LTM leader again

[mukul_dube]

This matter has been discussed earlier, but the last thread I found is

eleven months old and probably gets no attention now. My question is,

for any 35 mm camera, why a leader at all? There are sprocket holes

along both edges of the film, and the toothed roller has teeth for

both rows of holes. When I used to cut bulk film, I did not bother

with leaders. It was enough to make sure that there were no pointed

corners. If the full width of the film goes on to the take-up spool,

no part of it can snag on anything; and if the tooth at one edge

engages, so does that at the other. I'd like to hear from anyone else

here who has done this -- and also, of course, if there is a flaw in

my reasoning. Neither I nor friends to whom I gave cassettes loaded in

this way ever had practical troubles. The cassettes were used in

various cameras, screw mount Leicas included.

[jeff_wilson13]

It really is that simple. The factory leader does a good job of not fitting anything.

[blakley]

It's probably cheaper to produce film with a leader, since you can overlap the leader area for two rolls, so you save about two inches of material per roll - maybe a 5% savings in cost.

[35mmdelux]

manufacturers want to sell appearances. A leader looks better than a square cut. To a pro no big deal, but most sales are generated by the working masses retail.

[malcolm_tentt]

{If the full width of the film goes on to the take-up spool,}

 

There're quite few older 35mm cameras whose wind-on bobbins have a half-depth slot, and a single prong at one end. I can't say for certain but I believe many of the automated wind-on mechanisms in modern cameras require a half-depth leader as well.

[awahlster]

Malcome is correct. My Canons with the QL feature all require a half leader the Canonet the FTb the T90. My LTM bodies sure load better with a cut leader.

[dan flanders]

If you have a Barnack Leica it is certainly advisable to use the elonganted half-width leader to avoid feeding problems that occur as a result of the bottom loading feature. Of course there are other ways to avoid the foul-ups and in many instances the film has properly advanced with the full width leader. But, there is convincing evidence that use of the Leica style leader is the most reliable way to avoid trouble. I haven't encountered any loading or feeding problems with open back cameras, but neither has the existence of the contoured leader been any sort of hinderance to the camera's proper functioning.

[jerry_lehrer]

Bob Blakely-- NO, you cannot overlap leaders when cutting the roll. One leader would be on top, t'other on the bottom. The end that is taped to the cassette spool has an entirely differnt configuration.

[aadewar]

The only time I ever had film problems on my IIIf was on a "trimmed" elongated leader. A

square one would be just fine.

[john_shriver]

Well, considering that the form of the pre-loaded 35mm cassette and it's leader was designed around the requirements for the Leica I camera, that's why there's a leader. It needs one so you don't maul the shutter loading the camera. (The Leica is the cart before the horse in this case.) I wonder if the Retina I also requires a leader. The Contax I could care less, they are really designed for casette-to-casette operation. Those were all of the 35mm cameras when Kodak started offering 135 casettes.

 

Kodak used to cut them a lot longer, long enough for a Leica. But the bottom-load Leica's got to be a miniscule share of the market, and I'm sure that they made the whole roll shorter when they shortened the leader (shareholder value). I suspect that a lot of the autoload cameras assume today's short leader (it's probably part of an ANSI, ISO, or IEC standard), so it won't change again.

 

Also, all my Topcon cameras have take-up spools requiring a leader. But the Canon QL mechanism (as on the Canonet QL17) doesn't require one.

[neil_parker]

The majority of older 35mm cameras require a leader, Nikon F, F2, F3. FM/FE series all

require leaders, Oly OM series require them, and most cameras I've seen that don't have

some kind of self loading system all have a slot that requires a leader that is narrower than

the film.

 

The M2 looks like it could get by without one, and I recall that a lot of minoltas (and the

similar leica Rs) had an open tab that maybe didn't require a leader, but they often broke

off after a short period of time.

[david_clark4]

I use bulk film. I have had problems, failure to advance film, when I didn't cut a long leader, and I have had no problems since I got one of the metal tools for cutting the long leader. I assume the long leader works because of the design of the pressure plate of the LTM. I may be wrong, but I got the idea of a reason for this by taking a LTM a part and seeing the design of the pressure plate that holds the film flat against the openning. Seems like the cut-a-way on the leader slides under the pressure plate easier, and at the same time there is less friction/drag while taking a couple of wraps around the take-up spool. Using a long leader, if after inserting the film I can see a sproket sticking through the perferation in the film I can not recall a failure to advance the film.

