Highest resolving power BW film, chemistry, paper.

[2F/2F]

lp/mm or lines/mm??? Big difference (as in 2x). :munch:

- Leigh

What does the guy eating popcorn and drinking a soda mean?

 

[cmo]

What does the guy eating popcorn and drinking a soda mean?

"User has a dirty keyboard."

 

[georg16nik]

The aerial resolution of MF lenses needs to be tested with microfilm like Agfaortho25 used by Dr Kornelius Fleisher (see below).It can be over 250lppm.
Very few lens tests have been reported with microfilm, often T-Max was used. While this may represent practical conditions only microfilm can show how good the lenses are.
http://photo.net/medium-format-photography-forum/000X2t?start=10

Right on! Most lens/film "benchmarks" are a joke.
In the 135 format, Agfa copex rapid, Adox CMS 20, Rollei ATP/ATO, the slow Efkes etc. etc. puts to shame most of the films made by Fuji, Kodak and Ilford.
IMHO, The difference is like the day and night.
Kodak Technical Pan was a good option but long dead, so are other micro films by kodak.
Fuji Across and Ilford pan f + might be (for some folks) a good options but it is not serious to compare them with the high resolution films by Agfa, Adox, Rollei, Efke.

 

[cmo]

Again, what is a higher resolution good for if it is beyond the limits set by the lenses?

 

[georg16nik]

Again, what is a higher resolution good for if it is beyond the limits set by the lenses?

The so-called limits set by the lenses are not fully explored, so higher resolution films lets You enjoy the reality check yourself, while at the same time having a blast from the pretty awesome results You get by using high resolution films.
Oh, and most/all of them are using archival ready AHU PET base.
Also, sometimes the high contrats of such films gives You the graphic part of photography in a very graphic way

 

[Diapositivo]

Again, what is a higher resolution good for if it is beyond the limits set by the lenses?

According to the document by Tim Vitale which I keep quoting, a higher resolution makes sense also if the lens "outresolves" the film, and the better the lens resolution, the better the resolution of the final outcome, the "system" resolution.

For instance, if the film has a resolution of 80 lp/mm, and your lens has a resolution of 80 lp/mm, the final resolution you are going to obtain is 40 lp/mm. (That is the "system" resolution if we abstract from developing and camera differences).

If with that same film, which has a resolution of 80 lp/mm, you use a lens which has a resolution of 120 lp/mm, and which in theory "outresolves" the film, the resulting system resolution will be 48 lp/mm.

If for you application resolution is an important aspect, 48 lp/mm is certainly better than 40 lp/mm.

You can have it the other way.

For instance if the film has a resolution of 35 lp/mm, and your lens only resolves 20 lp/mm, your film has a resolution "beyond the limits set by the lens", and your final outcome is going to be 13 lp/mm according to Tim Vitale. BUT if the lens resolves 20 lp/mm, and the film resolves 80 lp/mm, which is not just more than the lens, but also more than the previous case of film "outresolving" the lens, the final result is 16 lp/mm instead of 13 lp/mm (which one can see as almost "25% resolution more" so to speak).

So, according to this document, even if your lens has a low resolving power, and the film "outresolves" it, you still have a system resolution gain by using an even more "out-resolving" film.

Film resolution and lens resolution can, if I get it right, be seen as "factors" of the final resolution, each with its own weight on the final resolution, rather than being each a limiting ceiling for the final resolution.

Fabrizio

PS In the document Vitale describes several "System resolving power equations", where system = camera + film + lens + processing and uses the equation published by Fujifilm.

 

[cmo]

The so-called limits set by the lenses are not fully explored...

One thing that is fully explored: you can see the difference between a Tmax 100 or Acros and high-reolution films in large prints only.

By the way, Zeiss states in a newsletter what they use for lens testing: APX 25, they purchased a lot before production stopped.

