Topic: Green tint on ZD (Read 5336 times)

Justinr · « **on:** July 05, 2008, 04:34:26 am »

It might just be my imagination but it seems that the ZD back on my AFD produces a green tint on many images. It is most noticeable on pictures containing a lot of green (grass or foliage) and more so on the left hand side for some reason. Anyone else noticed this?

Justin.

stefan marquardt · « **Reply #1 on:** July 05, 2008, 07:59:36 am »

do you see that cast mostly on wide angle pics?
I sometimes see - for example in white interiors - a green/mangenta cast when I use the 35mm lens on my ZD. (the samples of the 28mm I saw here on LL seemed to show the same cast - even though the 28mm is "optimised" for digital). another interesting thing my ZD shows is a nice centerfold. just play with the lightroom-sliders a bit and it can pop up.

stefan

thsinar · « **Reply #2 on:** July 05, 2008, 11:24:38 am »

Justin,

to be sure if it is a sensor issue or not, just take a shot of a neutral grey background (evenly lit), then play with the contrast curve: you should be able to see any green/magenta colour casts easily, if a sensor issue.

Best regards,
Thierry

Quote

It might just be my imagination but it seems that the ZD back on my AFD produces a green tint on many images. It is most noticeable on pictures containing a lot of green (grass or foliage) and more so on the left hand side for some reason. Anyone else noticed this?

Justin.
[a href=\"index.php?act=findpost&pid=205640\"][{POST_SNAPBACK}][/a]

ixpressraf · « **Reply #3 on:** July 05, 2008, 11:55:36 am »

I think i have until now not yet seen a perfect neutral mamiya ZD camera. I also had one with a slight green cast on the left side of the image. it was replaced 2 times but still it kept on showing a minor green cast ( not as the first one, wich was only usuable in Black and white). i have posted the question of how to get rid of that cast here on this forum but never got any answers. ( mamiya simply denied the existance of the cast)

rweissman · « **Reply #4 on:** July 05, 2008, 01:34:53 pm »

Quote

It might just be my imagination but it seems that the ZD back on my AFD produces a green tint on many images. It is most noticeable on pictures containing a lot of green (grass or foliage) and more so on the left hand side for some reason. Anyone else noticed this?

Justin.
[a href=\"index.php?act=findpost&pid=205640\"][{POST_SNAPBACK}][/a]

rweissman · « **Reply #5 on:** July 05, 2008, 01:41:22 pm »

I certainly see a green/yellow cast, particularly when using Lightroom. The cast is far less noticeable with CaptureOne and other raw developers. I showed this to friends at my local dealer (KSP in Palo Alto, CA) and compared the Lightroom and Mamiya's own software versions on their machines and they noticed the same thing. I have sent my ZD in for servicing because of frequent lockup, which requires removing the magazine battery (six AA magazine) so as to be able to continue shooting without a 'DB ERROR' preventing further shooting. The loaner from KSP has a similar but less pronounced color cast in Lightroom. And, yes, the more green in the image itself, the more pronounced the cast.

Ron

Justinr · « **Reply #6 on:** July 05, 2008, 05:54:48 pm »

Well at least I now know that I've not gone totally bonkers just yet. Here is a classic example of the problem although I have managed to reduce the cast somewhat using colour balance and the green channel in curves. (my PS skills are not particularly sophisticated)-

Lady and tree

Mind you there was a lot of bright sunlight filtering through the leaves and things were quite green to the naked eye on the day, but there's no doubt that the ZD exaggerated it. And yes it is more noticeable on WA lenses, I go only so far as an 45mm manual focus but it does show. It's also comforting to realise that I'm not the only one to suffer the camera jamming with a DB error, whatever that is. Removal of the battery, or just opening of the flap usually does the trick but precious seconds can be lost.

Justin.

Panopeeper · « **Reply #7 on:** July 05, 2008, 07:13:08 pm »

Justin,

do you have a color checker card, or something with different shades of the same grey (calibrated)?

Make a shot of the card, and pick WB on the white square; now check out the RGB values on the different grey squares. Do not check the RGB on a single point, but make a selection on most of the square and see the average. Then pick WB on a dark grey (but not the black) and check out the RGB values on the white and light grey square.

Try the same with different raw converters.

If you don't get close to identical values in R, G and B, then pls upload the raw file.

You can try this once in the left and once in the right side of the image, but I would be surprized if the result was depending on the location on the sensor.

Quentin · « **Reply #8 on:** July 06, 2008, 07:00:04 am »

I have a slight green cast on the left with my ZD camera. With many images it is not noticeable but it does seem to affect blue skies more than anything else, which can be problematic. I just live with it - but it is sometimes irritating.

Quentin

Anders_HK · « **Reply #9 on:** July 06, 2008, 10:42:53 pm »

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I think i have until now not yet seen a perfect neutral mamiya ZD camera. I also had one with a slight green cast on the left side of the image. it was replaced 2 times but still it kept on showing a minor green cast ( not as the first one, wich was only usuable in Black and white). i have posted the question of how to get rid of that cast here on this forum but never got any answers. ( mamiya simply denied the existance of the cast)
[{POST_SNAPBACK}][/a]

It is worthwhile to note Mamiya Digital's refusal to acknowledge any problem on ZD. Such were also the case with the problem I encountered and wrote of here [a href=\"http://luminous-landscape.com/forum/index.php?showtopic=22698&hl=]http://luminous-landscape.com/forum/index....topic=22698&hl=[/url].

