Dumb Question of the Day
I was wondering why 35mm film has a tapered leader. Why not just cut it off straight across?
(I feel ashamed asking this, since I'm an engineer.)
my best guess is that it's an attempt at saving a few inches of emulsion per roll.
Originally Posted by yeknom02
That's the way Oscar Barnack wanted it. BTW, the late model Practika cameras did not require a tapered leader.
John, Mount Vernon, Virginia USA
Sharp corners catch on sprockets, film gates and rollers.
Rounding the corners and tapering the ends of the leaders makes them easier to insert into their slots and run through the cameras, processors and/or projectors without the film getting hung up and being destroyed.
My Yashica Lynx has a slot sized for tapered film on the take-up spool, so when I bulk load I always have to cut a little notch in the leader so I can load it. That's probably a product of film having a taper though, rather than a reason for it...
My goal in life, is to be as good a person as my dog already thinks I am.
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Yep, some cameras need the little tongue to load into the takeup spool. A lot of manual Nikons are like this.
Originally Posted by SteveR
Both of mine are, Nikon FG and Nikkormat FT. 20 years apart they look almost identical inside.
Originally Posted by brucemuir
Indeed. If the film were straight-edged, the film that was not held into the slot would stand up from the wind on spool thus enlarging the diameter of the wind-on portion of the film which could lead to scratching and other in-camera defects.
The slot in the loading area is often not wide enough to take the full width of the leader, so it is cut down to a universal fit.
( Was checking and just opened the camera back, but unfortunately there's a roll of Velvia 100F mid-way in there... )
My neighbour is an engineer and asked me around Easter this year, while manhandling 'Brutus', if left-handed people have difficulty with cameras made predominantly for right-handed folk. What-ho. Well, do they?
Canon EOS1N ('Brutus', 1993—), TS-E 24mm f3.5L, 20mm f2.8, 17-40 f4L, 70-200 f2.8L
Pentax 67 ('Pentaximus', 2010—) + SMCP 45mm f4, 55mm f4 & 165mm f4LS;
Zero Image 6x9 multi-format pinhole (2008—); Sekonic L758D;
Olympus XA, Nikon Coolpix P7700
"If you're not having fun, then you're not doing it right!"
I expect the origin of this is historical - probably related to something about the configuration of the original Leica cameras.
Originally Posted by yeknom02
Of course, if one is manufacturing film, one is going to make the film to fit the cameras available.
Now, if one wants to build cameras to compete with the Leica cameras, one doesn't want to make them in a way that won't allow them to use the film that is already available.
You can see the trend...
So I expect that the answer to the question is - because it always has been done this way.
By the way, it wasn't a dumb question.
“Photography is a complex and fluid medium, and its many factors are not applied in simple sequence. Rather, the process may be likened to the art of the juggler in keeping many balls in the air at one time!”
Ansel Adams, from the introduction to The Negative - The New Ansel Adams Photography Series / Book 2