A quote from this website might ruin some myths:

Zeiss Camera Lens News 2003 #19 and 2004 #20, merged and sorted by resolution. These tests were done by microscope, so resolution is higher than can be obtained by scanning.

lp/mm film name (type)
----- ----------------
400 Gigabitfilm (B&W)
250 old Agfa Ortho 25 (B&W)
200 old Kodak Ektar 25 (C-41)
200 old Agfa APX 25 (B&W)
180 Kodak T-Max 100 (B&W)
170 Fuji Velvia 100F (E-6)
160 old Fuji Velvia 50 (E-6)
160 Kodak Farbwelt 400 (C-41)
160 Kodak Farbwelt 100 (C-41)
160 Fuji Neopan Acros 100 (B&W)
150 old Agfa Portrait XPS 160 (C-41)
150 Kodak Portra 400 (B&W)
150 Kodak Portra 160VC (C-41)
140 Kodak Portra 160NC (C-41)
140 old Kodak Tech Pan (B&W)
​

According to another apug member, Henning Serger, (there was a url link here which no longer exists):

Adox CMS 20 / Spur Orthopan UR: 230 - 260 Linienpaare pro Millimeter.
Agfa Copex Rapid / Spur DSX: 170 - 200 Lp/mm.
Rollei ATP: 170 - 200 Lp/mm.
TMX: 135 - 150 Lp/mm.​

That test was made with one of the best lenses available, the Zeiss Makro-Planar ZF 2/50. He describes himself as a 'film junkie', and he favours high resolution films. That is, he is definitely not the average amateur photographer but very experienced.

Gigabitfilm, by the way, is Agfa Copex Rapid, just like the other "high resolution films" are just relabeled Copex type films at a higher price. The different varieties of Copex cost ca. 30-40 cents per meter, e.g. 60 cents for the length of a normal 35mm film. With some softening developer and a new stick-on label you turn this cheap document film into an expensive "high resolution film" for 4-5 Euros per 35mm cartridge, plus the developer. That's the whole deal. If you want to roll your own, there are even Caffenol variants for this type of films.
We had Gigabitfilm, we had SPUR Orthopan film, we had ATP, Adox CMS and probably a few more that I missed - EHEC was not a film, right? Every one or two years a different pig is being run through the village.

But let's not forget the disadvantages:

- Most of these film/developer wonder wart-hogs are bitchy. Using them is not as foolproof as developing Tri-X in D-76. See this forum and others for questions like 'where do the white spots come from' or 'why are the shadow details gone'.

- The PET base is a big disadvantage. Don't fall for the marketing bla.
You get lightpiping problems, many of these films curl like a steel spring, and if you can't find the scissors in your darkroom you can't rip off the end of the film.
The only advantage of PET is for the manufacturer because it is much cheaper than normal triacetate. Regarding archival stability, I don't expect that just one of us will see his negatives on a normal base becoming unusable during his lifetime. We just don't live long enough to benefit from 500 years archival stability.

So, if these films are right for you, enjoy.

But, please, don't tell everyone that these films are as easy to use as normal films, and don't forget that many people even have difficulties developing normal films.

 

[georg16nik]

One thing that is fully explored: you can see the difference between a Tmax 100 or Acros and high-reolution films in large prints only.

The statement that the difference can be seen in large prints.., doesn't necessarily mean "fully explored" its is just an assumption, about somebody else experiences.

By the way, Zeiss states in a newsletter what they use for lens testing: APX 25, they purchased a lot before production stopped.

Zeiss is a great company, particularly Sports Optics, Astro and rest of the pro divisions.
Pay attention, that, they offer lifetime-transferable warranty ONLY for the above product lines and stand by their specs. I recently had my ~ 50 years old bino serviced by them, free of charge. The rubber eye cups needed a replacement..
However, the photo department is somewhat more like a hobby to them, in the recent ~ >40 years..

A quote from this website might ruin some myths:

Remind me why should either of us trust California Creeks - http://cacreeks.com/
We can read other people datas all day, wheres the fun in that?

