Film vs. Scanning resolution

flavio81

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May Ron RIP

Has he passed away?!

I haven't seen any announcement ... Is this true? If PE passes away this will be like another era for this forum. For me, Ron was the crown jewel of this forum.

If he has passed away, we should have some announcement, some memorial here.

Sorry for the off topic.
 
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grat

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It's not rude. It's just not relevant for my current use case. *shrug*
 

138S

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You can enlarge 35mm ADOX CMS 20 II as big as you want. If you look at it under a microscope with 100X enlargement factor (would be a 2.4 x 3.6 meter image) it delivers perfect sharpness, incredible resolution and still very fine grain.

Well, at 3m, the posted image will look like this...

Nice to learn who was the photographer, an exceptional job...

What we see is the far limits of the hassie horizontal motion blur is seen from the film advancing. Not many situations challenge a hassie

 
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warden

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I have a V700 that I'm quite happy with. For sharing MF images online and making smallish prints they're great, and cheap to use. When you need something better or bigger there's always Flextight or other options. I did a comparison between a Flextight and my V700 and shared the results on this forum last year and the Flextight was better but the difference wasn't huge.
 

MattKing

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I see you have now found Ron's In Memoriam thread - found here: https://www.photrio.com/forum/threa...rey-aka-pe-photo-engineer-feb-15-2020.173245/.
Yes, Ron (Rowland) Mowrey aka as Photo Engineer has passed away.
 

Helge

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SCHWARZZEIT

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That would be me. Thanks for the kind words.

As I have mentioned in my previous post, I have developed a high-end camera-based film digitization system (HXY Scanner) that outresolves any drum scanner and is also superior in dynamic range (high density rendition and shadow recovery) and color fidelity.

Drum scanners had been the best quality solution for film digitization for a long time. But their development stopped about 20 years ago while CMOS sensor technology matured to a level where it can match and exceed the quality of PMT-based digitization. Camera scanning is a highly modular field with a vast range of options from very affordable entrance DIY setups over highly sophisticated custom rigs and up to very expensive turn-key solutions for cultural heritage institutions as offered by Digital Transitions and Phase One.

Since my ICG 370HS drum scanner is optically limited to roughly half of its specified 12000 ppi resolution, the 8000 ppi representation is as good as the ICG can do. Some degree of oversampling yields slightly better results than scanning at 6000 ppi only.

Here is a sample of a 35mm Adox CMS 20 frame, shot handheld with the Canon EF 15mm Fisheye on a Canon EOS 5 in 2009, developed in the original Adotech and digitized recently with my HXY Scanner at 24110 ppi (almost 800 MP) showing much more of the film’s resolving power than a drum scan:



Detail crop of the original 24110 ppi scan:



-Dominique
 

Lachlan Young

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There are a whole lot of BW films you are ignoring - essentially all BW at 125 or slower and some older slightly faster K-grain emulsions were far more likely to have been single layer + topcoat(s) than not. Trying to compare colour films (which have additional complications) is rather beside the point - and even there, Kodachrome 25 was (I recall) going to be unprofitably costly to translate to slide coating (from a multi-pass slot die process I presume) because of how thin the layers were.

Again, you don't understand what infectious development is - or what it looks like in practice. If that was the case, unless you were working with development by inspection, you'd have seconds to slam the film into the stop bath. You'd also get the characteristics that lith processing gives to paper at shorter processing times - which would make really, really obviously strange highlights. Any upsweep in T-Max 100's curve is actually much more steady and controllable - and anyone who claims otherwise is usually either using inappropriate developers or bad techniques. The shoulder in older types of films is there in part to save you from major processing mistakes, not improve highlight separation.
 

138S

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There are a whole lot of BW films you are ignoring - essentially all BW at 125 or slower and some older slightly faster K-grain emulsions were far more likely to have been single layer + topcoat(s) than not.

Look, at one point ilford FP4, before (ISO 125) FP4+, was improved by adding a second layer, to improve its latitude.

If TMX was single layer it would be the only kodak pictorial film made in that way. Again you don't understand at all how critically necessay is coating two different emulsion layers for a film like TMX to reach that crazy high perfomance, get better informed. Look, that performace is not possible with a single layer, in color films they even coat 9 layers, 3 per color to extend latitude, and you say that TMX has to be made like in 1930 because something about glass plates... Lachlan, this is ridiculous, don't you catch it ?
 

Lachlan Young

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if you want ultimate sharpness/resolution it’s quite natural.
That enormous resolution of T-MAX 100 and CMS 20 II probably wouldn’t be possible with multiple layers.

