Film vs. Scanning resolution

Helge · Aug 31, 2020

138S said:
Let me explain it.

Thread Tittle: Film vs. Scanning resolution

1) Depending on film resolution you require more or less scanning resolution.

2) We were evaluating the resolution of an image posted by you, that clock...

3) Here someone says: "A simple test to check the effective level of detail of an image file is to downsize it (e.g. in Photoshop) to see at which resolution the image loses image content details. You can download that crop, load it into Photoshop, set the resolution to 5400 ppi (without resizing) and then resize to lower resolutions. Resizing the scaled down image back to the original resolution and adding appropriate sharpness will help seeing which details can be retained and which are lost in the process."

I pointed that downsizing to the checked resolution is not rights,a safety margin has to be accounted, IMO.

Then insisting: "The other crop of the Minolta 5400ppi scan contains finer details and some higher contrast lines that spread just over a single line of pixels indicating that the effective resolution and level of real detail in that area is very close to the sampling resolution."
(https://www.photrio.com/forum/threads/film-vs-scanning-resolution.177544/page-5#post-2314547)

Then I aslo provide evidence that your image is not 5400 worth but half: the number of pixels it takes the transition of an edge: https://www.photrio.com/forum/threads/film-vs-scanning-resolution.177544/page-5

If you downsize the image to 2600 and later you inflate it to 5400 you have some loss (try it), bit this is not because the image is worth more than 2600, this is because point 3) is wrong or a bit coarse precision.

So this may be interesting because we debated that the shrinking-inflating is not an accurate test and that we have the (super peeping) edge transition criterion to evaluate if we are scanning at overkill dpi, but first we have to evaluate the scanner's native edge transition to be aware of when the scanner can be the limiting factor.

But if one wants to debate this seriusly in Nyquist terms, I'd be happy...

______

Let me add another (relatively close) analogy. Human hearing is band limited to 20KHz, but as audio is an arbitrary signal and because of that CDs are sampled at 44.1KHz, around 2F0, you have also 96KHz and beyond... suggesting that 2600 dpi are not to record 2600 effective, as it hapens when requiring 20KHz but having to sample 44, we can go into the detailed math of that, if wanted.

______

All of this is interesting to realize what true scanning performance we require to exhaust what shots have. The Serger's Porsche in CMS and is challenging the hassie at its 35mm sweet point !! But this is not the usual situation, by far.

You provided zero evidence.
A. It was not a rigerous test situation, with a shot from at test chart with known features and known contrasts.
It was an image that relies on a sane, sympathetic (to the viewing) viewer, skilled in the art of looking at high magnifications of photos.
B. It is very obvious that the photo isn't scanned to it's fulled resolving potential, due to lack of any real visible grain, but lots of grain aliasing. Any transition edges, is no indication of anything other than physical features we can know very little about.
C. No one except for the poster thought the scaling idea was a good way of determining real resolution.
That might be a trick for artificial images, but for anything photo, it's too fraught with multiple obvious problems.

That said, the clock face marks and wires in the second crop is still clear evidence of an image of a very high resolution.

The trouble with posting anything online of this type, even photos of test charts, is that there is always the implied possibility of cheating, and people who think they have a different interpretation.

But now you have four learned, experienced guys, with good report, many realworld links and reputation on the line, telling you as clear as they could possibly, that it's not "just" CMS 20 II that is has far better resolution than your ridiculous cited 2600 dpi, but almost any film worth taking seriously!
And yet you persist?
How can anyone take that seriously?
It's almost as if you don't want film to have high resolving power, for some odd reason?

Lachlan Young · Aug 31, 2020

Helge said:
But now you have four learned experienced guys, with good report, many realworld links and reputation on the line, telling you as clear as they could possibly, that it's not "just" CMS 20 II that is has far better resolution than your ridiculous cited 2600, but almost any film worth taking seriously!
And yet you persist?
How can anyone take that seriously?
It's almost as if you don't want film to have high resolving power, for some odd reason?

The answer, 'fraid to say, is that the aforesaid individual you refer to can't handle the idea that the Epson he has constructed such lengthy paeans to may actually be a wee bit more than just a bit rubbish in just about every aspect of its useful (as opposed to hypothetical) optical performance. All those words, all that firehosing, is trying to cover that up - along with a loudly broadcast set of factually errant claims about so much of the rest of the fundamentals of the photographic process to such an extent that it seems increasingly intentional (the latest example being the denial of the Gaussian distribution of visible granularity in a particular film - and that it relates to where the film's characteristic curve places the midrange - not where 138S wishes it was).

