Achromatic Plus B&W Digital Back...

[Bernice Loui]

Got a chance to stop by the local Phase One dealer to look at sample digital prints in both color and black & white. They were extremely generous with their time spending well over an hour with me showing me their products and sample images.

This was the first chance I got to look at the current digital medium format backs and the hardware/software related to the digital image production process.

While the color images were good, they failed to impress me. There is something about the contrast range that appears to me as mechanical and less than real. The medium format digital backs do deliver better contrast rendition and resolution than DSLR's and smaller formats, they still appear to me as a artificial and not natural.

The sharpness/resolution is OK, yet I cannot get over the appearance that edge contrast enhanced images produces un-realistic sharpness in the print... Even when these images were produced by RAW files.

They had a B&W specific medium format back, Phase One's Achromatic Plus. While it produces images that are the best digital B&W I have seen, they are still not at the level of really good silver gelatin glossy fiber base paper prints made with large format film larger than 4x5. Again, the sharpness/resolution appears to me as artificial and edge contrast enhanced (these images are produced from RAW files), contrast rendition appears very linear indeed, but not visually appealing and artificial..
http://www.achromaticplus.com/Achromatic_Plus/Achromatic+.html

The B&W prints viewed are digital prints made on both glossy & semi matt photo print papers.

Something remains lacking.. highlighting again the reality that film / digital have an inherently different look and result, good or bad.

Maybe it is me, maybe it is my built in bias from years and years of creating B&W silver gelatin prints from large (larger than 4x5) negatives made using some of the best optics, film, enlarger and etc..

Regardless, this is the current reality and my opinions in the long run may mean not much of anything.. From what I learned today, film in the commercial and majority of other imaging markets is pretty much history.



Bernice

[sanking]

Maybe it is me, maybe it is my built in bias from years and years of creating B&W silver gelatin prints from large (larger than 4x5) negatives made using some of the best optics, film, enlarger and etc..

Regardless, this is the current reality and my opinions in the long run may mean not much of anything.. From what I learned today, film in the commercial and majority of other imaging markets is pretty much history.



Bernice

We all have built in bias. I personally have a bias for hand made contact printing processes.

Whether you begin with film or digital capture, when you take an image into the digital world there are many more possible results than with purely analog methods. Some of these results are so different that they shock, some are much like what you can get with analog methods of printing. I personally find hybrid type printing a more interesting way of making prints because it opens up creative possibilities that are difficult or impossible with purely analog methods.

Sandy

[Nathan Potter]

Sandy reiterates my sentiments about the flexibility of using a hybrid workflow. Bernice I know what you are saying but the differences you mention are difficult to put into words for photographers.

I think the crux of the difference you see relates to differences in the microcontrast within feature edges. Some of this was touched on in other posts here but not really elaborated on. There was a suggestion that comparing digital pixel structure to silver grain structure might be a useful discussion. I think this is so and relevant to your observations.

For fine grained films a typical halide grain size might be 0.5 to 1.0 µm in size. Upon exposure it will grow some depending on the exposure dose; perhaps a factor of two or a bit more. Still a pretty small receptor of photons. Upon film development the growth is more dramatic as larger amounts of silver is formed around the original nucleation site. In shadow area the growth is slight; in highlight areas the growth can be factors of 10 to 100 in size - much more in volume. I suppose, in effect, this can be viewed as a variable dimension pixel. It is in practice a bit more complicated because color films have attached dye couplers to enhance color rendition and the colors may be in three layers, but the principles are the same.

On the other hand the digital pixel has a very fixed spacial dimension with state of the art being, I believe 5 to 7 µm in extent. There is from design and layout necessity a gap between pixels and mostly adjacent pixels alternate between RG and B in a Bayer pattern. The Bayer pattern imposes limitations on the sensor resolution due to lack of full color data for every pixel. This also holds for B&W digital capture but to a lesser degree.
Generally then the minimum pixel size to extract full disclosure of information for each pixel requires toggling adjacent pixels at least one on each side of the pixel addressed. The additional information is so called demosaiced to establish the probable color or B&W density of the pixel being addressed. Such an arrangement forces the equivalent digital pixel to be about 3 times the size of the 5 to 7 µm original.

Essentially the digital capture discretizes the array of pixels in the X and Y plane while the halide emulsion
smears the grains in X and Y thus yields a smoother microcontrast. One can usually detect the difference upon close inspection just as you have noticed. Analog contact printing reproduces the fine detail of the microcontrast to a stunning degree while enlargement may loose some of the microcontrast depending on the hardness of the light source.

I don't think I'm saying anything here that most at this site don't already generally have a sense of. I happen to make use of both phenomena depending on the image subject matter.

Nate Potter, Austin TX.

