Help with Long exposure problem

[Daniel Browning]

Can you post an example?


There is a known problem with 5D Mark II and the 24-105 lens where the USM confirmation light reflects onto the sensor, which appears as a red flare in very long exposures. (It's too dim to appear in normal exposures.)

[SupraSonic]

[img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.25.83/574c32857f3e3bbccb6e7f7523196662_5F00_large.jpg[/img]


EF 100-400 L


B&W filters


EOS 1D MKII

[znxlegion]

I'm sorry I will post a picture tonight.

[znxlegion]

How long was ur exposure?

[Steve Eisenberg]

[img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.25.83/574c32857f3e3bbccb6e7f7523196662_5F00_large.jpg[/img]


EF 100-400 L


B&W filters


EOS 1D MKII
<div style="CLEAR: both"]</div>

What I see is not flare, but "hot pixels". Hot pixels can be a source of great frustration, in the way that getting dust inside of your new lens is. You really don't have much say about whether or not it happens. It is only really a problem if they shows up in fast exposures, and it's usually quite a few. But don't feel too bad about one hot pixel out of 8.2 million, that's only.0000122 percent of the sensor.


But here's the good news, you can do something about it. First and foremost, remap the sensor. In order to do that, leave the lens on, but set the camera to manually clean the sensor. Follow the directions to do it, but don't clean the sensor. Just let it sit for 30 seconds before you stop the process. This may reduce or eliminate the hot pixel.


The other thing to do is to turn on the Long Exposure Noise Reduction. What this does is after you take the picture, the camera automatically takes another with the shutter closed. The camera finds the hot pixels (and less hot ones as well)and eliminates them from the image (which is why turning on the noise reduction doubles the time it takes to make exposures of 1 second or longer). So in the case of a 25 second exposure, an extra 25 seconds would be added to the total time.


I do not recommend sending your camera in for repair. Canon will remap (which you can do yourself), or replace the sensor (which could be costly if the warranty has expired). Just know that hot pixels is one of those things that is likely to happen. If you have none now, they will probably show up eventually, and there are ways to minimize or eliminate the problem.


If you are getting hot pixels in exposures faster than one second, then you may need to seek repair or replcement.

[Vlad Xp]

Is znxlegion and SupraSonic the same person? I don't see any flare in SupraSonic's image; however, znxlegion is the one who reported the problem in this thread, so we'll need to see his image.

[znxlegion]

no i am not suprasonic. I will post my picture tonight.





Thanks

[znxlegion]

ISO: 100


Shutter speed: 25


AV: 8


450D, 70-200 F4L IS


if you look in the middle of the picture in the sky.





[img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.25.98/IMG_5F00_3848.jpg[/img]











ISO: 100


Shutter speed: 10


AV: 6.3


450D,24-70 F2.8L





Again its in the middle, I see it more on this picture then the other. My filter on both is B+W UV


[img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.25.98/IMG_5F00_3210.jpg[/img]





Thank you all for the help

[Daniel Browning]

The first one looks like an airplane to me. Not sure about the second. Can you post a 100% crop too? Does it happen in every long exposure?


EDIT: Now that I look at the second image more, it seems to be some sort of cable on the bridge itself.

[Yan]

I don't know for the second, but in the first pic,it is simply an aircraft that has passed. Ithink. Because I was taking pictures at night and I live near an airportand some of my photos, I see these bright streaks.





Yan