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Author Topic: OK, I Give Up  (Read 7162 times)

Kevin Gallagher

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OK, I Give Up
« on: May 23, 2017, 02:46:43 pm »

 I just received an email from Phase One touting this new (I Think!) "iXG Cultural Heritage Camera System". It looks to be a MF back and lens that you would mount on a copy stand to, I guess, make copies of something. But for the life of me, the "Cultural Heritage" moniker just does not compute. What am I missing?

  Thanks Gang,

 Kevin in CT
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Doug Peterson

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Re: OK, I Give Up
« Reply #1 on: May 23, 2017, 02:54:45 pm »

I just received an email from Phase One touting this new (I Think!) "iXG Cultural Heritage Camera System". It looks to be a MF back and lens that you would mount on a copy stand to, I guess, make copies of something. But for the life of me, the "Cultural Heritage" moniker just does not compute. What am I missing?

That's understandable. It's a niche term, so if it's not ringing any bells it just means you aren't living in that niche world! :)

The term "Cultural Heritage" (in this context) refers to museums, libraries, archives, universities, art reproduction facilities and similar. Their mission is to protect, preserve, and propagate our shared cultural heritage (Wikipedia: "the legacy of physical science artifacts and intangible attributes of a group or society that are inherited from past generations, maintained in the present and bestowed for the benefit of future generations."), and part of that mission is digitization (a scan or photo or other digital representation of a real world object like a document, photographic film, statue, artifact etc).

See also: DT Division of Cultural Heritage.

The iXG would make a pretty terrible sports camera or portrait camera, but it does phenomenally well at sitting on a copy stand, pointed down, capturing hundreds or thousands of images per day for years at a time. That's a use case general-purpose cameras like a Canon or Nikon dSLR can be used for, but are a bit fish-out-of-water. For example on a general purpose SLR the focus of the lens tends to slowly drift when pointed downward. You can ameliorate that somewhat by adding a rubber band, but even then the trend is that the lens will "settle in" to the elastic stretch of the rubber band over a period. The iXG focus system uses a linear slide with 6 micron accuracy and repeatability and zero slip.

Other examples of the Phase One iXG Camera specialization for copy-stand work:
- There is no grip, no top LCD, no battery, and no CF card slot
- The shutter is warrantied for a million captures
- It's native operation is via a self-locking lemo AC power cable (most general purpose cameras have an option to run off AC but do so through a flimsy port that is easy to have come off accidentally)
- Every single feature is controllable remotely within Capture One; in fact it's assumed the user will rarely, if ever, touch the camera itself
- It can do contrast-based autofocus within Capture One for absolute precise focus, it uses specialized Schneider lenses designed for high resolution flat-field reproduction imaging.
- Every lens/camera combo is tested for absolutely perfectly alignment (both lens-internal alignment and the alignment of the lens to the sensor)
- It pairs with Capture One Cultural Heritage Edition
- It has an extremely heavy duty L bracket built in to it's native design, which is extremely precisely made to be perpendicular to the camera.
- There will be some very cool features that integrate it with DT Copy Stands like the DT RGC180 and DT RG3040 and DT Atom; more details on that when they are ready to release.

In the last decade there has been a massive shift among institutions of cultural heritage institutions away from legacy flatbed scanners and planetary scanners toward instant capture solutions (taking pictures of things with cameras). The former are slow, low in image quality, and lack modern software and features. The latter, when combined with cameras and software made specifically for the purpose offers high speed, great image quality, and a modern featureful software. Nowhere is that trend more pronounced than in film scanning where drum scanners and desktop film scanners are being replaced by systems like the DT Film Scanning Kit which is faster, produces better image quality, and has modern software and hardware support. This camera is a reaction to that trend away from scanners to cameras; the more you use cameras for high volume copystand work the easier it is to justify a camera system designed to rock at copystand work.

