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Author Topic: This Test was completely flawed  (Read 69774 times)
Terry Mester
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« on: May 27, 2006, 02:25:51 AM »
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I reviewed the Web Article from the four Photographers regarding their experiments with different Digital Cameras / Lenses and 4x5 Inch Film Sheet.  Their undertaking had a major fatal flaw.  They didn't produce Optical Prints from the Film.  Instead, they just scanned the Film Sheet into their Computer which means that the original Resolution (86 Trillion) and Colour of the Film is lost.  Film has a Resolution of 6.9 Billion  Molecules of Dye per Square Millimetre, but this is only retained if the Picture Print is made using real Light -- not a Computer Scan.  The Attached File explains the inferiorities of Digital Photography.
« Last Edit: June 20, 2006, 05:59:28 PM by Terry Mester » Logged
michael
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« Reply #1 on: May 27, 2006, 06:31:17 AM »
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Well, now we know. Don't we?

I normally am polite and try and explain when someone is so off-the-wall as you are with this position. But, this is beyond the pale.

In a word – RUBBISH.

I won't delete this because even though it's total nonsense, I'm sure the discussion will be fun.  

I'm amazed that you actually have the temerity to post this unscientific drivil on a board where there are people who know what they're actually talking about.

Michael

PS: Have you ever compared a traditional enlarger made print with a good scanned inkjet of the same image? Have you even seen a Lightjet or Durst Lamba print from a good scan?

Likely not, or you wouldn't spout such indefensable nonsense.

PPS. The Flat Earth Society web site is over that way.

Michael
« Last Edit: May 27, 2006, 06:48:30 AM by michael » Logged
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« Reply #2 on: May 27, 2006, 06:58:21 AM »
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Michael
I suspect this thread is a practical joke and you've bitten. At the least it's psudo-science and misses the point of all the discussions on this website. You put enough disclaimers at the front of the test for most people to realize the limitations of it. Still it's the best test out there for all to use and criticize. You predicted the critics but said your skin was thick enough to take it. Believe me, when I speak for the thousands of "voyeurs" who come to this sight daily, we thank you for what was as scientific a test as was possible given the limitation of four independant professionals having to fund it by themselves.
Ken
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michael
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« Reply #3 on: May 27, 2006, 07:09:55 AM »
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I wish it were a practical joke.

This has been a heated topic of discussion on another board for the past few days. Someone brought it to my attention yesterday (Sorry, I don't have the link handy at the moment).

It is so outrageosly dumb that it would appear to someone knowledable as a joke, but regretably I believe that this person actually believes what he writes.

Michael
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« Reply #4 on: May 27, 2006, 07:44:20 AM »
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It's impossible to deny a negative. Let's move on to some practical discussion on how to get the best possible pictures with the tools at hand.
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Mark D Segal
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« Reply #5 on: May 27, 2006, 08:19:10 AM »
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Well, now we know. Don't we?

I normally am polite and try and explain when someone is so off-the-wall as you are with this position. But, this is beyond the pale.

In a word – RUBBISH.

I won't delete this because even though it's total nonsense, I'm sure the discussion will be fun.   ........................


Michael...............................

[a href=\"index.php?act=findpost&pid=66704\"][{POST_SNAPBACK}][/a]

If we don't make time for a bit of clowning around now and then, what is life? But this stuff is so obviously and outrageously foolish from the get-go it's best ignored.
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Mark D Segal (formerly MarkDS)
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« Reply #6 on: May 27, 2006, 08:21:36 AM »
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Sorry, but that's the funniest thing I've read in a long time and equating dye molecules to resolution really means that you've lost the picture! For starters, we all know the limits of resolution of what you record are down to the lens, and every time you make a film print (as you can see in any cinema) you throw resolution away.

What a wonderfully humourous way to start the morning! I Thank you!