[adrian bastin]

If you ever get into the shutter/winder mechanism of a thread mount Leica, chances are you will find a shread or two of film. You do hear of problems with shutters and winders which only show themselves intermitently and are probably caused by just one bad film loading. It's worth doing at it really does say on the tin.

[jtk]

There's a right way and a wrong way.

[adrian bastin]

Well, one right way and lots of wrong ways.

[jtk]

Right. Here's another: Been there, done that.

[mukul_dube]

You're right, Bob, and Jerry's wrong, at least where bulk film (and factories use that) is concerned. The Leica template cuts, at one end, a notch to go into the cassette and, at the other, the long leader. It thus leaves a long leader already cut for the next cassette to be loaded. Some 10 centimetres a roll adds up to a lot when you make rolls by the billion.

 

Mark, the FTb I've used since 1975 is before me, back open, and I can see no earthly reason why it shouldn't accept full-width film. The toothed shaft is full width, the roller with the rubber pads is full width (and the pads are in its middle, not at one end), and the metal flap is also full width.

 

Dan, just what is this convincing evidence? I should be delighted to be convinced. The point is not that a long leader is a hindrance. The point is that a long leader is unnecessary.

 

John, just how would full width film maul the shutter? I should think it would be less likely to do that than one which began narrow and later reached full width. No corner, not even a rounded one, which might spell danger.

 

Neil, the fact that the slot is narrower than the film is hardly a reason to conclude that you can start only with a narrow bit of film. If you start with the full width, one edge will engage in the slot and the other will go where it's meant to go.

 

I am willing to be corrected, but with reason: mere references to The Book represent no more than blind faith.

[john_shriver]

The reason for the long tapered leader is so that you don't try and push the curled film past the top side of the exposure aperture. Otherwise, it can snag on the frame, and you get a crinkled mess, and then something gets torn.

 

Yeah, folks avoid this by putting the shutter on T, removing the lens, and poking the film back as the slide it into the back. If you're lucky, you won't scratch the soft aluminum pressure plate.

 

Unfortunately, this doesn't work worth a darn on a Leica I, which has a non-removeable lens. THAT is the camera that the leader was designed for. Not a IIIf. Not an M3.

 

Also, remember that the 35mm film of the 1930's was a lot more brittle than today's film -- it was cellulose nitrate.

 

A small broken off chip of film can cause a lot of havoc inside a Leica, there's nothing to keep it out of the gears, etc. One blown sprocket is a large potential problem.

 

Yes, I suppose that you could cut alternate lengths of film from the spool in opposite directions, so that the leader tails overlap. With movie film, which isn't frame numbered, that would be just dandy. But with frame numbered film, it would be rather silly for half the rolls to number in the wrong order, with the numbers on the wrong edge. No thanks.

 

As I noted before, my Topcon Super D has a multi-slotted take-up spool, where all of the slots only go two-thirds of the way up the spool. I could not load a leaderless film on that camera.

 

But, the leader is there because Leica decided that should be "The Way". So it continues, but in a truncated way.

[neil_parker]

>If you start with the full width, one edge will engage in the slot and the other will go

where it's meant to go.

 

Sorry, your wrong on that one Mukul, look at most any older 35, the slot is too small for

the full 35mm width (and closed at the top). You must have a narrower leader, and it must

go all the way through (at least if you want any pictures). The exceptions are some

minoltas with open plastic tabs (that break easily), and a few self loading cameras like

some of the canons.

 

Of course, this doesn't help the original poster re. LTM cameras. All I can say there is that I

have seen more than one older Leica jammed or rolls of pics lost because the leader was

not right.

[mukul_dube]

John, something of a language problem here. By "exposure aperture" do you mean the rectangle through which the film is exposed when the shutter opens, and is that or is it not the "frame"?

 

Wouldn't the space available for the take-up spool and the film cassette make it difficult, if not impossible, to push the curled film above the top side of the whatever? There is real danger, I agree, when people load Leicas to build their muscles, specially when the film curls the way it shouldn't.

 

When you say that the long leader was meant for the Leica I and not for the IIIf or the M3, I assume you mean that only that model needs it. Thanks for supporting my stand.