Lachlan Young · Aug 31, 2020

SCHWARZZEIT said:
While I originally planned to replace my drum scanner with just the HXY scanner, it turned out the difference in rendering from the softer tonal transitions of the drum scanner are reason enough to keep the drum scanner as an option for clients preferring that particular output. Quality is not always about resolution. And sometimes a softer rendering with appealing character is preferable over an accurate sharply rendered presentation of the film grain where the added resolution leads to harsher tonal transitions.

This is very interesting - I've seen this self same sort of granularity effect when going from 6300ppi mode to 8000ppi mode on a Hasselblad/ Imacon - and it's certainly quite striking how 8000ppi scans compare to optical darkroom mural prints made with optimised lenses in terms of tonal transitions/ granularity representation.I think there's a lot to do with sharpness/ tonal transition as you say.

grat · Aug 31, 2020

When I originally posed the question, it was because I was considering how to proceed with negative scanning. Personally, I want to be able to scan 4x5 negatives, as well as 120 (anywhere from 6x6 to 6x17). Scanning 35mm isn't out of the question, but not a priority.

So the question was, how close is 2600 DPI to what I want for "maximum detail" for a film such as 400H? If, as it seemed, it was 3200 DPI, then there's not much point in investing in a new system. If the answer is closer to 6400, for instance, then perhaps it's worth it.

But apparently, I have asked how long is a piece of string. Everyone appears to have not just their own interpretation of "string" and "length", but also how to measure it.

Regardless, the knowledge there are even higher resolution B&W films out there kind of pushes me in the direction of finding an alternative method.

At the moment, I've sketched out a system that would be around two to three hundred in parts that aren't a DSLR and a macro lens (also required), that would be capable of producing automated overlapping frames suitable for stitching. For my current camera, that should give me about 7200 ppi pretty easily.

I'll probably start another thread about that if there's interest.

runswithsizzers · Aug 31, 2020

grat said:
When I originally posed the question, it was because I was considering how to proceed with negative scanning. Personally, I want to be able to scan 4x5 negatives, as well as 120 (anywhere from 6x6 to 6x17). Scanning 35mm isn't out of the question, but not a priority.

So the question was, how close is 2600 DPI to what I want for "maximum detail" for a film such as 400H? If, as it seemed, it was 3200 DPI, then there's not much point in investing in a new system. If the answer is closer to 6400, for instance, then perhaps it's worth it.

But apparently, I have asked how long is a piece of string. Everyone appears to have not just their own interpretation of "string" and "length", but also how to measure it.

Regardless, the knowledge there are even higher resolution B&W films out there kind of pushes me in the direction of finding an alternative method.

At the moment, I've sketched out a system that would be around two to three hundred in parts that aren't a DSLR and a macro lens (also required), that would be capable of producing automated overlapping frames suitable for stitching. For my current camera, that should give me about 7200 ppi pretty easily.

I'll probably start another thread about that if there's interest.

Awesome!

In spite of 9 pages of tangental meandering, off-topic discussions, excruciating examinations of arcane minutiae, and way too much back-and-forth bickering, you seem to have somehow found something close to an answer to your question.

I think you are on the right track. Good for you!

Helge · Aug 31, 2020

grat said:
When I originally posed the question, it was because I was considering how to proceed with negative scanning. Personally, I want to be able to scan 4x5 negatives, as well as 120 (anywhere from 6x6 to 6x17). Scanning 35mm isn't out of the question, but not a priority.

So the question was, how close is 2600 DPI to what I want for "maximum detail" for a film such as 400H? If, as it seemed, it was 3200 DPI, then there's not much point in investing in a new system. If the answer is closer to 6400, for instance, then perhaps it's worth it.

But apparently, I have asked how long is a piece of string. Everyone appears to have not just their own interpretation of "string" and "length", but also how to measure it.

Regardless, the knowledge there are even higher resolution B&W films out there kind of pushes me in the direction of finding an alternative method.

At the moment, I've sketched out a system that would be around two to three hundred in parts that aren't a DSLR and a macro lens (also required), that would be capable of producing automated overlapping frames suitable for stitching. For my current camera, that should give me about 7200 ppi pretty easily.

