Ad
Ad
Ad
Pages: [1] 2 »   Bottom of Page
Print
Author Topic: ZD has PROBLEM  (Read 31501 times)
Anders_HK
Sr. Member
****
Offline Offline

Posts: 1001



WWW
« on: January 27, 2008, 06:24:29 AM »
ReplyReply

Readers of this forum should already know that I in past have written much well of ZD and ZD camera. I also believe in being honest and correct.

ZD back is same internals as ZD camera and with identical image quality. It shall be stated that ZD is capable of very high image quality within its limitation of 50-100 ISO and normal shorter exposures. Using ETTR and much light is preferred. Within those limitations the ZD image quality is for most times similar to or near to other 22MP MFDBs and significant better than any DSLR.

Above said, I have encountered a problem with ZD camera that applies same to ZD back. I find the issue unacceptable in a product as expensive as ZD. My impression is that Mamiya is doing nothing. Thus I have sold my ZD camera at a loss. New owner appropriate knows of the problem issue, thus sold with honesty and fairness.

Attached file exemplifies the problem that at times occurs. This is a crop I did of setup with white board and black neoprene 50-50 in frame (about 4 to 5 stop difference). Light was diffused from window with overcast sky. In the lower two crops, saturation is erroneous set to 100%, as a guide to know what to look for. In order to better see this in also upper row it helps to look at computer display with no glare or reflections on it, such as when dark. These - what I label as problem artifacts - do show up in prints.
Logged
Anders_HK
Sr. Member
****
Offline Offline

Posts: 1001



WWW
« Reply #1 on: January 27, 2008, 06:25:06 AM »
ReplyReply

Here are more crops from above test, also from photos in actual shoots. These were by my agent sent to Mamiya Japan along with my ZD for investigation. I shot my test at varying ISOs and at less than 1 second exposure.

Exposure data for model: ISO 160, +0.5EV, 1/20s, f/4.5. Please note in face of model.

Exposure data at temple: ISO 100, -0.5EV, 1/30s, f/16. Please note in far most board in railing.

Since these shots I have also learnt more of ZD. Basically, depending on DR of the scene, one should ETTR to reduce risk of this problem. ETTR is similar to reducing ISO. If underexpose it is the opposite and risk more noise being noticed in dark and mid tones and with it these artifacts. However per my experience the issue of these artifacts will still be visual at times also at ISO 50. I also find difficult to photograph with such restrictions. My personal observation is thus that ZD is not very capable of proper handling situations with black and white as in dark and light in a photograph, or even a model with black sweater against white background in a studio. That would be fine if it would be limited to only high ISO because high ISO is pushing a sensor. At native ISO and short exposure times I am of view that this should not be present and that the dark shall be clean from artifacts or discoloration.

Two raw files - http://www.yousendit.com/download/MmdzclVQcGs1bmpIRGc9PQ
« Last Edit: January 27, 2008, 06:35:51 AM by Anders_HK » Logged
Anders_HK
Sr. Member
****
Offline Offline

Posts: 1001



WWW
« Reply #2 on: January 27, 2008, 06:25:30 AM »
ReplyReply

My agent at first doubted my word when I said that I saw problem with ZD. In early November I handed them my ZD and it was sent to Mamiya Japan for investigation. At that time my agent also did test on ZD and they did so also on three other ZD cameras and one ZD back, all of which all had same problem. Add to that the ZD camera that they gave me on loan at that time and we have five ZD cameras and one ZD back with this problem (all late series). It also showed up in black and near black when they photographed color chart in their office under office lights.

This problem does possibly relate to newer ZD with late firmware. These compared to earlier ZD have improved noise performances but these artifacts show up. You may reference a post by Stefan Marquardt (7 Sept 2007, see post #69 to subject "Has every ZD / ZD back owned given up" here http://luminous-landscape.com/forum/index....pic=19337&st=0) in which he stated that he did my test and his early ZD did not have same problem but was noisier.

You may also look at photos posted by others here: http://luminous-landscape.com/forum/index....topic=20741&hl=. If you inspect those photos careful with no glare on computer display (or in dark room) you will observe that most seem to have the problem I point out in black or near black areas.

