow direction. This counter-movement is your check that the film is really being transported.
9. Turn the counter dial counterclockwise to 0, release, wind again. The dial now shows 1.

Take off the lens and look inside. Many Barnack photographers unscrew the lens for loading. Through the opening they check whether the film really sits past the shutter and the sprockets engage. With the shutter held open on B, this works well. PetaPixel describes this move as common practice among Barnack users^[10]. It takes five seconds and saves you a blank roll.

The card trick, no trimming at all

Some Barnack photographers don't trim at all. Instead, they slide a thin, stiff card into the film channel. The film glides up along this ramp. Philip Dygeus has written up the process step by step and adds a sentence we don't want to leave out here: he never trims store-bought rolls and has therefore never had loading problems. He only trims the rolls he loads himself.^[11]

The key point: a thin card. A credit card is too thick; a parking ticket or a business card works. And the card has to come out again before the baseplate goes back on.

Two spools are better than one. If you change film on the go, you have three things in two hands: baseplate, spool, cassette. A second spool, loaded with the next film at home, turns the roadside change into a single move. The second spool was already the pro trick in the fifties and still is.

On the M models, the back flips open

Photo: Lëa-Kim Châteauneuf. CC BY-SA 4.0 via Wikimedia Commons.

On the M, the baseplate also comes off, but in addition the back flips open. This lets you see the film channel. The long trim is not needed. The procedure according to Leica's own short guide:

1. On the M3, first raise the switch lever.
2. Remove the baseplate, pull out the take-up spool, open the back.
3. Attach the film leader to the spool, insert the film.
4. Visual check with the back open: The teeth of the transport sprocket must fully engage the perforation on both sides. This check is the whole advantage of the M. Use it.
5. Close the back until it clicks, put the baseplate back on.
6. Turn the rewind knob in the direction of the arrow without force until you feel slight resistance. Wind and release twice.
7. On the M1 and M2, set the frame counter to 0 by hand. On the M3, the mechanism resets the counter by itself, provided the spool was out (see chapter 4).

Check it as with the Barnack: the red mark in the centre of the rewind knob must turn as you advance the film. If it doesn't, no film is moving.

A German-language video that shows exactly this procedure on an M2:

Video: “Leica M2 + Film einlegen + Leicameter Kurzbericht”tom vesab fotografie

And one for the Barnack, filmed out and about instead of at the kitchen table. The more honest situation:

Video: “Vintage Leica, the secret to loading film in a Barnack”rileyphotos

The five mistakes that actually happen

1. The rewind knob doesn't turn. The film has come loose from the take-up spool and isn't being advanced. Leica's own instruction: set the changeover lever to R and turn the rewind knob in the direction of the arrow, but only for as long as the shutter release button turns with it. Then stop immediately. At that moment the film leader has passed the release shaft and still sticks out a little. If it were pulled all the way in, you would need a darkroom.^[1]
2. The film tears at the sprocket. Almost always the result of a trimmed leader that runs through a perforation hole or has a sharp corner. Back to chapter 2.
3. Too much film pulled out of the cassette. More than two perforations out means the film sits crooked in the channel and the cassette won't go all the way in. Wind it back and start again.
4. The speed dial is set to T. The shutter can then be open during rewinding and the film can be exposed to light. Leica recommended the lens cap when rewinding, old-fashioned but free.^[1]
5. The film is still inside. Before opening, turn the pulled-out rewind knob in the direction of the arrow. If you feel resistance, the camera is loaded.

Rewinding at the end

When the winding knob won't turn any further, the film is used up. Set the changeover lever to R and turn the rewind knob in the direction of the arrow until you can feel resistance. At this point only the clamping spring is holding the film. Overcome this resistance, then give it two more full turns, and the film is completely inside the cassette.^[1]

If you want to use a partly exposed film later, stop earlier: watch the shutter release button and stop as soon as it no longer turns with it. The film leader will then still stick out.

4. When the take-up spool is missing

On the Barnack and early M models, the take-up spool can be removed. That is exactly why it goes missing so often: it gets left in the camera bag, rolls under the table during a film change, is forgotten when the camera is sold. Without the spool, you cannot take pictures with a Leica. Cameras like this turn up on the used market regularly.

