Mamiya ZD

[Mike Sellers]

I would like to know what are the shortcomings of this camera. Can it do long exposures? Image quality?
Mike

[Frank Doorhof]

Hi
Don't know how they are now but when I tested one I did not like what I saw.
Remember this was way before phase one took over Mamiya, they had just released the zd back.
I loved the image quality but there were all sorts of strange things I experienced with several backs.

* purple blobs, especially seen at higher iso's but after you saw them they were also there on 50.
* tethering actually never worked with me, sometimes I got 10-20 images in but than it would lock up and I couldn't get it working anymore.

I decided to change my back for a leaf one and never looked back to be honest.

[John_Black]

About a dozen pages of Mamiya ZD info here - pebbleplace.com.  The Mamiya ZD can do 3 or 4 second shots and the raw developer is critical.  See this post for more info - July 4th.

[BernardLanguillier]

Hum, the ZD did offer excellent image quality at ISO 50 for exposures shorter than 2 seconds.

Outside this range my Philips iron performed better. If you want to try 3 secs onwards, I hope that you are on MAc because Raw Developper was an order of magnitude better than all the other raw converters when dealing with the ZD's long exposure noise.

In terms of usability, it is a camera that generates pretty polarized feelings. I sort of liked it when the temperature was above 5C, below that even my fridge was more useful as a camera.

Cheers,
Bernard

[ondebanks]

Re. long exposures, I researched this aspect of digital backs carefully. Back in the spring I was ready to take my Mamiya 645 digital; being an astrophotographer I wanted four things:

1) decent long exposure capability (low thermal dark noise) - with user choice over whether the camera is to take and subtract dark frames
2) easy on-off IR filter
3) good base ISO
4) good H-alpha (656 nm) red response

and being happily married and wanting to remain that way, I needed a fifth thing:
5) price limit of around €3500

Constraint # 5) narrowed it down to used backs, and # 2) to the ZD back and the Kodak DCS 645M back.

PhaseOne P+ backs are the long exposure kings, but they suffer from 2 big limitations: the user cannot turn off dark frame recording and subtraction (this is a simple firmware thing, but they showed no inclination to change it when I raised it with them); and the IR filter is not removable (if you do, you void the warranty and risk destroying the back).

So I hit the sensor data sheets, and did up some excel calculations of my own. Here are some of my conclusions re. the Kodak 645M vs. the ZD:

(1) The DALSA/ZD chip has 3x worse thermal dark noise at a given temperature than the Kodak 645M chip. This correlates nicely with the advice given on when to enable dark-subtraction: 1/4 sec (645M) vs. 1/15 sec (ZD)
(2) The Kodak has higher QE in every channel (R,G,B), and lower readout noise (20 vs 25 electrons). This correlates with the higher Kodak base ISO (100 vs 25), although one would expect it to be more like 50 vs 25.
(3) Both are decent in QE at H-alpha 656nm, but the Kodak is still better (~17.5% vs. ~14%)
(4) The DALSA/ZD looks a comparatively poor choice for IR photography: beyond 750nm, the red response falls well below the Kodak's, while the blue and (especially) green drop to almost zero - whereas the Kodak green and blue recover strongly, and merge with the red soon after 800nm
(5) While the blue bandpasses match closely, the DALSA's green and red responses are "blue-shifted" with respect to the Kodak; so the DALSA/ZD will produce warmer colours than the Kodak; e.g. 590nm: DALSA = reddish orange, Kodak = yellow

The attachment here shows the QE curves: ZD (DALSA FTF4052C) [thin curves] superimposed on Kodak 645M (Kodak KAF-16802) [thick curves], with scales matched carefully.

So I bought a used Kodak DCS 645M. After several months of actual use, I have found that while it is a fantastic all-rounder, its relatively high dark noise and readout noise (both are better than the ZD, remember) would make a spectrally-modified CMOS DSLR a better overall choice if long exposure astrophotography was all I wanted to do. But with dark frame subtraction enabled, it will do clean 30-second exposures in M or Av mode; and it will do 59 seconds on Bulb before either it or the AFD body decides to terminate the exposure (60 seconds seems to be the firmware limit). I keep a stock of E200 MF film in the freezer for anything longer than that!

[Quentin]

Hum, the ZD did offer excellent image quality at ISO 50 for exposures shorter than 2 seconds.

Outside this range my Philips iron performed better. If you want to try 3 secs onwards, I hope that you are on MAc because Raw Developper was an order of magnitude better than all the other raw converters when dealing with the ZD's long exposure noise.

In terms of usability, it is a camera that generates pretty polarized feelings. I sort of liked it when the temperature was above 5C, below that even my fridge was more useful as a camera.

Cheers,
Bernard

What Bernard says...

I loved the handling, hated the poor rear screen and noise if underexposed.  Excellent camera for good light / low ISO / short exposures.

Quentin

[AnthonyHope]

Hi,
   I've been using a ZD (slr not Back) for nearly two years now in all kinds of weather. Its a fantastic camera to use and its DR, colours etc is fantastic at iso 50, noise creeps in even at iso 100. I've done expsoures up to 30 secs which were fine.

I used canon slr's (300D, 30D, 40D and 1Ds) with L lenses before switching to the ZD and I find the ZD to be better in every department, well apart from weight (lol). It's excellent to use, all controls are easy to hand and its auto white balance and exposure are fantastic. With the zd you can concetrate on the photo content rather worrying about settings. 

I wouldn't recommend it for anything other than stills photography though, as its a very slow camera.


Hope this info is of some help.

Cheers

Anthony

www.ahopephotography.co.uk

[djonesii]

The ZD back does a great job when used within it's limits, and those limits are WAY WAY different than many backs of the same age, and this is reflected in resale values.  I use capture one for my raw conversions, and that seems to help.

I have never tried to shoot tethered, but I'm pretty sure from all that I have read, that's not a real possibility. 

When used within low ISO/high shutter short exposure, it does way better than a D300, and will hold up pretty good against a D3X.  Relative to the same generation backs, shot in the same situation, from all I have seen on the web, they are comparable.

Underexpose just a tad, then try to push, and the dreaded purples and greens are there in spades.


This is a sample under good conditions:


This is under bad conditions:


You can do a search here on LL or getdpi, and find all the dirt, and those who feel Mamiya has never quite made the whole in the matter are easy to spot.   

I got mine on the used market for around 3K, and at that price, it was a good deal to me.  I have the AFD-II body, and a few primes, and for the most part it is workable.  I get the occasional lockup, and pop out the CF card, all usually comes good then.  If I'm in a studio setting where I have control of the lighting, I just adjust the strobes, and it works fine.  The system as a whole has never failed me, but twice, I have worked with models whose style just did not support the low frame rate of the camera.  Once I was in a studio situation where I could not control the lighting, and with a little nosie suppression, I was still better than than the D300 to 8X10 prints.   

It's not a modern back, but it is cheap, and for the way I use it a good value.  The question is, will I pony up another 7K to address the short comings?

Dave

[Anders_HK]

Here is more:

http://forum.getdpi.com/forum/showthread.php?t=21318

Regards
Anders