What is also worth noting is that the T-Max films seem to be noise-limited in their resolution (granularity overwhelming fine resolving power), rather than contrast limited - at its 200 cyc/mm limit, T-Max 100 is still delivering 30% response I recall, whereas (when presented with the same target) other more 'traditional' films max out their resolution at near contrast extinction. If T-Max 100 was less sharp, it would probably be able to resolve even greater cyc/mm - there are aerial recon films with immense resolutions, and poor MTF, latitude, granularity - which is fine if you need to resolve a tiny object on the ground from space under very high contrast imaging conditions on rollfilm up to 330mm wide, not so good for more normal photo imaging at sea level. The vital inter-relationship of latitude, MTF and RMS Grain tell far more about the suitability of a film for actual image making than any top-trumps style slobbering over resolution charts. As does actually using the damn film for its intended purpose, printing it in the darkroom with decent kit or scanning it on a scanner that's actually up to the task.


I'm not sure about the history of that aspect - I know Ron had said that a 400 speed K-Chrome was researched - and it has been disclosed in Bob Shanebrook's book that Kodachrome 200 had some T-Grain emulsions in it. Interestingly, the Kodachrome 200 layer order was different to the norm in the cyan and magenta layers, with the slow emulsions on top of the fast emulsions, apparently because the effects of the sensitising dyes in the fast emulsions would have made the slow emulsions need to have equally large grain (at least that's my understanding).
 

Lachlan Young

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Multiple emulsions in FP4 for latitude, not multiple layers. Every layer you add costs sharpness from internal reflections which have to be compensated for - but the thicker a layer is (for speed) the more turbidity/ reflections you can get - the tipping point for BW films seems to be somewhere between 125 and 250-ish speed where multilayers have advantages over single layers (probably due to equilibration or similar). T-Max 100 likely has a minimum of 2, more likely 3 emulsions blended for specific performance in a single layer. Colour films usually have 4-5 emulsions per colour sensitised layer set - each coated in 2-3 layers - there might be 5 green sensitised emulsions, coated in three layers. Avoiding equilibration etc of these emulsions seems to be why they are split into layers - as the blue sensitive layer is closest to the surface, it seems to be able to get away in many cases with just two layers. As before, you have clearly not read a word of what Ron wrote (extensively) about Photo System Engineering.
 

138S

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T-Max 100 likely has a minimum of 2, more likely 3 emulsions blended for specific performance in a single layer.

Even me I blend several DIY emulsions to coat dry plates, but we are talking about a different matter, look... TMX cannot be made with a single emulsion layer because the performance it sports it would be out of reach by far, this is quite straight to understand, TMX and TMY share the same technology, fat crystals in the outer layer and slow cubic in under that:



Can you see how well packet is the upper layer of TMY?

If both emulsions were blended that horizontal alingment of the T would be lost, to begin with, and high performance would be destroyed for several reasons.

The way to boost latitude is multi layer, TMX has an insanely large latitude like TMY, coating a single layer would not allow that.
 
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PhilBurton

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This is stuff that I, a mere mortal among gods, just never knew.
 

Lachlan Young

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This is stuff that I, a mere mortal among gods, just never knew.

It's also riddled with errors and fantasies. Unfortunately. If you want the real information, the book you want is the 2nd edition of 'Making Kodak Film' by Robert Shanebrook. And you might find the stickied posts by Ron (Photo Engineer) on Photo System Design in the emulsion making subforum make what goes on much clearer. Multiple polydisperse emulsions (because that is what 138S is making) blended together aren't going to be much use at improving response/ sharpness over one.
 

Helge

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Unfortunately Kodak literature (datasheets, books etc.) often uses sharpness as a synonym for resolution.
And using micro contrast in the original sense (they invented the term) as a descriptor of the rightmost part of the MTF curve.
That’s worth keeping in mind.

Apart from that, you are probably almost certainly right in that empirical observations of grain, clearly point to T-MAX 100 not being either a very homogeneously grained emulsion, neither a multilayer one.
400 and 100 T-MAX MTF and exposure curves gives us some hints that point in that direction too.
Just looking at the end product of scans and prints, 100 has a good long straight line and nice latitude. But it’s nothing compared to 400.
The real speed of (new) 400 is probably closer to 700 or 800.

Regarding the use of the one layer Kodachrome ideas used in later one layer films:
I’m afraid I have to delve into the same realm of unconfirmable “proclamations” that a certain other poster does.
But I have the information from two sources:

Wesley Hanson (inventor of the orange mask among other things) talks about one layer Kodachrome someplace in this video (I don’t have time to scrub through it to find the exact place right now, but if you haven’t watched it you really should take the time).

https://ethw.org/Wesley_T._Hanson

And an email conversation with a now deceased Kodak researcher, whom I mailed about if he knew of details about the one layer Kodachrome, among some other things.
Of course I can’t ask for permission to post the mails, and I won’t anyway, due to the information having a small but real likelihood of the still being under some kind of protection or NDA.
 
