Topic: Green tints on the ZD (Read 3317 times)

Justinr · « **on:** March 06, 2009, 10:45:12 am »

The subject of a green tint to the left hand side of an image taken by the ZD has been mentioned before, not least by me. It is a most definite problem and yet no cause or fix has been suggested so I don't know whether this might throw a light upon it. It was taken as a preliminary shot as I started to work on the lighting etc for the subject and is a small jpeg straight from camera. I have had the left section of a frame missing before and have reformatted the card to cure it, but never with this green glow in its place.

Justin.

Easton · « **Reply #1 on:** March 06, 2009, 12:07:48 pm »

Whoa - even I didn't get this on my old/replaced ZD back.

Panopeeper · « **Reply #2 on:** March 06, 2009, 12:49:00 pm »

This is not a "tint". It is a typical card or transmission error, though it could be a memory error within the camera.

What is the native orientation of this image? Is the green part at the bottom? Is this only in JPEG format?

JDBFreeheel · « **Reply #3 on:** March 06, 2009, 12:50:39 pm »

As a former ZD owner (2 different backs), I never got this specific issue but it seems consistent with what I thought were processing issues by the ZD. Basically, my non-technical diagnosis was that the ZD sometimes hiccuped and could not handle the processing needs of the sensor/image. It was almost as if the image would take and then the image processing module would choke on the image and get some part of the way through and then fault.

My experience with Mamiya USA (MAC Group) was that they absolutely knew about these issues and though they didn't explain the technical issues behind the issue, they confirmed that this was not isolated and that they had seen multiple examples of it.

-Josh

Justinr · « **Reply #4 on:** March 06, 2009, 01:47:37 pm »

Quote from: Panopeeper

This is not a "tint". It is a typical card or transmission error, though it could be a memory error within the camera.

What is the native orientation of this image? Is the green part at the bottom? Is this only in JPEG format?

Now this really is the weirdest thing, and I tell no word of a lie here for when I went back to check the RAW, both it and the accompanying jpeg were fine, the green slice had gone!!

The card had been sitting in the reader for about an hour and a half and when I went to check it, it was clear, I've even checked the card via the camera screen and it is OK there too! I had not copied the files to the PC, everything was taken straight from the card.

Blowed if I know.

Justin.

p.s. The green was to the left.

pps. As for my suggestion of a tint, I wondered if there was an underlying sensor problem that showed up in these circumstances.

Panopeeper · « **Reply #5 on:** March 06, 2009, 02:25:35 pm »

Quote from: Justinr

p.s. The green was to the left

Thanks, but it was not to the left. I DID see the picture you posted and I would not have asked you to tell me what I saw.

The ZD back's native orientation is upright (portrait). The picture you posted was rotated (automatically, I guess); the green part is either at the top or at the bottom of the native image. The relevance of my questions is:

1. the *raw* data of the ZD back is not sensitive to bit loss. If you "loose" a bit, that pixel value will be somewhat off, and that's it.

2. the JPEG compression is highly sensitive to single bit corruption. If that occurs on the "wrong place" (which is much of the data), then the rest of the image or of one color channel can be compromized; the "rest" is from that point to the end of the row and down to the bottom edge. If the green was at the bottom, then the bit corruption was possible. However, if the green segment was at the top, then this JPEG corruption could not have been the case.

Quote

pps. As for my suggestion of a tint, I wondered if there was an underlying sensor problem that showed up in these circumstances.

The sensor as source is not impossible, for example a contact error between the sensor and the board. An error on the sensor itself, occasionally, is IMO not probable, but I have no authority in hardware issues. Of course, the miraculous healing of the image excludes the sensor's responsibility.

Justinr · « **Reply #6 on:** March 06, 2009, 03:04:59 pm »

Quote from: Panopeeper

Thanks, but it was not to the left. I DID see the picture you posted and I would not have asked you to tell me what I saw.

The ZD back's native orientation is upright (portrait). The picture you posted was rotated (automatically, I guess); the green part is either at the top or at the bottom of the native image. The relevance of my questions is:

1. the *raw* data of the ZD back is not sensitive to bit loss. If you "loose" a bit, that pixel value will be somewhat off, and that's it.

2. the JPEG compression is highly sensitive to single bit corruption. If that occurs on the "wrong place" (which is much of the data), then the rest of the image or of one color channel can be compromized; the "rest" is from that point to the end of the row and down to the bottom edge. If the green was at the bottom, then the bit corruption was possible. However, if the green segment was at the top, then this JPEG corruption could not have been the case.

The sensor as source is not impossible, for example a contact error between the sensor and the board. An error on the sensor itself, occasionally, is IMO not probable, but I have no authority in hardware issues. Of course, the miraculous healing of the image excludes the sensor's responsibility.

The green was at the bottom. My misunderstanding.

I really don't know what happened to be honest for although the now complete picture is identical to the partial one (the subject is anyway) the numbering is all to cock. Did I reformat the card? I wouldn't have thought so because that would have lost the image completely, Did I take more exposures after the bad ones? I don't recollect doing so but the numbering suggests I did. Did I do something else which I'd forgotten about? Maybe. It's all a bit of mystery and until it happens again and I clearly log the sequence of events before and after the shot I don't think any useful conclusions can be drawn.

However, the green file was created as shown but now I no longer have it on the card or PC and partial loss of an image with a blank black section has been noted before. Once this happens the card will not accept any more files, showing '0' on the screen even though I may have only saved a dozen or so pictures to it. Reformatting cures the problem.

I'm going to carry on with the shooting.

Justin.

