11x14 + megapixels?

[Eric Lohse]

Hi all.
Just as a point of reference, does anyone know how many megapixels an 11x14 BW negative might be? Thanks
Eric Lohse

[sanking]

Hi all.
Just as a point of reference, does anyone know how many megapixels an 11x14 BW negative might be? Thanks
Eric Lohse

It would depend on the resolution of the scan.

At 2000 ppi a scan of a 11X14" negative would give a 616 mp file (22,000 X 28,000 pixels), at 2540 ppi the size would be 990 mp (27940 X 35,560 pixels).

Sandy King

[Steven Barall]

If you scanned it to the grain of the film so you maxed out the film's resolution how many megapixels would it be in the end?

[Nathan Potter]

That's kind of silly because it's not feasible. BUT if it were, it is easy to figure.

11 X 14 is 28 X 35 cm.
Assuming you wanted to capture grain you'd need at least 4 micron spot size.
A 4 micron pixel is equal to 2500 pixels per cm.
So you have in 28 X 35 cm. 70,000 X 87,500 pixels
Since a Mpixel is 1000 X 1000 pixels you have 70 X 87.5 Mpixels = 6125 Mpixels
or 5.125 Gigapixels

Way, Way beyond the ability of most any lens that would cover 11 X 14 inch format and resolve detail over the format.

Nate Potter, Austin TX.

Thats 6.125 Gigapixels of course - not 5.125

[PenGun]

That's kind of silly because it's not feasible. BUT if it were, it is easy to figure.

11 X 14 is 28 X 35 cm.
Assuming you wanted to capture grain you'd need at least 4 micron spot size.
A 4 micron pixel is equal to 2500 pixels per cm.
So you have in 28 X 35 cm. 70,000 X 87,500 pixels
Since a Mpixel is 1000 X 1000 pixels you have 70 X 87.5 Mpixels = 6125 Mpixels
or 5.125 Gigapixels

Way, Way beyond the ability of most any lens that would cover 11 X 14 inch format and resolve detail over the format.

Nate Potter, Austin TX.

Thats 6.125 Gigapixels of course - not 5.125

1024 Nazi. ;)

[Lenny Eiger]

Way, Way beyond the ability of most any lens that would cover 11 X 14 inch format and resolve detail over the format.
Nate Potter, Austin TX.

Yes, and then again, no. If you compare the size of the film to a smaller film, you have way more film describing the same area. So, if a lens can't resolve but a fraction, say 1/4 for discussion purposes, what if you gave it 4 times the film to work with?

No reflection on you but 1) many of the folks that espouse the lens can't resolve are talking about how great their digital cameras are and haven't ever scanned and printed a large neg - 2) resolution is only part of the game. The other side is tonality. It's rarely discussed....

I print from 8x10's a lot over here, after processing with my drum. It provides tremendous richness. The data is there - and primarily because the resolution and tonality are there - because of the film real estate that allows for lower resolution to be used.

I hope that's clear. I'm rushing around trying to do everything I'm supposed to...

Lenny

[Bruce Watson]

If you scanned it to the grain of the film...

That's a non sequitur.

Film grain size, and to a greater degree film grain clump size, varies widely. How widely depends on the film, developer, processing, exposure, SBR, etc.

It's not unusual for modern B&W negative films to have grain clump sizes at the 1-2 micron level (or even sub-micron) in the least dense areas (shadow detail). It is also not unusual for the same film to have grain clump sizes well over 20 microns in the most dense areas (highlight detail).

Scanners in general scan with a fixed pitch -- either CCD sensor size and spacing, or drum scanner aperture. That is, during the scan this can't be varied, while the film grain is varying widely.

So... how can one scan "to the grain of the film"?

But wait, it gets worse. It takes more than a single grain clump to define a line. It takes at least two (and one can of course get into religious fights over how many), and for it to be useful information, many more. There's a difference between the film grain data, and image information. A single "unit" of image information takes many film grain clumps to define.

Then there's the concept of how much image information the lens can transfer to the film. This gets you into the MTF tables for the lens, shooting conditions (wind, tripod footing, etc.), required f/stop (diffraction), focus and depth of field, etc.

I'm just saying that while it seems like a simple question, it's anything but. And there's really no general answer to it.

[Ben Syverson]

Assume that your 11x14 lens can deliver 30 lp/mm across the entire film. You'd need 60 pixels to represent 30 line pairs (Nyquist), so that's 21336 x 16764 pixels, or 357.67 megapixels. But because of Bayer sensors, you would need about 1.5X that number of raw pixels to achieve the same resolution on a digital camera. So you could say that 11x14 has roughly the same resolution as a hypothetical 530 megapixel digital camera.

Now, that's just to get the same level of detail, not to reproduce the tonality of the film. To get the same tonality of a fine-grained B&W film, we're much further in fantasy-land. You would essentially need a huge 11x14" digital sensor with giant 16.6 micron pixels and 530 MP resolution. Either that or a sensor of the same size at 2.1 GIGApixels but a more traditional 8 micron pixel size -- like a Nikon D3's sensor, if it kept going for 11x14"! Either way, we are firmly in la la land.

But the short answer is "530 megapixels."

[sanking]

But the short answer is "530 megapixels."

This is why I calculated size in megapixels based on scans of 2000 spi and 2540 spi. In my opinion there would rarely ever be any reason to scan a 11X14" negative at higher resolution than 2540 spi. The only exception would be when shooting with all of the subject on one plane where the lens can be used at optimum aperture and not stopped down to f/32 or more which is usually necessary with most pictorial subjects.

In terms of size, bear in mind that a scan of a 11X14" negative at 2540 spi would allow one to print at 88" X 112" in size at over 300 dpi.

Sandy King

[willwilson]

By the time 530mp digital cameras are around everybody will be shooting with the new 3d scanomatics and projecting holograms instead of making prints anyway.

[Ben Syverson]

IMO, if you're trying to figure out "equivalent megapixels" for a film format, you need to take scan DPI out of the equation, as it is more or less meaningless.

You could make a 100,000 DPI scan of a 35mm frame with an electron microscope, which would give you a 13 gigapixel file. But you wouldn't go around saying 35mm was equivalent to 13 gigapixels would you?

[John Berry]

By the time 530mp digital cameras are around everybody will be shooting with the new 3d scanomatics and projecting holograms instead of making prints anyway.
,or you plug the printer plug in the socket in your head and print winks at people.