In that post I also promised to post outcome after my ZD had been investigated by Mamiya Japan. Let me emphasize that what I point out as problem is at LOW ISO and LESS than one second exposure. If we use high ISO or long exposure we push sensor, likewise is same if we significant underexpose.

Following is Mamiya Japan reply:

"As to the ZD camera (FDxxxx), we think the customer's complaint is mainly about the noise level of the camera when using a higher ISO setting or a longer exposure time. Checking the camera and the images attached, we have to say the noise level of the camera is not irregularly high but it is an average level of the ZD camera. If the photographer almost always use a higher ISO setting and a longer exposure time and if he cannot accept the noise level, we have to say the camera does not fit his usage."

In their reply, please observe that they refer to high ISO and long exposure time, but that their reply rather ignores the fact that the problem issue I pointed out was at LOW ISO and SHORT exposure times.
 
In past four weeks I have tried achieve solution with my agent but it has failed. One key person there without seeming technical knowledge on this matter refers to above reply from Mamiya as saying that ZD has no problem. Indeed I am clear of different opinion: ZD has problem.

I should state that up to four weeks ago I have experienced the handling and services from my agent to be very exceptionally good. With this ZD problem I am disappointed and frank do not view ZD as an acceptable product.
« Last Edit: January 27, 2008, 06:32:27 AM by Anders_HK » Logged
Anders_HK
Sr. Member
****
Offline Offline

Posts: 1001



WWW
« Reply #3 on: January 27, 2008, 06:26:00 AM »
ReplyReply

Do you believe what I showed above is Moire? Please test. I did re-tests, but with less than 700 exposures on my original ZD and less than 700 on the loaner behind, and many of them trying narrow down above problem during my ownership, both on boring test shoots and in actual photography: I am frank tired and now want a product that does not give me problem.

I am now looking at Phase One and Leaf Aptus, even though still more $$ over my D200 or F100 was. Phase and Leaf can vaguely show magenta/purple in black/dark areas but it seems they significantly more control the artifacts, and they are also capable of higher ISOs and more stops below mid point neutral than ZD. I appreciate if someone with experience of such DBs would reply of those products in comparison.

Someone gave me a very interesting email reply on me sharing the same images sent by my agent to Mamiya above (confidential source):

“- The Image "All ISO": by looking at the different ISO settings one can easily notice noise at all ISO's, even with ISO 50. This noise can be seen in some green/magenta "patches". You can find exactly the same green/magenta patches in the 2 other images (girl & temple) in some shadow places. This shows simply a high noise level in coordination with an interpolation which seems not to be very good and efficient.

To be honest, all the ZD images I have seen so far have shown to me these very same green/magenta zones in the shadows and sometimes even in the 1/4tones. It seems here that the handling of the data out of the sensor is not really good (interpolation algorithm). Even if the sensor produces such noise, a good interpolation can get rid of it in most of the cases. In any case, "Neat Image" noise filter should be able to handle most if not all of this noise.

- What I can also notice in the 2 other images, besides the extreme high noise level, is a lack of details in the shadows: some (many) zones show RGB values of 0/0/0, this even by applying a "linear" curve in ACR. This with images shot at ISO 100 & 160: this is quite weird and unusual! Did you send the original data, or where those already manipulated by some toning curve applied?

- You are saying to have this noise problem under certain conditions: do you know when and under which conditions exactly?”

My reply to questions in that reply are following: Neat Image and other noise ware sometimes can help (emphasis on sometimes), but they make image softer. It can also be cleaned similar to moiré by using paint with color (not pixels) in Photoshop (see Moiré Go Away @ http://www.russellbrown.com/tips_tech.html ). However, this makes color uniform which is not very acceptable for nature photos since color in nature is usually not uniform. Files that I emailed this person had not been altered. They were RAW files, same as posted above, and with no curves applied, and JPGs with default settings from SilkyPix (using AdobeCamera RAW result in same). The conditions that this can occur in are as I have described in above with dark and light subjects.

