Mitchell Magazine base widths

~
Feel free to discuss any topic related to the Mitchell Camera. Both 35 mm and 16 mm models are welcomed here. Also consider posting topics of other major motion picture cameras that you feel are important to the development of the Mitchell Camera. Feel free to upload a photo from the option on each new post.
~
blueimperio
Posts: 9
Joined: Fri Nov 29, 2019 2:49 am

Mitchell Magazine base widths

Post by blueimperio » Wed Sep 09, 2020 11:38 pm

I have an NC, two Fries modified GC's and a MK II.  I have a couple of other (research) cameras that also use Mitchell mags. I've bought various mags along the way, typically all 400's.  I probably have a dozen mags plus a 400' bi-pack, all of different vintages.  They all fit my various cams, so nothing remarkable. Until now. A couple of 1000's popped up in the last year at a good price, so I bought a few jut for show. However, I discover there are two Mitchell mag-base mount widths. The 400's which fit my NC, GC and MK II and others are 1.940" wide. The 1000's I bought are all 2.200".  

The one with the brass throat is a West Hollywood build, the other 1000 is a Gendale build;  the inner 400 is a very late Glendale build, and the outer is a Flight Research unit (so built in Richmond VA from the late 80's to mid 90's after they acquired the tooling).

I was always told a standard, NC and GC are the same and the BNCR is the odd one out.  But on the other hand, I don't have a standard to test fit, so maybe it takes the wider mag base since it is the earliest design.  I was just surprised that different mag sizing has never come up in polite conversation.  A B&H 2709 mag is closer to the narrower Mitchell width.  

My MK II came with a 1000 mag, but both it and this mag are in storage and I don't have access as I write this.  However, I recall it took any number of 400 mags  I had at the time, so I think it also uses the narrow dimension. I could continue to speculate all day but clearly someone has the answer. Inquiring minds want to know.

marop
Posts: 125
Joined: Fri Mar 21, 2014 2:45 pm

Re: Mitchell Magazine base widths

Post by marop » Thu Sep 10, 2020 9:31 am

Blueimperio,

I thought it was just the NC and BNC/BNCR that had the wider magazine. I have a 1931 West Hollywood Standard but can’t measure the width. Why? Because Paramount Pictures (first owner of my camera) adapted it to fit the larger magazine (It has a plate attached on the opening). This larger magazine was made when the NC/BNC came out. It was redesigned for the “sound” cameras as it was made to be quieter for sound recording.

Hope this helps,

Mark
Director
Mitchellcamera.com

mediaed
Posts: 150
Joined: Wed Apr 06, 2016 3:53 pm

Re: Mitchell Magazine base widths

Post by mediaed » Tue Sep 15, 2020 12:50 pm

Sorry, It took some time to shoot and format pictorial description answer to your question. Did not include 70mm FC camera dimensions as a bit of overkill.I have a set of vistaVision magazines but not the camera. ED
CompareCameras.jpg

blueimperio
Posts: 9
Joined: Fri Nov 29, 2019 2:49 am

Re: Mitchell Magazine base widths

Post by blueimperio » Wed Sep 16, 2020 8:30 pm

Ah, I see now. My NC has been modified to take the narrower Standard/GC mags. You can see that the mag base has been modified. The visible silver metal shim rails are larger than what would be needed to neck down to the smaller width - I think the machinist made a mistake and took out too much metal on his first attempt (merde!) and shimmed it back to where he needed to be.

This is NC S/N 683 that I brought back from France. It has been machined quite a bit to add various strange features. In it last incarnation, in was set up with servo motors for remote operations. The Mitchell turret is replaced with a flat plate with a single mount for Cannon 35mm SLR lenses. This mod makes sense because the Cannon mount is a bayonet and everything mechanical required for mounting is proud of the face of the front plate.

