Help with Long exposure problem

[znxlegion]

Hi,


I've been shooting night pics at long exposures and i'm having some problems when i set the shutter speed to 25" or 30" the final picture will have flares..


I'm not sure what it is but there would be light that shows up on the picture. (do not have an example at the moment) My thoughts are that they are the filters I'm using, but the thing is i'm using B+W UV filters i thought that getting B+W will prevent these type of problems.


Does anyone know what the problem is? Should i just remove filters when taking long exposures?


Thanks

[Steve Eisenberg]

Are you covering the viewfinder?

[Itheone]

Could be the filter, could be the lens, also could be the camera. Give us more details on what equipment you are using and an example would be nice too. Might just be normal.

[znxlegion]

covering the viewfiner? what is that suppose to do?





I am currently at work no pics to upload i will do so tonight.


I am using 28-70 f.8L and 70-200 f4L IS both with B+W UV filters. happend both times.

[znxlegion]

Camera i'm using is 450D XSI

[Vlad Xp]

When I shoot long exposure, I always remove filters, and use a lens hood. Any stray light entering the lens at long exposure can easily turn into a flare and get exaggerated in size. Also, I've heard that leaving the viewfinder open may allow light to enter the camera body through the viewfinder opening and affect your exposure if it reaches the sensor.

[mpphoto12]

Yea i recomend removing lens hoods and all filters and also covering the eyepiece so there is no light source behind you

[Steve Eisenberg]

covering the viewfiner? what is that suppose to do?





I am currently at work no pics to upload i will do so tonight.


I am using 28-70 f.8L and 70-200 f4L IS both with B+W UV filters. happend both times.
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Stray light can come in the viewfinder. Your camera strap should have a little rubber piece used to cover it. You have to pull off the eye cup first.

[znxlegion]

I'll give it a shot. Thanks guys

[Vlad Xp]

I'd leave the lens hood on, because it's designed to keep the unwanted stray lights away from entering the lens.

[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]

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EF 100-400 L


B&amp;W filters


EOS 1D MKII

[znxlegion]

I'm sorry I will post a picture tonight.

[znxlegion]

How long was ur exposure?

[Steve Eisenberg]

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


EF 100-400 L


B&amp;W filters


EOS 1D MKII
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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.





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











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


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





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

[SupraSonic]

I'm Suprasonic. The picture shown is using Time Value and set to 30 seconds wiht F22.... if i can remember because i took this shot first few week of getting 1D MKII

[znxlegion]

Hi for my images i am not refering to that airplane or the cable on the bridge. if you look closely you can see a flare circle thing.. actually not sure what it is. Sorry cant post 100% crop as the image is too big and i dont really have a place to post it besides here.





Thanks for the imput

[SupraSonic]

I would recommend to TV mode set to 30sec F22 using tripond and remote switch.

[SupraSonic]

1st shot i would recommend F15 and above if it didin't focus lock use full mannual. same with 2nd shot

[Vlad Xp]

On the second sample I can barely see two faint circles (flares) above and slightly to the left of the horizontal line (cable).


/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.24.39/flare.jpg


OK, try this: while keeping the same filter on the lens, take two identical exposures using the same settings as above, where you have the same or similar kind of source of light(s) somewhere in front of the camera, but before you take the second exposure, remove your UV filter and definitely put a lens hood on. Compare the two, and tell us if the flare is still there on the second image.
Good luck.

P.S. If you want to maintain sharpness, don't go higher than f/10.