I'll probably start another thread about that if there's interest.

Don't put a naively relativist stamp in this thread. This isn't a magnanimous, conflict-averse "everybody is right in some sense" case.
There are limits to the resolution of film of course, plateaus and diminishing returns.
The bar is just much higher than film has been given credit for, for the last ten to fifteen years. And there are pitfalls, gotchas and much FUD spread out there.

If you really want a number, then it's 8000 dpi. As a starting point.
And that goes for all film. Most film has real image carrying detail to, or above this point.
Even if P3200 might not quite warrant it WRT image detail, it's still important to resolve the grain in good way.

That's the minimum you should aim for if you want an archival, relatively future proof format.
Sure you could do with less, for posting online. But even for downscaling to much lower resolutions you are going to see the benefits of the higher res scan.
And for prints, there is no competition.

runswithsizzers said:
Awesome!

In spite of 9 pages of tangental meandering, off-topic discussions, excruciating examinations of arcane minutiae, and way too much back-and-forth bickering, you seem to have somehow found something close to an answer to your question.

I think you are on the right track. Good for you!

If that is really your take away from this thread, then I'm afraid you didn't quite get it.
Tangents are there for reason. They are there for context. There is no way of getting to the point, when the terrain hasn't been surveyed. Don't mistake a clear view for a short journey.
It's easy to ask for an answer, but as Douglas Adams observed, the real challenge is often formulating the question in a meaningful way.

138S has been useful here in the sense that he has been an ersatz proxy for the collective hive mind of forum experts in the "film is quaint and fun, but far inferior to digital, and only something for quasi hipsters who will soon tire of it" brigade.

runswithsizzers · Sep 1, 2020

Helge said:
[...]

If that is really your take away from this thread, then I'm afraid you didn't quite get it.
Tangents are there for reason. They are there for context. There is no way of getting to the point, when the terrain hasn't been surveyed. Don't mistake a clear view for a short journey.
It's easy to ask for an answer, but as Douglas Adams observed, the real challenge I often formulating the the question in a meaningful way.

138S has been useful here in the sense that he has been an ersatz proxy for the collective hive mind of forum experts in the "film is quaint and fun, but far inferior to digital, and only something for quasi hipsters who will soon tire of it" brigade.

I guess I should have added an emoji to indicate my post was 'tongue-in-cheek' - at least, in part. You are right, I 'didn't quite get it' - but I got some of it, and I think the OP did, too. There was some good information shared here, both practical and theoretical - and, apparently, both accurate, and inaccurate. Which is Standard Operating Procedure for every internet discussion about any topic which is even slightly complicated.

I just thought the OP might need some cheering up after watching his thread turn into another Shoot Out at the OK Corral.

A couple more Douglas Adams quotes which may be apropos:
"I refuse to answer that question on the grounds that I don't know the answer."
"Human beings, who are almost unique in having the ability to learn from the experience of others, are also remarkable for their apparent disinclination to do so."

138S · Sep 1, 2020

Helge said:
You provided zero evidence.
B. It is very obvious that the photo isn't scanned to it's fulled resolving potential, due to lack of any real visible grain, but lots of grain aliasing. Any transition edges, is no indication of anything other than physical features we can know very little about.

...is has far better resolution than your ridiculous cited 2600 dpi...

Sorry, it's you that provided zero evidence, as you posted that image that is not worth 2600dpi effective. You will know if it is the scanner or the shot...

The edge transition in the super pixel-peeping of your image clearly shows that it is not worth the half. Have you any doubt ?

Without any calculation clearly under the half: https://www.photrio.com/forum/threads/film-vs-scanning-resolution.177544/page-5#post-2314574

Helge said:
C. No one except for the poster thought the scaling idea was a good way of determining real resolution.

Pixel-peeping is not worth to rate image quality, but it is quite useful to know if scanned resolution is an overkill. This is about of locating an ultra sharp edge in the film (or target) and counting ho many pixels the edge transition takes in the scanned image, this eveluates the amount of overkill you are scanning with.

Look, this is a very good recommendation followed several Pros I know, and belive me, those do know what they do.

Helge said:
It's almost as if you don't want film to have high resolving power, for some odd reason?

