History of BNC mount

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Re: History of BNC mount

by WinfordC » Wed Oct 11, 2017 10:34 am

Thanks for the explanation Lenstechdom. I had no idea about those differences between Series I and II.

Re: History of BNC mount

by lenstechdom » Sun Aug 13, 2017 3:31 am

I'd be happy to share any knowledge I have, although I don't own any Mitchell or 35mm lenses myself. The rental house I worked for previously had a wonderful collection of vintage cameras and lenses, including a blimped Mitchell on a geared head, which I spent a lot of time exploring. There was a complete set of Super Baltars in BNCR mount with that Mitchell which I converted to PL mount when I discovered them, which subsequently got rented out virtually non-stop and earned more than when they were last used on the Mitchell 40 or 50 years previously.

We also had sets of re-housed Cooke Speed Panchros, as well as quite a few originals (usually in Arri Standard mount). The re-housed Speed Panchros were also extremely popular. With the advent of digital cinema cameras that could finally rival film from around 2010 many Directors of Photography found that vintage lenses added an organic quality that humanised the potentially sterile, overly clean digital image. The value of Super Baltars, Speed Panchros, Zeiss Super Speeds, Canon K35s and many other older lenses designed for the cinema has exploded since then.

The difference between series I and II Speed Panchros is a slightly larger image circle and some additional aberration correction, but hard to tell from the outside. Series II are mostly marked as such on the front ring, alhough I have been confused by some marked with just a red "II" while later serial numbers were not. They came in all sorts of mounts including NC, BNC, Arri S and Cameflex (Eclair).

Re: History of BNC mount

by mediaed » Sat Aug 12, 2017 7:27 am


Embarrassed to say that I have not delved into lenses as much as I should. Know the BNC mount came about because of the desire to have different lenses available and a quick way of changing them. B&L supposedly had some input in the design. Could you post a few pictures here to show us what is different between each lens type you mention? I was planning to do an addition to my Mitchell Buyers Guide that would talk about the different lens mounts: Standard vs B&H, 16mm, widescreen anamorphic, large format, BNC, and BNCR. Would you like to collaborate on a more detailed lens section? Best. ED.

Re: History of BNC mount

by lenstechdom » Thu Aug 10, 2017 9:42 pm

Thanks for the reply, Ed. I did have a look through some older threads but couldn't find a direct answer to my query.

So the BNC mount dates all the way back to 1934! That's quite a heritage for a mount that is more or less still the industry standard today (given that the PL mount and Panavision's PV mount are direct derivations).

My interest was sparked by trying to identify Cooke Speed Panchro iterations, which were made from the 20s to the 60s. The series II and III lenses were introduced during either the 40s or 50s (probably over a span of years for different focal lengths, but it's hard to pinpoint and Cooke's own history webpage is full of mistakes) and I was trying to work out if a particular lens in the older Mitchell NC/Newall mount (a plate with 4 screws, correct?) could be a series II. All the series II and III Panchros I've seen have been in newer mounts like Arri, Cameflex or BNC/BNCR (though now I know that BNC mounts are quite old also).

Would lenses in the 50s have been available in a mount for the NC do you think? (Is it called a Mitchell/Newall mount?)

Any Mitchell owners have series II or III (only the 25mm and 18mm were III) Cooke Speed Panchros on an NC or GC?


Re: History of BNC mount

by mediaed » Thu Aug 10, 2017 4:57 pm

I might also add here that for a new visitor or member, please browse through the site as there is a lot of amazing information about Mitchell-the cameras and the company in the posts and articles. ED.

Re: History of BNC mount

by mediaed » Thu Aug 10, 2017 12:47 pm


If you check the serial numbers tab at the top right, you will find that 86 BNC' s were made before 1950. The first one was made for Sam Goldwyn in 1934 from an unsold NC. In design for a truly silent studio camera,(NC- 35db, BNC-21db) it was found the most noise after blimping the body came from the front of the camera. So, the redesigned single lens mount was a feature from the beginning. Regular Baltars from Standards could be modified to work in the mount but Super Baltars preferred in later years. A few cameras like my BNCR 104 went so far as to feature a front lens blimp as well that dampened the camera noise (to approx. 14db) so much the operator had to concentrate to hear it running. You can see and hear 104 in the member's article section along with other Mitchells. Hope that helps. ED.

History of BNC mount

by lenstechdom » Wed Aug 09, 2017 7:39 pm

I'm a camera/lens technician from Australia, I've just joined this group to see if the collective brain here can answer some questions for me.
I was wondering when the BNC mount was introduced? Was it with the first blimped NC cameras back in the 30s, or later. From my research it seems most BNC mount lenses are from the 50s and 60s, and earlier lenses used the older NC mount with 4 screws, but I suppose there weren't too many BNC cameras made before the 50s. Were the first BNC cameras equipped with only one lens?
Thanks for any insights.