[jp]

There's a fair chance the printing process for the sample digital prints were enhanced/altered slightly as a normal workflow to tinker with sharpness/contrasts, etc... It could emphasize difference between this camera and it's digital competitors while creating artifacts noticeable to a silver print practitioner.

The camera back described does not do bayer.

[Bernice Loui]

They sent me a RAW sample file from this digital back.

If anyone is interested in tinkering with it or anyone local can make a highest quality print from it (I'll pay for the best print that can be made from it) .. I'll be interested to see it.



Bernice



There's a fair chance the printing process for the sample digital prints were enhanced/altered slightly as a normal workflow to tinker with sharpness/contrasts, etc... It could emphasize difference between this camera and it's digital competitors while creating artifacts noticeable to a silver print practitioner.

The camera back described does not do bayer.

[Bernice Loui]

Thanks Nate for the info.

It appears that part of the solution to this problem with digital is to make a far larger image sensor. This would increase the amount of image information when the image data is created. It all goes back to information theory, Nyquist–Shannon sampling theorem (no less than two samples to retrieve viable information), filtering to re-create the information and....

Once the actual pixel dimensions are up past 20 microns, the optics are no longer the limitation, the limitation becomes the sensor.

While increasing the amount of information and data is technologically possible, is there a market need or does the market have a demand for it?

All this reminds me very much of digital audio when it was initially believed that a sample rate of 44.1 Khz at 16 bits was more than good enough. Turns out, it is not nearly good enough for high definition audio. Problem with the 44.1 Khz sample rate turns out to be a low dispersion/constant group delay filter design and 16 bits is simply not enough once any processing is done.

Only time will tell if the imaging industry tries to move to higher definition.. which is likely market demand driven.



Bernice

[Ken Lee]

Perhaps the photos they showed you were different, but the images shown on their Fine Art Gallery (http://www.achromaticplus.com/Achromatic_Plus/Fine_Art_Gallery.html) page may not demonstrate the full aesthetic potential of their system. By analogy, to fully appreciate the sound of a Stradivarius or Guarneri we may require the performance of a virtuoso.

[Robert Hall]

It all seems like a lot of money just to post something on Facebook.

[Lenny Eiger]

We all have built in bias. I personally have a bias for hand made contact printing processes.
Whether you begin with film or digital capture, when you take an image into the digital world there are many more possible results than with purely analog methods.
Sandy

I also see this flaw in Bernice's logic. (With all due respect to Bernice and the many others here who would agree with her.) When I discovered platinum, I gave up darkroom printing. For me, there was no contest.

I have since done many other processes. None of them would or should be compared to a darkroom print. I can appreciate the liquid quality of the experience, but I don't like the dried result, an image encased in an emulsion, or as I call it, goop.

The fine art papers that alternative processes use add a lot to the image, IMO. Now that I am also printing with an inkjet, I get to use these fine art papers. The prints match up well to alternative process prints. I am currently printing my own images with Kozo, which is translucent and has some of downright luminescent effects. However, they don't have the image encased in a emulsion, so they don't actually compare. They need to be compared with a platinum print, or something similar.

To come back to the point, when you compare this camera, and a resulting inkjet print, it needs to be compared to the right kind of print, vs a darkroom print.

My guess is that the back is probably pretty good. It looks like it's a matter of getting the right filter on the front for the correct spectral response. Of course, $45K is too much for a camera, IMO, unless you are shooting catalogues. Especially for one that will be obsolete very soon. It seems a very good way of going broke after very few iterations of new cameras every 3 years or so. Then there's being tethered, tilt shift lenses for the 645 - missing (I'm not sure about this)? and everything else...

I want one, but after about 6-10 iterations when the price goes down and they can go untethered, get stuck on my 4x5. Wait, I have a 4x5 already. And it works really well with that Ilford film I use. Why are we talking about this?

;-)

Lenny

[Nathan Potter]

Thanks Nate for the info.

It appears that part of the solution to this problem with digital is to make a far larger image sensor. This would increase the amount of image information when the image data is created. It all goes back to information theory, Nyquist–Shannon sampling theorem (no less than two samples to retrieve viable information), filtering to re-create the information and....

Once the actual pixel dimensions are up past 20 microns, the optics are no longer the limitation, the limitation becomes the sensor.

While increasing the amount of information and data is technologically possible, is there a market need or does the market have a demand for it?

All this reminds me very much of digital audio when it was initially believed that a sample rate of 44.1 Khz at 16 bits was more than good enough. Turns out, it is not nearly good enough for high definition audio. Problem with the 44.1 Khz sample rate turns out to be a low dispersion/constant group delay filter design and 16 bits is simply not enough once any processing is done.

Only time will tell if the imaging industry tries to move to higher definition.. which is likely market demand driven.