Panopeeper · « **Reply #7 on:** March 06, 2009, 03:22:28 pm »

It is possible, that the transmission from the card to the PC is broken; even the cable, or a pin may cause the error; it can be some dirt on the contacts, broken wire, etc.

JDBFreeheel · « **Reply #8 on:** March 06, 2009, 03:22:55 pm »

Quote from: Justinr

although the now complete picture is identical to the partial one (the subject is anyway) the numbering is all to cock. Did I reformat the card? I wouldn't have thought so because that would have lost the image completely, Did I take more exposures after the bad ones? I don't recollect doing so but the numbering suggests I did. Did I do something else which I'd forgotten about? Maybe. It's all a bit of mystery and until it happens again and I clearly log the sequence of events before and after the shot I don't think any useful conclusions can be drawn.

However, the green file was created as shown but now I no longer have it on the card or PC and partial loss of an image with a blank black section has been noted before. Once this happens the card will not accept any more files, showing '0' on the screen even though I may have only saved a dozen or so pictures to it. Reformatting cures the problem.

I'm going to carry on with the shooting.

Justin.

You can keep shooting, but my hunch is that this will reappear. I had similar issues with my second zd. I would take a shot, however, the picture would not appear on the lcd screen, I would take another shot, but this time the first picture would appear. And so on. File numbering was off then until I took the card out, and restated the zd. Additionally, the counter (shots left on the CF card) would get all wonky too. Sometimes pictures would appear as white "snow" on the lcd screen, then show as white and purple striped frames in a raw converter. TheiImages were just unreliable. This was the end of it for me. I sent this in for service, and they could tell "something was just not right" with the camera. Again, I think the sensor is fine. It's just all of the other electronics are shaky at best.

-Josh

Justinr · « **Reply #9 on:** March 06, 2009, 06:04:12 pm »

Quote from: JDBFreeheel

You can keep shooting, but my hunch is that this will reappear. I had similar issues with my second zd. I would take a shot, however, the picture would not appear on the lcd screen, I would take another shot, but this time the first picture would appear. And so on. File numbering was off then until I took the card out, and restated the zd. Additionally, the counter (shots left on the CF card) would get all wonky too. Sometimes pictures would appear as white "snow" on the lcd screen, then show as white and purple striped frames in a raw converter. TheiImages were just unreliable. This was the end of it for me. I sent this in for service, and they could tell "something was just not right" with the camera. Again, I think the sensor is fine. It's just all of the other electronics are shaky at best.

-Josh

Well, you were quite right Josh-

And the RAW file is exactly the same.

Justin.

Panopeeper · « **Reply #10 on:** March 06, 2009, 07:12:56 pm »

Quote from: Justinr

And the RAW file is exactly the same.

Can you upload the raw file?

Justinr · « **Reply #11 on:** March 07, 2009, 03:51:32 am »

Quote from: Panopeeper

Can you upload the raw file?

Hi Panopeeper

Sorry, bit slow this end, do you mean upload to my server so that it can be inserted onto a post? It is 35mb and would the system be able to recognise and show it anyway? I'm quite happy to pm it if you'd like a closer look.

Justin.

skywalker_shiva · « **Reply #12 on:** March 07, 2009, 05:39:20 am »

Hi Justin

I don't have a ZD but a Hasselblad 503 with an Aptus 65.

I have seen similar 'green goblins' images too.

In short, if you shoot faster than the back,
you will get this problem.

My winder speed is slightly faster than the back speed
hence I end up with this problem once in a while.

As my Leaf dealer/support has explained,
if the back is not ready for an exposure and camera is fired,
the data gets corrupted.

The sensor is not ready as it has not flushed out the data
and by triggering the camera again you are corrupting the data.

If the back has an option, you can enable the beep sound.
Don't shoot till the back beeps so you know its ready for an exposure.

I know its a scary looking image
but don't sweat it, your db is fine.

Cheers

Panopeeper · « **Reply #13 on:** March 07, 2009, 11:42:27 am »

Quote from: Justinr

Sorry, bit slow this end, do you mean upload to my server so that it can be inserted onto a post? It is 35mb and would the system be able to recognise and show it anyway? I'm quite happy to pm it if you'd like a closer look.

Justin,

I can take a look at the file in pure raw format with Rawnalyze. The file is too large to email (for my server). If you have a web space and you can upload it there, then I can download it. Of course it can not be shown in a message. Another option is to send it with yousendit; it requires a registration, but free.

Justinr · « **Reply #14 on:** March 07, 2009, 05:44:47 pm »

Quote from: Panopeeper

Justin,

I can take a look at the file in pure raw format with Rawnalyze. The file is too large to email (for my server). If you have a web space and you can upload it there, then I can download it. Of course it can not be shown in a message. Another option is to send it with yousendit; it requires a registration, but free.

Many thanks for the offer. I've had a couple of cracks at uploading it to my webspace but alas it breaks off half way through for some reason. I'll try again tomorrow.

Here's the shot I was after BTW-

Halina

Justin

Panopeeper · « **Reply #15 on:** March 07, 2009, 09:37:28 pm »

Quote from: Justinr

Many thanks for the offer. I've had a couple of cracks at uploading it to my webspace but alas it breaks off half way through for some reason. I'll try again tomorrow

If your site causes the problem, then use yousendit.com; it is very fast and reliable, and it is not bugging the sender nor the recipient with wait times, so that you have to watch an advertisement, etc. After uploading you receive a URL for downloading, which you can post. That way you don't even have to specify a real recipient address (you have to specify *something*).

Author Topic: Green tints on the ZD (Read 3317 times)