8mm Forum: WHY THE DIFFERENCE (in speed) ??

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Posted by David Pannell (Member # 300) on July 27, 2005, 12:27 AM:

Purely out of interest, does anybody know why silent speed for Standard 8 is 16fps and Super 8 is 18fps? - and why dual standard projectors only have the 18fps speed setting?

Being the pedantic engineer that I am - (a bit like having all the correct boxes for everything, I guess!) - if I shoot at 16fps, I want to project at 16fps, and likewise for 18fps.

It's not actually an issue for me, because I can use my Elmo E-80 for 16fps projection and of course the ST1200 HD for 18fps. However, my recently acquired Eumig 810D, (which is primarily intended for Standard 8 sound anyway, 24fps) will only do the 18fps thing on the slow speed setting. If I switch the frequency control to 60Hz, it runs at 14fps.

I should like to have the option of using the Eumig running at the correct speed and I wonder if it's possible to alter the cam on the speed switch to give the desired 16fps, or whether to experiment by putting a few ohms in series with the motor to slow it up a bit for the 16fps setting. Has anyone tried either of these ideas?

I know that probably 2fps is nothing to worry about, but it's just this 'thing' of having everything right. I would just add that in a previous thread, I spoke about a stroboscope which I use for calibrating my cameras and projectors, so I know exactly at what speed things are running.

Cheers,

Dave.

Posted by Tom Photiou (Member # 130) on July 27, 2005, 10:53 AM:

I must admit i thought the STD 8 was also 18fps [Confused]

Posted by Gary Crawford (Member # 67) on July 27, 2005, 11:34 AM:

On my 810 and on most of the Eumig designs, I've been able to show films at any speed between the upper and lower limits of the speed change lever...the metal drive ball lands on a different part of the disc that turns the unit. If you changed the frequency setting to get 14fps..you should be able to inch that speed lever up to an appropriate speed...but how you'd know exactly what speed you were running , I don't know.

Posted by David Pannell (Member # 300) on July 27, 2005, 11:59 AM:

Hi Gary,
Why didn't I think of that?? [Eek!]

Can't see the wood for the trees, I guess! How would I know what speed I was running? Simply by calibrating with a stroboscope and then marking the appropriate position for the slide switch!

That's usually my trouble - I tend to look for the most difficult solution first. Many thanks for bringing me down to earth. Can't think of anything simpler.

Dave.

Posted by David Pannell (Member # 300) on July 27, 2005, 12:01 PM:

Hi Gary,
Why didn't I think of that?? [Eek!]

Posted by Jan Bister (Member # 332) on July 27, 2005, 07:18 PM:

I did a little Google search and according to http://www.amianet.org/publication/resources/guidelines/ineditsQA.html#Question5 it seems that while 16fps had pretty much always been the standard speed for silent 8mm films back in the day, apparently the 18fps setting just showed up one day...and was silently adopted by the masses. The site doesn't mention whether this coincided with the advent of the super-8 format, but if it did I would imagine that Kodak & Co. decided this 2fps bump would increase the image (and motion) quality over standard 8mm film without "wasting" a lot of additional film for the same time duration. This is just a guess, though.

Posted by Kevin Faulkner (Member # 6) on July 28, 2005, 03:58 AM:

Interesting Jan. I too have often wondered why the speed between the two silent gauges should be like it is.
I wonder if the 16 was soemthing to do with the US TV system? I think if you transfer silnt film to video it has to 16 2/3 fps or the like. I think what you say about getting the slightly better quality at 18 sound like it might be right and lets face it Kodak would sell more film!

Kev.

Posted by Jan Bister (Member # 332) on July 28, 2005, 09:18 AM:

Actually, the 16 2/3 speed is necessary for transfers to PAL video (rather than NTSC) since 3 times 16 2/3 equals 50. Works out real neat with a 3-bladed shutter, actually. [Smile]

But I have my doubts that the 16fps speed originally had anything to do with television because TV wasn't even invented - or should I say, introduced to the masses - and standardized until long after film established itself and its own standards. (I'm thinking about the early years of the 20th century here)

Posted by Paul Adsett (Member # 25) on July 28, 2005, 10:06 AM:

16 fps was the standard speed for 35mm silent film in the early years of the cinema, therefore it was natural to adopt the same speed for silent home movie filming. At 16fps you still get just a little bit of flicker. 18fps gives a smoother motion and eliminates that last bit of flicker, and Kodak adopted this speed when they brought out the improved super 8 format. Many amateurs were already filming at 18fps on regular 8mm, and there was a gradual movement towards 18fps in reg 8mm equipment prior to super 8(like the Bolex 18-5 projector) because of the advantages noted above.

