Squared dark area appearing in several shots

C

Charles van Florop

Member
Hello !

I have some very strange dark area appearing in the right part of the image in several shots. It specially occurs in image with a lot of information or when the camera moves heavily. In the attachments you can see it in the right part of the image.

I use a Eos-Nex mount, ND fader, and have my shutter speed set to manual.

Why does it appear ? Is it adjusting settings in the camera, or a problem with the sensor ?

Best regards,

Charles van Florop

Picture 2.jpgPicture 1.jpg
 
That is a pretty sharp line for a light leak. I would be looking for electronic culprits. Bit starvation on the codec or some DSP issue. I doubt the camera is "broken" you may have simply found a weak spot that is cannot deal with very well. When that camera moves fast, it is more likely the compression engine cannot keep up. Can you see these things directly out of the HMDI?
 
It's definitely not a result of compression effects from a fast moving camera alone.

I would run additional tests without the Fader and perhaps an E-mount lens (try to rule out the adapter).

What kind of adapter are you using, btw?
 
rx8pilot said:
That is a pretty sharp line for a light leak. I would be looking for electronic culprits. Bit starvation on the codec or some DSP issue. I doubt the camera is "broken" you may have simply found a weak spot that is cannot deal with very well. When that camera moves fast, it is more likely the compression engine cannot keep up. Can you see these things directly out of the HMDI?
Click to expand...

I had the exact same issue, along with many others. The problem was solved by covering the release point on the adapter with a piece of tape, fixed it right away.
 
rx8pilot said:
That is a pretty sharp line for a light leak. I would be looking for electronic culprits. Bit starvation on the codec or some DSP issue. I doubt the camera is "broken" you may have simply found a weak spot that is cannot deal with very well. When that camera moves fast, it is more likely the compression engine cannot keep up. Can you see these things directly out of the HMDI?
Click to expand...

I've never seen compression cause an issue like this, mainly from how the data is stored in memory and how it would be compressed, you'd not see a line like that. I have the FS100 and have moved the camera CRAZY fast when I was testing the footage with highly detailed very large DR scenes.

As others have stated, this is a known issue with some adapters letting in light. There are plenty of other examples of this here showing the same thing.
 
Since we make adapters, I guess I am thankful I have no idea what a light leak may look like. ;-) I have seen various leaks on film cameras but they all tended to look like a fog because the light was always bouncing off a dark surface.
 
rx8pilot said:
Since we make adapters, I guess I am thankful I have no idea what a light leak may look like. ;-) I have seen various leaks on film cameras but they all tended to look like a fog because the light was always bouncing off a dark surface.
Click to expand...

Yeah, it wouldn't have been my first guess either, so strange how different things can look in different situations. I am thinking the light washes out the rest of the image and the dark spot is where the light cannot touch due to how the light is coming through. Think of like a flashlight being blocked by something opaque over part of it.
 
I'll do a test tomorrow with another EOS to NEX adapter and see if the problem still appears. I don't have NEX mount lenses so I can't do a comparison with that. I discover that the Kiwi adapter I have and possibly gave the problem doesn't click when I attach it, while the other markless adapter clicks. Let's see tomorrow what it will give in bright sunlight.
 
I did a test, and indeed it was a light leak from the Kiwi adapter, that doesn't make a clicking sound while attaching it to the camera body, and lens. The cheaper Chinese adapter I ordered through ebay works well, doesn't have leaks, and with that there are no strange lines in the image anymore. Thank you DM_rider !
 
Yeah, Kiwi and some others with a lever instead of a button are known to produce that effect.
Has nothing to do with the price, just the construction of the release.

Quick fix is some black gaffa tape. If you want to go fancy (like I did) and also prevent internal reflections, line the adapter (inside) with black muslin or velvet.

Here is an example:


Frank
 
have this same problem with my fotodoix nikon adapter. not a huge deal since i just did some casual filming yesterday but definitely gonna tape it up next time.
 
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