Graeme
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« Reply #7 on: May 27, 2006, 11:28:10 AM »
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I have to agree with Michael. While it would be "nice" to have output, to what device? Optical printer? Get a room full of Lightjet and Lambda owners together and they will yell about which is better as quickly as a Mac versus PC or Canon versus Nikon group. Then the question could be "well what about Ink Jet" or "what about ink on paper". This could end up being another never ending cluster F%#K that diminishes from the initial work done. Buy the DVD, output the files as you like. End of story.
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« Reply #8 on: May 27, 2006, 04:39:10 PM »
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Film has a Resolution of 6.9 Billion  Molecules of Dye per Square Millimetre,

Nice stat -- but I note you carefully avoid discussion of how many individual dye molecules it takes to make the actual dye cloud that forms the grain dot in the image?  It takes 1,000 of them to make that cloud!

Let's do a little aritmetic... 6.9ee9 / 1ee3 = 6.9ee6 or 6900000.  But you still have three individual dye colors, so we need to divide that 6900000 by 3^2 or 9, which = 76667 color dots per sq mm.  Now we take the sqrt of 76667 to arrive at the linear resolution of film: 276 color dots per mm. 276 dots per mm means that your film can resolve about 276/2 or 138 lpmm maximum.   (Which BTW helps explain why even the best color film tapped out at around 140 lpmm for resolution...)

~~~

My stat: Kodak themselves claim most consumer color films can only resolve between 40 and 65 lpmm.  Even if you use the best figure, 65 lpmm = 130 dots per mm.  1mm/130 = .007mm or 7u. Hence, any digital sensor with a pixel pitch at 7u is essentially equal to the best color film in terms of resolution.  

Someone remind me, what is the pixel pitch of the P45 again?

Cheers,
« Last Edit: May 27, 2006, 05:14:03 PM by Jack Flesher » Logged

michael
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« Reply #9 on: May 27, 2006, 05:54:16 PM »
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The P45 pixel pitch is 6.8 microns.

Michael
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Ben Rubinstein
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« Reply #10 on: May 27, 2006, 06:05:11 PM »
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My stat: Kodak themselves claim most consumer color films can only resolve between 40 and 65 lpmm. Even if you use the best figure, 65 lpmm = 130 dots per mm. 1mm/130 = .007mm or 7u. Hence, any digital sensor with a pixel pitch at 7u is essentially equal to the best color film in terms of resolution.

Technically that would work but only for the same size of sensor/film. In real terms however I'm sure few would argue that a 39 megapixel back can outresolve 645 film eventhough they are the same size. Why is that given the same lens? Is it a grain thing?
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michael
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« Reply #11 on: May 27, 2006, 08:28:39 PM »
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Our recent Measuring Megabytes [/b]comparison answers the question very nicely, I think. Even though we didn't do a 6.9 billion molecule optical / chemical print.

God – don't you wish we actually did have molecular level imaging? (Just kidding folks; at the expense of our scientifcally challenged thread originator, whom I've notice hasn't returned for his spanking.

Michael
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Jack Flesher
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« Reply #12 on: May 27, 2006, 08:48:44 PM »
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Our recent Measuring Megabytes [/b]comparison answers the question very nicely, I think. Even though we didn't do a 6.9 billion molecule optical / chemical print.

Michael
[a href=\"index.php?act=findpost&pid=66754\"][{POST_SNAPBACK}][/a]

Yes it did and pretty conclusively IMO  

But even if you had done a 6.9 billion molecule optical/chemical print, you still would have received complaints --
« Last Edit: May 27, 2006, 08:53:45 PM by Jack Flesher » Logged

Terry Mester
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« Reply #13 on: May 27, 2006, 09:57:54 PM »
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Dear Micheal,

I'm assuming that you're the Photographer Michael Reichmann from the Article.  It certainly was not my intention to insult you or the others with my comments, and I do apologize if you were insulted.  Being a perfectionist, perhaps I'm a bit too over-scrupulous in how I like things to be done.  Now you referenced an Optical Photographic Print (made with the Enlarger) being of lower quality than a Digital Printer Print.  What SIZE were the Prints you referred to, and what was the Size and Speed of the Film used to make the Optical Print?


Quote
Well, now we know. Don't we?

I normally am polite and try and explain when someone is so off-the-wall as you are with this position. But, this is beyond the pale.

In a word – RUBBISH.

I won't delete this because even though it's total nonsense, I'm sure the discussion will be fun.   

I'm amazed that you actually have the temerity to post this unscientific drivil on a board where there are people who know what they're actually talking about.

Michael