We also sell a good number of DT Rcam + XF kits to Cultural Heritage institutions. The advantage of that is the modularity; you can remove the digital back from the DT RCam (which is similar to the iXG in that it is designed for copy-stand work) and place it on an XF for more general purpose photography (e.g. to shoot an installation art piece or an architectural shot of the institution).
« Last Edit: May 23, 2017, 03:26:03 pm by Doug Peterson »
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eronald

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Re: OK, I Give Up
« Reply #2 on: May 23, 2017, 04:11:45 pm »

I just received an email from Phase One touting this new (I Think!) "iXG Cultural Heritage Camera System". It looks to be a MF back and lens that you would mount on a copy stand to, I guess, make copies of something. But for the life of me, the "Cultural Heritage" moniker just does not compute. What am I missing?

  Thanks Gang,

 Kevin in CT

It means 'MONEY NO OBJECT'

Edmund
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Kevin Gallagher

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Re: OK, I Give Up
« Reply #3 on: May 23, 2017, 04:26:25 pm »

  Hi Doug and thanks for taking the time to put forth a thoughtful and informative post! It sure explains everything to me. Hi also Edmond, I bet it is a Money Is No Object kind of thing, but for a museum or some such, it's the cost of doing business. Doug again, thanks also for the links to the copy stands, they were also very enlightening.

 Thanks again to you both!

 Kevin in CT
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Kevin In CT
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Endeavour

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Re: OK, I Give Up
« Reply #4 on: May 23, 2017, 05:01:43 pm »

For example on a general purpose SLR the focus of the lens tends to slowly drift when pointed downward. You can ameliorate that somewhat by adding a rubber band, but even then the trend is that the lens will "settle in" to the elastic stretch of the rubber band over a period. The iXG focus system uses a linear slide with 6 micron accuracy and repeatability and zero slip.


or you could save money on the rubber band by mounting horizontally

;)
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eronald

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Re: OK, I Give Up
« Reply #5 on: May 23, 2017, 05:05:14 pm »

  Hi Doug and thanks for taking the time to put forth a thoughtful and informative post! It sure explains everything to me. Hi also Edmond, I bet it is a Money Is No Object kind of thing, but for a museum or some such, it's the cost of doing business. Doug again, thanks also for the links to the copy stands, they were also very enlightening.

 Thanks again to you both!

 Kevin in CT

If museums really wanted scientifically useful imagery, they would go for hyperspectral acquisition - color information is more useful than absolute resolution.

Edmund

Edmund
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yaya

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Re: OK, I Give Up
« Reply #6 on: May 23, 2017, 06:21:20 pm »

color information is more useful than absolute resolution.

For certain applications, yes
For certain applications, colour is 100% meaningless
For certain applications, resolution is king
For certain applications, sensitivity at specific wavelengths is key
For certain applications, it's all about workflow and productivity
These all fall inside the CH realm and we make the products that accommodate most if not all of them.

Yair
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eronald

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Re: OK, I Give Up
« Reply #7 on: May 23, 2017, 08:44:46 pm »

For certain applications, yes
For certain applications, colour is 100% meaningless
For certain applications, resolution is king
For certain applications, sensitivity at specific wavelengths is key
For certain applications, it's all about workflow and productivity
These all fall inside the CH realm and we make the products that accommodate most if not all of them.

Yair

So where is the multispectral product line?

Wait - I know, it's top secret and export-controlled, if the chinese got their hands on it they could scan the walls of the Imperial Palace :)

The amusing thing is that the only decent repro cameras I've seen really were repurposed remote-sensing units.

Edmund
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Doug Peterson

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Re: OK, I Give Up
« Reply #8 on: May 23, 2017, 11:45:13 pm »

So where is the multispectral product line?

https://dtdch.com/dt-rcam-multispectral-camera/

https://dtdch.com/multi-spectral-imaging-solution-display-ala-expo/

Note that this is based on the older IQ260 Achromatic and we've recently added an IQ3 100mp Achromatic and iXG 100 Achromatic which will be the basis for most of our multi spectral systems moving forward.
« Last Edit: May 23, 2017, 11:50:07 pm by Doug Peterson »
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scyth

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Re: OK, I Give Up
« Reply #9 on: May 24, 2017, 12:25:36 am »

or you could save money on the rubber band by mounting horizontally

;)

not sure what is the issue with a prime AF lens refocusing each time using CDAF on dSLM (or even dSLR) - drift as much as they want in between...
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RandB

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Re: OK, I Give Up
« Reply #10 on: May 24, 2017, 02:36:50 am »

Doug demonstrated the DT Film Scanning Kit for me, and it is no exaggeration to say it is a massive advance on previous film scanners. We compared my Imacon scans of 35mm, 645, and 4 X 5 transparencies, and the superior sharpness and dynamic range of the DT Kit results were immediately obvious. What is more, you can complete all image adjustments on the RAWs before rendering a TIFF. And the workflow is 400% faster.

