|
|||||||||
|
Thread Tools | Search this Thread |
June 2nd, 2007, 10:54 AM | #1 |
Regular Crew
Join Date: Apr 2006
Location: taiwan
Posts: 30
|
URGENT - I am in the middle of a shoot and have lost zoom and focus!
Hi all, I am in Nepal in the middle of nowhere, with an XL1s and the zoom has gone out. I power on the camera and all is well until I hit a zoom button. The zoom indicator moves a bit and then locks in postion.
Q: where is the motor, in the lense? Q: what does the watch bat do, cr2025? I have extras and replaced with no results. Q: there is only one other post here like this, with a mention of a fuse inside the lense. Is this true? Q: does anyone have any repair tips. There isn't a service center for thousands of kilometers from here. Thanks! PhoenixStudios |
June 2nd, 2007, 11:11 AM | #2 |
Inner Circle
Join Date: Sep 2002
Location: San Mateo, CA
Posts: 3,840
|
Assuming you are using the stock lens. Yes, there's a fuse in it. If the zoom is funtioning partially, then I doubt the fuse is blown.
Can you zoom and focus manually? The watch battery keeps the data records for the camera constant. Time/Date/ Settings and such. No functionality regarding the mechanics IS the lens switch set halfway between manual and auto? Does the zoom switch work on the handle? IS the zoom switch on the handle 'locked'? Just some things to check. Short of that, you might have to replace the lens. |
June 2nd, 2007, 01:56 PM | #4 |
Inner Circle
Join Date: Dec 2003
Location: PERTH. W.A. AUSTRALIA.
Posts: 4,477
|
As a desperate measure you could try pointing the lens directly towards ground or directly skywards (not at sun) when trying to operate the zoom and gently tap the lens body whilst triggering the zoom.
This manouvre may cause gravity to assist if a burr has built up on the internal actuators due to rough transport and is binding the mechanical movement. Turning the camera upside down and triggering the zoom may also assist. Taking the lens off the camera, taking a good grip on it and oscillating it vigorously in rotational movement around the optical axis with wrist action may also help if there is a burr. I understand that focus and zoom are driven off the same motor. If the temperature is cold, some lube might have gone a bit sluggish and the changeover from driving the focus to driving the zoom might be sticking. Warming the lens may help but be gentle and slow doing this. Caution though. Trying to get the zoom to work might disable the focus which may be a bigger loss. Last edited by Bob Hart; June 2nd, 2007 at 02:01 PM. Reason: error |
June 2nd, 2007, 08:12 PM | #5 | |
Regular Crew
Join Date: Apr 2006
Location: taiwan
Posts: 30
|
thanks, tried all this...
Quote:
|
|
June 2nd, 2007, 08:16 PM | #6 |
Regular Crew
Join Date: Apr 2006
Location: taiwan
Posts: 30
|
Thanks
|
June 2nd, 2007, 08:30 PM | #7 | |
Regular Crew
Join Date: Apr 2006
Location: taiwan
Posts: 30
|
Thanks, but what's a Burr?
Quote:
Ps. I remember about a month ago now the lens motor, which I thought was in the handle under the main zoom rocker, made a funny rumbling noise during a shoot but went away. the noise did not come from the lens itself, but the area where the watch battery is housed. what's in there? thx. Last edited by Herojig Gaton; June 2nd, 2007 at 08:47 PM. Reason: add info |
|
June 2nd, 2007, 09:41 PM | #8 |
Inner Circle
Join Date: Dec 2003
Location: PERTH. W.A. AUSTRALIA.
Posts: 4,477
|
A "burr" is maybe a incorrect description. In this, I mean a worn spot with a high edge in the slot/track the roller/peg in the zoom mechanism travels/slides along as it moves the group of travelling elements forward or back.