Bernice

Large area sensors absolutely need a market to be cost effective to the consumer/photographer. There is an important market already existent, and that is the medical xray imaging industry. There are at least several suppliers of x-ray cassettes for hospital scanning systems. Sizes can be up to 14 X 16 inches or so at down to 50 µm pitch. These would not be too shabby for ULF applications (of course only in B&W). The cost for one cassette now runs about $1000 to $1500. A cassette would be good for perhaps 20000 to 40000 lifetime cycles. Of course one needs a reader with software to dump the data to a computer.

But I think using these for large format is a viable option as I have mentioned here previously. There are limitations using visible light since they are designed for x-ray absorption. I think the most common sensor uses amorphous Si with a scintillator in order to convert high energy x-ray photons to visible light that can then be detected by an amorphous Si type device. However I suspect it would be a simple step to remove the top scintillator material (or not apply it in the first place) and just use the CMOS device for visible light. This would require no special fabrication line beyond what is used currently. The substrate in the case of amorphous Si active devices can be inexpensive glass. The basic design of the current panels require a very thick depletion layer for the capture of higher energy x-rays (100µm for 10,000 eV) but that would be easily compatible with the the penetration depth of visible light of 0.1 to 10 µm. There is refinement of process going on continually with some amorphous pixel pitches down to 30 µm or so. I think we are closer to large area B&W sensors than some realize.

Having come from the IC industry I can see an 8X10, 25 µm pixel pitch sensor (80MP) right on the horizon especially since the medical x-ray industry is being fiercely driven to provide better x-ray resolution, lower noise floor and higher contrast. In fact x-ray phase contrast technology is a recent very hot area.

Nate Potter, Austin TX.

[Peter De Smidt]

Having a preference isn't a logical flaw.

[Lenny Eiger]

Having a preference isn't a logical flaw.

Peter,

Maybe I can put this another way. It's Fri, been a long week... I'm tired and maybe not communicating clearly.

I don't think that inkjet prints can be compared to darkroom prints, as the image in a darkroom print is encased in an emulsion and in the inkjet it is clearly not. I don't question Bernice's, or anyone else's, preference. I am just saying that inkjets compare to other types of printing where the emulsion, if any, is not so apparent.

Just an opinion....

Lenny

[Jim Galli]

Personally, I'm appalled that someone selling high end digital backs would state that film is 'history'. :rolleyes:

[Peter De Smidt]

It doesn't follow that because two things are different that they can't be compared. In fact, to say that they're different requires that you compare them!

But I get Lenny's point. They two types of prints have a different aesthetic. Edward Weston compared platinum prints and silver gelatin prints and preferred the latter. Lenny prefers the former, and that's perfectly alright.

[carl geyer]

I think sereral things in the digital world have a profound influence on the overall image quality of the print.

1. Diffraction limits: Due to a smaller size CCD, there are diffraction limits. A full frame 35 mm is usually limited to f8 or f11. Hence, the cost of faster lenses. I usually use a Zeiss 25mm/f2 and a 35mm/f2.

2. Pixel size per CCD: The larger the pixel size, the better the resolution. With the correct lens and a smaller f stop, the better the resolution. The human eye can discriminate 40-50 lp/mm. Anything greater than that resolution is generally overkill. Remember those tests were done on a control population that was younger than the average reader of this forum.

3. Depth of field is greater with a smaller CCD. With a lens perpendicular to the film plane, this is an unbroken law. Hence, camera movements.

4. The advantage of digital: In this day and age short of contact prints, all of us do some form of digital capture. Photoshop CS6 and Lightroom 4 work on 64 bit. All film scanners cannot go beyond 32 bit or a limited to CS5 and Lightroom 3.

5. The new frontier in digital will be mirrorless cameras and larger CCD's. The larger CCD's will probably be DSLR cameras. Two new Zeiss lenses are being manufactured to embrace this technology.

Although I still have a 4 x 5 Canham, the Nikon 800e plus the correct lens is a great way to produce a digital image. Large format is limited by the accuracy of focusing. Digital cameras have to have extremely sharp focus. The bottom line is that any camera is just a tool. The final image is merely a reflection of what we see.

[Bernice Loui]

This is very much an experiment and learning experience for me. I'm still trying to figure out,

*What is the current state of the art digital for both B&W and color.

*What are the resulting images like compared to old analog methods of Silver Gelatin, Cibachrome/Ilfordchrome, C-prints and etc..

Comparing other print making technologies to silver gelatin should be expected due to it's history and being so common for so long.