First, look, I know "what is" on print resolution because I contact copy 8X10" negatives (for the moment I lack a 8x10 enlarger) and I inspect the prints with an x60 magnifier, a bit (irony) beyond what eye resolves.

By 1885 shots were resolving beyond 100MPix effective:

http://hubicka.blogspot.com/2016/03/resolution-of-historical-photographs-in.html

But provia, for example, resolves this:

You can see that even at 1000:1 extreme high contrast by 50cy/mm only 30% of the contrast remains, pictorial situations are usually under 8:1 contrast.

Fuji just don't show the low contrast MTF, saying only that extintion is at 60. This is before degradation from lenses, vibrations, focus miss, DOF vs perfect focus...

This is important to know what effective scanning resolution we need usually. Of course there are exceptions were an extraordinary high effective dpi is required, but this is not the usual case.

Provide you have a Porsche GT3: Top speed is 305km/h but average speed may be 80km/h in some real trip.

Adrian Bacon · Sep 1, 2020

grat said:
Even though I have a lowly v800 (I guess the useful discussion is over, may as well descend into irrelevance and await Godwin's arrival), "smear" isn't something I associate with the output. That sounds like poorly focused scanning (the lack of adjustable focus is a serious oversight on these things, personal opinion), or badly processed images.

Can you provide an example? I've seen a number of 120 film scans of very high quality done with an Epson. I've seen few bad scans, except for people trying to prove a point.

I suppose people are unlikely to post their bad scans, but if these scanners were truly as horrible as you and Lachlan claim, no one would use them-- and yet, there are commercial photographers who seem to think they're moderately useful.

Even the test scans I've been doing at 6400 PPI, which is (to my mind) a mostly useless resolution given the preceding discussion, look reasonable (not great, merely reasonable) at the completely pointless 100% size on a 1080p monitor at less than 2 foot viewing distance.

You'll note I haven't posted any of these images-- I'm not entirely happy with my MF efforts so far. Even on shots I was certain were in focus, I'm having difficulty finding the in-focus point. Whether it's equipment or technique, I don't know-- I suspect equipment, as most of them were taken with a TLR (Mamiya C33). Or, perhaps the scans are not quite in focus.

Depending on the output you require, a V800 or v850 can be totally useful... For me, at the end of the day, its the output that I need that dictates what I'm going to go for. It really is that simple. You either need to extract as much resolution as possible from the film or you can get by with less. If you need to extract as much as possible, a v850 isn't the tool to use, though, depending on how you use it, you can get surprisingly good results (i.e. scan bw film with monochrome output using only the blue channel at the native sensor resolution, then scale it down afterwards). The commonly quoted ~2400 dpi resolution is done in full color. When scanning bw using Vuescan, it's pretty easy to do a monochrome scan using just the red channel, then do a monochrome scan using just the blue channel and look at the differences between them. The shorter blue wavelengths get more spatial information through the optical system and onto the sensor than the red does. Is it twice as good? No, but it's a simple and easy way to boost the spatial quality using what you got. For a flatbed, it's pretty high quality, however, if you want to get real, there are better ways.

138S · Sep 1, 2020

Adrian Bacon said:
The shorter blue wavelengths get more spatial information through the optical system and onto the sensor than the red does.

Some are recommending to use the green channel http://www.kennethleegallery.com/html/scanning/scanningGreen.php

Probably the dominanting factor is chromatic optimization in the lens, and probably this favors the green.

138S · Sep 1, 2020

grat said:
So the question was, how close is 2600 DPI to what I want for "maximum detail" for a film such as 400H? If, as it seemed, it was 3200 DPI, then there's not much point in investing in a new system. If the answer is closer to 6400, for instance, then perhaps it's worth it.

It depends on the scanner, skills and on the shot and personal taste, print size.

personal taste.

There are very diminishing returns in a higher resolution, what you additionally extract with higher dpi is of very decreasing quality, so it depends on how you value the slight improvement from a higher effort (time, file size...)

skills

A proficient edition takes more advantage of an slight enhacement, a careless edition will provocate some degradation that will destroy that slight improvement from the scanning

scanner

A pro scanner may require a lower dpi for the same quality than a consumer/prosumer machine

print size

If we want to enlarge a crop then the scanned image may be more stressed, if print is large.

_______

IMO with an Epson you extract all what Fuji 400H / 160 or Potra is to record from a real shot, with not many exceptions.