Posted by David Pannell (Member # 300) on July 28, 2005, 10:30 AM:

Just to show my ignorance, Paul, I wasn't aware that there were Regular 8 cine cameras operating at 18fps. I thought they were all 16fps, and of course the 24fps! Have I missed something here?

Dave.

Posted by Paul Adsett (Member # 25) on July 28, 2005, 10:54 AM:

Hi Dave,
Many Reg 8mm film cameras had a continously wariable film speed capability. For instance the Bolex C8/B8/D8 cameras all had a calibrated speed selector knob which could be set anywhere from 8fps to 64fps(for slow motion) with calibration marks at 8,12, 16, 24, 32, 48 and 64 fps. I think the Bell and Howell "Sportster/ Viceroy" cameras also had similar facilities. You could easily set these cameras at 18fps because there was calibration marks for 16 and 24 fps, so it was easy to estimate where the 18fps position would be. Later versions of the Bolex's had a red 18fps setting mark. What sweet cameras those little 8mm wind-up Bolex's were. I still have mine (a C8 with impressive Pan-Cinor zoom lens), and everytime I pick it up the quality of design and finish just amazes me.

Posted by David Pannell (Member # 300) on July 28, 2005, 12:30 PM:

Cheers, Paul.

We live and learn!!!!!!!!!!!!!!!

Best,

Dave.

Posted by Kevin Faulkner (Member # 6) on July 28, 2005, 03:34 PM:

Great Paul, Thanks. [Smile]

Kev.

Posted by Jan Bister (Member # 332) on July 29, 2005, 03:28 PM:

So I anticipated exactly what Paul explained. Am I good or what [Big Grin]

But regular-8 cameras having variable speed dials was a new one to me, too. They are starting to really intrigue me. [Smile]

Posted by Thomas Dafnides (Member # 1851) on December 18, 2009, 12:20 AM:

I believe it was Bolex that initiated the move to 18fps in their cameras and their 18-5 projector. Kodak adopted it for Super 8.
If you stop and think...they sold more film with the shorter running time at 18fps.

Posted by Alexander Lechner (Member # 1548) on December 18, 2009, 12:34 AM:

There must have been a very strong movement towards 18 fps in the mid 60s: I am a big fan of the Leicina 8SV, which is a great standard 8 camera, and I was always convinced that it is only a 16 - 24 fps camera; until I found a model that was originally set on 18 and 24 fps! So where did the pressure for the producers to even change their existing models from 16 to 18 fps come from? Was it already the time when standard 8 and super 8 were co-existing?

Posted by Thomas Dafnides (Member # 1851) on December 18, 2009, 11:45 PM:

It was the early 60's when Bolex cameras/projectors were set at 18fps as standard. They were the first as I recall.

Posted by Joe McAllister (Member # 825) on December 20, 2009, 04:37 AM:

The 16 to 18 change came about because Bell and Howell couldn't manufacture a projector that was flicker free at 16fps. This was probably due to the need to get more light on the screen which affected shutter design coupled with the improvement in bulb brightness at the time. The brighter the output the more apparent the flicker. Other manufacturers had the same problem so 18fps was adopted as the standard for 8mm silent speed. Although it was not universally adopted for cameras until super 8 appeared and std 8 cameras were always 16 fps sometimes with an 18 fps option.
Professionally 16fps was nominally the speed for silent films as 16 frames of 35mm = 1ft of film. However as cameras and projectors were hand cranked for much of the silent era this was only a guide. When filmed comedies were often under cranked to give them more zip and dramas over cranked to give them more gravity when projected. Exhibitors would often over crank films to reduce their playing time and get more shows in. In short there is no "right" speed for silent cinema and the most authentic presentation would be with a variable speed projector which is set to whatever looks right and would vary from subject to subject and sometimes from scene to scene within the reel.
The TV documentary series "Hollywood" encountered this problem and utilized an early form of telecine machine which employed a rotating prism arrangement that allowed the film to be run at any speed and recorded at 25fps which is the PAL standard. Today there are other post production methods which would achieve the same thing.

Posted by Thomas Dafnides (Member # 1851) on December 21, 2009, 10:26 PM:

Thanks Joe, for this enlightment.

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