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-   -   Lens repairs. Seeking tech advice. (http://www.dvinfo.net/forum/silicon-imaging-si-2k/531148-lens-repairs-seeking-tech-advice.html)

Bob Hart February 12th, 2016 12:01 AM

Lens repairs. Seeking tech advice.
 
I have an Angenieux 15-150mm zoom which I bought off eBay as suitable for parts only as the optics have been irrecoverably fungussed.

I was only after the iris to repair a 10-150mm The iris assembly itself is apparently exchangeable but I have encountered a bit of snag in dismantling the rear groups and iris from the main barrel.

Retention on the 10-150mm is by a shouldered collar. Retention on the 15-150mm appears to be similar but there are only dimples not slots in the collar for tooling to engage in. If it is a press-assembly secured by brass grub screws then that is my lot. However in the hope that it is not, this is my enquiry for advice.

I am also looking for a damaged Angenieux 16-44 16mm zoom. I have front and rear optics in good condition but internal groups and travelling groups are damaged, the usual opposite of damaged lenses.


Any help is much appreciated.

Bob Hart April 11th, 2017 02:59 AM

Angenieux 16-44 "variable prime" lens
 
I am restoring a complete lens of this type from two damaged examples. Before I go to the torment of designing and building a PL or direct IMS mount for this lens, does anyone have a clue on a machine design diagram for a PL mount for this lens?

Alastair Traill April 12th, 2017 05:54 AM

Re: Lens repairs. Seeking tech advice.
 
Hi Bob,

Will you be doing the machining yourself and do you have access to an autocollimator? I have done this sort of work in the past and found that the PL system was relatively straight forward but time consuming. I assume you have a camera body with a PL mount?

Jim Feeley April 12th, 2017 10:07 AM

Re: Lens repairs. Seeking tech advice.
 
Bob, as you go ahead with this project, I hope you post some pictures and keep us up to date!

Sounds like a fun and worthy challenge!

Bob Hart April 13th, 2017 07:41 AM

Re: Lens repairs. Seeking tech advice.
 
1 Attachment(s)
Alistair.


It is likely that only the front element will have to be replaced and a new mount made for the better or the two lenses. The front moving group in the worst lens is not too bad.

It was the rearmost groups which were halfmooned the worst plus one of the smaller elements in the rear inner group which should have been recelled had been shoved in loose, rattled around and chipped on the edges with one spall coming in about 1mm.

The previous owner had been really done over. The image was sharp enough with a very slight rainbow on one side from the chipped element but like looking through a milk bottle because of the halfmoons.

I came soooohhhh close to being able to fix the thing except when that last element to be separated exploded. The lens techs had not wanted to touch it. I now know the reason why.

I will probably make an ARRI standard tail and use a PL adaptor which I will shim to collimate to the camera. I have made PLs and an IMS for the Metabones Speedbooster but they are a real pain to get right on a hobby lathe.


Jim.

I will do my best. They will probably be picture phone photos. This image is of the lens type saved from an eBay page, a better specimen to look at. With everybody going 4K plus these days, the 16mm/Super16mm lenses might be going the way of the feather duster.

Alastair Traill April 14th, 2017 12:27 AM

Re: Lens repairs. Seeking tech advice.
 
3 Attachment(s)
Hi Bob,
Sounds like an ambitious project. At one stage I acquired al lot of Arri bits from a retiring film camera mechanic. There was a bag of Arri Std mounts for Schneider lenses and a more heavily constructed standard mount extension tube. I still have the Kilfit extension tube and at least a couple of the Schneider mounts if that is of interest. I also have a couple of Arri S camera movements if you want to go back a bit further. There were also a lot of lens elements unfortunately unlabeled.

My machining set up is centred on a lathe and a vertical mill. I can remove the chuck from the lathe and set it up centrally on a revolving table on the mill to do some more machining eg drilling accurately spaced holes removing bites from flanges etc. I also have an autocollimator.

My interest in the Arri 16S was for underwater use. Instead of using a massive housing the camera fitted with a turret and 400 foot magazine I removed the movement from a 16 S and fitted it to a waterproof body. See pics. The larger unit housed a 12-120 Angenieux and two Micro-Nikkors (one with extension tube), the other unit was fitted with a 9.5 57 mm Angenieux. The magazines were coaxial and the running cost, many years ago, was $0.48 per second and running time around 10 minutes. I am looking for good homes for both, I believe there is a film equipment museum in Perth?


http://www.dvinfo.net/forum/attachme...1&d=1492151069

Bob Hart April 14th, 2017 10:38 AM

Re: Lens repairs. Seeking tech advice.
 
Alistair.


Thank you for your kindly offer.

I am on the lookout for some iris blades for an Angeniuex 10-150 I had on my CP16R. The iris blades onioned and two broke when some lube crept into them during a long storage. How long it has been like that I have no idea except after fitting the lens to the SI2K, I was getting some weird bokeh. When I looked through the lens, the iris was a goat's eye.

There was a vendor in France who stocked some new blades but after one reply, furthur communication from him ( or her ) did not occur.

It is interesting that you built a submersable ARRI. I understand that someone over on our East Coast also built one many years back.

There is a young guy here, Johnny Ma, who runs a film studio who also has a camera collection. A camera museum here I don't know about but I am sure our Western Australian ACS Branch which is active and has a lively membership may know. I shall enquire with them.

My machining gear is very basic, a Taiwanese small lathe which was designed for marketing into US high schools as a desk machine. I enquired with our local vendor if there ever would be a model was a long bed. The manufacturer's reply to him was "how many container loads"? So that fixed that notion.

I also have a Taiwanese mill which looks like a lathe bed stood on end and modified. Both machines are not really accurate but get the job done at least to the extent of my skill limits.


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