Luminous Landscape Forum
Equipment & Techniques => Digital Cameras & Shooting Techniques => Topic started by: Kirk Gittings on September 23, 2011, 11:14:18 am
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I have to shoot a couple of MRI (magnetic resonance imaging) setups at a new local hospital. The MRI's are running. I have managed to do this when we were shooting view cameras and film since my VC and tripod were aluminum. Contrary to popular myth. The magnetic field did not affect the aperture mechanism ie the exposure.
But what about a DSLR. Any thoughts on the effect on electronics or anything?
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bump
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Not sure whether this will be helpful, but here's one thread on the topic: Is photographing an MRI machine dangerous to the camera? (http://www.sportsshooter.com/message_display.html?tid=23701)
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I don't think that anyone can answer this without knowing the particular MRI machine nor how/where the camera will be used relative to it. Probably the only people that can help your here will be the technician(s) operating the machine, who will be experts on the strengths and location of the fields and how risky these are.
It may be wise to be slightly more cautious with a DSLR than perhaps with other electronics. The camera and lens contains several (magnetic) coils for things like mirror/shutter release and for AF and IS in the lenses. These could receive quite large induced currents, increasing the chance of damage. A small point-and-shoot type of camera with electronic shutter is probably less vulnerable to damage (as well as being cheaper to replace).
FWIW, when I had an MRI a few years ago I talked with the technicians of the particular machine. The rule for that particular set up was simply no electronics at all allowed in the room at all.
[Edit] Of course, you could always use a suitable vintage film camera...
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Of course, you could always use a suitable vintage film camera..]
Thanks all. Can't turn it around in time-there are no labs left in my area.
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Kirk,
I have shot an open an closed MRIs a few years ago with a Canon 1D mk2 and with canon strobe on remote. I had no problems up to within about arm length away. While composing I did get closer once and it froze the camera, made a scary hissing sound. I thought it was cooked, but I backed away, turned off the camera, took the battery in and out and it restarted. I only lost the file I shot when the camera locked, which surprised me. The operators should probably know what you can and cannot get away with. I'm sure they have taken cell phone photos and pushed the limits. Have back ups.
Good luck
http://johnkishiv
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I've photographed an open MRI with a Nikon D3, and my only issue was that the IR flash system (I was using 4 or 5 Nikon SAB-800's and 900's) became a bit hinky. I finally had to switch everything over the optical slave settings which seemed to work fine, although I do remember one or two unexpected pops. Not sure if it was the MRI, or all the affiliated electronics that was the cause.
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I just checked the link a few messages above. In my case, and my guess in the case above, the MIRs were not turned on. That sounds like an important point.
John
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Just a bit of trivia - unless you stop cooling the super-conductive coils, the magnetic field of an MRI doesn't "turn off". An MRI draws current during commissioning, and also draws current for the RF part of the MRI and the electronics, but the magnet itself doesn't draw any current once the unit is commissioned. This is because the coils are super-conducting - as counter-intuitive as it seems, current continues to flow, and the magnetic flux of over a Tesla continues to be maintained, for as long as the coils are below the magic temperature that permits superconductivity.
So, bringing anything ferrous close to an MRI is a really Bad Thing to do, even if the unit is "off".
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I shot it from the entry doorway with a fresh card. The angle was a bit compromised but all went well.
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I shot it from the entry doorway with a fresh card. The angle was a bit compromised but all went well.
Hi Kirk:
Glad all was well. I wish I had seen this thread earlier. I don't deal with MRIs, but I am familiar with nmr which uses similar magnets. Coincidentally I was filling the nmr with liquid helium yesterday and took a shot of the ice forming on the exhaust port, which gets very cold during a fill as the transfer gas vents into the room. Anyway my DSLR was only a few feet from the magnet with no ill effects.
Tom