Randy
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Doug Peterson

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Re: OK, I Give Up
« Reply #11 on: May 24, 2017, 10:02:15 am »

not sure what is the issue with a prime AF lens refocusing each time using CDAF on dSLM (or even dSLR) - drift as much as they want in between...

That's a great question and one I wondered years ago when I started working on products in this niche. The short answer is:
- Jitter
- Wear and tear
- A 99.99% success rate in CH is not good enough

Cultural Heritage volumes and standards pose interesting challenges to methods that would work very well in more generic settings.

Digitization image quality standards are usually set quite high and judged through numerical analysis of a target left aside of the object. Sharpness is judged by three points on an SFR curve and must be what could be colloquially called "extremely sharp" at all points within the frame (safeguards are in place to prevent a camera from passing by virtue of adding a bunch of sharpening after capture). Good modern general-purpose AF systems are very accurate and very reliable. But say they achieve "good" focus 99.999% of the time and "nearly perfect" focus 99.99% of the time, that still means that an institution like NYPL's Digitization Lab (who have something like a half dozen of our systems) would generate over 50,000 mis-focused pages per year because "good" focus is not acceptable (because even slight misfocus will result in dropping below the FADGI guidelines for image quality. Every page that is discovered to not meet standards is devastating from a workflow point of view because the book has to be recalled/re-imaged, the new image has to be manually swapped out in the collection management system.

Cultural Heritage digitization, especially of works-on-paper is a manufacturing process (see our Process Control for Cultural Heritage Workflows) where eliminating variables is king, and productivity (while maintaining strict quality standards) is paramount. It's really not "photography" in the creative arts sense; it's using a camera (and bench, light rig, etc) as an industrial-grade imaging device. The emphasis on creating an ideal static setup and then not worrying about it is so intense that there is even terminology associated with each phase of it. Setting up for a given PPI and lighting style is known as preflight and the step-and-repeat portion is known as production. During production you want nothing to change other than file names and the object in front of the camera. Note these terms used in our Cultural Heritage Preflight and Production.

When doing bound materials such as books or diaries there is an additional issue that the very slight variation in focus distance from one shot to the next can create a "jitter" when flipping through the pages. This isn't a big problem but it's not desirable. Ideally you want the PPI (aka magnification, aka focus+distance) to be identical from one frame to the next.

The slight delay caused by the autofocus isn't huge, but every fraction of a second starts to add up. Production rates on a BC100 for example are spec'd at 1200 pages per hour (one page every 3 seconds). So even an increase of 0.3 seconds per page drops production 10% which isn't profound, but certainly not where I'd chose to lose 10%.

Finally, AF motors break. If the camera refocuses for every page that is a lot of wear and tear. Many institutions have dedicated staff that work the entire shift at a digitization station and production rates of many thousand per day are not uncommon, especially for book scanners. It's also the case that equipment often does not last as long in the pointed-straight-down orientation, presumably because of the engineering is done based on the camera pointing straight out (as 99.9% of all Canon/Nikon/Sony cameras are usually used). It's pretty common to see dSLR shutters die before their expected longevity.

So in other words, if you were setting up in your garage to shoot your parents wedding album, diaries, and a few dozen love letters then AF would be a perfectly fine solution. But if you're setting up a station that's going to work its way through a collection of 30,000 postcards and 80,000 historical menus, and that's just the schedule for the first couple months... little things really start to add up.

Bottom line: When the numbers are big, small things matter.

---

Note that the world of museum object photography is quite different. There creative lighting that helps illuminant (pun intended) the viewer's understanding of the object is often encouraged and the production rate is usually much slower, affording the digitization staff more time per object. But the general public is usually unaware of the very low percentage of a collection that museum objects like statues represent. There are, by a few orders of magnitude, more book pages, letters, drawings, notes and other works on paper in Cultural Heritage collections than there are statues, large paintings, and dinosaur fossils.

