04-28-2014, 05:28 AM
(This post was last modified: 04-28-2014, 05:40 AM by Arthur Macmillan.)
You know what they say? I little knowledge is a dangerous thing! It's like this...a guy I met at an open air market looking at used camera lenses and I got to talking. He had managed to get some spectacular flairs by shooting wide open in the direction of the sun. He described how he did it, and he showed me a couple examples on his iPhone. They were very unusual...one part was the shape of a square sheet draped over a sphere but elongated as though pulled at on the corners. There was another part that was like a diamond with one corner stretched out, so it was like a long spear head. Part of the recipe was to use a lens that was not fully coated. Such as the 135mm Takumar.
Before I tried it I wanted to find out if it would harm the sensor. I normally am pretty careful with my camera. So I read some about the subject, and it seemed as though the sensor was considered capable of withstanding very high temperatures. But someone was worried about people risking there eyesite looking at the sun. So I thought why not try to aim in live view, so that I wouldn't be looking in the sun. Well, this wasn't such a great idea. I have never used live view before in a situation where I was not glad to have the exposure of the screen normalized they way it does when it normalizes a view that would be too dark for you to focus or frame your subject. Without getting into details, as far as I could see live view does not know how to present either the sun, nor the vicinity when it is aimed in the general direction of the sun. It didn't take me too long to figure that out. But, yes, there was a tripod, and yes the mirror was locked up for live view. The shutter should have been open, except when the mirror was down. I don't think I would have been using mirror lock-up alone.
I'd like to think I didn't do anything really stupid to cause this, but failing that, I'd like to learn something from the experience so that I don't do it again.
I'm very grateful for your comments. I feel a sort of kinship with those of you who have shared their thoughts, especially because I believe you know a great deal. I was afraid as a humble Rebel user I would find myself being asked to step to the back of the forum. But I may have to put your patience to the test one more time in order to try to understand this.
I gather the sensor produces quite a bit of heat when it is...sensing. What condition causes the heat? For instance, it is not unusual to have a long exposure, but normally this would only happen when there was not much light hitting the sensor. The shutter is open longer, but the total amount of light is fairly consistent. We can add 2 or 3 EV's. Using manual exposure we could keep the shutter open for 30 seconds even in a bright setting. My question is does the sensor get hotter when exposed to a very bright light for a period of time than it would if it were exposed for the same amount of time in a low light setting. Could the sensor get hot enough to melt the shutter if exposed for a long time to normal light?
There is a reason I ask, other than the ill-fated flare shoot. But if that can't happen I'll spare you the details.
Disclaimer:
-When I say cleaned the sensor, or expose the sensor I mean the filter over the sensor. That is what appeared smoked, and that is what I cleaned. It seemed to clean up well. Today I shot about 250 photos the majority of them outdoors since cleaning the sensor last night. The sensor/filters look clean still, and the shutter doesn't look any worse.
I should go through my photos for some clues. Sorry, about my impatience. It's hard on me because I don't know enough about the way the camera works to make an intelligent guesses.
-Arthur
Before I tried it I wanted to find out if it would harm the sensor. I normally am pretty careful with my camera. So I read some about the subject, and it seemed as though the sensor was considered capable of withstanding very high temperatures. But someone was worried about people risking there eyesite looking at the sun. So I thought why not try to aim in live view, so that I wouldn't be looking in the sun. Well, this wasn't such a great idea. I have never used live view before in a situation where I was not glad to have the exposure of the screen normalized they way it does when it normalizes a view that would be too dark for you to focus or frame your subject. Without getting into details, as far as I could see live view does not know how to present either the sun, nor the vicinity when it is aimed in the general direction of the sun. It didn't take me too long to figure that out. But, yes, there was a tripod, and yes the mirror was locked up for live view. The shutter should have been open, except when the mirror was down. I don't think I would have been using mirror lock-up alone.
I'd like to think I didn't do anything really stupid to cause this, but failing that, I'd like to learn something from the experience so that I don't do it again.
I'm very grateful for your comments. I feel a sort of kinship with those of you who have shared their thoughts, especially because I believe you know a great deal. I was afraid as a humble Rebel user I would find myself being asked to step to the back of the forum. But I may have to put your patience to the test one more time in order to try to understand this.
I gather the sensor produces quite a bit of heat when it is...sensing. What condition causes the heat? For instance, it is not unusual to have a long exposure, but normally this would only happen when there was not much light hitting the sensor. The shutter is open longer, but the total amount of light is fairly consistent. We can add 2 or 3 EV's. Using manual exposure we could keep the shutter open for 30 seconds even in a bright setting. My question is does the sensor get hotter when exposed to a very bright light for a period of time than it would if it were exposed for the same amount of time in a low light setting. Could the sensor get hot enough to melt the shutter if exposed for a long time to normal light?
There is a reason I ask, other than the ill-fated flare shoot. But if that can't happen I'll spare you the details.
Disclaimer:
-When I say cleaned the sensor, or expose the sensor I mean the filter over the sensor. That is what appeared smoked, and that is what I cleaned. It seemed to clean up well. Today I shot about 250 photos the majority of them outdoors since cleaning the sensor last night. The sensor/filters look clean still, and the shutter doesn't look any worse.
I should go through my photos for some clues. Sorry, about my impatience. It's hard on me because I don't know enough about the way the camera works to make an intelligent guesses.
-Arthur