ETTR (exposing to the right) do reduce the issue. ETTR at ISO 50 is similar to shooting at ISO25 and is the safest way to reduce the problem, but it is of course also dependent on the DR of subject scene. ISO 25 is very slow for my landscape and nature photography. Per my testing the problem artifacts can show at ISO50 when exposed per camera meter neutral. If one instead underexpose it is similar to using higher ISO setting and can bring out noise and these artifacts in dark tones and mid tones (this is normal what happens to normal noise in dark and mid tones when underexpose). However, as shown by my test when scene exceeds 4-5 stops it seems artifacts may or may not become present in dark areas depending on the scene. This leaves that artifacts can occur at just 2-2.5 stops below mid point. In such conditions it seems slide film is more capable, or a DSLR. Medium format sensors are otherwise said to have about 12 stops of DR which is more than negative film and DSLRs.

Having now demoed and seen test samples from Phase One and Leaf Aptus (and correct me if I am wrong), it seems all MFDBs can show similar to above. However those other products much better control this so that at low ISO it seems as an insignificant problem, seemingly done both by more appropriate algorithms within the digital backs and in their designated RAW converters. Mamiya has not done so. In fact the Leaf Aptus 22 apparent have same Dalsa sensor as ZD but performs very significant better than the ZD.

Above are reasons why I have given up on ZD. Likewise I am frank not pleased that nothing was done to correct the problem when I reported it, and that I was not even given an appropriate fact reply from Mamiya.

The issue of very limited ISO range and indeed the above described problem made me give up. Else I see the ZD camera as having the best user interface of any DSLR I have used or seen. It is disappointing.

I believe Mamiya need to wake up!

Any comments from other ZD or MFDB users are most welcome.
« Last Edit: January 27, 2008, 06:45:15 AM by Anders_HK » Logged
amsp
Sr. Member
****
Offline Offline

Posts: 788


« Reply #4 on: January 27, 2008, 07:13:27 AM »
ReplyReply

I would be devastated if I payed $8000 for that kind of performance. Your ISO160 looks like my P25 when I underexpose at ISO800.
Logged
Quentin
Sr. Member
****
Offline Offline

Posts: 1118



WWW
« Reply #5 on: January 27, 2008, 07:45:27 AM »
ReplyReply

I have not seen anything like that with my ZD camera.  It has the old firmware, so maybe upgrading to the new firmware would be a bad move (but then I like the look of the new 28m lens, which requires the firmware upgrade).

I agree, its not acceptable and if my ZD was that bad I'd be just as peeved as you are, Anders.

Quentin
Logged

Quentin Bargate, ARPS, Author, photographer entrepreneur and senior partner of Bargate Murray, Law Firm of the Year 2013
Quentin
Sr. Member
****
Offline Offline

Posts: 1118



WWW
« Reply #6 on: January 27, 2008, 08:00:35 AM »
ReplyReply

As I usually use Silkypix as my raw converter, I tried a couple of images with ACR.  I pretty much only shoot at 50ISO with the ZD.  With colour noise removal set at 12 in ACR, the shadows are smooth and noise free with ACR as well as Silkypix as you'd expect (and demand).  There are some very small colour discrepancies in deep shadow areas if absolutely no colour noise reduction is used in ACR, but a low setting of 12 removes it (the standard setting is 25). Compared with other dslr's the ZD has great dynamic range, but I am inclined to think its true ISO is 25, not 50, and that you should as a rule expose to the right, as you have discovered.  However the images I have just checked were if anything underexposed.

My further checks simply confirm what you already know; you have problems and Mamiya should address them.

Quentin
« Last Edit: January 27, 2008, 08:02:03 AM by Quentin » Logged

Quentin Bargate, ARPS, Author, photographer entrepreneur and senior partner of Bargate Murray, Law Firm of the Year 2013
stefan marquardt
Full Member
***
Offline Offline

Posts: 142


WWW
« Reply #7 on: January 27, 2008, 01:06:51 PM »
ReplyReply

just like Quentin, i dont have any problems with my zd. I shoot at iso 50, never look at the lightmeter and expose till i get blinking highlight warnings at the display. than I get noiseless shadows even when pushed up a lot! with my zd files i regularly use lightooms fill-light in the middle (50%?) position. (but than again, I never slide the saturation levels to the max - perhaps I would see green and magenta blobs here too).

