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Nikon mount for Arri 35-3, is it possible ?


Gregory PAUL

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Hello !

 

I was wondering if it was possible to have a Nikon F mount on an Arri 35-3.

I noticed that some 35-3 had lens port fitted by 4 screws. I guess they are the latest versions of the camera.

So, if it's possible to change the lens port, is there any manufacturer still making such mount ?

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The Nikon F mount has a flange focal distance of 46.5 mm, while the Arri PL is 52 mm. That means that the Nikon mount would have to extend 5.5 mm deeper into the camera body than the PL. Even if there's room to do that, it would be an expensive machine shop job, requiring some milling that would permanently modify the camera front casting.

 

 

 

 

-- J.S.

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Hello John,

 

Yes I already know about the focal flange distance difference. But since the front casting of some 35-5 seems to be removable with the four screws, I was more thinking about a new front catsing with a Nikon mount that could replace the original one without deep modification. Maybe it's not that simple although !

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There were Nikon F mounts made for the 2C ....

 

That may be the way to go -- buy an existing hard front 2C with the Nikon F mount. It'll cost less, and you don't reduce the value of your 35-3. Run some "WTB" ads and see if something turns up.

 

 

 

 

-- J.S.

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I recall seeing ads in AC quite sometime back for an interchangable Nikon F mount for the Arri III made by one the german companies which specialize in making Arri accesories.

 

But I cannot remember the name, other than it was not PS Technik.

 

 

The interchangeable front on the 35-3 is just a simple plate with the mount and the screws to attach it to the body. If you brought it to a machine shop and had them look at it they should be able to reproduce the mounting board. Then you just have to give them a F-Mount (there are tons of F to C mount adapters on ebay) give the machine shop the centering and the flange focal distance and they should be able to make this part up easily.

 

-Rob-

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Hi Gregory,

I've just designed and had made a hardfront Nikon mount for my 2b. I had the plate made using my drawings at a local engineering shop...cost £60. I used a mount from a broken Nikon FE...£10...this bolts onto the new plate with thin bolts. And it works a treat...I can now use Nikon lenses and even convert it back to the old arri front if necessary.

Saves a fortune in hiring lenses as I have my own Nikon set...I Haven't really looked into the 35-3 but they have very simple hard fronts which simply bolt on. It should be far easier than converting a 35-2b or c. As said you'll have to check that you wouldnt be fouling the mirror. Just do lots of measuring and go for it!

cheers

rob

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Rob,

 

Thanks for the pics.

 

I apologize as I misunderstood. So you put a Nikon Mount on the front of your IIB to use for macro and closer up work, since the FFD of the Nikon glass is shorter than the FFD of the Arriflex IIB. I thought you meant that you had sunk the Nikon mount into the front of the IIB so that the Nikon mount would be at the right FFD and you could use your Nikon lenses all the way out to infinity.

 

Still a cool conversion though. Bravo.

 

Best,

-Tim

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Hi,

Here's a shot showing the old and new front ( as best I can ), I did consider getting the original front milled down , drilled etc but I didn't want to ruin it. As I never went ahead with this route I'm not 100 per cent sure it would work, but I think it could.

best

rob

 

http://s1178.photobucket.com/albums/x379/robspence7/fitted%20hard%20front%20arri/

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Rob,

 

Okay, so you sunk the mount in 5.5mm, I see. Did you have any clearance problems with the mirror? That's an area I would be concerned about since the nikon mount is a larger in diameter than the ARRI standard/bayonet mount that the camera came with, and you're sinking it into the camera 5.5mm. Is the mount centered for the Academy gate or the Full Frame (Silent) gate?

 

That's very cool.

 

Best,

-Tim

 

PS: Looking at your photos, it looks like your Arriflex 35 IIB is in remarkably good shape.

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Hi Tim,

There are no problems with the lens hitting the mirror, plenty of room there. I haven't checked but I think any slr lens system could be fitted, Pentax etc as they are built to clear an slr flip up mirror. The gate fitted is academy and the lens is centered to the measurements of the arri original front. My camera is in very good shape and is originally from New York, it has a Camera Equipment Co. Incorporated 31, West 43rd Street New York 26.NY plate ( in blue ) rivetted to the eyepiece door.

Do you know if there would be a clearer view using an Arri 2 door, or would it be basically the same?

 

cheers

rob

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Do you know if there would be a clearer view using an Arri 2 door, or would it be basically the same?

 

Rob,

 

I'm a little confused. Do you mean "would there be a clearer view using an Arri 2C door?"

 

If that is indeed your question, my answer would be "maybe". I love the Arriflex IIB and IIC cameras, but the one issue I had with my IIC was difficulty focusing. It used to drive me crazy when I was focusing the camera, I had to have my eye directly centered in the eyepiece or the image would slightly shimmer, which made critical focus really tough. I finally talked with a couple of "old time" camera operators about this and they confirmed that it was a known issue with those cameras. Something to do with the optics and the way the ground glass and viewfinder optics worked with each other. I think that's one of the reasons the "Italian Door" came along, it supposedly made the focusing easier. I even tried one of the Jurgen's doors on my IIC, but it did not resolve the issue.

