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This topic comprises 3 pages: 1 2 3
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Author
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Topic: Anyone here familiar with Cartrivision?
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Mark Ogden
Jedi Master Film Handler
Posts: 943
From: Little Falls, N.J.
Registered: Jun 99
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posted 09-29-2007 01:14 PM
You could probably get a fairly good coarse alignment with a grid chart, but yeah, you really should use an EIA registration chart to get better results. You’ll notice that the lines are more condensed in the sides and corners, out where the scanning gets more critical; you’ll be able to finesse the finer pin/trap type adjustments if you use one. Also, better registration equals better electrical focus and resolution (which as I recall, if everything was dead-nuts on, maxed out at a whopping 650 TVL.)
The rule was always to start at the centers and move out. That is, get your R/B centering, rotation and skew dead on, and then deal with H & V sizes and linearity after. As I mentioned above, the corners and sides are the hardest part, and you will notice the pin-cushioning adjustments and trap really come into play here, so note where they are.
As far as the cable goes, this camera was introduced after the U-Matic era and if my dubious memory serves you actually cannot control a VTR from this camera. The side buttons on the lens, where the traditional REC buttons were, were actually for view finder return selection. That multi-pin connector on the back was for interface with the CCU unit, or with the optional triax adaptor if you were going that way. I spent years with these cameras, and I can safely say that I never saw anyone roll a tape from it (but that’s not to say that is not possible, and I could be happily corrected on this point).
Hope this helps. We may have an old manual around the shop; e-mail me at ogd/at/cbsnews.com if you get hung-up and if I can get a spare second I'll hunt around for it.
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Mark Ogden
Jedi Master Film Handler
Posts: 943
From: Little Falls, N.J.
Registered: Jun 99
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posted 09-29-2007 03:11 PM
Well, the question is can you achieve sharp focus at any focal length? Bearing in mind what we said above, if the tube alignment is significantly out you will not get a truly sharp image anywhere, and the softness will be exaggerated at telephoto range. The way to eliminate the camera from the equation is to monitor the G channel only on either a B/W monitor (preferred) or thru the viewfinder, and see if a sharp image can be obtained. If you can get a good image that way, then the camera is at least OK (and be sure, BTW, that the 2x lens extender is up and out before doing any of this).
If you turned the back-focus flange, then before you make any kind of evaluation you need to reset that, as front and back focus play off each other. The procedure is:
1. Open the iris as far as possible, dial in an ND on the filter wheel if you need to.
2. Look at the Green channel only, as above.
3. Zoom into a sharply defined object at least 30 ft. away, and set front focus on the lens ring as best as possible. Having the viewfinder peaking cranked up will help.
4. Zoom all the way out, and rotate the back focus flange till the same image is as sharp as possible.
5. Recheck things a few times before locking the flange down.
If none of that helps, the lens probably needs to be collimated.
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Scott Norwood
Film God
Posts: 8146
From: Boston, MA. USA (1774.21 miles northeast of Dallas)
Registered: Jun 99
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posted 09-29-2007 09:00 PM
Wow...thanks to both Marks for all the tips. Please keep them coming, along with any other comments from anyone who has worked on these beasts.
So, each tube has three adjustments: focus, beam, and "cal." I assume that focus does the obvious, but haven't messed with that one. Beam seems to have something to do with comet-tail reduction (or increase). What is "cal" and what is the proper setting for "beam"? I have a small manual for this camera, but it's badly translated from Japanese and seems to be written for people who already understand camera alignment.
I don't have a separate waveform monitor and vectorscope, but I do have an SGI workstation that can run "videoscope" (software implementations of both). Not sure how accurate this is, but it is probably better than nothing. I have a pretty good color monitor (Sony PVM-8045Q), but no B&W monitor. Would a B&W security-camera monitor work, or do I need a studio model?
On my camera, the blue tube seems to be pretty noisy until it warms up (takes about 30-45 minutes), then it works fine. Not sure if this is normal or not. The hour meter is about halfway to 5000 (is this the recommended tube replacement interval?).
[ 09-30-2007, 10:34 AM: Message edited by: Scott Norwood ]
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Mark Ogden
Jedi Master Film Handler
Posts: 943
From: Little Falls, N.J.
Registered: Jun 99
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posted 09-30-2007 10:39 AM
The adjustments are this: FOCUS is the tube electrical focus, as opposed to optical focus. This is another reason why it’s a good idea to use an EIA registration chart; there are vertical wedges that will allow you to set this up by looking at them on a waveform monitor and then peaking the adjustment. BEAM is an anti-comet-tail adjustment; you want to set it to cancel any color lag. There is an automatic beam optimization (ABO) circuit on the camera, but it never worked very well and is best left off. The best way to set this manually is by very brightly illuminating a white object, and with the iris quite far open pan the camera very quickly left to right and see how much trailing flare you get. You can then tweak it out with this adjustment. Be warned: BEAM and FOCUS play off each other, so when changing one you will have to double check the other. CAL is the overall output level of the individual channel. If you hunt around on the camera, somewhere you will find a switch that applies a sawtooth voltage across the tube’s pre-amp. Looking at a waveform monitor, set the RGB CAL levels to 1V for each of the RGB channels.
Strictly speaking, you don’t need a B/W monitor to do this stuff, but you will get better and less frustrating results if you have one, it’s easier to look at R/B/-G with a monochrome set. If you can hunt one up that underscans, then mo' better. Any monitor that you can feed an image to via an RGB or other connector will do.
The B channel noise is not normal at all, but I’d be surprised if it’s the tube and not the pre-amp itself, very likely a transistor somewhere that is having a thermal issue.
Yeah, Ikegami was pretty well known for it's poor and sometimes unintentionally hilarious manual traslations. The worst, though, was the Thompson TV1515, the first triax-able camera. Everything inside was in French. Sacrebleu, what a pain.
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