Turn camera (Nikon) off when changing lenses ?
Nov 10, 2014 23:15:23 #
Merlin1300 wrote:
From all I've read - - CMOS REALLY doesn't like el... (show quote)
:thumbup: :thumbup: :thumbup: :thumbup:
Nov 11, 2014 00:17:14 #
Merlin1300 wrote:
From all I've read - - CMOS REALLY doesn't like electrostatic charges.
They tend to FRY the CMOS circuitry - -
So you can probably be DANG sure camera manufacturers go to GREAT lengths to prevent such from accumulating on the sensors.
They tend to FRY the CMOS circuitry - -
So you can probably be DANG sure camera manufacturers go to GREAT lengths to prevent such from accumulating on the sensors.
The CMOS circuitry in the sensor is well protected. But also the entire chip is charged.
There of course is an optical glass plate between the actual sensor and the exterior. It's the glass plate that collects dust, not the sensor electronics. The plate is an insulator, which allows it to build up a static charge.
Merlin1300 wrote:
I am NOT sure how much charge differential exists in the proximity of a sensor - but unlikely the 6-volt battery creates an adequate pull to attract anything.
Trust that 6 volts is a great plenty! Open up any old computer power supply (or any low voltage power supply for any electronic equipment), and you'll find the positive voltage lines are all covered with a thick coat of dust.
Merlin1300 wrote:
I'd more believe that a couple of thousand volts on a dust mote might cause it to drift toward the nice flat sensor.
Also unlikely any 'magnetic fields' are around the sensor - and even if they were - that would only be a problem for ferromagnetic dust particles.
Also unlikely any 'magnetic fields' are around the sensor - and even if they were - that would only be a problem for ferromagnetic dust particles.
Magnetic fields aren't a problem.
Generating a couple thousand volts of electrostatic charge is extremely easy to do. Lay two pieces of dry paper in a stack, and remove one of them! Or worse, use a couple inches of Scotch Tape on any non-conductive surface, and remove it. That will cause far more than a couple thousand volts.
Merlin1300 wrote:
And sure - - there can be high voltages running around inside a camera - the flash unit comes to mind - however the CMOS image sensors tend to be low voltage devices - typically on the order of 3.5 to 5 volts.
That's all it takes!
Nov 11, 2014 01:31:09 #
Slick Willie wrote:
Don't be a fool and "judge a book by its cove... (show quote)
Often one can judge a book by its cover!
For example if one has read 1/2 a dozen Tom Clancy novels
and sees a book that he has not read by that well known author, he can have a fair idea of what it may be like just by having prior knowledge of the writers style and genre... The Authors name being on "the cover" of course. On the back cover of that book one may read something like: "Clancys greatest achievment": New York Times. further evidence of what the book is like... on the cover.
Nov 11, 2014 02:48:14 #
Video Vinny wrote:
In lens researsch I read that Nikon recommends doi... (show quote)
I turn mine off when changing lens to protect it from dirt. I was told electricity can attract dust on the sensor
Nov 11, 2014 03:12:10 #
rob s wrote:
Delderby you started this dissent by hijacking the thread to voice your views on a topic of personal interest completely unrelated to the topic under discussion.
Please take your distaste for hunting to a different forum or start a new thread.
Please take your distaste for hunting to a different forum or start a new thread.
I did not raise the subject of hunting. Another hog compared the power switch on his camera to the safety catch on his gun - "while hunting"
Nov 11, 2014 10:02:46 #
Nov 11, 2014 10:32:45 #
CHOLLY wrote:
Put 5 volts on the plate of a Gold-leaf electroscope - - no movement.Yep. Case closed! :thumbup:
Sorry Cholly (and Apaflo) - - you're off base on this one.
Nov 11, 2014 10:59:29 #
You are too if you think your example is even REMOTELY applicable to this situation. :roll:
However, this is America, and you and everyone else is free to do whatever you wish within the confines of the law.
Leave your camera on when you change lenses. Hell, stick it under water if you want.
It's YOUR dime... ;)
However, this is America, and you and everyone else is free to do whatever you wish within the confines of the law.
Leave your camera on when you change lenses. Hell, stick it under water if you want.
It's YOUR dime... ;)
Nov 11, 2014 12:02:10 #
Merlin1300 wrote:
Put 5 volts on the plate of a Gold-leaf electroscope - - no movement.
Sorry Cholly (and Apaflo) - - you're off base on this one.
Sorry Cholly (and Apaflo) - - you're off base on this one.
No, your are missing the forest because of all the damned trees!
First, an electroscope measures electrical charge, not voltage.