PS: Have you ever compared a traditional enlarger made print with a good scanned inkjet of the same image? Have you even seen a Lightjet or Durst Lamba print from a good scan?

Likely not, or you wouldn't spout such indefensable nonsense.

PPS. The Flat Earth Society web site is over that way.

Michael
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michael
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« Reply #14 on: May 28, 2006, 12:02:06 AM »
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An interesting question under the circumstances.

I've done both B&W and colour printing in the chemical darkroom for about 30 years, finally closing my last darkroom in about 1998.

The answer to your question depends on the film format, though I've had literally billboard-sized blowups from medium format for advertising clients.

Assuming a high quality neg or transparency in all cases, and a fine-art application, I was never happy with larger than an 11X14" print from 35mm, or a 20X24" print from 6X6cm film. After that it seems that you're just enlarging grain, not displaying any additional real information.

Film speeds? Everything from ASA 2 (High Contast Copy film developed to continious tone back in the 1960's) to ISO 3200.

Why?

Michael

Ps: If you've never done any extensive darkroom work yourself, be aware of the potential pitfalls preventing achieving optimum image quality. These include...

- paralellism (or its lack) of the enlarger's head and base
- enlarging lens quality and allignment
- film flatness with glassless carriers.
- Newton rings with glass carriers
- paper flatness
- criticality of enlarger focus
- negative buckling from bulb heat
- use of the enlarging lens' optimium aperture (which may be at odds with having enough light to make a large print)
- eveness of illumination of the enlarging head
- resolution characteristics of the enlarging paper (and related limitations)
- loss of contrast when large prints are made, including reciprocity effects with related long exposures.

And, oh yes, did I mention film buckling? Speaking of which, medium format suffers from film flatness problems – big time, especially on the first shot after the roll has sat in the camera for more than 24 hours with a reverse curl.

And sheet film, well, did you remember to tap the holder to ensure that the film isn't buckeled in the holder? Nothing can screw up large format faster than buckled film, which happens more often than most LF photographers care to admit.

Digital prints on the other hand. Humm. Let's see. No film flatness problems, no buckling, no secondary optical path during the enlarging process, no focusing issues when enlarging, no Newton rings, no paralellism issues, no paper flatness issues.

Oh yes. Add to that an almost total lack of grain (noise) at all reasonable ISOs, no processing variability, no reciprocity failure, etc, etc.

I could go on. But, it's late, and I think (hope) I've made my point.

The good old days of film with it's superior quality? Uhh... No thanks. No way. No how.

PPs. Yes, I do still have a Canon 1V, as well as a film back for my Hasselblad. I do even occasionally shoot film, when its attributes are appropriate for a particular project. But, I would never go back to optical / printing in the chemical darkroom. Never.

Why? Image quality above all. Plus greater convenience, perfect repeatability, faster turn-around and lower cost. And finally, not having to work in the dark for hours (days) at a time breathing toxic chemical fumes. Give me a glass of Merlot in front of the computer screen any day.

M
« Last Edit: May 28, 2006, 12:04:19 AM by michael » Logged
Terry Mester
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« Reply #15 on: May 28, 2006, 12:11:29 AM »
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I'm afraid that you don't possess knowledge of Molecular Chemistry or the Physics of Light.  The numbers you suggested are impossible.  The Article Attached to my original posting explains in detail the matter of Resolution, and so I'm not going to reiterate those facts in this Reply.  You can download the Article to read.
It is not possible for there to be 1000 Molecules per Dye Cloud on lower Speed Films.  Kodak for their part hasn't even bothered to calculate the Resolutions of their Films.  In addition to that, Kodak and Fuji don't provide any information which they consider "proprietary".  As well, the question of Dye Clouds is a complete variable depending upon the Film's ISO, Shutter Speed and Aperture, the amount of light on the Subject and the number of Light Waves affecting given Molecules of Dye.  It is probably impossible to have 1000 Molecules forming a Dye Cloud even with a Film of 1000 ISO Speed.



Quote
Nice stat -- but I note you carefully avoid discussion of how many individual dye molecules it takes to make the actual dye cloud that forms the grain dot in the image?  It takes 1,000 of them to make that cloud!

Let's do a little aritmetic... 6.9ee9 / 1ee3 = 6.9ee6 or 6900000.  But you still have three individual dye colors, so we need to divide that 6900000 by 3^2 or 9, which = 76667 color dots per sq mm.  Now we take the sqrt of 76667 to arrive at the linear resolution of film: 276 color dots per mm. 276 dots per mm means that your film can resolve about 276/2 or 138 lpmm maximum.   (Which BTW helps explain why even the best color film tapped out at around 140 lpmm for resolution...)

