Strange white band running through image

[forrest.berkshire]

<p>A coworker of mine is having trouble with his 1dMKIIN and his images. While he was on assignment he noticed a white band running through the center of the image, he describes it as a ghostly streak running across the center, and the right-hand side of the image was not exposed at all. He detatched the lens and saw some piece of black plastic hanging down over the shutter, originating from the top of the chamber near the prism. He ripped it off. He said that stopped the underexposure of the image, but the white streak continued. When he shoots indoors, he said it was less pronounced. However, when he shot outdoors, it was very pronounced.<br>

Anyone dealt with this before? Save the chastisement about him ripping out a piece of his camera without knowing what he was doing (I've already yelled at him for that, as well as getting his fingerprints all over the sensor).<br>

I am attaching an image he gave me to better illustrate.</p>

 

[rainer_t]

<p>Looks like a damaged shutter to me.</p>

[sarah_fox]

<p>Sometimes strips of black vinyl tape are used to prevent light leakage, for instance where the mirror hinges. Perhaps a light leak occurred when the "black plastic" came loose, and he made it worse by removing it entirely. A good test would be to snap a shot with the camera wrapped in a towel/cloth, with the lens sticking out. If the white stripe goes away, then it's probably a light leak.</p>

<p>Related question: Is the white stripe always in the same place, or could it be higher or lower in the frame? If it's the latter, then that would support the theory of a light leak.</p>

[cabbiinc]

<p>Unless the shutter was open when he went ripping into his camera there shouldn't be any fingerprints on the sensor. Now if he screwed with the focussing screen that's a different issue.</p>

<p>I bet it's like Sarah said. Although I think that if the stripe was in the same spot all the time it would support a light leak. If it's in a different spot all the time there's something more serious wrong. It's probably the light seal between the pentaprism and the mirror. Covering the eyepiece with your thumb would prove or disprove that as there would no longer be light coming through the pentaprism to add the the exposure.</p>

<p>Dan</p>

[mark soares]

<p>Hi Forrest,<br>

Well, i dare say your friend has ripped one of the shutter blades out... and may i say.. ouch :)<br>

The reason it probably doesn't show up as much in indoor pictures is because indoors the shutter speed is usually lower because there is less light and therefore a missing shutter blade would not affect the exposure as significantly.<br>

I would test the camera the way Sarah indicated and do it at 1/250th or higher. My prediction is if you did a really long exposure of 30 sec or more that the white band would be much less visible.<br>

Mark</p>

[geoffs1]

<p>I wonder if it's light coming in via the eyepiece? He might try a test shot with the eye-piece completely blocked to see if the streak is less/gone.</p>

[sarah_fox]

<p>Mark! I think you might have nailed it! Oh no! 8-\</p>

<p>Here are some better tests: </p>

<p>Is the white stripe there when shooting a frame with the lens cap on (or better still, using a body cap)? If so, then it's a light leak.</p>

<p>Now set the camera up for an exposure of several seconds. Open the shutter, remove the lens cap, count the exposure out, put the cap back on, and then close the shutter. (That's the way shutters were done in prehistoric times.) No white stripe? Almost certainly a missing shutter blade. Ouch!</p>

[www.danahoff.com]

<p>Your shutter is done. It happened to me. A new one is @ $350.</p>