With a sharp BW film the Epson can be stressed, specially in 35mm, but not as often as it some think, if focus and flatness are nailed.

_______

The human eye can see upto 60MPix effective in the field of view with saccades, moving the eyes. Without moving the eyes we see around 8MPix, mostly concentrated in the Fovea (center)

_______

> So, let me reiterate: compare the digital image with direc x60 inspection on the light table.

> tets different resolutons, scan a little crop of the sharpest or interestind area, to see. I do that before scanning large LF negatives that will take a lot of time.

Helge · Sep 1, 2020

138S said:
Sorry, it's you that provided zero evidence, as you posted that image that is not worth 2600dpi effective. You will know if it is the scanner or the shot...

The edge transition in the super pixel-peeping of your image clearly shows that it is not worth the half. Have you any doubt ?

Without any calculation clearly under the half: https://www.photrio.com/forum/threads/film-vs-scanning-resolution.177544/page-5#post-2314574

Pixel-peeping is not worth to rate image quality, but it is quite useful to know if scanned resolution is an overkill. This is about of locating an ultra sharp edge in the film (or target) and counting ho many pixels the edge transition takes in the scanned image, this eveluates the amount of overkill you are scanning with.

Look, this is a very good recommendation followed several Pros I know, and belive me, those do know what they do.

First, look, I know "what is" on print resolution because I contact copy 8X10" negatives (for the moment I lack a 8x10 enlarger) and I inspect the prints with an x60 magnifier, a bit (irony) beyond what eye resolves.

By 1885 shots were resolving beyond 100MPix effective:

View attachment 253617

View attachment 253618
http://hubicka.blogspot.com/2016/03/resolution-of-historical-photographs-in.html

But provia, for example, resolves this:

View attachment 253619

You can see that even at 1000:1 extreme high contrast by 50cy/mm only 30% of the contrast remains, pictorial situations are usually under 8:1 contrast.

Fuji just don't show the low contrast MTF, saying only that extintion is at 60. This is before degradation from lenses, vibrations, focus miss, DOF vs perfect focus...

This is important to know what effective scanning resolution we need usually. Of course there are exceptions were an extraordinary high effective dpi is required, but this is not the usual case.

Provide you have a Porsche GT3: Top speed is 305km/h but average speed may be 80km/h in some real trip.

The crops are very close to a millimeter on each side.
The third image has borders where there is 100 dots with negative dots in between, so 200 dots per side in total per side.

I’d say this very well matches the claimed resolution of the film if you compare across the frame.

It is not in any way as low as 2600 dpi.

Even discounting the above for whatever reason, there is still the rigorous test shots from Parkin. Where it is clearly shown how all of the films warrants at least 8000 dpi.
And the microscope crops shows that much more is there for most film stocks.

Helge · Sep 1, 2020

138S said:
The human eye can see upto 60MPix effective in the field of view with saccades, moving the eyes. Without moving the eyes we see around 8MPix, mostly concentrated in the Fovea (center)

There are hundreds of these kinds of speculations on the humans eyes equivalent resolution. All totally missing the point that it’s a scanner and not a camera.
The eye is developed to be constantly moving, on a moving head with a moving body.

Even with the head in a vise it would seem a low resolution for optimal eyes, in daylight with optimal contrast.
Do you have a source on that, or are you just pulling stuff out of your arse again?

138S · Sep 1, 2020

Helge said:
View attachment 253623

The crops are very close to a millimeter on each side.
The second image has borders where there is 100 dots with negative dots in between, so 200 “lines” per side in total per side.

I’d say this very well matches the claimed resolution of the film if you compare across the frame.

It is not in any way as low as 2600 dpi.

Helge... no ruler is required... the scan is made a 5400dpi (hardware), isn't it ?

Then the edge transition takes al lest 5 or 6 pixels (consider both sides of the edge), belive me: it is not worth the half of the scanned resolution... can you see it ?

Click to enlarge...

Helge said:
Even with the head in a vise it would seem a low resolution for optimal eyes, in daylight with optimal contrast.
Do you have a source on that, or are you just pulling stuff out of your arse again?

This is what I was teached at college (8/64 aprox), if you want I can search references for you, I've seen them sometimes.