The piece which has the slot/track in it is for most zooms, a cylinder shape which turns as a sleeve inside the lens body. There are usually a pair of tracks 180 degrees opposed around this cylinder and two pegs on the body of the moving group. There is often a second pair of slot/tracks in the turning sleeve towards the front which move a focussing element forward or back to compensate for the zoom movement. To stop the sliding groups from turning, there are usually some more slot/tracks which run directly along the optical axis. When a lens is transported in a modern aircraft assembled to a camera, espeically if it is in an aft baggage store or on the floor between a cameraman's feet, there is a lot of shaking going on which might move the mechanism to cause a localised area of wear or buildup of lube and debris in one spot. The nature of the zoom movement puts the power input, either the human hand, or a motor at a mechanical disadvantage and a high torque motor may be used in the Canon. This I don't know for sure. My suspicion is that the frictional resistance of the zoom has reached the point of overwhelming the motor or the motor has deteriorated and lost performance enough that the greater frictional resistance of the zoom movement overwhelms it. The focus movement I don't kow about but as it is coupled to the same motor, my imagining is that when zoom inputs are not selected, there may be some sort of mechanical brake applied which then locks the zoom from movement and transfers all motor torque to the focus action. Because the focus action will be a shorter throw, there will likely be less frictional resistance and the motor will still manage to move it. Your description of the motor noise hunting for initial focus on powering up, then the screen going black, suggests to me the camera is sensing an unusual power demand and shutting down before damage is done. The fault might also be electronic in that the internal power supply routed to the motor may be insufficient. If the motor or power routing has begun to fail, I don't think there is much to be done. A really bad workaround might be to decide which task you can give this camera to do at the zoom point it has jammed at, choose a focus point you want the camera to be at, power up, let the autofocus find it, then power down, remove the lens and mask over the conductor pins in the camera body with a small piece of sticky tape, gaffer tape or elastoplast. This will isolate the lens from furthur power draw but you will lose any internal iris or ND controls if these functions are contained within the lens. The camera will report a fault but will likely continue to function. You will only have shutter speed and gain settings remaining to control exposure levels so if you get snow in your shot, the image may go soft due to light spread across the CCDs. You may be able to sacrifice a sunglass lens to cut down and make a ND filter to go in back of the lens in front of the CCD port, but be careful it does not damage anything in there when you remount the lens. a piece of neutral density filter gel would be better but I doubt you have any film camera shooters with you who might carry it. Sorry I cannot provide a solution for you. A long shot might be to email Canon lens techs to see if there is a better work around. |
June 3rd, 2007, 12:36 AM | #9 |
Regular Crew
Join Date: Apr 2006
Location: taiwan
Posts: 30
|
Hi, thanks for all that info, I think the most relevant is this:
"Your description of the motor noise hunting for initial focus on powering up, then the screen going black, suggests to me the camera is sensing an unusual power demand and shutting down before damage is done." Holding the cam up or down sometimes convices the zoom motor to go one way or the other before stopping. Then the viewfinder slowly goes dark, so there does seem to be a power problem. What causes that? |
June 3rd, 2007, 05:05 AM | #10 |
Inner Circle
Join Date: Dec 2003
Location: PERTH. W.A. AUSTRALIA.
Posts: 4,477
|
You describe the viewfinder as slowly going dark. In your XL1 is the viewfinder a miniature cathode ray tube display or miniature LCD screen?
It may not matter which way. By your description, it may be that the camera is not shutting down as I imagined but two things might be going on. If the lens servo is drawing excessive power, it might be 1. triggering a false closure of the iris. 2. drawing the whole power system down and the viewfinder fading (going dark). In the event of 2. I would expect the camera to shut itself down before a viewfinder failed due to a power drop. If you have the camera recording to tape when this happens, do you get a continued recording past the point where your screen goes dark or does the transport stop recording at that point? If you get a fade to black but an otherwise uninterrupted recording to tape, then it is more likely the iris servo is also implicated. I think this also lives in the lens itself. This all keeps me now pointed in the directon of an excessive power drawdown or failure of the camera to maintain power to the servo motor. This problem might also have two sources. 1. Fault in the lens zoom/focus servo motor drawing excessive power. 