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What's the cause of the ghosting?
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Feb 9, 2023 16:30:05   #
SalvageDiver Loc: Huntington Beach CA
 
Grahame, did you have a UV filter on the lens? If not, disregard everything beyond this point.

I've seen this ghosting when using lens filters. It doesn't happen very often because it's dependent on where and how a bright light ray enters the lens and reflects between the filter and the front lens element. And, it can happen on just a portion of the image rather than the whole image. AR coatings reduce the effect but can't totally eliminate them.

I destroyed a once-in-a-lifetime shot using a cheap UV filter. Never use them anymore.

Just another thought for your investigtion.

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Feb 9, 2023 19:03:34   #
Grahame Loc: Fiji
 
SalvageDiver wrote:
Grahame, did you have a UV filter on the lens? If not, disregard everything beyond this point.

I've seen this ghosting when using lens filters. It doesn't happen very often because it's dependent on where and how a bright light ray enters the lens and reflects between the filter and the front lens element. And, it can happen on just a portion of the image rather than the whole image. AR coatings reduce the effect but can't totally eliminate them.

I destroyed a once-in-a-lifetime shot using a cheap UV filter. Never use them anymore.

Just another thought for your investigtion.
Grahame, did you have a UV filter on the lens? If... (show quote)

Thank you for the response.

Yes, I did have a filter on the lens. It was a B+W XS-PRO UV Haze MRC nano coated, these I use on all my lenses as I regularly work in wet, dusty and salt laden atmospheres. I have also carefully checked the filter and lens after and both were impeccably clean.

I'm suspecting you are correct in your assumption of the cause and I have also since posting this read a similar diagnosis in a web article. Considering that there is no other feasible explanation I'm just going to put it down to a one off result of the bright backlighting and filtered strong low side lighting at those positions interacting and doing strange things in the lens.

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Feb 12, 2023 14:36:34   #
photosbytw Loc: Blue Ridge Mountains
 
Was the image posted after it was processed? On closer inspection, I'm also seeing a bit of haloing.........just curious. I've seen this from others who tried to process their image on multiple layers that became misaligned.

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Feb 12, 2023 17:33:32   #
Grahame Loc: Fiji
 
photosbytw wrote:
Was the image posted after it was processed? On closer inspection, I'm also seeing a bit of haloing.........just curious. I've seen this from others who tried to process their image on multiple layers that became misaligned.

The anomaly is visible prior to any post work. For info, 99% of post work on the thousands of images of this genre I take is undertaken on the RAW file ACR/LR, and saved from there to jpeg, no layers in PS involved.

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Feb 13, 2023 20:05:48   #
StanRP Loc: Ontario Canada
 
Grahame wrote:
The attached image is a crop from one that shows a strange 'ghosting', only at this area, as indicated. Whilst the image was one of which I had missed focus on the face, out of focus areas and those that show subject movement do not normally appear like this. The exception being those using fill flash where a double exposure is evident.

The subject was moving, running and had a bright background of sea and sky that was not overexposed. An image of another runner taken a few seconds before with their hand in a near identical position, same background, same settings does not show similar ghosting.

Equipment - Z6, 70-200mm @ 200mm, 1/1600s, f/3.5, ISO640, VR On.

Any clues?
The attached image is a crop from one that shows a... (show quote)


Looking at an increase in DPI. I could be the hand moving back away from the camers during the exposure:



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Feb 14, 2023 19:28:13   #
Grahame Loc: Fiji
 
StanRP wrote:
Looking at an increase in DPI. I could be the hand moving back away from the camers during the exposure:

1/1600s is normally sufficient to freeze all movement in road runners but there will always be a slight possibility of a specific body part having excessive movement.

Having looked through my numerous similar older images where I have used much lower shutter speeds clearly showing motion blur caused by the subject I can find no similar anomaly.

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Feb 14, 2023 20:13:47   #
StanRP Loc: Ontario Canada
 
Grahame wrote:
1/1600s is normally sufficient to freeze all movement in road runners but there will always be a slight possibility of a specific body part having excessive movement.

Having looked through my numerous similar older images where I have used much lower shutter speeds clearly showing motion blur caused by the subject I can find no similar anomaly.


I agree - however if that is the cause - it should be repeatable. Using the same camera and settings, take a photo of the hand while it is being rapidly moved away from the camera.

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Feb 14, 2023 21:02:14   #
Grahame Loc: Fiji
 
StanRP wrote:
I agree - however if that is the cause - it should be repeatable. Using the same camera and settings, take a photo of the hand while it is being rapidly moved away from the camera.

If hand movement was the cause I would expect to see the anomaly on all edges, unless individual parts of the open hand were moving at different speeds.

As for testing for repeatability, a bit difficult to set a runner up to do it. But, a hand moving away from the camera whilst the rest of the subject (body) is moving towards the camera actually presents less of a problem to the camera. The backwards hand speed cancels the forward subject speed.

For info just looking into speeds and doing some quick calcs the average speed of a marathon runner is 6mins/km. During the 1/1600s shutter opening the 'body' has moved 1.68mm. I think?

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Feb 14, 2023 21:26:20   #
StanRP Loc: Ontario Canada
 
Grahame wrote:
If hand movement was the cause I would expect to see the anomaly on all edges, unless individual parts of the open hand were moving at different speeds.

As for testing for repeatability, a bit difficult to set a runner up to do it. But, a hand moving away from the camera whilst the rest of the subject (body) is moving towards the camera actually presents less of a problem to the camera. The backwards hand speed cancels the forward subject speed.

For info just looking into speeds and doing some quick calcs the average speed of a marathon runner is 6mins/km. During the 1/1600s shutter opening the 'body' has moved 1.68mm. I think?
If hand movement was the cause I would expect to s... (show quote)


Hi again: you don't need to have anyone running - have anyone hold their hand in front of the camera and move it back fast.

Regarding the 1/1600 second. That is the time the sensor is exposed to light: I do not know your camera - those with a travelling blind there are two going across (or down) with a gap between them. The closer the gap the shorter time light is on the sensor - the overall time being how long it takes for both blinds to cross from one side to the other. If the blinds are close, the finger could be moving back during the time the two blinds pass. (Hard to describe). There is another possibility: The 'computer' in the camera uses the digital data from the sensors to create the image to record. If you have both the Raw and the further processed JPG/TIFF - compare and see if they are the same. Interesting..

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