There is also a x1.5 variability, depending on subject:

"Peak cone density varies highly between individuals, such that peak values below 100,000 cones/mm2 and above 324,000 cones/mm2 are not uncommon.[21] Assuming average focal lengths, this suggests that individuals with both high cone densities and perfect optics may resolve pixels with an angular size of 21.2 arc seconds, requiring PPI values at least 1.5 times those shown above in order for images not to appear pixelated."

https://en.wikipedia.org/wiki/Fovea_centralis

It has to be remarked that this is debatable, Ctein (in Postexposure) cites a very high mumber (30, IIRC), but inspect by eye your USAF 1951 glass slide and tell me what you see in Element 2.6 !!! (6.35 lp/mm )

There is some controversy because one thing is Visual Acuity and another one Hyperacuity, and many people don't state what they are talking about when speaking human vision.

Perhaps Hyperacuity is not popular concept, but it's quite interesting:

"Transcending by far the size limits set by the retinal 'pixels', depends on sophisticated information processing in the brain." https://en.wikipedia.org/wiki/Hyperacuity_(scientific_term)

If we speak about Hyperacuity then rating is higher, perhaps what Ctein says, but pictorial situations are not about that, we are more in the Graphic industry ratings: 6 or 7. IMO Hyperacuity vs Acuity ratings is what fuels any controversy.

Koen Van Crombrugghe · Sep 1, 2020

138S said:
Then the edge transition takes al lest 5 or 6 pixels (consider both sides of the edge), belive me: it is not worth the half of the scanned resolution... can you see it ?

While I agree that the transitions take several pixels I don't see this as a useless waste of resolution.
Oversampling is never a bad idea, it helps avoiding aliasing (moiré) increases signal/noise ratio and can increase perceived sharpness.

138S · Sep 1, 2020

Koen Van Crombrugghe said:
While I agree that the transitions take several pixels I don't see this as a useless waste of resolution.
Oversampling is never a bad idea, it helps avoiding aliasing (moiré) increases signal/noise ratio and can increase perceived sharpness.

Of course, I fully agree with you.

But we were debating what resolution the image has in order to see what effective resolving power is required.

For example, if that image has "2400 dpi effective" resolving power then an EPSON V700 scanning at 3200 or 4800 would take all what the negative has.

What I say is in for image that was posted by Helge the Epson would perform like the Minolta, and probably 5400dpi are not required, perhaps there is not much benefit in scanning beyond 3200 to ger 2600 effective. Both the minolta and the epson would outresolve the medium.

Insted the Serger's Porsche...

(https://www.photrio.com/forum/threads/film-vs-scanning-resolution.177544/page-6#post-2314921)
(https://www.photrio.com/forum/threads/film-vs-scanning-resolution.177544/page-7#post-2314988)

It looks it is challenging a Hasselblad Flextight scanner, at least this time edges show motion blur of the film advancing, so the scanner is showing flaws before exhausting the CMS capability. Think that the Flextight resolves beyond 6000 when doing 35mm film...

I guess that this comparison is interesting because we see the two extremes: In general color negative film is easy to scan and resolution is more limited in practice. In the other extreme we have CMS, a wild BW stuff difficult to use but delivering all what the lens and the steadiness would allow.

grat · Sep 1, 2020

Helge said:
Don't put a naively relativist stamp in this thread. This isn't a magnanimous, conflict-averse "everybody is right in some sense" case.
There are limits to the resolution of film of course, plateaus and diminishing returns.
The bar is just much higher than film has been given credit for, for the last ten to fifteen years. And there are pitfalls, gotchas and much FUD spread out there.

And some of it made it in here, too. I'm very good at picking out useful information from crap information-- I'd say it's a necessary skill for the internet, but social media proves most lack it. I try not to make assumptions about others, and I expect that to be returned in kind.

I genuinely appreciate the information in this thread (and got far more than expected)-- but I also fully expected from the moment I hit "Submit Post" that Lachlan and 138S would be at it, and I knew opinions would vary wildly. And I was right-- my metaphor about strings was simply an acknowledgement of that.

If you really want a number, then it's 8000 dpi. As a starting point.

So according to you, virtually no one is getting sufficient detail from film. Got it.

That's the minimum you should aim for if you want an archival, relatively future proof format.

No. If I want an archival, future-proof format, I go with glass plates. I still have the negatives-- while I'm sure there's someone out there who will argue that every time I scan a negative I'm doing irreparable harm to the negatives, storing negatives isn't too terrible, although color will be problematic over time.