Doug Peterson

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Re: OK, I Give Up
« Reply #12 on: May 24, 2017, 10:06:58 am »

Doug demonstrated the DT Film Scanning Kit for me, and it is no exaggeration to say it is a massive advance on previous film scanners. We compared my Imacon scans of 35mm, 645, and 4 X 5 transparencies, and the superior sharpness and dynamic range of the DT Kit results were immediately obvious. What is more, you can complete all image adjustments on the RAWs before rendering a TIFF. And the workflow is 400% faster.

Good to see you here Randy. I saw you joined GetDPI a short while ago as well. It's always nice when someone you know in real life joins an online community you participate in.

Doug Peterson

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Re: OK, I Give Up
« Reply #13 on: May 24, 2017, 10:11:24 am »

or you could save money on the rubber band by mounting horizontally

For art reproduction of large framed paintings this is not just a viable option it is usually the preference. It's more space-flexible (i.e. you can do an 80" x 60" painting without having to make a gigantic table that sits taking up most of a small room when it's not being used), and the quantity (a facility might shoot anywhere from 1 to a few dozen large paintings in a day but they will never shoot hundreds or thousands per day) are such that it's not terribly important how long it takes to mount the object to be ready for digitization.

But for a stack of a few thousand loose manuscript pages it's much faster to place them on a flat horizontal surface than to have to handle them on a vertical or near-vertical-reclined surface. I'm not aware of any US institution that captures works on paper in a vertical mount.

Doug Peterson

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Re: OK, I Give Up
« Reply #14 on: May 24, 2017, 10:36:31 am »

If museums really wanted scientifically useful imagery, they would go for hyperspectral acquisition - color information is more useful than absolute resolution.

As Yair says it depends on the use.

The most typical purpose of digitization at an institution is access and preservation (mutually reassuring goals).

A very small percentage of an institutions collection is on display publicly at any given time (or ever, for that matter). So for a researcher to access an undigitized item they must go physically to the institution to something like a Reading Room or Research Room and ask a staff member to go to the archive/storage/collections and bring the item physically to them. The problem with this is two-fold; it's very undemocratic (only rich or well funded researchers can fly across the world to see a particular piece in person) and it places wear and tear on the item (no matter how careful the handling is) which is an obstacle to preservation.

A FADGI-4 compliant scan creates a Preservation Digital Object which can be used as a surrogate to such in person access (i.e. in person visual assessment). The vast majority of researcher need is handled by replacing in person visual assessment. So FADGI 4 Compliant Digitization with high-quality RGB cameras with preservation-grade color profiles takes care of most researcher need.

It does NOT replace in person physical sampling (usually frowned on, but sometimes employed) or spectrophotometer analysis or XRay analysis or or or. To replace those multispectral or hypersectral imaging is invaluable and is done at many institutions, generally as an offshoot of the general-purpose digitization, and in much smaller quantities. Such techniques can help prove authenticity, can help trace provenance, can identify underpaintings, can show the inside of a mummy, can reveal otherwise faded or obscured content, can identify specific pigments or materials etc.

Doug Peterson

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Re: OK, I Give Up
« Reply #15 on: May 24, 2017, 10:39:26 am »

It means 'MONEY NO OBJECT'

Wouldn't that be nice? Our most typical Cultural Heritage client has to fight aggressively and consistently to get budget allocated for digitization capital expenses. If you've ever worked in government or a non-profit and worked to get a piece of equipment above a couple hundred dollars you know that there are a lot of hoops, paperwork, and politics involved.

But institutions do (correctly) tend to focus on the net cost of digitization rather than the cost-of-entry. For example "how much will it cost to digitize all of the historical menus in our collection?" which requires survey, pull, transport, and prepare the collection for digitization before it makes it in front of the camera, then post-process, upload, describe (metadata), report, and in some cases publicize after it is in front of the camera. So if you cheap out on the camera/capture station you're still spending all that money/overhead, but in return you're receiving lower quality and lower productivity.