Photo: Rama. CC BY-SA 2.0 fr via Wikimedia Commons. The M3 needs a different spool than any Barnack, plus a trick with the frame counter.

The identification table

Over the years Leica built two basic types of removable take-up spools, plus a few special cases. The Leica Society International has untangled these types^[7], and KEH and Kamerastore use the same classification in their catalogues. In short:

14021 and 14022 get mixed up all the time. The two numbers are close together, and the spools look alike. Even so, they are not interchangeable. Rule of thumb: everything before 1957 takes the 14021, the IIIg and the early M take the 14022 (SPOOM). Within the 14021 family there are variants with their own codes, such as SVOOP and SPULM; that makes no difference to how they work, only to collectors.^[7] Mix-ups also happen in listings on the used market: the wrong number turns up there more often than you'd like.

Where to get a spool

There are three ways. None of them leads to Leica itself, because the spools have been out of the range for decades.

Original, used. Specialist dealers regularly stock the spools individually: KEH lists the 14021 as well as the 14022, and so does Kamerastore in Finland. They turn up all the time on eBay and in classifieds. There, however, the description isn't always accurate. Check the catalogue number, not the photo.

From a copy camera. The Soviet FED and Zorki models are Barnack copies. Their spools fit in many cases, some of them a little tightly. If you have a broken Zorki lying around, you may already have the solution in your cupboard. For the IIIg or an M, however, this route won't work.

Modern reproductions. There are several makers producing replacement spools; we are one of them. What surprises us most, though, is something else: in everyday use, what counts is not the price, but the fact that you no longer have to remove the spool. Mike Eckman sums it up in his review. The classic method, he says, is “certainly not difficult, but tedious”^[8].

Independent reports on replacement spools: Three publications have looked into the topic independently of us. We link to the articles because they describe the problem well. We disclose here that we are mentioned in them:

1. Leica Society International. Jason Schneider puts the spool types into historical context and describes why they are so often missing. The Great Leica Take-up Spool Kerfuffle
2. Mike Eckman describes the classic loading method step by step and contrasts it with an alternative. A Better Way to Load Your Leica, July 2024
3. PetaPixel. Johnny Martyr on replacement spools for Barnack cameras. A New Quick-Load Spool for Barnack Leica, April 2024

Where we have to contradict two of these reports

Both articles state that with a quick-load spool there is no need to trim the film leader. That sentence originally came from us. We have since retracted it: our product description now states that you still need to trim the start of the film to about 10 cm.

The spool isn't to blame. It's the path to it: in a Barnack, the film has to pass the cloth shutter from below. If a full-width, stiff film leader catches on the shutter curtain there, the repair gets expensive. Usually it goes fine. But with a cloth shutter from the fifties, we don't want to rely on “usually”. So: trim the leader, even with a quick-load spool.

The special case of the M3

The M3 has a quirk that trips up many people: its frame counter automatically jumps back to the starting position as soon as the take-up spool is removed. If you use a quick-load spool, you no longer take the spool out at all. The reset doesn't happen, and the counter is wrong.

Leitz knew about the problem and wrote it into the instructions for the retrofit quick-load spool in 1968: “The quick-load spool in the LEICA M3 must therefore be briefly pulled out and pushed back in before loading the film.”^[9] Incidentally, the same instructions mention what else was part of the retrofit back then: a spacer for the bottom cover and a stick-on diagram. At Leica, the quick-load spool was never standard equipment in the M3, but an accessory.

Video: loading with the spool in place, without removing itAusgeknipst on YouTube (our own video)

Film spool for Leica I, II, III Barnack (replacement for 14021) (from EUR 34,95) · Film spool for Leica M1, M2, M3 & IIIg (replacement for SPOOM) (from EUR 34,95) · Film spool for Leica CL & Minolta CLE (from EUR 24,95) · Take-up spool for Zorki 3 & Zorki 4 (LTM) (EUR 19,95)

5. When rolling your own film is worth it

So far we have covered the route most people take: buy film, trim the leader, load. This chapter is for everyone else. Bulk film and self-loaded cassettes are a niche, but three reasons speak in their favour. The best known of them is the weakest.