Digital is not future-proof. Storage technology is ever changing (Got any zip drives handy? Floppies? Even optical disks are rapidly becoming dinosaurs), and poorly stored bits are barely better than no bits at all. I do better than most-- I've got stuff on my NAS that dates from 1992, having been migrated from one system to another over the years. I'm even willing to say that the majority of it hasn't suffered bit-rot (I think I've lost two photos to that particular phenomenon). But as soon as I stop putting effort into that, all of it becomes ephemeral-- the two photos that no longer load correctly are proof. At some point when I wasn't using parity-protected storage, those files got corrupt, and I didn't notice in time to go back to my previous storage.

Helge · Sep 1, 2020

grat said:
So according to you, virtually no one is getting sufficient detail from film. Got it.

No. If I want an archival, future-proof format, I go with glass plates. I still have the negatives-- while I'm sure there's someone out there who will argue that every time I scan a negative I'm doing irreparable harm to the negatives, storing negatives isn't too terrible, although color will be problematic over time.

The people drum scanning and using well calibrated Flextights are getting close.
And in recent years the thousands and thousands doing camera scanning either are doing it, with crop stitching, or could potentially do it.

It’s a given that we are talking digital formats here. Archival as they come.
Archival in this context means that there is a lesser chance that you have to, or feel inclined to do the job twice.

warden · Sep 1, 2020

grat said:
But apparently, I have asked how long is a piece of string. Everyone appears to have not just their own interpretation of "string" and "length", but also how to measure it.

You nailed it. Very good!

This has been a good thread and I'm glad to hear you have a path forward, although I feel for anyone wasting their time for a lowly payoff of 7200 ppi. << Joke right there.

For your 4x5 negatives you already have an excellent tool in the Epson IMHO, assuming of course you aren't planning on printing larger than a barn door. But for medium format it'll be interesting to read your impressions about print quality differences between the Epson and your home brew digital solution. Please start that thread and share when you can!

Lachlan Young · Sep 1, 2020

138S said:
A pro scanner may require a lower dpi for the same quality than a consumer/prosumer machine

138S said:
IMO with an Epson you extract all what Fuji 400H / 160 or Potra is to record from a real shot, with not many exceptions.

138S said:
For example, if that image has "2400 dpi effective" resolving power then an EPSON V700 scanning at 3200 or 4800 would take all what the negative has.

These statements are completely contradictory. The Epson cannot adequately address its supposed resolution because it severely lacks MTF performance. Under the most generous circumstances (no matter how high you set the ppi), a V700 might give a useable resolution equivalent in the 1000-1400ppi range (in other words before its inability to capture low frequency detail/ turn that detail into bizarre wooly 'fuzz' from its interpolation & 1/2 pixel offset between sensors becomes very apparent) - which means that you are inherently claiming that a 4x - 4.5x enlargement of Pro 400H or Portra 160 is the absolute maximum they can be enlarged to! If you have enlarged Portra 400 in the darkroom (let alone 160) you would understand how monumentally ludicrous a statement this is. While a nominal 2000-2400ppi should allow a 6x7 neg to comfortably make a better-than-OK 16x20" or a little bigger, it is entirely dependent on the scanner/ camera scanner MTF and noise performance being adequate for the purpose. There are plenty of systems that can do this, it's just that none have 'Epson' written on them. And with the appropriate lens and scan etc, 40x50" off 120 Portra 160 looks pretty impressive & the granularity is fine & sharp, as it should be. Heck, even 50s/60s 120 FP3 can go to 1.5m wide with an adequate scan...

warden · Sep 1, 2020

grat said:
When I originally posed the question, it was because I was considering how to proceed with negative scanning. Personally, I want to be able to scan 4x5 negatives, as well as 120 (anywhere from 6x6 to 6x17). Scanning 35mm isn't out of the question, but not a priority.

You might have already shared this information but how big are you planning on printing, if you know?

The questions about transferring the maximum possible information from a piece of film to a computer are of interest to me intellectually, but from a practical standpoint I know I have yet to need all the information in any negative I've ever made. I consider the negative the asset and archive, and scans are temporary tools to use with a printer when I don't want to wet print. So my thinking usually goes:

1 - How big is the print?
2 - How much information can the selected printer deliver?
3 - Can I hit that quality target given a) the size of my negative and b) the scanners that I own?