2. Fault in the power amplifier stage in the camera which supplies controlled power levels to the servo motor resulting in low power to the motor. If there is a single return line or earth return to the camera from the lens and this has gone resistive, this might also account for errant performance of the iris servo because return power might be trying to get back through the iris servo supply line and thus powering the iris servo on its way back through. The contact pins inside the lens mount below the CCD window might have become resistive or one may be slightly shorter than the others or slightly bent. When you mount the lens up to the camera and twist to the point where the latch clicks, try turning the lens back against the latch to see if any slight movement in the opposite direction whilst the lens is still locked alters the behaviour. Don't attach or dismount the lens whilst the camera is switched on. this practice will likely do damage. If one of the little spring loaded pins has itself become resistive, you might try very carefully using a thin match-end and pressing each little pin in and out many times to wear away any oxide which may have formed. File a little groove in the bare end of the match stick to avoid it slipping off the pin into the gap between two pins and the risk of bending a pin. If there is a pin hanging a little bit short, this might be part of the design and not necessarily a fault. sometimes it is beneficial to have one pin always touch first especially if it is a common return line. Don't try to pull any pin out furthur with tweezers or suchlike, just move it in and out against the srping pressure in hope that if it is hanging up, the pin may eventually come furthur forward towards the matching contact point on the back of the lens. Even with the camera powered down and the battery removed, there may be enough juice left in a capacitor to short across and damage something sensitive. So definitely keep metals away from the pins. I don't know what stops the pins from flying right out so I would not move the pins in and out too many times. A fault in the power amplifier stage of the servo control system might be as simple as a tiny trimpot needing to be adjusted, or it could be a component failure, dry resistive solder joint of a part in a board. None of these are likely to be user seviceable in the field. One last thought - Nepal. Is that a very cold place? If your batteries have been well used, they may not be liking lower temperatures. I would expect the normal telltale lights or viewfinder messages to show or the camera to shut itself off but sometimes things behave oddly. If none of these fixits work, you might still get some use out of it by isolating the lens electrics entirely as I previously suggested by covering the pins with tape. I am really making a lot of guesswork assumptions here which most likely will be wrong. Last edited by Bob Hart; June 3rd, 2007 at 05:17 AM. Reason: error |
June 5th, 2007, 11:32 AM | #11 |
Wrangler
Join Date: Sep 2001
Location: Northern VA
Posts: 4,488
|
The standard XL1 lens has separate motors for focus and zoom.
It is controlled by a serial data connection back to the camcorder body. It contains several integrated circuits that interpret data to/from the camcorder body to control the iris, zoom, variable angle prism, and focus function. As I recall, one fuse powers all lens functions. The viewfinder screen is color LCD, not CRT.
__________________
dpalomaki@dspalomaki.com |
June 5th, 2007, 02:55 PM | #12 |
Inner Circle
Join Date: Sep 2002
Location: San Mateo, CA
Posts: 3,840
|
It's possible he has the FU-1000 monochrome viewfinder, which IS a crt screen. Though he doesn't mention it.
I was told the 3x has only one motor for both zoom and focus, not certain about the 16II. |
June 5th, 2007, 05:34 PM | #13 |
Inner Circle
Join Date: Dec 2003
Location: PERTH. W.A. AUSTRALIA.
Posts: 4,477
|
My recollection is that a FU-1000 has been implicated in disabling one camera that I know of and there has been another account here a fair way back. It was a NTSC off ebay which was fitted up to a PAL camera. The internal fuse was blown, but this camera was a XLH1, not XL1.
If indeed there is one of these on the camera and it is pulling power, it might be drawing down the available power to the lens servomotor (or motors). This could be tested I guess by simply unplugging the viewfinder and starting the camera. The internal fuse I assume may be a fuse link soldered onto a board. These, like glass enclosed fuses can become cracked and become resistive or the solder jont itself become resistive. Whatever, I think Herojig may have a workshop problem on his hands, not something easily fixed in the field, though the problem may be an easy fix in a workshop. |
June 29th, 2007, 12:10 AM | #14 |
Regular Crew
Join Date: Apr 2006
Location: taiwan
Posts: 30
|
help still needed here...
Hi all, thanks for your help. We got the shoot done using sub-par cameras gathered from the crowd. I am back in Kathmandu and there is no one here who feels qualified to open the camera up, or who has parts, or another lens to do any testing.
So here is my question: The lens seems to work on powerup - it seeks and finds an object, and even focuses. ND works. Adjusting Exposure in various modes works. The only things that don't work is zoom or focus after the initial seek. The Push AF does not work. SO.... With that in light, is it the lens or the body? The reason I ask is that if I knew it was the lens, I could have the studio order from Singapore. If it's the body...well... So you see where I am at. I don't want to order a new lens for a dead body, with little hope of repairing in the near future. But getting another lens and having that work is viable. So, please help with that diagnosis, and if it's the lens, please recommend a new one. Ps. I do have the color viewfinder (stock). Thanks! BS |
July 2nd, 2007, 07:38 AM | #15 |
Wrangler
Join Date: Sep 2001
Location: Northern VA
Posts: 4,488
|
Short of trying another known good lens, no simple way to determine where the problem is, but if exposure and recording are otherwise OK, try get your hands on the older Canon 14x fully manual lens.
__________________
dpalomaki@dspalomaki.com |
| ||||||
|
|