As of yet I have not seen or heard anything of that they have corrected the problem I pointed out in the link above. The ZD appear to remain a not correctly functioning product.

Having Mamiya 7ii and Mamiya 645 systems please note that my view is very good of those products.

Regards
Anders

Panopeeper · « **Reply #10 on:** July 06, 2008, 10:57:20 pm »

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I have a slight green cast on the left with my ZD camera. With many images it is not noticeable but it does seem to affect blue skies more than anything else, which can be problematic

Quentin,

have you made a black frame shot (lens, viewfinder sealed), with 1sec and 5sec (or about)?

I wonder how the raw file of such shots look like.

Quentin · « **Reply #11 on:** July 07, 2008, 01:59:53 pm »

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Quentin,

have you made a black frame shot (lens, viewfinder sealed), with 1sec and 5sec (or about)?

I wonder how the raw file of such shots look like.
[a href=\"index.php?act=findpost&pid=206081\"][{POST_SNAPBACK}][/a]

If I had the time I might check that out But I don't.

Somehow I am starting to feel let down by digital. Can't quite explain why, it has nothing to do with the ZD or any other camera. Odd. Maybe I'm going mad.

Quentin

Panopeeper · « **Reply #12 on:** July 07, 2008, 02:31:47 pm »

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If I had the time I might check that out But I don't

Well, making such a shot and sending the raw file via yousendit should not be so much laborous. I would analyze the raw pixels to find out for example if only the greens are affected, how much is the difference from left to right, etc.

TMARK · « **Reply #13 on:** July 07, 2008, 02:35:43 pm »

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If I had the time I might check that out But I don't.

Somehow I am starting to feel let down by digital. Can't quite explain why, it has nothing to do with the ZD or any other camera. Odd. Maybe I'm going mad.

Quentin
[a href=\"index.php?act=findpost&pid=206235\"][{POST_SNAPBACK}][/a]

The more time I spend in front of the monitor the more I feel digital has let me down. I also think its too expensive for the market we face. Rates are stagnant or decreasing in real terms, as usage and media buys become harder and harder to fathom and value. Meanwhile, our digital video bretheren have cheaper gear, higher and growing rates, and their digital equipment simply works. As a business matter, I have to start pushing towards video.

MichaelEzra · « **Reply #14 on:** July 07, 2008, 03:17:49 pm »

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I would analyze the raw pixels to find out for example if only the greens are affected, how much is the difference from left to right, etc.
[a href=\"index.php?act=findpost&pid=206244\"][{POST_SNAPBACK}][/a]

Panopeeper,

I will send you a message with a download link in a few days.

Panopeeper · « **Reply #15 on:** July 07, 2008, 03:52:58 pm »

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I will send you a message with a download link in a few days.

Thanks, Michael. We will see what is there.

As verification of the validity, you should make a "normal" shot at the same time, to see if the tinting occurs. Perhaps the phenomenon depends on some particular circumstances, like the temperature of the back; it has no sense to look for any signs in the black frame images, if the normal image does not exhibit the phenomenon in that particular setting.

The shutter of the black frame should be the same as that of the "normal" shot. If your experience shows, that the degree of tinting depends on the shutter time, then please make a second black frame with much longer shutter, like 1sec.

I do see, that the examples posted here and on another related thread are not in low light situation, but the longer exposed black frame images are revealing a lot about the sensor's behaviour.

skid00skid00 · « **Reply #16 on:** July 07, 2008, 04:16:54 pm »

You're shooting a lady in the shade, lit by light reflected by green grass...

SecondFocus · « **Reply #17 on:** July 07, 2008, 04:41:29 pm »

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You're shooting a lady in the shade, lit by light reflected by green grass...
[a href=\"index.php?act=findpost&pid=206265\"][{POST_SNAPBACK}][/a]

I saw that too, good call, I just didn't want to get into another ZD thread. And there is a firmware upgrade for the body for the error message that keeps getting reported about. You might check with MAC Group about your 645 bodies.

Justinr · « **Reply #18 on:** July 07, 2008, 05:39:07 pm »

Err.... I also went on to say-

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I have managed to reduce the cast somewhat using colour balance and the green channel in curves.

It was an awful lot greener than it now appears and if you have a check back on my postings (and others) you will note that I also said that it appears to pick up and exaggerate the green in an image. It just so happens that I had this picture handy on the web, which is why I drew your attention to it. There is another where the effect can be seen at -

Pony Camp

Click on the Pony camp link at the bottom of the page and the group shot on page six was affected although again I have corrected it to a certain extent. But there are others in that gallery which display the symptoms.

Justin.

SecondFocus · « **Reply #19 on:** July 07, 2008, 11:34:25 pm »

I once did a lot of shooting at a favorite spot; beautiful green grass, green tall hedge and a graceful grapefruit tree. But I got tired of correcting green skin tones. All shot on a Canon 1DMkII.

With the better color rendition of a MFDB, even the 645ZD, I could imagine that the green cast would be more prominent in that circumstance.

Author Topic: Green tint on ZD (Read 5336 times)

ixpressraf