I like the direction you're headed with digital camera scanning, which I think is the future when we talk about printing large.

138S · Sep 1, 2020

Lachlan Young said:
The Epson cannot adequately address its supposed resolution because it severely lacks MTF performance.

It can, see this:

https://www.largeformatphotography....bed-scanners&p=1557267&viewfull=1#post1557267
https://www.largeformatphotography....rum-Scanners&p=1479178&viewfull=1#post1479178
https://www.largeformatphotography....Epson-Flatbed-Eversmart-Flatbed-Drum-Scanners

If you can't it's because of your shortcomings, send me PM with the problems you have and I'll teach you, I'd be glad if I can help. You also have an address yet to send a negative sample to compare, do it when you want.

I'm not to debate more about that with you because enough evidence is there, and this is only noise in this thread, if you want PM and I'll teach you how to do it, if not bye.

Alan Edward Klein · Sep 1, 2020

jawarden said:
You might have already shared this information but how big are you planning on printing, if you know?

The questions about transferring the maximum possible information from a piece of film to a computer are of interest to me intellectually, but from a practical standpoint I know I have yet to need all the information in any negative I've ever made. I consider the negative the asset and archive, and scans are temporary tools to use with a printer when I don't want to wet print. So my thinking usually goes:

1 - How big is the print?
2 - How much information can the selected printer deliver?
3 - Can I hit that quality target given a) the size of my negative and b) the scanners that I own?

I like the direction you're headed with digital camera scanning, which I think is the future when we talk about printing large.

Your point of view is along the line I was thinking. Pixel peeping is good but doesn't answer the primary question. Will the scan give me a good print at the size I want? If it does, great. If it doesn't than you have to do something different. Arguing about the rest of the stuff is just conversation. Until you actually make a print or use it for what you want (such as internet or display on a large screen TV), you won;t know.

grat · Sep 1, 2020

Helge said:
The people drum scanning and using well calibrated Flextights are getting close.
And in recent years the thousands and thousands doing camera scanning either are doing it, with crop stitching, or could potentially do it.

I would suspect the number of people using either well-calibrated venerable commercial solutions, and the number of people doing stitched DSLR "scans", are both fairly low compared to the people who take a 20 MP snap of their 135 or 120 negative. With a 32MP DSLR, I need two shots of a 6x6 negative to match the 2400 ppi scans I'm doing now.

It’s a given that we are talking digital formats here. Archival as they come.
Archival in this context means that there is a lesser chance that you have to, or feel inclined to do the job twice.

I view the "archival" version as either the one I can always go back to and start over with, or the one that's an acceptable substitute if the original goes up in flames. Either way-- "archival" and "digital" are difficult to reconcile, given that technology tends to substantially alter every 5-7 years-- a serious problem for archiving the "Digital Age".

grat · Sep 1, 2020

jawarden said:
You might have already shared this information but how big are you planning on printing, if you know?

Well... that's a good question isn't it? I realize, particularly in the film world, the The Print seems to be more important than the Negative-- for example, I've noticed a tendency in some to define characteristics of the negative in terms of the final print, which to me is a bit backwards. Or it's quantum physics, I'm not sure.

Generally, I'm producing a down-sampled final image that will be uploaded, displayed on perhaps a 4K display, or occasionally, printed and hung on a wall. 2400 PPI is overkill for such images. Over the years, very few of my pictures have become prints, partly due to limitations of digital imaging (until recently, I was still using an 8MP DSLR). However, now that I've caught up with 2020 and 1990 simultaneously, and I expect to have more free time "soon", there's a distinct possibility that may change.

I like the direction you're headed with digital camera scanning, which I think is the future when we talk about printing large.

So doing some quick math early on told me, for a 6x6 negative, I could almost hit 2400 PPI with a single frame from my current DSLR, that I could hit 2800 PPI (roughly-- all the PPI here are approximate) with two frames, something like 5600 PPI with 4 (2x2) frames, and I could hit full 1:1 resolution of my sensor (7600 DPI) with 9 (3x3) frames. So for a roll of 12 exposures, to hit 5600 PPI, I need 48 images. For maximum resolution, I need 84 images.

For a single 4x5, I need 42 (6x7) separate images to reach maximum resolution (at 1:1). As I'm lazy, that means I need automation.

Film vs. Scanning resolution

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