According to another apug member, Henning Serger, (there was a url link here which no longer exists):

Adox CMS 20 / Spur Orthopan UR: 230 - 260 Linienpaare pro Millimeter.
Agfa Copex Rapid / Spur DSX: 170 - 200 Lp/mm.
Rollei ATP: 170 - 200 Lp/mm.
TMX: 135 - 150 Lp/mm.​

That test was made with one of the best lenses available, the Zeiss Makro-Planar ZF 2/50. He describes himself as a 'film junkie', and he favours high resolution films. That is, he is definitely not the average amateur photographer but very experienced.

Gigabitfilm, by the way, is Agfa Copex Rapid, just like the other "high resolution films" are just relabeled Copex type films at a higher price. The different varieties of Copex cost ca. 30-40 cents per meter, e.g. 60 cents for the length of a normal 35mm film. With some softening developer and a new stick-on label you turn this cheap document film into an expensive "high resolution film" for 4-5 Euros per 35mm cartridge, plus the developer. That's the whole deal. If you want to roll your own, there are even Caffenol variants for this type of films.
We had Gigabitfilm, we had SPUR Orthopan film, we had ATP, Adox CMS and probably a few more that I missed - EHEC was not a film, right? Every one or two years a different pig is being run through the village.

OK, Henning Serger looks like he is member of apug, that is the only undeniable fact.
He did his tests and I trust he had fun with that.

and btw, a roll of Fuji Across (135) in Europe goes for around 4 Euros - ~ 6 US$
a roll of Kodak T-MAX 100 (135) in Europe goes for above 4 Euros - ~ 6 - 7 US$
a roll of Ilford PAN F (135) in Europe goes for above 4 Euros - ~ 6 - 7 US$
Now, even the adorable Rollei RETRO 80S goes for 2,20 Euros - ~ less than 3 US$

If we really have to benchmark them in the price department, especially in Europe, then Kodak, Ilford and Fuji doesn't make financial sense, at all, and its not only film prices but paper, chemistry etc. etc. as well....
Anyone is free to spent ~ 4 Euros for a film, based on triacetate.. that is prone shrink, develop acid, growth bacterias and God knows what more in just a few decades...
No doubt that Kodak, Ilford and Fuji have a good financial, sense of humor.

But let's not forget the disadvantages:

- Most of these film/developer wonder wart-hogs are bitchy. Using them is not as foolproof as developing Tri-X in D-76. See this forum and others for questions like 'where do the white spots come from' or 'why are the shadow details gone'.

OK, so Tri-X in D-76 is foolproof.. but what happens when You are not a fool and You need something that allows You to go out of the mainframe?

- The PET base is a big disadvantage. Don't fall for the marketing bla.
You get lightpiping problems, many of these films curl like a steel spring, and if you can't find the scissors in your darkroom you can't rip off the end of the film.

Is there a darkroom without a scissors? and I guess I am lucky, in glassine bags for a few hours and they dont curl. So?

The only advantage of PET is for the manufacturer because it is much cheaper than normal triacetate. Regarding archival stability, I don't expect that just one of us will see his negatives on a normal base becoming unusable during his lifetime. We just don't live long enough to benefit from 500 years archival stability.

The triacetate is prone to degradation known as Vinegar syndrome, that means, over period of time, the triacetate material releases acetic acid.
Polyester (polyethylene terephthalate (PET) (Kodak trade-name: ESTAR)) is NOT prone to degradation.
The late Kodak Technical Pan was on ESTAR, so was Kodak Imagelink HQ Microfilm..

So, ts the camera industry that don't like it, because is so strong, that it could jam the transport of motorized cameras.
But who cares about motorized cameras anyway?

So, if these films are right for you, enjoy.

Totally fine for me.

But, please, don't tell everyone that these films are as easy to use as normal films, and don't forget that many people even have difficulties developing normal films.

So, again, where did I said they are easier to use as normal films?

The so-called limits set by the lenses are not fully explored, so higher resolution films lets You enjoy the reality check yourself, while at the same time having a blast from the pretty awesome results You get by using high resolution films.
Oh, and most/all of them are using archival ready AHU PET base.
Also, sometimes the high contrats of such films gives You the graphic part of photography in a very graphic way

The original poster named the thread "Highest resolving power BW film, chemistry, paper"
Does anyone here thinks that Highest resolving power BW films doesn't require extra effort in the case where You need them to do stuff they were not designed for in first place?