~~~

My stat: Kodak themselves claim most consumer color films can only resolve between 40 and 65 lpmm.  Even if you use the best figure, 65 lpmm = 130 dots per mm.  1mm/130 = .007mm or 7u. Hence, any digital sensor with a pixel pitch at 7u is essentially equal to the best color film in terms of resolution. 

Someone remind me, what is the pixel pitch of the P45 again?

Cheers,
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Terry Mester
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« Reply #16 on: May 28, 2006, 12:26:08 AM »
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Thanks for the info.  Those top sizes for 35mm Prints sound correct from a Physics / Light perspective.  From your original comment it sounded like you were talking about a 4x5 Sheet.  I just wanted to verify what Film Size you were referring to.  I don't question for a second that it's more convenient to use Digital processing.  Commercial clients are also completely satisfied with Digital prints.  From a Personal Photography perspective -- i. e. people taking their important family memories -- Film Photography is the only smart route to take if you wish to ensure that you preserve your important Pictures for the future.  Computer Picture Files don't come with long-term guarantees.  Best regards.

Terry


Quote
An interesting question under the circumstances.

I've done both B&W and colour printing in the chemical darkroom for about 30 years, finally closing my last darkroom in about 1998.

The answer to your question depends on the film format, though I've had literally billboard-sized blowups from medium format for advertising clients.

Assuming a high quality neg or transparency in all cases, and a fine-art application, I was never happy with larger than an 11X14" print from 35mm, or a 20X24" print from 6X6cm film. After that it seems that you're just enlarging grain, not displaying any additional real information.

Film speeds? Everything from ASA 2 (High Contast Copy film developed to continious tone back in the 1960's) to ISO 3200.

Why?

Michael

Ps: If you've never done any extensive darkroom work yourself, be aware of the potential pitfalls preventing achieving optimum image quality. These include...

- paralellism (or its lack) of the enlarger's head and base
- enlarging lens quality and allignment
- film flatness with glassless carriers.
- Newton rings with glass carriers
- paper flatness
- criticality of enlarger focus
- negative buckling from bulb heat
- use of the enlarging lens' optimium aperture (which may be at odds with having enough light to make a large print)
- eveness of illumination of the enlarging head
- resolution characteristics of the enlarging paper (and related limitations)
- loss of contrast when large prints are made, including reciprocity effects with related long exposures.

And, oh yes, did I mention film buckling? Speaking of which, medium format suffers from film flatness problems – big time, especially on the first shot after the roll has sat in the camera for more than 24 hours with a reverse curl.

And sheet film, well, did you remember to tap the holder to ensure that the film isn't buckeled in the holder? Nothing can screw up large format faster than buckled film, which happens more often than most LF photographers care to admit.

Digital prints on the other hand. Humm. Let's see. No film flatness problems, no buckling, no secondary optical path during the enlarging process, no focusing issues when enlarging, no Newton rings, no paralellism issues, no paper flatness issues.

Oh yes. Add to that an almost total lack of grain (noise) at all reasonable ISOs, no processing variability, no reciprocity failure, etc, etc.

I could go on. But, it's late, and I think (hope) I've made my point.

The good old days of film with it's superior quality? Uhh... No thanks. No way. No how.

PPs. Yes, I do still have a Canon 1V, as well as a film back for my Hasselblad. I do even occasionally shoot film, when its attributes are appropriate for a particular project. But, I would never go back to optical / printing in the chemical darkroom. Never.