 

I too feel silly when I realise that I only imagine that I am advancing film when in fact it is moving backwards in terms of edge numbers, never mind the dumb frame counter. That I can't see this happening without fogging the roll is really no excuse. And I am entirely unable to tell which is the right edge of a processed roll of film: the one with the numbers or the one without them. Maybe I should try turning the thing upside down, or perhaps even looking through the emulsion side if there is one in this crazy un-numbered world.

 

Neil, I haven't ever seen the sort of thing you talk about, and I'm not exactly young; but (a) I can hardly have seen everything, and (b) since I can picture (no pun intended) what you describe, I think it entirely possible.

 

We're left with two probable and plausible conclusions: the first is that 35 mm still film was made with leaders because of the Leica; and the second is that at least some later cameras had their take-up spools shaped to suit the leaders.

[john_shriver]

All bottom load Leica cameras need the long trimmed leader if you are to follow the manufacturer's instructions for loading the camera. Not just the Leica I. The Leica IIIg needs it every bit as much, being fundamentally the same camera. (I think that sticking one's finger into the lens mount to poke at the film is not a very sound work-around.) So there were about 750,000 Leica cameras made that need the long leader.

 

By exposure aperture I indeed mean the frame. There is a rectangular hole in a flat plate of brass, no rounding of the corners. The pressure plate is spring loaded against it. You are sliding the film between them towards the top of the camera, and it is curled towards the hole in the frame. It goes into the frame, and wont go past. Meanwhile, it is far enough into the slot that you can't push properly on the other edge of the film. You really can only "tease" the film into these cameras.

 

It is hard to explain if you can't look at a bottom-load Leica.

 

Suffice it to say that the most practical way to load a bottom-load Leica is with a long leader.

 

Since the Leica IS THE CAMERA that pre-loaded 35mm film was designed to fit, it's rather obvious why Kodak followed Leica's lead with the leader.

 

Since then, cameras were designed around the leader, and now it is required for those cameras. However, since only the bottom-load Leicas need the long leader, it has been allowed to become stubby.

[mukul_dube]

John, here one of the keys is "if you are to follow the manufacturer's instructions...". Manufacturers, specially quite remarkably intelligent and innovative ones like Leitz, are usually right about the handling of their products. Their words, however, are not gospel.

 

By "tease" I take it you mean what might be described as a pushing pulling wiggling first to left then to right motion which involves the take-up spool, the film cassette, and both hands.

 

My understanding is that all cameras have apertures through which films or plates are exposed to light (I have never seen a rectangular aperture with rounded corners, so I cannot understand what you mean) and that the light sensitive material is pressed against these apertures by spring-loaded pressure plates, now almost always of metal, once almost always of glass. Maybe I shall look into the bottom of the IIIc sitting two yards away from me, maybe I shall just rely on my memory of other screw mount Leicas I have owned or used: IIIf, IIc, IIIb, others I can't remember. Suffice it to say that what is the most practical for Person A may not be the preference of Person B. And yes, while I haven't ever stuck in a finger or a toe through the lens mount to make loading easier, I do that all the time near the take-up spool.

[dan flanders]

Once you have lost a whole load of exposures because you didn't realize the film was jammed, or you have to have the camera disassembled to remove that chip of film you just might be convinced that there is a valid reason for using the long leader, Mukul's logic notwithstanding. <p> I've tried the lens removal and business card sytems but neither is as assuring and reliable as the long leader. I have a built in resistance to SOP imposed by others, but over sixty years experience with Leicas has conviced me that irrespective of my own logic, there is usually a valid reason that the SOP was established.

[mukul_dube]

Dan, while I can't match your six decades with Leicas -- not my fault, really, I haven't been on the planet quite that long but should get there in a bit -- I share your views on SOP (if that is Standard Operating Procedure, because it can be something else as well). However, I dislike dire warnings too: and I have this terrible habit of watching the rewind knob, a sort of rotating fixation you could call it.

 

John, here's someone who agrees with you about the danger posed by the top edge of the film gate: http://leica-users.org/v20/msg07512.html. I too can see the danger, but I have the deepest regard for what is perhaps the oldest principle to do with machines: Force Nothing.

 

As for economising on film by getting two leaders with one cut, a search for ABLON should be enough.

[mukul_dube]

Dan, after "but should get there in a bit", please add "if I advance correctly and don't get jammed because my, er, leader's too short."

 

John, please read "oldest principle to do with machines, humans, animals, evrything" in place of what I wrote earlier. I'm not so sure about mules, but let's give them the benefit of the doubt.