 

[Leigh B]

... a higher resolution makes sense also if the lens "outresolves" the film, and the better the lens resolution, the better the resolution of the final outcome, the "system" resolution.

Absolutely true.

A point that many posters seem to miss is that image degradation is cumulative.

You start with a perfect image, that being the original subject in situ. Everything you do to that image, up to and including rendering it on a print, degrades it. And each degradation cannot be reversed by subsequent effort of any kind.

If you want the highest possible print quality, you need to use the highest quality at each and every step in the process.

Whether or not it "makes sense" is a totally specious consideration.
-----
As for tests run by "internet experts", they're totally meaningless, not worth the electrons used to write them.

When one of these guys can demonstrate that he has
1) a multi-million dollar lab dedicated to such testing, and
2) an operating budget to support its annual calibration and certification, and
3) a staff of properly trained technicians to run it, and
4) a properly credentialed scientific staff to define the tests and interpret the results,
then I might pay attention to the conclusions.

Until then they're just blowing smoke, for their own self-aggrandizement.

- Leigh

 

[cmo]

However, the photo department is somewhat more like a hobby to them, in the recent ~ >40 years..

So, that means that Zeiss' testing methods are stupid?

We can read other people datas all day, wheres the fun in that?

It might save some time in discussions. Well, not in all discussions...

and btw, a roll of Fuji Across (135) in Europe goes for around 4 Euros - ~ 6 US$
a roll of Kodak T-MAX 100 (135) in Europe goes for above 4 Euros - ~ 6 - 7 US$
a roll of Ilford PAN F (135) in Europe goes for above 4 Euros - ~ 6 - 7 US$
Now, even the adorable Rollei RETRO 80S goes for 2,20 Euros - ~ less than 3 US$

Well, Acros and T-Max are significantly cheaper here, but maybe I buy them in the wrong places...

Adorable Retro 80s... sorry if I have to smile when I read this. No comment.

If we really have to benchmark them in the price department, especially in Europe, then Kodak, Ilford and Fuji doesn't make financial sense, at all, and its not only film prices but paper, chemistry etc. etc. as well....

Oh, really? Go on, it's really getting interesting now.

Anyone is free to spent ~ 4 Euros for a film, based on triacetate.. that is prone shrink...

Zero point zero something percent. Red Alert. Honey, I Shrunk the Kids Portraits. Are photos of shrunken heads just an urban myth created by film shrinking?

None of the buildings, landscapes, macros and portraits I ever shot suffered from shrinking. Please, ask at apug whether shrinking is a popular problem... 99% of film users will not even know that their films shrink zero point zero something percent. What about fiber-based paper? It really shrinks and creates interesting problems while drying. Is shrinking of films by zero point zero something percent a huge problem? Should we start an apug group about shrinking?

What does that mean for photography as long as it is not reconnaissance aerial photography, field mapping or some quantum physics experiments? None of my models ever complained that they shrunk by zero point something percent though some of them asked why they look so fat on the photos (reason: they were fat), but I think in the future I will not blame McDonald's but the film Hey, I might turn the camera 90 degrees and make them look slim

develop acid

Depends. If you store your films in Mumbai, India, for 50 years without a/c you might smell some acid. 50 monsoons, that's a problem. I visited a movie archive in India, and they had that problem with films dating back to the 1930s and 1940s. The films affected were in a room in the basement., many of them had not even been stored in a metal or plastic container. Now they start restoring these films - they digitize them, improve them (digitally, I admit) and print them to film again.

That reminds me, I have to write a sentence in my last will: 'x Euros of my inheritance is reserved to copy all my negatives to new film after 50 years, just in case and only if someone gives a sh**. If not, take the money and have fun.'

So, if I buy and use film today and develop, fix, wash, dry and store it properly we need some very serious progress in medical science to create a problem with these films. None of us lives for 150 years.