Second, if the charge is enough to move the gold leaf, and the gold leaf weighs 10,000 times as much as a single particle of dust, how much charge is required to move the dust? And how would you measure that with a gold-leaf electroscope?
Third, there really is no controversy about this topic among authoritative sources. They all agree. You can find almost anything on the Internet, but you can't find a credible source that won't agree with what I've described.
"The sensor has an electrostatic charge when the camera is on in its
normal mode (but not in sensor-cleaning mode) and it will attract
dust like a magnet."
http://www.adorama.com/alc/0013666/article/The-Secret-of-Effectively-and-Safely-Cleaning-Your-Digital-Camera-Sensor-Yourself
Note that camera manufacturers provide a mirror up for cleaning mode, and the single purpose of that mode is to allow access with the sensor disabled so as not to have a charge. Otherwise it would be just as easy to use the B setting for the shutter...
Nov 11, 2014 12:16:16 #
Nov 11, 2014 12:36:51 #
Apaflo wrote:
I always wondered why I couldn't see the dang forest :shock: :shock: No, your are missing the forest because of all the... (show quote)
Always possible that the electrostatic charge isn't the result of the 5vdc working voltage, but is related to all the charge pumping and switching transients that happen within the sensors energy wells.
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I guess the practical question would be - when changing lenses, the mirror is usually down - blocking the sensor. Is the electrostatic charge on a powered sensor strong enough to reach through the mirror and outside the camera body bringing in more dust than would otherwise find its way into the camera when powered down? If your camera is mirrorless YMMV.
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Sure tangential - but if one minimizes the time the camera is open (I strive for about 1 second or less), and no (or minimal) wind - dust can be minimized.
Nov 11, 2014 15:42:19 #
There is NO seal between the mirror and the lens mount opening. Air can and DOES pass freely between the sensor surface and the interior of the camera, which, thanks to the lens being removed, is now open to the environment.
Consider also that the dust contaminating a charged sensor doesn't particularly have to enter the camera when the lens is off; it could have entered PREVIOUSLY, but because the sensor is now charged, the dust is no longer on a neutral surface or suspended in the air, but is in fact attracted to the sensor where it affixes.
Consider also that the dust contaminating a charged sensor doesn't particularly have to enter the camera when the lens is off; it could have entered PREVIOUSLY, but because the sensor is now charged, the dust is no longer on a neutral surface or suspended in the air, but is in fact attracted to the sensor where it affixes.
Nov 11, 2014 16:06:51 #
CHOLLY wrote:
Cholly - - that was my point. Having the sensor on or off during a lens change would only be a factor IF having the camera ON caused MORE dust to enter the camera body than when the camera was OFF. THAT would depend on the magnitude of the electrostatic charge, any shielding provided by the lowered mirror, how long the camera was open, and environmental factors such as wind and dustiness.Air can and DOES pass freely between the sensor surface and the interior of the camera, which, thanks to the lens being removed, is now open to the environment.
Consider also that the dust contaminating a charged sensor doesn't particularly have to enter the camera when the lens is off; it could have entered PREVIOUSLY, but because the sensor is now charged, the dust is no longer on a neutral surface or suspended in the air, but is in fact attracted to the sensor where it affixes.
Consider also that the dust contaminating a charged sensor doesn't particularly have to enter the camera when the lens is off; it could have entered PREVIOUSLY, but because the sensor is now charged, the dust is no longer on a neutral surface or suspended in the air, but is in fact attracted to the sensor where it affixes.
Nov 11, 2014 17:33:21 #
Ranjan
Loc: Currently Cyber-Nation!
Do surfaces charged with static electricity (like sensors etc lose their charge as soon as the rest of the circuit is powered-off?
Nov 11, 2014 17:48:12 #
Ranjan wrote:
Do surfaces charged with static electricity (like sensors etc lose their charge as soon as the rest of the circuit is powered-off?
That depends on the conductivity of whatever paths are available to disperse the charge.
Generally speaking, to get very much of a static charge means the object is either a fairly good insulator or that there is an active source of charge. A camera sensor has an active source, so it doesn't generally act as a good insulator, and discharges fairly quickly. There is still a problem though... where does it discharge to and what is the total effect?
The camera is just large enough that spreading that small a charge over the entire camera is enough to make the sensor area less of a dust magnet.
Note that by "fairly quickly" in terms of a discharge, maybe from half a second to 2 seconds. Faster discharge times, due to a highly conductive path, might result in a variety of effects from ESD (Electro Static Discharge) such as induction of a charge into nearby conductors.
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