Photo: VSchagow. CC BY-SA 4.0 via Wikimedia Commons. The old ORWO can says it itself: 3 × 1,70 m. A 36-exposure roll is still right in this range today.

The money argument is smaller than it sounds

Leica itself reckoned with 1,60 m of film for 36 exposures. That is what the instruction manual for the IIf/IIIf says^[1]. A 30,5-metre roll therefore works out to 18 to 19 films on paper, 18 in practice. At current prices, the calculation looks like this:

Prices as of August 2026, both from the same retailer so the comparison holds up: Fomapan 100 135/36 and bulk film 30,5 m or 17 m at Fotoimpex. Calculated with 18 rolls per 30,5 m. Run the numbers yourself, the market keeps moving.

So with the budget emulsions you save around 40 percent. Further up the range things look different: 30 metres of Ilford HP5 Plus cost 169,99 euros at Fotobrenner, which works out to around 9,30 euros per 36-exposure roll. A single Ilford factory-loaded cartridge is in the same range. FP4 Plus is around 12,00 euros. This is not a clean like-for-like comparison within the same emulsion. The order of magnitude is still clear: with Foma, bulk film clearly pays off; with Ilford, the advantage is largely used up.

And the loader costs something too. A Legacypro Lloyd is around 50 euros, an AP Bobinquick 85 to 100. With Fomapan you save 2,14 euros per roll. That means the Lloyd pays for itself after about 24 rolls, the AP after about 45. If you shoot two rolls a month, you will spend a year just breaking even.

Factor in the cartridges. Reusable cassettes cost money. Spent factory cartridges can only be pried open on the older designs. Leica itself wrote in its instructions as early as 1952: “Cartridge shells, however, are no substitute for an original LEICA cassette and should not be refilled.”^[1]

The two better reasons

Short rolls. This is the reason that really counts with a Barnack. If you want to try something out with 36 exposures, you first have to shoot the whole roll before you can develop it. Twelve exposures are done much faster. Leica even printed a table for this. It is further down and is still accurate today, because nothing about the film format has changed.

Films only available as bulk rolls. Cinema emulsions, remaining stock, specialty material. If you want to shoot Kodak Double-X or something similar in a Barnack, there is no way around loading it yourself.

How much film for how many exposures

This table comes from the Leica Guide and applies including trimming: the waste for the long leader is already included^[2]. Each exposure adds 38 mm, which is exactly eight perforation holes.

Crank turns instead of metres. Nobody measures with a folding rule inside a changing bag. That is why Leica gave the figures in turns: twelve full turns of the hand winder give about 12 exposures, 18 turns are enough for 19, and 32 turns make a full 36-exposure roll^[2]. Modern loaders with a frame counter do the counting for you. The order of magnitude still holds today.

Cartridges, cassettes and the bulk loader

The loader is one half, the cartridge the other. We have already written a separate article about loaders, in which five models are compared side by side on price, light traps and film waste. So this one covers what isn't in there: which cartridge belongs in a Leica and why the answer is not the same for Barnack and M.

Which bulk loader suits you? AP Bobinquick, Lloyd, Watson, Alden and LPL compared head to head, with prices and the weaknesses nobody mentions. Go to the loader comparison.

Six designs, two principles

Photo: Runner1616. CC BY-SA 3.0 via Wikimedia Commons. From left to right you can see how different the designs are. On the far right is a modern factory-loaded cartridge. You are not meant to open it again.

For all the differences in detail, it comes down to two principles. Which one is in your cartridge decides whether your negatives get scratched.

The felt trap. The film slot is sealed with two black velvet lips that the film rubs against as it is pulled out. These velvet lips sit in every ordinary factory-loaded cartridge and in most reloadable plastic cartridges. The felt works and is cheap. But every speck of dust that lodges in it draws a fine line along the entire film.

The slit cassette. Leica's own metal cassettes have no felt at all. Each one consists of two nested shells whose slots can be rotated against each other. When you turn the locking key on the bottom cap to “ZU”, the slit opens. Only then does film come out. When you turn it to “AUF”, the slit closes again, and you take a light-tight cassette out of the camera. Along the whole way, the film never touches a sealing lip. Why this elegant system is still tiring in everyday use has been written up by the Leica Society International, under the fitting title “The Inconvenience of Perfection”.

