chuck colburn

Hi Jon, What is a glass die? Chuck

Put your head, (the geared one) on some Big sticks. Mount (attach) your camera with a standard focal length lens to the head. Now put a bunch white tape Xs on the wall. Put eye to eyepiece and practice in a random manner going from X to X. When you stop having to think about which way to turn the wheels your ten percent of the way there! It's so easy, just ask any old time operator. LOL

Hello Brian, Just a suggestion on your beam splitter. I see your using plate glass which has a couple of disadvantags for this application. First it is not very flat and second it has an intrinsic coloration (see green coloration when looking at the edge) inherent in the formula of the pour. A better choice would be a water white float glass (that's a glass thats poured on a bed of liquid tin) it's much closer to being optically flat (without being ground and polished) and does not add coloration to the image. Also try and keep the thickness as thin as possible. Chuck

Alessandro Disregard the above (except as some info on how zooms work) I misread your question as asking if one should start at a FOCAL LENGTH in the middle of the range not as you asked as a FOCUS RANGE. You can pretty much do it at any distance you want though I would avoid the absolute closest focusing distance. Gotta cut back on my speed reading! LOL Chuck

Hello Alessandro, As are favorite Vulcan would say, "That is illogical" ! And I'll tell you why. A zoom lens, any zoom lens, only comes to best focus at three points. These are its longest, shortest and some point (appx. half way inbetween) focal lengths. This is due to the fact that all zooming optical devices suffer from what is known as the "S" curve. That is to say as you zoom from the longest focal length to the widest the lens goes (albeit a small amount) out of optimum focus on one side of the film plane and then comes back to best focus (that point inbetween the longest and shortest focal lengths) and begins to go out of optimum focus on the other side of the film plane. Untill it reaches its shortest focal length where all things being equal it once again has reached it's best focus. So if you begin at any point besides the longest focal length you are not going to get the best result possible from a given lens. I hope this makes some kind of sense. It's the reason why when you take your zoom lens in for overhaul it entails more then just a lube job and some lens mount shimming. Thus resulting in that wallet busting bill you get upon its return. Chuck "thirty years of doing the above repair work" Colburn

The answer to your question is yes. It's just easier to do with a focus chart no matter where you are. Just do it twice at least if you had to move the back focus adjuster the first time. Chuck

Here's one. http://cgi.ebay.com/Arriflex-periscope-for...1QQcmdZViewItem

Back to the subject at hand. Changing the back focus has a slight effect on the front focus. So be sure to do it a least twice. That is zoom in tight on your target, focus the lens, zoom wide and set back focus. Now zoom tight and refocus. Zoom wide again and see if your back focus has held. If not, reset the back focus this should take care of any front focus shift that might have occured the first time. Chuck

Newspapers Frank Newspapers! You know those things printed on paper and sold in little vending machines out in front of the liquor store. Yeah those vending machines right next to the other vending machines selling other printed matter that you don't want anybody else see you buying. I know what you mean by that slight drifting problem... mayby my "crystal" is starting to wear out? Chuck

Hello Frank, Yeah, what you said. Old timers would sometimes use the front page of a newspaper. I guess that was before the 1951 Airforce resoultion target and Siemens stars. LOL By the way gotta love your member number, 1440, does that mean your always in sync? http://www.cinematography.com/forum2004/st...icons/icon4.gif

A sound rerecordist once told me to always store my mag tape, be audio or video, tails out. Something about reducing print thru. Has anyone else ever heard this before?

Jon, You say that you can't afford a cine tripod. Does that mean you do not plan on doing any tilting or paning with your camera?

Hi David, That's interesting. Not quite sure what you mean by "a set". Never saw any film cameras with shutters that divided the expouser into segments. If I remember right the eyemo had a 180 degree fixed shutter opening. Use to convert them to dc drives in the seventies and eighties. Jimmy Beaumonte and I were always fooling with Mike Ferra's crash cameras. Back then you could pick them up all over town for 20-50 bucks. Wish I had stockpiled a hundred or so. Would like to see that eyemo shutter you saw just for my own edification. Happy new year, Chuck

Hi David, Was that a camera shutter? Sounds more like a projector shutter type. Chuck

Good morning Phil, The Arri 2C Hi-Speed could be set up to run a very steady 80 f.p.s. If you look at the gate door of the speed version there are four small adjustable screws with lock nuts on them on the back side. These are to control the adjustment of the travel of the pressure plate. We used to set the top pair up a little tighter then the bottom two. This and some tweaking of the tension on the mag clutches resulted in a more then useable image at high speed. There were tension gauges for both of these adjustments, but we just kinda got use to the feel of them after a while and could tell by touch when they were right. Have a happy new year up there in Big Sky Country, Chuck

This is true Nick. A forty five degree beam splitter or such. You would'nt even need to use any more stock as each camera would be running at half speed. This would compensate for the fifty percent light loss at the beam splitter. Though this would make for jittery pans if the shutter was left wide open. Can't even imagine the horrors in printing what with one image flipped and it certanily gives a new meaning to alternate printing. :blink: Must drink faster... Happy New Year! Chuck

Hello Jonathan, 360 degrees? Wow that sure doesn't leave much time for pull down. Or am I missing something here? Happy New Year! Chuck

Happy frigging new year! Whoppe! Commeeer Baby! Oh wait it's ony 9:00 o'c;olock. Matthew, What means this "ratty" ? Chuck p.s. David, Thanks for the heads up on the B&W ASA. I must have been thinking still camera, Panatomic X and such. Happy New Year to all. Chuck

Gilbert Taylor This shot from '65 ASA 25 mayby 32 does anyone know? http://www.theasc.com/magazine/feb06/taylor/image12.html

Hi Leo, What I meant is that there were three hole turrets on some 2C's that had one hole with a S/B mount in them. We were doing BNC hard fronts back in the seventies. It was a tight fit, you even had to mill some of the shutter housing portion of the body away to clear the locking ring on the lens mount as I recall. Happy new year, Chuck

Good morning Satsuki, Your observations on the S/B mount are correct. The stainless bayonet (S/B) mount was designed for just this reason. I would use a lens support with the Cooke as it it rather heavy. If I remember correctly some of the 2C turrets with S/B mounts in them had little locking levers on the turret to help hold them flush to the body and keep them from wanting rotate under the weight of heavy lenses. But it's been some time now since I did camera repair (the sixties thru the nineties) so I might be mistaken. If in doubt, support the lens. Have a happy new year, Chuck

Hello Andy, First off let me say what a lovely country populated with gracious people that you come from. I was there in the early nineties as the camera tech for the Showscan 65mm production of the "Kiwi Adventure". I will always have vivid and lovely memories of that time. Since your problem is near the end of the roll and is progressive in nature my first guess would be that the magaine clutches need to be cleaned, lubed and adjusted for proper tension. If you have more then one mag and it only happens with the one you used for this test then that would verify this. Also did the roll feel really tight when you down loaded the mag? That is to say if you held it between your thumbs and fingers and tried to flex it and it would not move then this would also be a sign that the clutches are to tight. If you have a roll of test film that you can use for a test then check for this and also for progressive perf damage as both are a sign of clutch problems. I have never worked on these cameras before but cine cameras pretty much all work upon the same principals. But it could be something else so mayby one of the other cam techs lurking around on this site might chime in with other info. Hope to return to NZ someday and continue the search for the elusive "GIANT KIWI BIRD" that the other members of the crew and I searched for after some late evenings of pup hopping. Chuck Colburn

Good morning David, If the film plane and the ground glass are showing the same relative image in the collimator eyepiece then chances are that any error in collimation is within the lens being checked. Chuck