If Lenny or anyone else is willing who, the sample Achromatic Plus image file can be forwarded to them to make a proper print as an example of what this current image work flow can produce. I simply do not have the experience, knowledge, skills with digital imagine to make this technology result in a high quality print.
I do know something about information theory, how it works and what it is possible. In theory digital imaging can exceed film based images for fidelity, but this is theoretical, and may not hold true in reality-practice.

Bernice

[Lenny Eiger]

If Lenny or anyone else is willing who, the sample Achromatic Plus image file can be forwarded to them to make a proper print as an example of what this current image work flow can produce. I simply do not have the experience, knowledge, skills with digital imagine to make this technology result in a high quality print.Bernice

Bernice,
The best scenario would be to have a digital neg made, and then have someone make a darkroom print from that. That would be a more accurate comparison to a darkroom print... Of course, one could also make an alt process print of an image, and then make something similar using inkjet...

However, it is likely we are destined to meet soon. We are both part of the Bay Area Large Format Photography Meetup Group. I haven't attended much lately as I live in the North Bay (Petaluma) and a lot of the outings are down South... If you are ever up this way, by all means, give me a call and visit my studio... I can show you what is possible with alt process vs inkjet printing... I had the whole group over here last year. It was fun...

Lenny

[sanking]

I think sereral things in the digital world have a profound influence on the overall image quality of the print.

2. Pixel size per CCD: The larger the pixel size, the better the resolution. With the correct lens and a smaller f stop, the better the resolution. The human eye can discriminate 40-50 lp/mm. Anything greater than that resolution is generally overkill. Remember those tests were done on a control population that was younger than the average reader of this forum.




At close viewing distance (10 inches/25 centimeters) the resolving power of a young human eye ranges from about 5 lpm to 20 lpm. An image that contains more than 25 lpm has more detail than the unassisted eye can ever see.

To put this in perspective, the resolution of inkjet printers at 360 dpi is about 7 lpm, at 720 dpi it is about 14 lpm. If you are over 40 years of age it is highly unlikely that you can resolve even 7 lpm at viewing distance of 10 inches, without pulling out the magnifying glass of course.

The issue that many do not address is that in order to get real resolution of 720 dpi on a print size of 16X20 or larger from a 4X5" negative you must begin with at least 4000 dpi of real resolution in the negative, assuming you are able to capture it with a high level scanner. So regardless of how much you rezz up a digital file, if the detail was not there to begin with, it will not be there when you finish rezzing up.

Same issue for printing analog negatives optically. An enlarging lens can not print detail that is not there to begin with, and very few 4X5 negatives or transparencies contain over 80 lpm (4000 dpi) of real information.

Sandy

[carl geyer]

This article has been posted in the past, but may shed some light to the above discussion. Tim Parkin looks at the above issue with certain controls to compare the many limiting factors on both film and digital systems:

http://www.onlandscape.co.uk/2011/12/big-camera-comparison/

[Jim Andrada]

I may be wrong about this but if the B&W back is the same one I looked into a few months ago it was my understanding that there was no Bayer filter.

[Bernice Loui]

Hello Lenny,

I'll give you a call to visit next time we are up in that part of the Bay Area for a visit. This would be a good thing in many ways.

The next scheduled meet up is in March, I'm planning to be there and it will be the first time for me... with varying degrees of apprehension not knowing much about the folks at Meet up and ...



Bernice.



Bernice,
The best scenario would be to have a digital neg made, and then have someone make a darkroom print from that. That would be a more accurate comparison to a darkroom print... Of course, one could also make an alt process print of an image, and then make something similar using inkjet...

However, it is likely we are destined to meet soon. We are both part of the Bay Area Large Format Photography Meetup Group. I haven't attended much lately as I live in the North Bay (Petaluma) and a lot of the outings are down South... If you are ever up this way, by all means, give me a call and visit my studio... I can show you what is possible with alt process vs inkjet printing... I had the whole group over here last year. It was fun...

Lenny

[Lenny Eiger]

The next scheduled meet up is in March, I'm planning to be there and it will be the first time for me... with varying degrees of apprehension not knowing much about the folks at Meet up and ...Bernice.

Bernice,
I guarantee you will be pleasantly surprised. They are one of the nicest groups I've been involved in. A lot of great people, happy to help, share, etc. I was very surprised - I wasn't expecting to enjoy it as much. Don't know if I am going to make it there for the 23rd or not.. its a maybe.-- Lenny

[bob carnie]

First thing that popped into my head, put the equipment in competent hands and I do not think the OP would notice the difference. btw not dissing the operators but I have seen the posters at some of the phase dealerships and they are not usually great prints.


There's a fair chance the printing process for the sample digital prints were enhanced/altered slightly as a normal workflow to tinker with sharpness/contrasts, etc... It could emphasize difference between this camera and it's digital competitors while creating artifacts noticeable to a silver print practitioner.

The camera back described does not do bayer.