Why? Image quality above all. Plus greater convenience, perfect repeatability, faster turn-around and lower cost. And finally, not having to work in the dark for hours (days) at a time breathing toxic chemical fumes. Give me a glass of Merlot in front of the computer screen any day.

M
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DarkPenguin
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« Reply #17 on: May 28, 2006, 01:00:19 AM »
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*chomp*
From a Personal Photography perspective -- i. e. people taking their important family memories -- Film Photography is the only smart route to take if you wish to ensure that you preserve your important Pictures for the future.  Computer Picture Files don't come with long-term guarantees.  Best regards.

Terry
*chomp*

Film does?
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michael
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« Reply #18 on: May 28, 2006, 06:59:57 AM »
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Film does?
[a href=\"index.php?act=findpost&pid=66767\"][{POST_SNAPBACK}][/a]

Exactly.

First of all, I'm glad that the preposterous premise of billions of molecules is now behind us, or are you still riding that particular hobby horse?.

Colour transparency film as well as colour negatives have a very short life span. Most will fade to the point of unusability in a couple of decades at best. The only one with staying power is Kodachrome, which is regretably fast on its way to oblivion. (How many Kodachrome labs are left in the world? A half dozen?)

B&W film is better, maybe 100+ years, but only assuming that it's been archivally processed. Otherwise, again, just decades.

The real Achilles heel of film is that it is a single physical object, subject to loss and damage. A digital file though can exists in multiple copies. Lose or destroy one, and the others are unaffected.

Yes, data storage media are subject to deterioration and obsolecense, but by making new copies from time to time they can be made to literally last forever.

As for prints, well again you're wrong. Colour prints using chemistry are fugative. A typical C print will start to seriously fade after just a few decades. Cibachrome prints after about 50-70 years. Even Dye Transfers not much more.

On the other hand Epson inkjet prints using K3 pigment inks are rated by Henry Wilhelm (the industry standard) as 100 years+ on display, and much longer in dark storage. In fact an inkjet print made on cotton rag paper with K3 inks is the longest lived colour photographic reproducttion media ever! (Carbro prints are another story, but one that's only relevent to the 4 people left in the world who know how to make them).

B&W, is also another story. An archivally processed, selenium or gold toned B&W print made on silver gelatin paper (not RC) will last for hundreds of years. But (and it's a big but), with the exception of a limited number of very skilled darkroom workers who still make such prints, you're likely to never see them outside of galleries and museums, and certainly not with your family photographs.

So. We've debunked your mythology about the superiority of optical enlargements. Now we see clearly that chemical prints in fact don't last as long as inkjets, to "ensure that you preserve your important Pictures for the future".

Any more misinformation you'd like to share with us?

Michael
« Last Edit: May 28, 2006, 07:09:55 AM by michael » Logged
Mark D Segal
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« Reply #19 on: May 28, 2006, 07:05:14 AM »
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Thanks for the info.  Those top sizes for 35mm Prints sound correct from a Physics / Light perspective.  From your original comment it sounded like you were talking about a 4x5 Sheet.  I just wanted to verify what Film Size you were referring to.  I don't question for a second that it's more convenient to use Digital processing.  Commercial clients are also completely satisfied with Digital prints.  From a Personal Photography perspective -- i. e. people taking their important family memories -- Film Photography is the only smart route to take if you wish to ensure that you preserve your important Pictures for the future.  Computer Picture Files don't come with long-term guarantees.  Best regards.

Terry
[a href=\"index.php?act=findpost&pid=66766\"][{POST_SNAPBACK}][/a]

Terry, this got me piqued enough to ignore my own previous advice that this foolishness is best ignored. My photographic life is "personal photography" - and I have left film behind for good, except for about a thousand or so legacy images from my film days that I'm scanning so I can make prints from my Epson that are noticeably superior in every reespect to just about anything from a wet-lab. As for print permanence, you obviously haven't done your homework on this subject. Go to www.wilhelm-research.com and start reading, because you have a lot to learn.
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Mark D Segal (formerly MarkDS)
Author: "Scanning Workflows with SilverFast 8....." http://www.luminous-landscape.com/reviews/film/scanning_workflows_with_silverfast_8.shtml
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