Apart from that, how long do your prints last? Do you use fiber-based paper (though it shrinks like hell) or resin-coated paper (it shrinks just a little, probably like film) though it does not last till the end of the universe?

growth bacterias

Bird flu or EHEC? I have to admit I don't even know someone who had a problem with bacteria on his films. If you want to create such a problem you probably need to store films in a wet environment. By the way, most wetting agents contain substances that have an anti-bacterial effect.

and God knows what more in just a few decades...

Did you know that triacetate films do not stand fires, hurricanes and nuclear explosions?

No doubt that Kodak, Ilford and Fuji have a good financial, sense of humor.

I don't think they have much reason to laugh if they look at their balance sheet.

So they bamboozle their customers? Shocking.

OK, so Tri-X in D-76 is foolproof.. but what happens when You are not a fool and You need something that allows You to go out of the mainframe?

In the first line, I would improve my technique.

But after a while I will probably find out that prints sell much better if they are printed from non-shrinking negatives that don't smell like vinegar after one hundred years. These prints will look much better.

Or, alternatively, glass plates (no shrink at all):

(there was a url link here which no longer exists)

Is there a darkroom without a scissors?

Is there a darkroom in which nobody ever shouted "damn, where are the scissors?"

The triacetate is prone to degradation known as Vinegar syndrome, that means, over period of time, the triacetate material releases acetic acid.
Polyester (polyethylene terephthalate (PET) (Kodak trade-name: ESTAR)) is NOT prone to degradation.
The late Kodak Technical Pan was on ESTAR, so was Kodak Imagelink HQ Microfilm..

Because they are document films, made for a business area where that is important... and as I mentioned before, it's much cheaper.

So, ts the camera industry that don't like it, because is so strong, that it could jam the transport of motorized cameras.
But who cares about motorized cameras anyway?

A lot of people. You find many of them around here. EOS users, for example. Users of motorized Konicas like the FS-1, for example. Many, many users of Nikons with built-in motors. Konica Hexar AF and RF users. Hasselblad ELM owners. Rolleiflex 600x series users. Contax G1 and G2 users and many, many more. Oh, and all people that have a normal 35mm or medium format SLR with an attached motor.

But you are right, that is just a minority (50%?) of film users?

Totally fine for me.

Fine, but why are you on a crusade to persuade all of us?

 

[georg16nik]

So, that means that Zeiss' testing methods are stupid?

Well, if they offer just 3 years for their consumer photo stuff and a lifetime warranty for their selected pro optic products. Then it suggest that they are paying more attention to their pro customers. Photography, obviously is not a serious / critical business to them. Hence most of their photo stuff being made in Japan.

Well, Acros and T-Max are significantly cheaper here, but maybe I buy them in the wrong places...

Ok, I said in Europe, so lets see:
Fuji Acros 100 (135)-36 - £3.65 -
http://www.fujilab.co.uk/catalog/neopan-acros-blackwhite-film-p-839.html
Fuji Acros 100 (135)-36 - 3,80EUR - http://www.macodirect.de/fuji-acros-13536-p-307.html?osCsid=00a81d4cf9e37f3f5d9aaeca5a1c0ede
KODAK PROFESSIONAL T-MAX 100 Film / 135 / 36 exp - £5.29
http://shop.kodak.co.uk/store/ekcon...p/baseProductID.188116000/productID.188116100
Kodak T-MAX 100 135-36 - 4,49EUR - http://www.macodirect.de/kodak-tmax....html?osCsid=00a81d4cf9e37f3f5d9aaeca5a1c0ede

Zero point zero something percent.

OK, then how come, even Kodak's pro films used (while being made) PET... and what about the YCM Separation Archival Master, know in the movie industry as Black-and-White Polyester Film Stock ?
Are you suggesting that the movie industry and the Oscar academy are way behind Your knowledge of how good the triacetate is?
You know what A.M.P.A.S is, I hope.

Because they are document films, made for a business area where that is important... and as I mentioned before, it's much cheaper.

So, its not clear.., they use PET because is important or because is cheaper?

Is there a darkroom in which nobody ever shouted "damn, where are the scissors?"

