Since the ghosting appears only at shutters speeds faster than 1/500 - alundeb
If this is true, then I speculated that it's most likely the buffer cache contained the image did not clear from internal memory fast enough, and the current image is written over most it, allowing some bit & bytes of previous image remained, hence the ghost. I wondered if this phenom. happened only with slower/older CF card, or all CF card speed, along with the shutter speeds.
Sam tran wrote:
If this is true, then I speculated that it's most likely the buffer cache contained the image did not clear from internal memory fast enough, and the current image is written over most it, allowing some bit & bytes of previous image remained, hence the ghost. I wondered if Sam
Probably more of an analog thing, like the photocells themselves not being given enough time to reset down to 0V (completely clear out) between rapid-fire shoots, or the ADCs that monitor those photocells not being given enough time to fully reset.
what can go wrong in a camera to have these error images ?
Light is captured at a cmos censor. After the image is captured there is this digital information floating to memory with or without an image of the noise. When there is a memory failure, you will have no image at all. Or a totaly scrambled image. Digital mean nothing or everything. With this in mind I think there can be a problem with this cmos censor.
Now what I can see, is that it happened with dark subjects. Dark on a cmos mean no information or no bits. Every camera has noise reduction especially in this dark areas. So another theory is that you see some of the noise reduction from the previous frame.
But that's mine theory.
alundeb wrote:
Hard to tell.
Since the ghosting appears only at shutters speeds faster than 1/500, it makes me guess that it has something to do with too short discharge times between exposures for the sensor, and the discharge time is programmable and linked to the exposure time somehow. In that case a firmware fix could be a true fix.
I have mailed canon to have more information about this problem. They told me that the firmware 1.0.9 has resolved the problem. This makes sence because I have tested the ghosting issue with my cam. Bacause it has the latest firmware I wasn't able to have this efffect.
Marc C wrote:
I have mailed canon to have more information about this problem. They told me that the firmware 1.0.9 has resolved the problem. This makes sence because I have tested the ghosting issue with my cam. Bacause it has the latest firmware I wasn't able to have this efffect.
Marc, it is great that you were not able to see that "effect", which is only visible if you tweak certain settings of images taken at fast sequence using shutter speed higher than 1/500 sec. I believe that effect was first reported about 10 days ago, around October 18th or so. According to Canon website, the latest firmware, Version 1.0.9 was updated on October 19th. As such, I don't think that version of firmware addressed that issue yet. I hope I am wrong, though .
I upgraded from FW 1.0.7 to 1.0.9 today and did a before/after test. To begin with, it was difficult to even provoke it. At ISO 200, I shot some leaves in silhouette against the clouds, and I had to underexpose and go to 1/4000s before it appeared.
Conclusion: Firmware 1.0.9 does not eliminate the ghosting.
RobAmy wrote:
Should I wait for the Yellow dot box then
If you want a box with a yellow dot, yes, for everything else, no
Since this is a rarity that occurs only under certain circumstances in the first place, and is invisible even then, unless you push the contrast to artistic levels, it is nothing to worry about.
A firmware fix to correct for a hardware problem? I think I'll wait for the 7D mk II to be available on the used market.
I wonder if a firmware fix is even going to fix the exposure problems that show up with the wireless flash controller and then go away when an ST-E2 is fitted to the top of the 7d.
nads wrote:
A firmware fix to correct for a hardware problem? I think I'll wait for the 7D mk II to be available on the used market.
I wonder if a firmware fix is even going to fix the exposure problems that show up with the wireless flash controller and then go away when an ST-E2 is fitted to the top of the 7d.
Workarounds and band-aids... what a camera!
1: Ghosting is not a problem. It is a rarity that has zero implication on normal photography.
2: It is not necessarily caused by hardware. All sensors on all digital cameras need some time to discharge between exposures. The discharge time may be controlled by either hardware or firmware.
AGeoJO wrote:
How do you know it is a hardware problem? I am not saying that it is not but you seem to be sure of what you are saying....
The problem is either software or hardware. It would be insane to conclude that the ghost is a result of the software saving information from a prior exposure and applying that information to a new frame.
The hardware is obviously incapable of striping away all exposure information and resetting itself prior to the onset of the next exposure. End of story.
They may be able to eliminate the double exposure through a software change, but not without reducing the peak performance of the equipment from the original spec.
alundeb wrote:
1: Ghosting is not a problem. It is a rarity that has zero implication on normal photography.
2: It is not necessarily caused by hardware. All sensors on all digital cameras need some time to discharge between exposures. The discharge time may be controlled by either hardware or firmware.
1) A rarity is not equal to zero.
2) They aren't going to get the sensor to discharge faster by having the software tell it to do so.
3) When canon has to alter the peak performance of the body to eliminate this problem the result has the potential to affect numerous scenarios that would be considered normal photography.
It equals to zero in normal photography because even when it occurs, you must do absurd things with the contrast to make it visible. Things that are not common in normal photography.
2) They aren't going to get the sensor to discharge faster by having the software tell it to do so.
But they can allow for correct discharge time, if the case is that the discharge time sometimes is too short.
3) When canon has to alter the peak performance of the body to eliminate this problem the result has the potential to affect numerous scenarios that would be considered normal photography.
It will not alter peak performance, because it doesn't occur at shutter speed slower than 1/500, and that is plenty time margin to keep 8 fps.
Think about responsibility before spreading uninformed bashing.
nads wrote:
The hardware is obviously incapable of striping away all exposure information and resetting itself prior to the onset of the next exposure. End of story.
The hardware is obviously capable of striping away all exposure information and resetting itself prior to the onset of the next exposure. This is obvious because it happens in most cases, and suggesting that it is not fixable for the rest is speculative at best.
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