Need help with my gear (Phase One + ZD Back)

[MaxKißler]

Hi everyone,

first of all, thanks for taking your time to read this.

I have to admit I'm not only new to this forum but also new to photography itself. I bought my first dslr in April this year and taught myself to take images and postprocess them. So I'm still devoloping myself and haven't figured out, which "photographic direction" to turn to. One thing's for sure, I do want to make my living out of it.

Now I've recently discoverd MFD and it fascinated me so badly (I knew this was what I needed, without having to try it out first)... So I ended up, spending what I've got for a refurbished Phase One 645AF and a good as new ZD Back. It wasn't a difficult decision for me since I'm not the economical kind of guy anyway and I convinced myself with the thought, that if I someday want to play among the big boys, I better get to know the gear asap.

On friday I received my first lens, a Mamiya AF 45mm f/2,8, which I thought might be a good focal lentgh for shooting handheld. Sadly I haven't discovered this forum earlier, as I just read that this lens might be total crap.

Today's available light was good enough for my first test run but later on as I developed my raws I recognized a lot of, I don't know, is that chromatic abbaration? Especially when recovering dark areas. In almost every backlight shot I recovered, there are these purple shades. (Sorry, I'm not yet familiar with photographis terms in the English language).

Now my actual questions are: Does this have something to to with the lens or is something wrong with my back? Are 12 bits per channel too less to effectively recover dark areas? Are the old Mamiya AF lenses "good enough" for the ZD Back?

P1 645AF + ZD Back + 45mm @ ISO 100, 1/80s, f/8

View attachment 37672

Here's a 100% crop of what I was talking about.

View attachment 37673

^^I hope this works.

Thanks for your info of any kind!

Max

 

[tim driver]

Max - I'm new here as well and still asking questions but the guys are very helpful and I'm sure you will get an answer quickly - Most are based in the USA so on a different timezone to Europe

Tim

 

[dougpeterson]

The phrase you are looking for is "purple blobs" - a google search for "Mamiya ZD purploe blobs" will uncover a lot of information about this.

 

[Jan Brittenson]

Looks like something is wrong with the back... did you buy it from a store? If so take it back! Off-hand I'd guess the coating on the IR filter is uneven or peeling.

 

[SergeiR]

The phrase you are looking for is "purple blobs" - a google search for "Mamiya ZD purple blobs" will uncover a lot of information about this.

Well i am not getting those with mine.

 

[SergeiR]

Max, welcome to forum

ZD is not very well handling pulling of shadows, in fact most of MFDbs are, except may be for newest ones (havent touched P65+ yet.. or newest Leafs.. MUST RESIST TEMPTATION).
Looks like you did that in the image, to even out contrasts between sky and road.

And secondly - what you used to process RAW?

And thirdly - what white balance setting you used? (yes it does matter for even for RAW, trust me on this one)

 

[MaxKißler]

Thanks guys.

I used the automatic white balance and later corrected it with Lightroom. I didn't know that white balance had an impact on raws. Good to know.

Unfortunately I bought the back on ebay so there's no chance for an easy fix...

Could it be possible, that the sensor is just dirty as hell? I have discovered a lot of dust particles on the sensor's surface. Sadly I can't yet clean it.


Sergei,

don't you get these "blobs" when recovering a severely underexposed image?
Now you obviously own a ZD Back, how are your experiances with long exposures?

 

[dougpeterson]

ZD is not very well handling pulling of shadows, in fact most of MFDbs are, except may be for newest ones

That's absolutely untrue. Even a 2003 vintage Phase One H25 or 2004 era Leaf Valeo 17 can pull enormous (clean, color accurate, and natural looking) detail from deep underexposed shadows. That's one of the major advantages to use a digital back. That said: not every digital back is created equal...

 

[Terry]

How under exposed were the shadows. Can you post a sample of the shot before you boosted the shadows?

 

[dougpeterson]

Thanks guys.

I used the automatic white balance and later corrected it with Lightroom. I didn't know that white balance had an impact on raws. Good to know.

Unfortunately I bought the back on ebay so there's no chance for an easy fix...

Could it be possible, that the sensor is just dirty as hell? I have discovered a lot of dust particles on the sensor's surface. Sadly I can't yet clean it.


Sergei,

don't you get these "blobs" when recovering a severely underexposed image?
Now you obviously own a ZD Back, how are your experiances with long exposures?

You may get better results in Capture One than LightRoom. However, I fear you may not find a great "fix" - this is a problem found/discussed by many (numerically - I have no idea % wise) ZD users, especially early in the life of the back - from my memory Mamiya addressed/fixed/improved it in later production, but to be clear I am NOT a ZD expert. I would contact your local Mamiya rep and see what their policy is. And read through the various threads that come up when you google "mamiya ZD purple blobs".

Hopefully you can get it resolved!

 

[SergeiR]

That's absolutely untrue. Even a 2003 vintage Phase One H25 or 2004 era Leaf Valeo 17 can pull enormous (clean, color accurate, and natural looking) detail from deep underexposed shadows. That's one of the major advantages to use a digital back. That said: not every digital back is created equal...