Yes, there is.

Fine, but why are you on a crusade to persuade all of us?

I did? and I guess You still insist that I said high res films are easier to use than normal film?
Internet is funny place

 

[cmo]

Right, and that's why I stop discussing with you.

 

[joefreeman]

seems paper is being ignored. i think it's a major factor.
for one, some papers are sharper than others: chloride > bromide, bromo/chloride.

and two (this is educated guesswork on my part); unless really dramatic enlargements are being made, the paper (type of surface and type of emulsion) can be a limiting factor worth serious consideration.

 

[georg16nik]

Paper is not being ignored, its just that we are not there yet

 

[Alan Johnson]

Here is Ctein on the subject of paper resolution, see p37,"How print materials see".
"A typical color-negative material can record about 65 line-pairs per millimeter, but a black and white paper can reach 125 lppm."
http://ctein.com/PostExposure2ndIllustrated.pdf

 

[Diapositivo]

I don't print, so I just ask here for my personal culture.

When people talk about film resolution or lens resolution, and they quote line pairs per millimetre, they mean on the film. If the film-lens system resolves 30 lp/mm, that is you can count 30 line pairs on each millimetre of film surface.

When they say, on the other hand, that a paper has a resolution of 65 lp/mm, that means "on paper", after the enlargement.

So if the negative is enlarged let's say 6 times, a paper with a resolution of 65 lp/mm shouldn't limit that much a film-lens system capable of let's say 18 lp/mm on film as that would correspond to 3 lp/mm on the paper plane during enlargement. I understand resolution undertakes a cumulative degradation with each step (it's not a matter of ceilings) but I would imagine the paper to be less critical than other factors, if it reaches 65 lp/mm and if the film is actually enlarged before printing.

Does this make sense?

(I'll read Ctein tonight)

EDIT. Mumbling a bit over it. If we take the Fuji equation, which sums the reciprocal of the lp/mm resolution of each factor, and sum them, considering an enlarging lens capable of resolving 200 lp/mm (possibly non-existent according to Vitale) we would have, before paper, an equation of this kind:

Portra 160 NC 73 lp/mm; 1/N = 0,0136;
Camera lens 140 lp/mm (very very very good stuff); 1/N = 0,0071;
Enlarger lens 200 lp/mm (very very very very good stuff, "you won't find one"); 1/N = 0,0005;

System resolution (film + camera lens + enlarger lens) = 0,0136 + 0,0071 + 0,0005 = 0,0212 = 47 lp/mm.

Now how do we proceed in finding an approximate system resolution if we want to take into account paper resolution? We certainly cannot just add paper resolution, unless we do contact printing, as the image on paper is enlarged.

 

[georg16nik]

The short-wavelength paper sensitivity in combination with the relatively not-so-advanced characteristics of most enlarger lenses are long standing stop gaps.
APO-Rodagon or Rodagon-WA are indeed classy lenses

 

[Alan Johnson]

Diapositivo,
Your system resolution actually adds up to 1/.0257 not 1/.0212.
But keeping the figure of 47 lppm,a contact print on paper resolving 65 lppm I guess might give 1/47 +1/65 = 1/R so R= 27 lppm.For reasons Ctein mentions it is not out of the question that there may be some perception of such high resolutions.

Ctein suggests "it's sharp" is about 5 lppm on the print.The resolution of the paper 65 lppm is not a controlling factor.
From 47 lppm one can make an enlargement 47/5 = 9 times and "it's sharp".

 

[Diapositivo]

Diapositivo,
Your system resolution actually adds up to 1/.0257 not 1/.0212.

You are right. I corrected the figures. I wrote 0,005 where it should be 0,0005 (resolution of 200 lp/mm must be better than 140 lp/mm after all ).

But keeping the figure of 47 lppm,a contact print on paper resolving 65 lppm I guess might give 1/47 +1/65 = 1/R so R= 27 lppm.For reasons Ctein mentions it is not out of the question that there may be some perception of such high resolutions.