The electrical plug mounted on the side finder is interesting. A flapper lever moves a focal plane side mirror that shuts off the path to the eyepiece element and allows a high intensity light to be projected through the film aperture and out through the lens. A theory is that this would effectively allow the field of view of the lens to be reverse illuminated through the lens and perhaps allow for some type of remote precision focusing. Some of the machined parts were very well made, others are a bit sloppy so I think the modifications were done in several stages over time by different caliber of machinists. So I guess if you have a preponderance of mags of one type, you adapt to what you have. The Mitchel MK II I assume uses the wider NC 2 1/8" width mag mounting base to be compatible with BNC/BNCRs? I'll have to drag it out and check.

Thanks Ed for the mag chart.

mediaed
Posts: 150
Joined: Wed Apr 06, 2016 3:53 pm

Re: Mitchell Magazine base widths

Post by mediaed » Thu Sep 17, 2020 8:13 am

Yes on the Mk1& 2's. Both were designed for the NC mags which were thicker for sound usage. NC mags come only in 1K size because of sound.
You could use standard mags and 400' on NC's and Sr35' s with an insert shim called a fork.

The projection light through the viewer is a feature used on rostrum animation cameras shooting a flat surface. You see the focus screen for size
Run the camera up and down to adjust and simply focus the lens that way. I would imagine there is a motorized rack over as the camera pointing down might be rather high on the column.

Your pictures did not load. You need to watch the progress bar on the load graphic. It takes more time on this site.

Please consider registering your cameras on our registry page by clicking on the top.graphic to get to the index page and buttons on the right.

Best,

ED

admin
Site Admin
Posts: 36
Joined: Tue May 22, 2012 7:13 pm

Re: Mitchell Magazine base widths

Post by admin » Thu Sep 17, 2020 9:20 am

Hello blueimperio. Instead of using a not link, try clicking the ATTACHMENTS button at the bottom of the new post window and upload directly from your computer. I deleted the dead links on your first post.

Admin

blueimperio
Posts: 9
Joined: Fri Nov 29, 2019 2:49 am

Re: Mitchell Magazine base widths

Post by blueimperio » Thu Sep 17, 2020 2:13 pm

I re-posted those first two pictures from my original post below in the method you suggest. I'm using Google pix and I think it has strict permissions which is the issue. It works fine in Chrome when I'm logged in, but I see the pictures don't load in FIrefox. Always best to check in a second browser. However, uploading as you suggest resolves this problem and is much, much easier. Thanks !

gap.JPG

The relative difference in width is shown.

all.jpg
all.jpg (63.3 KiB) Viewed 29128 times

The 1000' with the brass throat is a West Hollywood build, the other 1000' is a Gendale build; the lower 400' is a very late Glendale build, and the upper 400' is a Flight Research unit (built in Richmond VA from the late 80's to mid 90's after they acquired the tooling). The 400' throats look smaller in the pic as the 400's are not on the same plane as the taller 1000 mags when the picture was taken.

So in summary,

Standards and GCs use the narrower 1 15/16" throat base plate mag
NCs, BNCs and BNCRs all use the wider 2 1/8" throat base plate mag
Mitchell MK I / MK II's follow the route of BNC/BNCRs as they were designed as a sound camera from scratch and use the wider 2 1/8" mag
You can adapt down from the wider to the narrower mag using shims.

Did Mitchell offer this shim arrangement ("fork") as an official part?

mediaed
Posts: 150
Joined: Wed Apr 06, 2016 3:53 pm

Re: Mitchell Magazine base widths

Post by mediaed » Thu Sep 17, 2020 4:01 pm

Yes. I do believe Ken Stone has one. I have seen one recently on eBay maybe from Wayne Goldwyn....

Have you investigated registering? Most often we have the date of sale and the original buyer on file. You get a nice certificate, the list is an international registration and the registration fee is small which goes to supporting this site. The goal of having a definitive list of survivors for the future is certainly a goal worth the effort.

Ed Johnson, MitchellCamera.com director.

blueimperio
Posts: 9
Joined: Fri Nov 29, 2019 2:49 am

Re: Mitchell Magazine base widths

Post by blueimperio » Fri Sep 18, 2020 12:37 pm

Ask, and sooner or later ebay shall provide. In this case, sooner...

Voila! - an example of a "fork" magazine adapter.

s-l1600.png
s-l1600.png (579.28 KiB) Viewed 29095 times
s-l1600 (5).png

Post Reply