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138S

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Multiple polydisperse emulsions (because that is what 138S is making) blended together aren't going to be much use at improving response/ sharpness over one.

Lachlan, Lachlan...

Look, a DIY emulsion has many technical limitations, one of the limitations is that, while you may increase the speed of the emulsion, latitude won't increase what we may desire, if you blend two or more DIY emulsions of different speeds you in fact increase the resulting latitude, this is the reason why we may mix several DIY emulsions.

Another reason to blend emulsions if making a variable contrast emulsion for photopaper, you mix ortho emulsions with a raw blue sensitive (color blind) emulsions to coat paper or to print on glass. IMO, the carce people making dry plates don't usually blend much the emulsions for a greater sharpness, anyway mostly an straight emulsion is used because most of the joy comes from the involved adventure.

____

Here we were speaking agout the well known multi-layer effect in the latitude boosting. The 1 layer kodachrome was a pitfall, still slides have a way narrower latitude requiring less the latitude boost, while print film (color/bw) has evolved to deliver insane highlights latitude, provided by the multi layer: 9 layers, 3 per color in good color print film !! Why they take that effort ? Are you aware of the latiude boost it provides ?

Let me repeat it a final time: The core technology of the TMax films (TMX, TMY, TMY-II, TMZ) is laying extraordinarily well aligned ultra flat crystals over cubic crystals, all TMax films sport this core concept to provide insane latitude, insane linearity and fine grain.

With TMX you easily get 14 stops, or 18 with a careful processing, For that you require multi layer. If you blend the cubic in the T you destroy the alignment provided by the SHEAR THINNING (https://en.wikipedia.org/wiki/Shear_thinning) in the coating cascade, but you need the cubic emulsion for the linear extreme highlight latitude, so you won't find a way to avoid multi-layer for the TMX if wanting those 14 to 18 stops.

It is totally ridiculous your theory of TMX being a totally different concept than TMY, beyond speed, they are different flavors of the same, sharing linearity and insane latitude. You won't find a serious evidence stating that TMX is single layer, this is a urban legend with no base.

Your deduction that TMX is single layer because of glass plates is simply ridiculous, this is not being aware of the core technology that shapes the TMax product range.

I won't say more about this off-topic.
 

Lachlan Young

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Ah, yes, packet couplers - it seems that it never proceeded much after multilayer curtain coating showed itself to be workable in the very early 1950's - I was getting confused by the way that there seemed to be an implication that it was a late 70's research project - from Ron & Bob's comments, packet coupler work for papers seems to have carried on into the 1960's, then multilayer fully won out.

There are some really interesting papers from the early 70's looking at image structure/ content - the Mike Kriss one Ron often referred to as being 'seminal' in its impact takes some tracking down, but it pretty clearly shows the analytical framework from which the information in those datasheets is derived. If you enjoy 60 pages of calculus that is.
 
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PhilBurton

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Not that I am about to do a DIY emulsion, but I'm curious. How can this be done in a practical sense. Presumably you need a completely, completely lightproof working area. And the emulsiion solution must be uniform after mixing, which must also be done in total darkness. And must be spread evenly. How can all this be done by someone at home?


Sounds like an argument for TMAX over more traditional films like Tri-X. Is there a downside to TMAX?
 

MattKing

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So why does Kodak still sell Tri-X? Why would anyone still use Tri-X?
Why does anyone drive a Jeep when a minivan will carry everything comfortably?
Many people familiar with using Tri-X like Tri-X, and many people who aren't familiar with Tri-X know it by reputation and want to try it.
Tri-X continues to be a very fine film - it is certainly finer grain than when I used it a lot in the 1970s.
 

Lachlan Young

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It's a lot less difficult to do at a basic practical level than you'd think (but vastly more complex to understand and control) - if accepting the technological limits of somewhere between 1950 & 1960 is reasonable - and not having panchromatic sensitivity. Denise Ross's work is probably the most readily accessible at the moment, though some copies of Ron's emulsion making book (which is a remarkable & excellent work) may still be findable. The latter makes clear just how vast the technological change of postwar emulsion making was - in both sensitising technology & approaches, but also in grain structures & uses - yet there is technology available which with some determination & effort should allow the home emulsionist to get beyond simple single-run emulsions.
 
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