Ektar vs Alpha 900/Velvia revisited: new scans

[Photo Engineer]

All grains in all films are randomly distributed unless packed shoulder to shoulder which is impossible to achieve.

PE

 

[dynachrome]

Ektar vs Alpha 900?velvia revisited

Does this mean that Imakelink's grain is any less random or just that it is extremely fine?

 

[Photo Engineer]

It is probably not less random as that is not possible due to the limitations of the coating process. As for fineness of grain, what is their definition. Kodak, Agfa, Ilford and Fuji all can make grains in sizes less than 0.2 microns. The problem is that there is little ROI on these very very slow films. The market is tiny.

But, more specifically, most MP color print films run in the range of 0.2 microns and are monodispersed. They have an ISO ranging from 25 - 100 depending on layer, and are fast due to the sophisticated sensitizing capabilities of the major film producers. These can be enlarged to auditorium sizes.

PE

 

[alanrockwood]

I have only read about half the posts on this thread, but I thought I would ask a question related to resolution testing on film. What about photographing a small section of film through a decent quality microscope and then print this out and/or measure it? One could also digitize the small section and post it. It seems to me that this could be a way of determining resolution of film without using a drum scanner. Of course, this would not cover the full frame... unless one were to take multiple shots and stitch...

 

[Rudeofus]

The problem is that there is little ROI on these very very slow films. The market is tiny.

But, more specifically, most MP color print films run in the range of 0.2 microns and are monodispersed. They have an ISO ranging from 25 - 100 depending on layer, and are fast due to the sophisticated sensitizing capabilities of the major film producers. These can be enlarged to auditorium sizes.

I know your background, highly respect your inside opinion and mostly agree with it (never cared for pixel peeping either). Still, it flies in the face of all these digital folks screaming for dozens of mega pixels, because "they need all the resolution they can get". It's not just clueless amateurs but capable pros who claim they can't do full body portraits with less than 20MP.

I'd really like to know how much pro film is sold for different speeds. Is ISO25/50 film something everybody drools about but nobody uses in practise? Is ISO400 film the kind that most people use most of the time despite claiming they "just accidentially loaded it into their camera but really, really never intended to even use it"? Or are both film types used by their intended user base but the ISO25 user base is just tiny?

 

[Poisson Du Jour]

Sorry to say, it will not be analogue.

Then we won't be buying a Leica, will we!?

 

[Athiril]

It is probably not less random as that is not possible due to the limitations of the coating process. As for fineness of grain, what is their definition. Kodak, Agfa, Ilford and Fuji all can make grains in sizes less than 0.2 microns. The problem is that there is little ROI on these very very slow films. The market is tiny.

But, more specifically, most MP color print films run in the range of 0.2 microns and are monodispersed. They have an ISO ranging from 25 - 100 depending on layer, and are fast due to the sophisticated sensitizing capabilities of the major film producers. These can be enlarged to auditorium sizes.

PE

Sorry for my ignorance, whats MP stand for, and is such a film still made?

Ah, motion picture film, oops!

But there's no 25 colour film? Just F-64D and Kodak 50D, are those films that fine? (I have some on order in single perf 16mm).

 

[Mike1234]

Photo Engineer rightly points out the fineness of grain in motion picture films but grain is mostly hidden (or the brain forgives it) due to the 24FPS? random patterning. This gives the perception of much finer grain than it actually is.

 

[Photo Engineer]

To answer a few questions....

If you photograph a neutral density scale and enlarge it then read it, you will get some measure of granularity which can be loosely defined as the variation in density over a given area of space. It is the reverse of taking the small image and reading it with a microdensitometer. So, you do not need a microscope at all. All you need to do is magnify an image and measure density fluctuations in a straight line across the surface of a print. The root mean square of this fluctuation might be considered the grain at that density. Doing it repeatedly over all densities and then plotting the resultant RMS values will give you "RMS Granularity" of the film as a function of density or exposure.

As for motion picture films, Mike is partially correct. Color Motion Picture films are the finest grained of all color negative and print films. The fineness of grain and resolution are astounding. But, nothing is perfect. In fact, there is a minimum value for grain due to noise. You can cast a pure grainless dye on transparent support, and it will yield a finite value for RMSG due to the noise in the measuring system.

PE

 

[patrickjames]

PE, is there any practical way to develop these films? They all use a backing don't they? Different chemical process?

 

[Photo Engineer]

PE, is there any practical way to develop these films? They all use a backing don't they? Different chemical process?

I'm not sure I understand the question.

PE

 

[Jack Xavier]

I think he is reffering to motion picture films. I've read about some of them having a different layer also. As in they can't be processed in C41 chemistry. I was looking at Kodak Tungsten films. Kodak 5247 I think? And read that it required a certain wash to remove a coating. I'm entirely ignorant when it comes to any kind of colour processing but that's what I think he means.

 

[patrickjames]

Sorry. I am typing on my iPhone and made the question too brief. I was simply asking if MP film can be shot in a 35mm camera in a convenient way. From my memory it has a remjet backing and a different chemical process than C-41. Is this correct?

 

[Photo Engineer]

Sorry. I am typing on my iPhone and made the question too brief. I was simply asking if MP film can be shot in a 35mm camera in a convenient way. From my memory it has a remjet backing and a different chemical process than C-41. Is this correct?

You are correct.

PE

 

[Athiril]

To answer a few questions....

If you photograph a neutral density scale and enlarge it then read it, you will get some measure of granularity which can be loosely defined as the variation in density over a given area of space. It is the reverse of taking the small image and reading it with a microdensitometer. So, you do not need a microscope at all. All you need to do is magnify an image and measure density fluctuations in a straight line across the surface of a print. The root mean square of this fluctuation might be considered the grain at that density. Doing it repeatedly over all densities and then plotting the resultant RMS values will give you "RMS Granularity" of the film as a function of density or exposure.

As for motion picture films, Mike is partially correct. Color Motion Picture films are the finest grained of all color negative and print films. The fineness of grain and resolution are astounding. But, nothing is perfect. In fact, there is a minimum value for grain due to noise. You can cast a pure grainless dye on transparent support, and it will yield a finite value for RMSG due to the noise in the measuring system.

PE

I could have sworn that Pro 160S was finer than Ektar 100 though.

 

[Photo Engineer]

Measure them.

PE

 

[stradibarrius]

has anyone ever used the Tetnal press kit to develope Ektar 100?

 

[ajuk]

If a DSLR is reaching defraction limits at nearly 25 MP then imagine what compact with a zoom lens and sensors over 25x smaller and 12MP sensors are doing am I right in thinking those cameras in reality can't get close to their rated resolutions for real?