Photo: Runner1616. CC BY-SA 4.0 via Wikimedia Commons. Soviet copies of the Leica principle: on the left the shell with the driver, on the right the film slot with a felt strip as a stopgap solution.

Why the FILCA does not fit in the M

Leica built two generations of these metal cassettes. The Leica Guide describes the difference in one sentence that you should remember:

The short version from Leica's own instructions: The newer cassette Model N fits the M models and all older cameras. The older cassette Model B fits all Leicas from the I to the IIIg, but not an M. You can tell the two apart by the knob on the inner shell: chrome on the N, black on the B.^[2]

In collectors' jargon these two are called FILCA (Model B) and IXMOO (Model N). If you search the used market, you will find almost nothing but these codes. The IXMOO is the safe choice because it fits everywhere. The FILCA is about two millimetres taller and therefore too big for the M. How both hold up in everyday use is discussed in a long thread on the Photrio forum in more detail than would fit here.

Not every loader gets along with metal cassettes. Watson and Alden loaders were built for exactly these slot cassettes and open them mechanically. With the Alden 74 you need to rework the inside a little for the older FILCA cassettes; the newer IXMOO fit straight away. If you want to work with metal cassettes, choose your loader accordingly. Not the other way round. Details are in the loader comparison.

The first step happens in the dark

You only put the 30,5-metre roll into the loader in total darkness, so in a changing bag or a dark bathroom. After that, you fill the individual cassettes in daylight. If you have never done this before, practise the move once in the light with an old, exposed film. After that, the motion sticks. Otherwise, in the changing bag you will be missing exactly the feel for which way is up.

Notches on the table edge. Leica recommended putting notches or drawing pins on the edge of the work table for 12, 24 and 36 exposures^[2]. If you load without a frame counter, this lets you measure more reliably in the dark than any estimate. A strip of masking tape on the table does the job too.

Filmschneider für AP, Legacypro & Watson Lader (EUR 19,95) · Filmdose für 35mm Analogfilm (3er / 5er) (from EUR 24,95)

6. Other cameras with the same problem

The Barnack was so influential that half of Europe and half of the Soviet Union copied its loading principle. Once you've mastered the leader trim, you can do it for a good dozen other cameras. And if you're looking for a spool for one of them, it's almost always for the same reason as with the Leica.

Photo: Kameraprojekt Graz 2015. CC BY-SA 4.0 via Wikimedia Commons. The Leica I from 1927: this is where bottom loading began. The copies kept it until the seventies.

Film spool for Contax II, III, Kiev 4, Smena 8M (EUR 25,95) · Film spool for Exakta Varex, VX 1000, IIa, IIb (EUR 19,95)

When the film isn't just trimmed but split lengthwise

Two formats take the same principle further: there you don't just cut the 35mm film at the start, you slit it lengthwise to 16 mm or 9,2 mm and load it into small cassettes. The steps are similar, the tools are not. Both formats have their own guide that goes deeper than would make sense here:

• Minox 8x11: cutting film, loading cassettes, developing and scanning, the smallest format where rolling your own really pays off, because hardly any ready-made cassettes are left.
• 110 pocket film: cutting, loading, developing, scanning, with the special case that many 110 cameras also run without perforation.

The Barnack leader trim is the easiest of them all. Anyone who has ever slit 35mm film lengthwise to 9,2 mm in a changing bag will find the Leica trim pleasant afterwards. The trim can be done in daylight, needs no guide rail and forgives a second attempt. That only costs you two frames.

7. Developing and digitizing

You develop hand-rolled film like any other, with one exception you should know about beforehand.

Photo: Joost J. Bakker. CC BY 2.0 via Wikimedia Commons.

Tell the lab. Short rolls and bulk film without a DX code confuse automatic processing machines. Some labs charge a surcharge, others refuse, still others develop without comment. One sentence in your order saves follow-up questions, and with a 12-exposure film also frustration over the price per frame.