 

The IIC door might be brighter than the IIB door, but the "shimmering" issue is still there.

 

Best,

-Tim

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Hi Rob,

 

that looks like a nice job, well done.

 

Do you know what tolerances the machine shop worked to? I'm guessing you don't have a depth gauge to check the FFD? It doesn't matter too much if it's a little out when you're using primes and focusing by eye (just throws the focus scale out and the lens may not reach infinity), but the mount flatness from edge to edge with respect to the gate is fairly critical, ideally within one or two hundredths of a mm. And of course the ground glass depth needs to be spot on. But if a test film shows an even and sharp focus you're OK.

 

Are you planning on having the new front anodised? If you haven't already done so I would recommend painting the interior surface matte black to avoid any reflections.

 

Regarding a IIC door, I believe the optics are a little better, but if fitted to a IIB it may cause a light leak. Where it mates with the turret block it is slightly larger (for this reason a IIB door won't fit on a IIC). You could probably fix that easily with some sort of felt seal though.

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Hi Tim and Dom,

 

Thanks for the info on the door...does anyone have a photo of an Italian Door, I can't find one on the web ?

Obviously the issue of peering around inside the arri viewfinder wasn't solved with the 2C !

 

The machine shop got the collimation spot on after 2 or3 fittings, we used a small aluminium billet in the gate and measured using engineering callipers which had a drop down arm ( courtesy of a pal of mine ), I even took into account the -0.03 as recommended by the Arriflex manual to take account of the film curveture . I was thinking of an aluminium acid etch primer on the front of the turret and then paint it to match the camera and somehow matching the flock black on the indide ,as is inside the original camera. Not sure how to achieve this as yet, maybe glueing some sort of thin velvet flock perhaps. Paint sometimes flakes off aluminium, which is ok on the outside of the camera ...but not inside. Any suggestions.

cheers

rob

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Hi Rob,

 

Here's a picture of an Italian Door that Gregory Paul (of these forums) was selling a few weeks ago on eBay.

 

ItalDoor.jpg

 

As far as the FFD issue that Dom brought up, it would be best if you had a flange focal distance gauge to check the FFD and flatness of your new mount, and then a calibrated test lens (one that overstrokes past infinity) to check your ground glass, those are what we use when we service the cameras.

 

And finally the black paint issue, that's a tough one. You're right, you definitely don't want any paint flaking off on the inside of the mount face, that could cause real problems. Maybe anodizing would be good, just be aware that it might add thickness to the part of the aluminum plate that seats against the camera body, thereby increasing your FFD. Just stuff to keep in mind.

 

Best,

-Tim

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Hello !

 

About the 35-3 Nikon mount :

 

The interchangeable front on the 35-3 is just a simple plate with the mount and the screws to attach it to the body...

-Rob-

 

That's exactly what I was thinking about. Good to know that it's possible to do.

 

About the 35II Nikon mount :

 

I've just designed and had made a hardfront Nikon mount for my 2b. I had the plate...

rob

 

Rob, you've made a very nice job ! When I bought my 35IIC, it was already converted to a Nikon mount (Academy centered) by a tech, but I don't know who has made the modification although. The only drawback is that it's not easy to rotate the Iris ring because the mount is deeper in the hardfront. Rob, do you have the same drawback on your Nikon mount ?

 

About the 35II viewfinder and italian door :

 

Here's a picture of an Italian Door that Gregory Paul (of these forums) was selling a few weeks ago on eBay.

 

The Italian door is very comfortable to use and it becomes easier to focus. Although I decided to sell it because I prefer the original door for its compactness.

As far as I remember from my IIB, the IIC viewfinder is better !

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The interchangeable front on the 35-3 is just a simple plate with the mount and the screws to attach it to the body.

 

-Rob-

 

Hi Rob,

 

A little FYI on the 35-3......

 

 

In the last 4 or 5 years Arri made the 35-3 - 3rd Generation, the model that would go to 130fps forward and reverse, 15 to 180 degree shutter and "washboard" gate, Arri eliminated the interchangeable lens mount plate, the nice solid steel one, with the 4 screws.

 

35-3lensmount001.jpg

 

 

 

 

Arri instead machined the softer housing to accept the the mounts directly, making it not so easy to change them.

 

Be careful using heavy lenses on this version, make sure you have good support before you take your hands off the lens after mounting it to the camera. Damage the mounting that is screwed directly to the housing, you might distort the housing and then you'll have to replace the "skeleton" or housing. More $$$$. One would have to question if extreme heat/cold would be more apt to change the tolerances of the flange distance do to the softer material used in the housing. ??? Then the 435 came out........

 

I couldn't find a picture of the modification / change.

 

Charlie

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