Random Halos in Pictures

[Achickseyeview]

Please bare with me, first time posting. 

I have a Canon 5D Mark ii that has about 57K actuations on it. I am a racetrack photographer and take anywhere betwee 300 - 1500 shots per event I work. After each event, I wipe down all my equiptment and make sure everything is cleaned and covered when I put it away. Recently I've been noticing that there have been these starange halo like lines through some of my pictures. It happens very randomly, and I have tested the camera with 3 different lenses. It's happened with all thre lenses but there seems to be no rhyme or reason for it to happen. I've taken it into a Canon repair shop, and they are just as baffled by it. They suggest that I send it into Canon, however I simply can not afford to send my camera out for 2-3 weeks right in the middle of race season. I'm hoping that someone in here might have an idea what could be happening. 

Note- I did have the repair shop clean the sensor and I will be taking the camera out this evening to see if the issue still occurs. 

Here are some pictures->

[RobertTheFat]

Forgive me if I wander off-topic. But if you're a professional (or even semi-professional) photographer and don't have a spare camera, your problem is more pressing than your initial post suggests. There are certain chips that are necessary for a seat in the game, and a backup camera is one of them. If your camera needs to go to the shop, there's really nothing we can do to change that.

[Achickseyeview]

I'm not sure why you are feeling the need to tell me how to run my photography. If you're offering to purchase a second camera for me so as I can have an extra on hand, then great, otherwise, your comment is not only completely uneccessary but quite ignorant as you do not know my situation. Your comment is unwarrented and unhelpful. 

[Johnw1]

When you say random what do you mean by that? Is it happening on some photos and not others? By testing with more than one lens it appears to be an in camera issue. I have no idea what it might be or the cause. I'm sorry about that. 

[Achickseyeview]

Yes, I mean random as in there is no rhyme or reason... there are hundreds of pictures that dont have the halo markings.. then, all the sudden two or three will have them.. its strange as can be

[kvbarkley]

It looks like dust/hair on the sensor. You can follow the instructions for dust mapping to try to see anything.

[Achickseyeview]

That's what I'm hoping for... lol. I'm having it professionally cleaned today... going to pick it up tongiht and head to the track to see if it does it anymore. FIngers crossed hahah 

[RobertTheFat]

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@Achickseyeview wrote:

Yes, I mean random as in there is no rhyme or reason... there are hundreds of pictures that dont have the halo markings.. then, all the sudden two or three will have them.. its strange as can be

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I wonder if what you're seeing could be lens flare, especially in the second of your three pictures, where you're facing two strong reflections of the sun. Flare depends on the angle at which sunlight strikes the lens and can therefore seem random in the aggregate. Also, flare can be exacerbated by filters. Have you recently started using a filter that you didn't use before?

[Johnw1]

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@Achickseyeview wrote:

Yes, I mean random as in there is no rhyme or reason... there are hundreds of pictures that dont have the halo markings.. then, all the sudden two or three will have them.. its strange as can be

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That makes it darn near impossible to figure out. Being on some and not on others may point to a shutter problem. I wonder if  those photos with the problem have a common shutter speed?  

[cicopo]

I'm also thinking possible shutter problem. Assuming you are shooting drag racing & using higher shutter speeds than I'd use for road racing. Run a series of sample shots increasing shutter speed as you go through the series. It may show up in the higher shutter speed shots consistently if it's a shutter problem.