(but i did lately see a lot of vertical centerfold lines when using a fair amout of pushing and pulling a lot of sliders in LR!).

stefan
Logged

stefan marquardt
stefanmarquardt.de
architecture & interior photography
www.stefanmarquardt-architekturbild.de
Snook
Guest
« Reply #8 on: January 27, 2008, 05:47:45 PM »
ReplyReply

I would say you were wise to get rid of it , especially when Mamiya and Phase are coming out with the "New" camera..:+}
The ONLY thing interesting about the ZD WAS it's price...:+}
And even now that is not good when you can pick up P30's or Aptus 22 for around 10K.
Snook
Logged
david o
Sr. Member
****
Offline Offline

Posts: 310



WWW
« Reply #9 on: January 27, 2008, 06:09:53 PM »
ReplyReply

frankly I did download the file with the girls on the window.
Exposing for the window wouldn't allow any room for the shadow to be "alive" even with a phase or leaf.

I needed to push your file almost 4 step to bring the curve back... That's way too much.

I have similar shot with my 5D and if I want to bring up the shadow it become really nasty. Lines, green, mag. so at least the window girl shot it's not relevant.

I would be interested in the pagode shot though to see the fence.
Logged
david o
Sr. Member
****
Offline Offline

Posts: 310



WWW
« Reply #10 on: January 27, 2008, 06:11:35 PM »
ReplyReply

del.
« Last Edit: January 27, 2008, 06:13:42 PM by david olivier » Logged
Quentin
Sr. Member
****
Offline Offline

Posts: 1118



WWW
« Reply #11 on: January 27, 2008, 06:28:43 PM »
ReplyReply

Quote
The ONLY thing interesting about the ZD WAS it's price...:+}
And even now that is not good when you can pick up P30's or Aptus 22 for around 10K.
Snook
[a href=\"index.php?act=findpost&pid=170080\"][{POST_SNAPBACK}][/a]

That's a load of nonsense.  the ZD was and is an outstanding camera, but obviously some units are faulty.

And by the way, there is no need to SHOUT

Quentin
« Last Edit: January 27, 2008, 06:30:44 PM by Quentin » Logged

Quentin Bargate, ARPS, Author, photographer entrepreneur and senior partner of Bargate Murray, Law Firm of the Year 2013
Snook
Guest
« Reply #12 on: January 27, 2008, 06:58:17 PM »
ReplyReply

No shouting..:+}
And One of the faulty ones??? I think your lucky if you do not have a faulty one.
There were more faulty ones than non-faulty ones.
EVERY ( No shouting intended ) ZD file I saw on the net or downloaded had funky Blobs, Purple blotches or Horrible noise, take your pick.
And it is supposedly slow as molasses..
Snook
Logged
Anders_HK
Sr. Member
****
Offline Offline

Posts: 1001



WWW
« Reply #13 on: January 27, 2008, 07:32:46 PM »
ReplyReply

Quote
No shouting..:+}
And One of the faulty ones??? I think your lucky if you do not have a faulty one.
There were more faulty ones than non-faulty ones.
EVERY ( No shouting intended ) ZD file I saw on the net or downloaded had funky Blobs, Purple blotches or Horrible noise, take your pick.
And it is supposedly slow as molasses..
Snook
[{POST_SNAPBACK}][/a]

Snook and all,

Lets keep to facts. This issue I post is separate from the one Frank Doorhof had months back. His was DIFFERENT and indeed blotches that look different from what I posted above. See here for his [a href=\"http://www.htforum.nl/fotofrank/albums/userpics/10001/defectiveback.jpg]http://www.htforum.nl/fotofrank/albums/use...fectiveback.jpg[/url]. That problem was said to be cause of a batch of sensors and that problem is nonexistent since.

The issue I point out seem not limited to a few faulty ZDs, since I pointed out in above that I know of 5 newer ZD cameras and one ZD back but of no newer ZDs without this problem. Or does someone have newer ZD without this problem? Look at LL links I posted in above of images posted a few months back in this forum. They show this problem. Read Mamiya's reply above that does not recognice the problem at low ISO and short shutter speeds, also the one from confidential source referring to the interpolation algorithms in ZD. Actually at my demo of Leaf in Seoul the gentlemen who spoke not much English said "algorthms" when I described ZD problem in brief...

I much agree with Quentin, the ZD is really lovely camera (& back)... but it should not have this problem.

