Tonal range in large format?greenspun.com : LUSENET : Large format photography : One Thread
I keep hearing about the better tonal range of larger format chromes/negs. I don't understand it really. Isn't the tonal range a function of the film/paper mainly and to some degree of the lens? And since smaller format lenses are often better (coated, resolution, etc) then large format older ones and the film emulsion is the same, how/why is the tonal range better in the larger format? I currently shoot chromes in 6x9 and 35mm and aside of the more detail in the 6x9, I didn't notice any difference in the tonal range (same emulsion, same shot).
-- Sorin Varzaru (firstname.lastname@example.org), January 05, 2001
Images look better as the film gets bigger because there is more emulsion to capture finer tonalities. It is a surface area thing, instead of one grain to capture a branch, you now have ten. That allows for a much richer separation of tonality. In color the effect is probably lessened by the overall cast looking the same. In black- and-white, one sees an immediate difference, especially between 35 and 6x9. That is a huge jump for B&W.
-- E.L. (email@example.com), January 05, 2001.
If all were equal and you could live with 35mm contact prints, it wouldn't make any difference. But we look at our images. Teenie-tiny negs have to be enlarged more to get to 8x10 than the much larger formats do. So with the smaller film sizes "ultimate sharpness" and grain become obsessive/compulsive problems that sap the creative energies of so many who use them. Blow up the images a bit & everything is magnified, thus the search for sharpness & grain free magic solutions that don't exist. Blow up the images & tonal quality in delicate separations suffer. Start with a bigger negative or chrome where grain isn't a factor and you can concentrate more on the tonal range, separation and the fine points of the images rather than the techncal aspects of what the film can or can't do.
Want a real world demo? Take an 8x10 contact print from almost any half decent lens, even a 50 year old one and match it to the same shot from 35mm or 120, blown up to the same size. With the much larger neg you will see the spider webs in the windowsill while with the smaller ones you will may see it but the sharpness & range won't quite do it. Then when you move up to 11x14, 12x20, 16x20 or larger you can really see it. These larger sizes which are usually made as contact prints are as good as it gets. But they tax the creativity since each shot basically stands on its own. Most are not shot to be cropped or manipulated too much. It sharpens the vision and pushes technique to the max and allows one to concentrate more on the image than they may on the technical aspect.
If we shoot the same image, same framing, same everything, with 35mm and 5x7, I will have more on the negative or chrome to be used in the final print than 35mm can ever get. Same with medium format. Kind of like trasporting a load of kids in the family car as compared to a Greyhound bus.
-- Dan Smith (firstname.lastname@example.org), January 05, 2001.
Sorin: I agree with Dan and E.L. that the difference comes from the room on the negative. I shoot mostly 4x5 with a little 8x10 thrown in and the difference is tremendous between those formats and 35mm. Look at a 4x5 or 8x10 neg or contact and you will see light and shadow on even the tiniest twig or blade of grass instead of just a streak on the 35mm neg. I have an 8x10 negative of a work boat at anchor about 100 feet away. With a loupe, you can read the commercial vessel registration sticker of the boat, and read a street sign two blocks away. That was made with a 50 year old lens and ASA 400 film. Nothing magic about it, just room enough on the negative to register the information. Look at the smoothness of an 8x10 contact print. It gives the print a look that you can't get with smaller negs. The 35mm lenses are a lot sharper in many instances than LF lenses simply because they have to be. That is one reason why you see mamy LF shooters with old lenses. The lenses are sharp enough to make good prints, sharp as they have to be. Grain and sharpness are not a concern for LF users for normal size prints.
-- Doug Paramore (email@example.com), January 05, 2001.
Guys, your explanations are in the vicinity, but you need to talk about grains. Grains are like pixels. Say you have a continuously smooth area that goes from black to white through all the shades of gray. If you capture this on 2 grains or 2 pixels, one will be white the other black. If the eye can distinguish both it will see 2 shades, not a continuous flow. If it can't distinguish, it will average them and see middle grey. Neither of these represent the subject well.
Add 1 more grains (pixels) and you'll get black, gray, and white. Still a poor representation. When you've got lots & lots or grains, everything seems smooth, and the more you have the smoother the transition. This is the improved tonality of LF.
In all cases, everything in the negative (transparency) gets better if the negative (transparency) is bigger.
Sharpness improves. Graniness imrproves. Tonality improves. Imperfections & inconsistencies in the emulsion appear smaller (because they won't be enlarged as much.)
Every quality you can find in a negative is better in a LF negative, and the bigger the better.
A bigger negative costs more. The cameras are heavier. Working is slower. Depth of field suffers. Lenses cost more. Processing isn't as easy.
But none of these downsides are the quality of the negative. They do, however, impact our choices. It's all a compromise, and very personal.
-- Charlie Strack (firstname.lastname@example.org), January 05, 2001.
I don't think anyone directly answered your question so far. The tonal range is the same (tonal range being defined as the total density range). The difference is in the "gradation". With more square area being available to represent tones and the areas between them (given the same ultimate image size which results in lesser magnification of the larger negative) the larger format is "smoother". The reduction in grain also is a big influence in the perception of gradation.
-- email@example.com (firstname.lastname@example.org), January 05, 2001.
Sorry to be pedantic, but grains are nothing like pixels. In B&W, a film grain can be developed, or not. It can only represent one of two states, black or 'white'. A pixel can be any of 256 levels of grey, and, in this respect, film grain is actually more digital than a pixel.
To get the same tonal range as a digital pixel, we need a film area capable of holding 255 individual grains. This film area has a limit to its physical size, whereas a pixel has no fixed dimensions. This is where the continued argument about film v digital, based purely on resolution, falls down.
-- Pete Andrews (email@example.com), January 08, 2001.
Pixels giving 256 steps represent 8-bit accuracy. Each bit is on or off (digital). This still isn't analog. To me, digital is digital whether it's 1-bit, 8, 16, or 32-bit. None of it is analog. Thus, I see similarity.
Further, what we see are clumps of grain which is composed of many individual grains, each grain being black or white (on or off?).
So, visible grain clumps relate are much like pixels, and an individual grain (not clump) is much like the bits that comprise a pixel.
I still think my analogy is valid.
-- Charlie Strack (firstname.lastname@example.org), January 08, 2001.