“The percentage of overall cost of digitization at NYPL represented by capture and processing probably falls somewhere between 20 and 30%. This is an extremely rough estimate based on an estimated average salary and factoring in an estimate of average annual equipment cost.” – Eric Shows, Assistant Manager, Digital Imaging Unit, New York Public Library

So the cost of a purpose-made Cultural Heritage camera setup is very quickly amortized by better use of the staff and overhead. A flatbed scanner only costs a couple hundred bucks, but (even putting image quality, and handling considerations aside) are a fraction of the speed. You can even buy several flatbed scanners and have a single operator go around in circuits loading each one and you still won't approach the net productivity of one of our systems (and you'll have a dizzy operator).

See "The Minimal Cost of Imaging in the Full Digitization Chain" in Digitization Program Planning Guide for more on that topic.

gerald.d

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Re: OK, I Give Up
« Reply #16 on: May 24, 2017, 01:42:22 pm »

Doug -

"But say they achieve "good" focus 99.999% of the time and "nearly perfect" focus 99.99% of the time, that still means that an institution like NYPL's Digitization Lab (who have something like a half dozen of our systems) would generate over 50,000 mis-focused pages per year because "good" focus is not acceptable (because even slight misfocus will result in dropping below the FADGI guidelines for image quality"

Assuming you're referring to the 99.99% figure (it cannot by any stretch of the imagination be referring to the 99.999% figure), the implication here is that 50,000 pages represents 0.01% of the output.

That's 500,000,000 pages per year.

Across "half a dozen" systems, that's around 85,000,000 pages per system annually. There are 31.5 million seconds in a year.

Are you sure about these numbers?

I'm not challenging the rationale or viability of these systems here - everything you say apart from the numbers makes perfect sense to me.

Kind regards,


Gerald.
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Doug Peterson

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Re: OK, I Give Up
« Reply #17 on: May 24, 2017, 02:58:32 pm »

Doug -

"But say they achieve "good" focus 99.999% of the time and "nearly perfect" focus 99.99% of the time, that still means that an institution like NYPL's Digitization Lab (who have something like a half dozen of our systems) would generate over 50,000 mis-focused pages per year because "good" focus is not acceptable (because even slight misfocus will result in dropping below the FADGI guidelines for image quality"

Assuming you're referring to the 99.99% figure (it cannot by any stretch of the imagination be referring to the 99.999% figure), the implication here is that 50,000 pages represents 0.01% of the output.

That's 500,000,000 pages per year.

Across "half a dozen" systems, that's around 85,000,000 pages per system annually. There are 31.5 million seconds in a year.

Are you sure about these numbers?

I'm not challenging the rationale or viability of these systems here - everything you say apart from the numbers makes perfect sense to me.

Yes, looking at it now I have no idea where in the math I went wrong. I must have flipped decimal value and percentage at one (or two?) points?? Thanks for pointing it out as it is off by quite a bit.

Six stations might produce between 100,000 and 1,000,000 per year in a non-profit institution digitizing works on paper, depending on a variety of factors. In a commercial digitization facility (many of those use our systems as well) the quantity might be 2-4 times higher due to running multiple shifts and ability to directly incentivize the workers (i.e. cash bonuses for producing X pages that meet the quality guidelines).

If you're producing 500,000 images per year and focus is right 99.99% of the time you'll have a 50 mistakes per year.

Anyway, all of the numbers here are speculative. There are no institutions using autofocus-on-every-page in any meaningful production quantities. Looking at all this again, probably 99.99% focus reliability is a bit overconfident. But regardless, the overall point remains the same. CH (at least for works on paper) is image manufacturing. We're looking for 6 sigma like results. Every variable that can be controlled needs to be.
« Last Edit: May 24, 2017, 03:04:38 pm by Doug Peterson »
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scyth

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Re: OK, I Give Up
« Reply #18 on: May 24, 2017, 03:46:46 pm »

Production rates on a BC100 for example are spec'd at 1200 pages per hour (one page every 3 seconds). So even an increase of 0.3 seconds per page drops production 10% which isn't profound, but certainly not where I'd chose to lose 10%.

  ;D too much time with MF Doug... you probably know that on a static object any decent dSLM can refocus using CDAF & shoot several times per second...
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Doug Peterson

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Re: OK, I Give Up
« Reply #19 on: May 24, 2017, 05:04:23 pm »

on a static object any decent dSLM can refocus using CDAF & shoot several times per second...

Just curious, is copystand work part of your core work?
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