Ctein suggests "it's sharp" is about 5 lppm on the print.The resolution of the paper 65 lppm is not a controlling factor.
From 47 lppm one can make an enlargement 47/5 = 9 times and "it's sharp".

Yes but how would one calculate those factors in a system resolution equation?

If we contact print, there is no enlarging lens so if the paper is 65 lp/mm, in the example above we have:

1/73 + 1/140 + 1/65 = 1/R so R = 28 lp/mm

But if we print with an enlarger enlarging let's say 6 times, how do we compose the system resolution equation? Could be:

1 / resolution of film +
1 / resolution of camera lens +
1 / resolution of enlarging lens +
(1 / resolution of paper) / enlargements?

That would give, in our example:

1/73 + 1/140 + 1/200 (using this "ideal" enlarger lens) + (1/65)/6 = 0,0215 = 46,5 lp/mm which would mean paper resolution is really irrelevant for the final theoretical system resolution. Resolution would be higher by enlarging than by contact printing. So this equation should definitely be wrong.

But how do we make a system resolution equation keeping into account enlarger lens, paper, and enlargement factor?

 

[Diapositivo]

Maybe the equation should be:

[(1/47)*6] + 1/65 = 7 lp/mm

That is: we calculate the system resolution of film, camera lens, enlarging lens, then we divide it by the number of enlargements, and finally we add to the equation the paper resolution.

Actually Ctein in Chapter 1 says that 5 lp/mm is acceptable sharpness but the human eye can perceive a sharpness improvement up to 30 lp/mm when considering an 8" x 10" print observed at 0.5 metres by a viewer with a (very!) good sight.

This is interesting.

By those numbers and theories, if one wants to print "perfectly" sharp (30 lp/mm on paper), supposing obtaining 160 lp/mm from Kodak T-Max, using a 140 lp/mm camera lens and having a 180 lp/mm enlarger lens, which might possibly exist, one must enlarge the negative less than 2x.

(0.00625 + 0.0071 + 0.0055 = 53 lp/mm before enlarging and before considering paper resolution).

So if you really need Ctein's "perfect" sharpness you either buy a LF or you use microfilm... (with some side effects, that is).

[hybrid warning]
And if I take that negative, 53 lp/mm, and scan it with a 4000 ppi scanner, that is, with a 80 lp/mm scanner, the resulting system resolution should be: 1/R = 1/53 + 1/80 R = 32 lp/mm on the file (before printing).
[/hybrid warning]

 

[DREW WILEY]

It's pretty damn simple. I ignore all the equations and simply look at the final print. Different combinations
of lenses and films will tell you everything you need to know. The proof is in the pudding. But I do believe
in apo enlarging lenses and optimizing all the mechanical factors first.

 

[Alan Johnson]

Diapositivo,
I don't know the answer to your question on how to include the paper resolution but dont like to push the "just try it" button.
I would suggest that the reason why it is not mentioned by Ctein or in "Image Clarity" by John Williams is that its effect is negligible.

 

[DREW WILEY]

The paper does count. No conventional fiber-based or even RC paper is capable of recording as much resolution as a high-gloss polyester paper like Cibachrome of Fuji Supergloss, though under certain circumstances you might need a magnifier. If I was trying to find out the optimum performance of a film
and enlarging lens, I'd enlarge onto a sheet of high-resolution sheet film in a precise vacuum filmholder.
I do this when making enlarged interpositives or internegatives. It's a much more critical test than
enlarging onto paper.

 

[Top-Cat]

A lot of interesting opinions about film and paper, but is there any particular B&W chemistry I should use? Is Xtol good enough? Or is sharpness more important than fine grain (such as Rodinal)? Or maybe even any other types of developers, and maybe even fix (if that has anything significance) I should use?

 

[Leigh B]

I've used Rodinal as my standard developer for over 50 years, so I guess I've been pleased with the results.

It's not considered a fine-grain developer, but enlarging 120 to 11x14 I focus on image details, not on grain, because the grain is too fine to be seen with my high-power focuser.

I only shoot slow films. My standard for many decades was Agfapan 25. I still have an unopened case of it in 120.

- Leigh