Is there any real utility to ULF?

[Jorge Gasteazoro]

and providing that c' may depend on the focal length of the lens.

I have to disagree with this. The CoC is independent of focal lenght. The important thing is the magnification ratio, regardless of what lens one used to attain that ratio.

[Asher Kelman]

>
Jorge, it would be prudent IMO to stop now, as statements like this truly demonstrate your lack of understanding of basic photo optical principles. Before I found it humorous, now, I kinda find it sad that someone with your lack of knowledge can scream so loud. Really, its time to read a book on basic optics.

> Someone would buy a LF camera, could not take a sharp picture with it and blamed the camera, the lenses, etc, etc.

Well, some of my best shots are on ULF, cause I fit the camera to the application well....but, that's irrelevant to your rant. It's amazing how you know so much about me, and we never met! Well, I guess this is an improvement over your previous allegation that I am a covert digital disciple who was pushing the digital agenda! LOL :-) Your imagination really has run wild.... and you have provided some great entertainment value in this thread.... I can only guess - this is your defense mechanism.

> If you call throwing stones showing how wrong you are, you are correct, I am throwing stones at you.

........Too bad you are so headstrong - because you could really benefit from these exchanges if you would stop throwing stones, comprehend what others are writing, and try to back-up your position instead of trying to win a debate by continuous insults.

I think you guys, arguing incessantly as you have, do a good job in stirring up juices. Maybe people will now consider ULF for their own work. It's so easy to make DOF calculations and only the photographer knows the destination of the final print: contact or enlargement and how detail rich the scene is or graded or contrasty the light range is to decide what format is appropriate.

One kind of photograph might be initiated with an M8 digital rangefinder camera (or from a scan of a 4x10) and made into a trannie and contact printed at 8x20 whereas another will only look impressive with an 8x20 negative from direct exposure of film. Do you really need the silver grains or can you tolerate spots or holes in the first negative and then in a second negative and degradation of the tone curves in going to a larger negative however well scanned.

If one is going to the trouble of doing a platinum print, then how one gets there can be critical. I can hand hold a digital camera and map a huge building or Arizona desert scene to get a large digital file. However for trees and leaves or moving clouds only a ULF exposuret can get a perfect image irrespecitve of any other compelling esthetic such as liking the "look" or grain and special favorites lenses.

If the two of you weren't naturalyl so stalwart in your stands, then the information eked out would be sparse.

So kudos for you for each being mostly right. Jorge you are sometime overreaching, that's your nature. On the whole, this is a very useful thread. What would be helpful would be to move to a new and practical stage. Examples of real photographs showing the limits of different choices for format would be appreciated right now.

Asher

[Jorge Gasteazoro]

Examples of real photographs showing the limits of different choices for format would be appreciated right now.

Here is one for a subject not at infinity....The mision is about 35 meters from the camera, taken with a Korona 12x20 made in the 1930s at f/90 with back movement.



Another one where the remains of a small chappel is about 40 meters and in the print you can see sheep grazing close to the horizon line, they must have been about 500 yards or so.

[timparkin]

Here is one for a subject not at infinity....The mision is about 35 meters from the camera, taken with a Korona 12x20 made in the 1930s at f/90 with back movement.
Another one where the remains of a small chappel is about 40 meters and in the print you can see sheep grazing close to the horizon line, they must have been about 500 yards or so.

Hi Jorge,

What are the vertical lines and discontinuities on both pictures? It almost look like they've been cut into slices?

Tim

p.s. From my recollection, the f-stop of a lens is lens diameter over focal length - I don't think the shutter size has anything to do with it (although you need a large shutter to fit larger aperture's in the lowest f-stop is determined more around the optical design and then a shutter is chosen to fit around this).

[Jorge Gasteazoro]

Hi Jorge,

What are the vertical lines and discontinuities on both pictures? It almost look like they've been cut into slices?

Tim

p.s. From my recollection, the f-stop of a lens is lens diameter over focal length - I don't think the shutter size has anything to do with it (although you need a large shutter to fit larger aperture's in the lowest f-stop is determined more around the optical design and then a shutter is chosen to fit around this).

I had a bad scanner, I bought one of those HP scanners that was worthless right out of the box. I called them and they said those lines were "normal"... took it back to the store and will never touch and HP product again. Unfortunatelly Perez moved from HP to Kodak and brought with him the same attitude..

You are correct in the focal lenght determination. It has nothing to do with the shutter, but the bigger the lens cells to correct for aberrations the bigger the shutter and the bigger the entrance pupil. I am sure you have seen two lenses of the same focal lenght but one is much smaller than the other. While the ratio of the f stop is the same, the diameter of the entrance pupil is much bigger for the bigger lens, thus avoiding difraction. Of course this does not mean you do not have difraction with the bigger lenses, but it is mostly at the edges, and since they have such great coverage it is negligible.

WHat the previous poster does not understand is that a 500 mm in a 4x5 and 500 mm lens in a 12x20 DOES NOT deliver the same image. Depending on the lens design the 12x20 500 mm can deliver a much greater image than the one for 4x5 and that we are only cropping with the camera and holders. Regardless, this has nothing to do with the circle of confusion and why it increases with film size.

[John Kasaian]

Uhhh.....what do you guys mean by "real utility?"

[Ole Tjugen]

Just FYI, there's a lab in Sweden with an enlarger that takes negatives up to 20x24". send then a contact print along with the negative, and they will match it as well as possible, at any size up to the width of a master roll of paper.

[Mick Fagan]

I also would like to know what "real utility" is as well.

As of yesterday, with a new acquisition, I obviously became the third person in the world, who can enlarge 11x14 negatives, I don't think so!

17 years ago I was making single 6'x18' colour enlargements, they were very sharp. I still have a couple of 6'x17' prints, they still have a wow factor when put alongside current state of the art prints manufactured by commercial ink printers 48" and 72" wide.

Mick.

Ps:- some of this has been very interesting, it's a nice ride :-)

[Jorge Gasteazoro]

Just FYI, there's a lab in Sweden with an enlarger that takes negatives up to 20x24". send then a contact print along with the negative, and they will match it as well as possible, at any size up to the width of a master roll of paper.

I know, there is another in France that takes some as big as well.

[Patrik Roseen]

Ole, I have visited that lab (in Stockholm right?) I have seen Teddan's portrait of Lennart Nilsson which is an enlargment from 12x20 if I remember correctly and where it is possible to see the reflection of the flash on the inside/backside of the eyeglobe.

I do not do ULF myself, but to me 'the real utility' might be - 'making an impression'!

PS: Now I need to get my knowledge corrected regarding DOF, Diffraction, CoC etc...elsewhere.