Doug - i tried to pull shadows when was deciding between Phase One and Leaf, about year ago. And i seen Drew Gardner doing same on his DVD with his P45+. Its getting real ugly real fast. May be these are just two occasions (well ok, i has same deal with Hassel, but i wont go there), i am sure you have access to wider array of gear than i am. So i am speaking purely from my personal experience - highlights - yes. Shadows , while it can pull out more details in general (having 16 bit of which 4 bits are roughly go to lower end of curve, so more details than dSLR) - pulling isnt something they are very good at. They do have more details from scratch, but if you go and pull them artifically - you getting "blooming" zones of weird colour noise, unless you getting it done with better RAW convertors (RAW Developer and C1 do come to mind - they handle it better.. just like Bibble used to be best for pushing highlights for about year, till everyone caught up ).

 

[SergeiR]

Could it be possible, that the sensor is just dirty as hell? I have discovered a lot of dust particles on the sensor's surface. Sadly I can't yet clean it.


Sergei,

don't you get these "blobs" when recovering a severely underexposed image?
Now you obviously own a ZD Back, how are your experiances with long exposures?

you can just get filter glass off the ZD back and use dust blower to clean. Just be carefull as there is real sensor surface under there ))

This is fairly unique feature of them - made them desired for IR photography for a while.

--

ZDs arent great with long exposures. I did up to 12s, and cleaned it in C1, and its somewhat useable.. But not in heat. Passive cooling makes this back lightweight , but prone to high temp == noise.

Oh and - i do not pull shadows on normal basis (and when i did - my ZD is more or less ok on those blobs, except for some weird and rare occasions). I hate doing that with dSLRs and i dont like it with MFDbs. Thats why we have flashmeters I dislike to be off even by as much as stop. Only time when i do underexpose on purpose - when i have to build up array of images like sky + river, for gluing them later together. Everything else - i'd rather adjust settings on camera or light power, or move a bit. Photography is all about light and shadows. Got to control them But get a trial of C1 - they indeed do much better job on these things and you get some extra control over things - like moire removal.

 

[MaxKißler]

I only have this problem when shooting directly towards the sun and later pull shadows. My light meter indicated an almost "proper" exposured and so did the histo on the back. However, these shadow areas might just be too underexposed?

Since this is my first digital back and the first time I took some pictures with it, I simply don't have the experiance on how far one can go.

Here are some examples.

View attachment 37701 View attachment 37702

@ Doug,

I checked other forums as you implied and begin to lose hope after all I read on Luminous Landscapes.

Now I just called Mamiya Germany and that guy said I should be using their software instead of C1 or LR. Somehow I don't think this will change anything...

 

[SergeiR]

Yeah, i thought about it a bit more when woke up this morning - most of those artifact-ish shadows you will ever get - will be in contra-light. In normal conditions you can get 2 stops out of shadows easy.

PS: Mamiya got actual software for backs? Oy..
But seriously - try C1 and instead of just getting expsure comp - try their shadow/highlight tool. It does wonders sometime.

 

[SergeiR]

I checked other forums as you implied and begin to lose hope after all I read on Luminous Landscapes.

Yeah, if you got to shoot for real you cant do it with anything less than arca cube, newest and greatest gear & etc.

Or you can just shoot and enjoy it, working around limitations of your gear, while growing into new one. Choice is always yours

- almost contra-light ZD on RZIIProD, with 140mm lens (while i couldnt figure how to get RZ to work with Leaf )

- controlled light ZD on AFDIII (my Leaf was away for upgrades/calibration at MAC)

- controlled light , ZD on AFD (one of first shots i made with ZD, when i got it)

 

[MaxKißler]

Sergei,

these are great shots indeed! If you might have plenty of spare time, would you please be so kind and do some tests with your back. I mean, if yours can pull details out of shadows comparable to mine above, we know for sure that my back is malfunctioning.

Apart from that, I better live with these limitations which definitely won't stop me from enjoying this camera system. It's so much fun to take pictures with it.

 

[SergeiR]

Dallas got rainy days for whole week in forecast, but i will try to see what i can do with flashes - tonight or tomorrow.

I dont really think you got any unique issues there - remember that asphalt on the road is pretty much gray, so when you starting to pull it - RAW processor will try to "invent" colours sometime, if it feels like there should be some colour

 

[MaxKißler]

Thanks a lot Sergei,

I guess it is nothing to worry about since I'm not using it commercially anyway. I would love to know how a back with 16 bits would handle equal conditions.

I would really appreciate if you could do some tests with your back!

 

[Valentin]

...
But seriously - try C1 and instead of just getting expsure comp - try their shadow/highlight tool. It does wonders sometime.

I agree that the software plays a big part on the outcome. Also, I've seen people having problems in LR and after creating a custom profile with the DNG editor (free from Adobe), the problems disappeared. The problems were similar to yours but the blotchines was not purple.

 

[dougpeterson]

I dont really think you got any unique issues there - remember that asphalt on the road is pretty much gray, so when you starting to pull it - RAW processor will try to "invent" colours sometime, if it feels like there should be some colour

Again, when you pull up shadow detail the quality of the result depends very heavily on the quality of the camera/back you were using and the quality of the raw convertor. If you pull up shadows and get large blobs of green/purple worms it points to sub-part quality of either the camera/back or raw convertor.