If you develop yourself, you don't have this problem anyway. The short roll is in the tank faster, and the chemistry is enough for several of them. If you don't have a lab yet or are looking for one near you, this will help:

• Finding the right photo lab, what matters with a mail-in lab, and what a hand-processing surcharge means.
• All film labs in the German-speaking region on one map. Radius search, no sign-up.
• Buying analog film: which film, which ISO, which format, in case the emulsion question is still open.

Nothing changes when digitizing just because you rolled the film yourself. The negative strip looks like any other; only the first frame on a Barnack sometimes sits a little further back, because the long leader trim took up space. How to get from there to the scan is covered in the guide to the modular scanner setup and in the system comparison of all common film holders.

What you really need for the Leica, and what it costs

Finally, everything in one table, because the question shows up in our inbox almost every week. The column on the far right is the honest one: you don't need much of this at all.

And because an honest guide should say so: you can buy the spool used as an original (see chapter 4), you cut the leader with a pair of scissors, and the card trick costs nothing at all. If this article gets you to load your Leica again, it has served its purpose, no matter where the parts come from.

Sources

The measurements in this article come from Leica's own manuals, not from forums. If you want to read up, you'll find the originals here, free of charge, because Mike Butkus has been digitising camera manuals for decades and has done analogue photography a greater service than most manufacturers. His site carries a request for donations, and it is well deserved.

1. Leica If / IIf / IIIf instruction manual (German, PDF) and the English version. Chapter “Loading the Leica”, film cassettes and packs. Source for: 1,60 m per 36 exposures, “no more than 2 perforation holes”, loading procedure, rewinding, note on pried-open cassette shells.
2. Leica Guide. How to work with all Leica models from I to M3 (PDF). Source for: arc between the 23rd and 24th lower perforation, “not through a perforation hole”, table of film length per number of exposures, crank turns, cassette model N versus model B, loading procedure of the M models.
3. 135 film. Format standards ISO 1007 and KS-1870: perforation pitch 4,75 mm (0,1870 in), eight perforations per frame = 38,00 mm.
4. Cutting Leica Leader and Leica film loading, Jay Fedka, independent confirmation of the leader length (10–11 cm) and the loading sequence.
5. Blue Moon Camera. Listing of an original Leica ABLON 14126 with description and current used price.
6. Do You Have to Trim the Film Leader on Modern 35mm Film Cassettes to Load Leica III?. Leica Forum, practical description of the freehand cut. In German: Zuschneiden Filmende für IIIf.
7. The Great Leica Take-up Spool Kerfuffle, Jason Schneider, Leica Society International. Assignment of 14021 versus 14022 and the codes SVOOP, SPULM, SPOOM. Supplemented by the catalogue entries from KEH and Kamerastore.
8. A Better Way to Load Your Leica, Mike Eckman, July 2024.
9. Leitz: instructions for the rapid loading spool for LEICA M3, M2, M1 and MD (PDF, 1968). Source for: frame counter reset on the M3, spacer and schematic drawing as part of the retrofit solution.
10. Barnack Quirks: An Intro to Shooting with Early 35mm Leica Cameras, Johnny Martyr, PetaPixel, December 2022.
11. How I load a Barnack camera, Philip Dygeus, the card trick, with plenty of illustrations.

Further reading elsewhere: 35mmc on the road to a screw-mount Leica · Photrio: Loading an old Leica · Rangefinderforum: Barnack film loading, a long leader idea · Meine Schraubleica-Geschichte (German-language blog) · Zenography: How To Use A Barnack Leica.

To print yourself: the replica template is available as a free print file on Thingiverse (PariahProps, 2016), and a rapid take-up spool for the screw-mount Leicas as Leica barnack (I/II/III) rapid take up spool by Rayfor on Printables. We have neither printed nor measured either of them. The measurements in this guide come from Leica's manuals, not from these files.

Found something that isn't right? If you spot a wrong measurement or a wrong attribution in this guide, write to us. We'll correct it and name you as the source. Contact.

Accessories by camera brand Spools, battery adapters, light seals and spare parts, sorted by manufacturer. Go to the overview.

All guides at a glance. From batteries to light seals to scanning, our collected guides. Go to the blog overview.