Regards
Anders
Logged
John_Black
Sr. Member
****
Offline Offline

Posts: 263


WWW
« Reply #14 on: January 27, 2008, 08:07:45 PM »
ReplyReply

Anders - ISO 100 on a P25 isn't all that great either, so you may want to look at the "+" backs if higher ISO's are important.
Logged

amsp
Sr. Member
****
Offline Offline

Posts: 788


« Reply #15 on: January 27, 2008, 08:46:51 PM »
ReplyReply

Quote
Anders - ISO 100 on a P25 isn't all that great either, so you may want to look at the "+" backs if higher ISO's are important.
[a href=\"index.php?act=findpost&pid=170107\"][{POST_SNAPBACK}][/a]
Huh? ISO100 isn't great on a P25? What are you rambling about?
Logged
mcfoto
Sr. Member
****
Offline Offline

Posts: 938


WWW
« Reply #16 on: January 27, 2008, 09:07:44 PM »
ReplyReply

Hi
I still have not had a firm ware upgrade for my ZD camera & it is almost two years old. I will talk to L&P here in Sydney & see if they are having any problems. I got one of the first cameras off the line here in Australia & it has been a great camera. BTW did anyone download the raw ZD & 1Ds3 files I posted last month?
Denis
Logged

Denis Montalbetti
Montalbetti+Campbell
www.montalbetticampbell.com
mcfoto
Sr. Member
****
Offline Offline

Posts: 938


WWW
« Reply #17 on: January 27, 2008, 10:47:28 PM »
ReplyReply

Quote
frankly I did download the file with the girls on the window.
Exposing for the window wouldn't allow any room for the shadow to be "alive" even with a phase or leaf.

I needed to push your file almost 4 step to bring the curve back... That's way too much.

I have similar shot with my 5D and if I want to bring up the shadow it become really nasty. Lines, green, mag. so at least the window girl shot it's not relevant.

I would be interested in the pagode shot though to see the fence.
[a href=\"index.php?act=findpost&pid=170086\"][{POST_SNAPBACK}][/a]

hi
I agree & I downloaded the file & put it in RD. There is a huge stop range & the shadows are very under exposed. The Dalsa chip can be noisy & hence it is very film like. Too me you would get a better result from a Canon or Nikon with the CMOS sensor for a shot like this. I also darkened the shadows & this improved the shot right away. Looking at this shot I could not see my ZD  doing any better. From my experience with CCD sensors they have higher noise when that underexposed. Most likely Phase would do a better job & they are using noise reduction to do so. like I said before the Aptus 22 is better than the ZD ( skin color & tethered software ) but it is also a lot more expensive too. If you wanted better shadows use a fill card or light & this shot would be better. Just my 2 cents worth. I will get a firmware upgrade now.

Denis
Logged

Denis Montalbetti
Montalbetti+Campbell
www.montalbetticampbell.com
SecondFocus
Sr. Member
****
Offline Offline

Posts: 463


WWW
« Reply #18 on: January 28, 2008, 05:33:34 PM »
ReplyReply

I just finished shooting with the 645ZD for about 10 days. Everything was excellent. I shoot in my typical circumstances for two magazine features and for a cover shot for a third magazine. All were very successful.

I did some testing for some of the problems I have heard about with this system and found none present with the camera I was using. I even did a subsequent test based on an e-mail conversation with Frank Doorhof and found that one of his concerns/experiences with the 645ZD had also been corrected.

I also spoke with MAC Group in New York and was assured that prior problems with earlier shipments have been corrected and any of those still out there replaced as necessary.

I think either the 645ZD camera or back is a great buy and would not hesitate to use it on subsequent assignments.
Logged

Ian L. Sitren
SecondFocus
Anders_HK
Sr. Member
****
Offline Offline

Posts: 1001



WWW
« Reply #19 on: January 28, 2008, 07:06:57 PM »
ReplyReply

Ian,

Lets bear in mind your location of Palm Springs California, just like Sydney for Denis (mcfoto) it is a very sunny place. The ZD is sensitive to light, which also effect. Thus I imply that not only the DR of white and black can effect but also light intensities.

Regards
Anders
Logged
Pages: [1] 2 »   Top of Page
Print
Jump to:  

Ad
Ad
Ad